The Tor Browser: layout/base/nsLayoutUtils.cpp@b8a032363ba2

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

     1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

     2 /* vim: set ts=2 sw=2 et tw=78: */

     3 /* This Source Code Form is subject to the terms of the Mozilla Public

     4  * License, v. 2.0. If a copy of the MPL was not distributed with this

     5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     7 #include "nsLayoutUtils.h"

     9 #include "mozilla/ArrayUtils.h"

    10 #include "mozilla/BasicEvents.h"

    11 #include "mozilla/MemoryReporting.h"

    12 #include "nsPresContext.h"

    13 #include "nsIContent.h"

    14 #include "nsIDOMHTMLDocument.h"

    15 #include "nsIDOMHTMLElement.h"

    16 #include "nsFrameList.h"

    17 #include "nsGkAtoms.h"

    18 #include "nsIAtom.h"

    19 #include "nsCSSPseudoElements.h"

    20 #include "nsCSSAnonBoxes.h"

    21 #include "nsCSSColorUtils.h"

    22 #include "nsView.h"

    23 #include "nsPlaceholderFrame.h"

    24 #include "nsIScrollableFrame.h"

    25 #include "nsIDOMEvent.h"

    26 #include "nsDisplayList.h"

    27 #include "nsRegion.h"

    28 #include "nsFrameManager.h"

    29 #include "nsBlockFrame.h"

    30 #include "nsBidiPresUtils.h"

    31 #include "imgIContainer.h"

    32 #include "ImageOps.h"

    33 #include "gfxRect.h"

    34 #include "gfxContext.h"

    35 #include "nsRenderingContext.h"

    36 #include "nsIInterfaceRequestorUtils.h"

    37 #include "nsCSSRendering.h"

    38 #include "nsThemeConstants.h"

    39 #include "nsPIDOMWindow.h"

    40 #include "nsIDocShell.h"

    41 #include "nsIWidget.h"

    42 #include "gfxMatrix.h"

    43 #include "gfxPoint3D.h"

    44 #include "gfxPrefs.h"

    45 #include "gfxTypes.h"

    46 #include "nsTArray.h"

    47 #include "mozilla/dom/HTMLCanvasElement.h"

    48 #include "nsICanvasRenderingContextInternal.h"

    49 #include "gfxPlatform.h"

    50 #include <algorithm>

    51 #include "mozilla/dom/HTMLVideoElement.h"

    52 #include "mozilla/dom/HTMLImageElement.h"

    53 #include "mozilla/dom/DOMRect.h"

    54 #include "imgIRequest.h"

    55 #include "nsIImageLoadingContent.h"

    56 #include "nsCOMPtr.h"

    57 #include "nsCSSProps.h"

    58 #include "nsListControlFrame.h"

    59 #include "mozilla/dom/Element.h"

    60 #include "nsCanvasFrame.h"

    61 #include "gfxDrawable.h"

    62 #include "gfxUtils.h"

    63 #include "nsDataHashtable.h"

    64 #include "nsTextFrame.h"

    65 #include "nsFontFaceList.h"

    66 #include "nsFontInflationData.h"

    67 #include "nsSVGUtils.h"

    68 #include "SVGTextFrame.h"

    69 #include "nsStyleStructInlines.h"

    70 #include "nsStyleTransformMatrix.h"

    71 #include "nsIFrameInlines.h"

    72 #include "ImageContainer.h"

    73 #include "nsComputedDOMStyle.h"

    74 #include "ActiveLayerTracker.h"

    75 #include "mozilla/gfx/2D.h"

    76 #include "gfx2DGlue.h"

    77 #include "mozilla/LookAndFeel.h"

    78 #include "UnitTransforms.h"

    79 #include "TiledLayerBuffer.h" // For TILEDLAYERBUFFER_TILE_SIZE

    81 #include "mozilla/Preferences.h"

    83 #include "mozilla/LookAndFeel.h"

    85 #ifdef MOZ_XUL

    86 #include "nsXULPopupManager.h"

    87 #endif

    89 #include "GeckoProfiler.h"

    90 #include "nsAnimationManager.h"

    91 #include "nsTransitionManager.h"

    92 #include "RestyleManager.h"

    94 // Additional includes used on B2G by code in GetOrMaybeCreateDisplayPort().

    95 #ifdef MOZ_WIDGET_GONK

    96 #include "mozilla/layers/AsyncPanZoomController.h"

    97 #endif

    99 using namespace mozilla;

   100 using namespace mozilla::css;

   101 using namespace mozilla::dom;

   102 using namespace mozilla::layers;

   103 using namespace mozilla::layout;

   104 using namespace mozilla::gfx;

   106 using mozilla::image::Angle;

   107 using mozilla::image::Flip;

   108 using mozilla::image::ImageOps;

   109 using mozilla::image::Orientation;

   111 #define GRID_ENABLED_PREF_NAME "layout.css.grid.enabled"

   112 #define STICKY_ENABLED_PREF_NAME "layout.css.sticky.enabled"

   113 #define TEXT_ALIGN_TRUE_ENABLED_PREF_NAME "layout.css.text-align-true-value.enabled"

   115 #ifdef DEBUG

   116 // TODO: remove, see bug 598468.

   117 bool nsLayoutUtils::gPreventAssertInCompareTreePosition = false;

   118 #endif // DEBUG

   120 typedef FrameMetrics::ViewID ViewID;

   122 /* static */ uint32_t nsLayoutUtils::sFontSizeInflationEmPerLine;

   123 /* static */ uint32_t nsLayoutUtils::sFontSizeInflationMinTwips;

   124 /* static */ uint32_t nsLayoutUtils::sFontSizeInflationLineThreshold;

   125 /* static */ int32_t  nsLayoutUtils::sFontSizeInflationMappingIntercept;

   126 /* static */ uint32_t nsLayoutUtils::sFontSizeInflationMaxRatio;

   127 /* static */ bool nsLayoutUtils::sFontSizeInflationForceEnabled;

   128 /* static */ bool nsLayoutUtils::sFontSizeInflationDisabledInMasterProcess;

   129 /* static */ bool nsLayoutUtils::sInvalidationDebuggingIsEnabled;

   130 /* static */ bool nsLayoutUtils::sCSSVariablesEnabled;

   131 /* static */ bool nsLayoutUtils::sInterruptibleReflowEnabled;

   133 static ViewID sScrollIdCounter = FrameMetrics::START_SCROLL_ID;

   135 typedef nsDataHashtable<nsUint64HashKey, nsIContent*> ContentMap;

   136 static ContentMap* sContentMap = nullptr;

   137 static ContentMap& GetContentMap() {

   138   if (!sContentMap) {

   139     sContentMap = new ContentMap();

   140   }

   141   return *sContentMap;

   142 }

   144 // When the pref "layout.css.grid.enabled" changes, this function is invoked

   145 // to let us update kDisplayKTable, to selectively disable or restore the

   146 // entries for "grid" and "inline-grid" in that table.

   147 static void

   148 GridEnabledPrefChangeCallback(const char* aPrefName, void* aClosure)

   149 {

   150   MOZ_ASSERT(strncmp(aPrefName, GRID_ENABLED_PREF_NAME,

   151                      ArrayLength(GRID_ENABLED_PREF_NAME)) == 0,

   152              "We only registered this callback for a single pref, so it "

   153              "should only be called for that pref");

   155   static int32_t sIndexOfGridInDisplayTable;

   156   static int32_t sIndexOfInlineGridInDisplayTable;

   157   static bool sAreGridKeywordIndicesInitialized; // initialized to false

   159   bool isGridEnabled =

   160     Preferences::GetBool(GRID_ENABLED_PREF_NAME, false);

   161   if (!sAreGridKeywordIndicesInitialized) {

   162     // First run: find the position of "grid" and "inline-grid" in

   163     // kDisplayKTable.

   164     sIndexOfGridInDisplayTable =

   165       nsCSSProps::FindIndexOfKeyword(eCSSKeyword_grid,

   166                                      nsCSSProps::kDisplayKTable);

   167     MOZ_ASSERT(sIndexOfGridInDisplayTable >= 0,

   168                "Couldn't find grid in kDisplayKTable");

   169     sIndexOfInlineGridInDisplayTable =

   170       nsCSSProps::FindIndexOfKeyword(eCSSKeyword_inline_grid,

   171                                      nsCSSProps::kDisplayKTable);

   172     MOZ_ASSERT(sIndexOfInlineGridInDisplayTable >= 0,

   173                "Couldn't find inline-grid in kDisplayKTable");

   174     sAreGridKeywordIndicesInitialized = true;

   175   }

   177   // OK -- now, stomp on or restore the "grid" entries in kDisplayKTable,

   178   // depending on whether the grid pref is enabled vs. disabled.

   179   if (sIndexOfGridInDisplayTable >= 0) {

   180     nsCSSProps::kDisplayKTable[sIndexOfGridInDisplayTable] =

   181       isGridEnabled ? eCSSKeyword_grid : eCSSKeyword_UNKNOWN;

   182   }

   183   if (sIndexOfInlineGridInDisplayTable >= 0) {

   184     nsCSSProps::kDisplayKTable[sIndexOfInlineGridInDisplayTable] =

   185       isGridEnabled ? eCSSKeyword_inline_grid : eCSSKeyword_UNKNOWN;

   186   }

   187 }

   189 // When the pref "layout.css.sticky.enabled" changes, this function is invoked

   190 // to let us update kPositionKTable, to selectively disable or restore the

   191 // entry for "sticky" in that table.

   192 static void

   193 StickyEnabledPrefChangeCallback(const char* aPrefName, void* aClosure)

   194 {

   195   MOZ_ASSERT(strncmp(aPrefName, STICKY_ENABLED_PREF_NAME,

   196                      ArrayLength(STICKY_ENABLED_PREF_NAME)) == 0,

   197              "We only registered this callback for a single pref, so it "

   198              "should only be called for that pref");

   200   static int32_t sIndexOfStickyInPositionTable;

   201   static bool sIsStickyKeywordIndexInitialized; // initialized to false

   203   bool isStickyEnabled =

   204     Preferences::GetBool(STICKY_ENABLED_PREF_NAME, false);

   206   if (!sIsStickyKeywordIndexInitialized) {

   207     // First run: find the position of "sticky" in kPositionKTable.

   208     sIndexOfStickyInPositionTable =

   209       nsCSSProps::FindIndexOfKeyword(eCSSKeyword_sticky,

   210                                      nsCSSProps::kPositionKTable);

   211     MOZ_ASSERT(sIndexOfStickyInPositionTable >= 0,

   212                "Couldn't find sticky in kPositionKTable");

   213     sIsStickyKeywordIndexInitialized = true;

   214   }

   216   // OK -- now, stomp on or restore the "sticky" entry in kPositionKTable,

   217   // depending on whether the sticky pref is enabled vs. disabled.

   218   nsCSSProps::kPositionKTable[sIndexOfStickyInPositionTable] =

   219     isStickyEnabled ? eCSSKeyword_sticky : eCSSKeyword_UNKNOWN;

   220 }

   222 // When the pref "layout.css.text-align-true-value.enabled" changes, this

   223 // function is called to let us update kTextAlignKTable & kTextAlignLastKTable,

   224 // to selectively disable or restore the entries for "true" in those tables.

   225 static void

   226 TextAlignTrueEnabledPrefChangeCallback(const char* aPrefName, void* aClosure)

   227 {

   228   NS_ASSERTION(strcmp(aPrefName, TEXT_ALIGN_TRUE_ENABLED_PREF_NAME) == 0,

   229                "Did you misspell " TEXT_ALIGN_TRUE_ENABLED_PREF_NAME " ?");

   231   static bool sIsInitialized;

   232   static int32_t sIndexOfTrueInTextAlignTable;

   233   static int32_t sIndexOfTrueInTextAlignLastTable;

   234   bool isTextAlignTrueEnabled =

   235     Preferences::GetBool(TEXT_ALIGN_TRUE_ENABLED_PREF_NAME, false);

   237   if (!sIsInitialized) {

   238     // First run: find the position of "true" in kTextAlignKTable.

   239     sIndexOfTrueInTextAlignTable =

   240       nsCSSProps::FindIndexOfKeyword(eCSSKeyword_true,

   241                                      nsCSSProps::kTextAlignKTable);

   242     // First run: find the position of "true" in kTextAlignLastKTable.

   243     sIndexOfTrueInTextAlignLastTable =

   244       nsCSSProps::FindIndexOfKeyword(eCSSKeyword_true,

   245                                      nsCSSProps::kTextAlignLastKTable);

   246     sIsInitialized = true;

   247   }

   249   // OK -- now, stomp on or restore the "true" entry in the keyword tables,

   250   // depending on whether the pref is enabled vs. disabled.

   251   MOZ_ASSERT(sIndexOfTrueInTextAlignTable >= 0);

   252   nsCSSProps::kTextAlignKTable[sIndexOfTrueInTextAlignTable] =

   253     isTextAlignTrueEnabled ? eCSSKeyword_true : eCSSKeyword_UNKNOWN;

   254   MOZ_ASSERT(sIndexOfTrueInTextAlignLastTable >= 0);

   255   nsCSSProps::kTextAlignLastKTable[sIndexOfTrueInTextAlignLastTable] =

   256     isTextAlignTrueEnabled ? eCSSKeyword_true : eCSSKeyword_UNKNOWN;

   257 }

   259 template <class AnimationsOrTransitions>

   260 static AnimationsOrTransitions*

   261 HasAnimationOrTransitionForCompositor(nsIContent* aContent,

   262                                       nsIAtom* aAnimationProperty,

   263                                       nsCSSProperty aProperty)

   264 {

   265   AnimationsOrTransitions* animations =

   266     static_cast<AnimationsOrTransitions*>(aContent->GetProperty(aAnimationProperty));

   267   if (animations) {

   268     bool propertyMatches = animations->HasAnimationOfProperty(aProperty);

   269     if (propertyMatches &&

   270         animations->CanPerformOnCompositorThread(

   271           CommonElementAnimationData::CanAnimate_AllowPartial)) {

   272       return animations;

   273     }

   274   }

   276   return nullptr;

   277 }

   279 bool

   280 nsLayoutUtils::HasAnimationsForCompositor(nsIContent* aContent,

   281                                           nsCSSProperty aProperty)

   282 {

   283   if (!aContent->MayHaveAnimations())

   284     return false;

   285   return HasAnimationOrTransitionForCompositor<ElementAnimations>

   286             (aContent, nsGkAtoms::animationsProperty, aProperty) ||

   287          HasAnimationOrTransitionForCompositor<ElementTransitions>

   288             (aContent, nsGkAtoms::transitionsProperty, aProperty);

   289 }

   291 template <class AnimationsOrTransitions>

   292 AnimationsOrTransitions*

   293 mozilla::HasAnimationOrTransition(nsIContent* aContent,

   294                          nsIAtom* aAnimationProperty,

   295                          nsCSSProperty aProperty)

   296 {

   297   AnimationsOrTransitions* animations =

   298     static_cast<AnimationsOrTransitions*>(aContent->GetProperty(aAnimationProperty));

   299   if (animations) {

   300     bool propertyMatches = animations->HasAnimationOfProperty(aProperty);

   301     if (propertyMatches) {

   302       return animations;

   303     }

   304   }

   306   return nullptr;

   307 }

   309 template ElementAnimations*

   310 mozilla::HasAnimationOrTransition<ElementAnimations>(nsIContent* aContent,

   311                          nsIAtom* aAnimationProperty,

   312                          nsCSSProperty aProperty);

   314 template ElementTransitions*

   315 mozilla::HasAnimationOrTransition<ElementTransitions>(nsIContent* aContent,

   316                          nsIAtom* aAnimationProperty,

   317                          nsCSSProperty aProperty);

   320 bool

   321 nsLayoutUtils::HasAnimations(nsIContent* aContent,

   322                              nsCSSProperty aProperty)

   323 {

   324   if (!aContent->MayHaveAnimations())

   325     return false;

   326   return HasAnimationOrTransition<ElementAnimations>

   327             (aContent, nsGkAtoms::animationsProperty, aProperty) ||

   328          HasAnimationOrTransition<ElementTransitions>

   329             (aContent, nsGkAtoms::transitionsProperty, aProperty);

   330 }

   332 static gfxSize

   333 GetScaleForValue(const nsStyleAnimation::Value& aValue,

   334                  nsIFrame* aFrame)

   335 {

   336   if (!aFrame) {

   337     NS_WARNING("No frame.");

   338     return gfxSize();

   339   }

   340   if (aValue.GetUnit() != nsStyleAnimation::eUnit_Transform) {

   341     NS_WARNING("Expected a transform.");

   342     return gfxSize();

   343   }

   345   nsCSSValueSharedList* list = aValue.GetCSSValueSharedListValue();

   346   MOZ_ASSERT(list->mHead);

   348   if (list->mHead->mValue.GetUnit() == eCSSUnit_None) {

   349     // There is an animation, but no actual transform yet.

   350     return gfxSize();

   351   }

   353   nsRect frameBounds = aFrame->GetRect();

   354   bool dontCare;

   355   gfx3DMatrix transform = nsStyleTransformMatrix::ReadTransforms(

   356                             list->mHead,

   357                             aFrame->StyleContext(),

   358                             aFrame->PresContext(), dontCare, frameBounds,

   359                             aFrame->PresContext()->AppUnitsPerDevPixel());

   361   gfxMatrix transform2d;

   362   bool canDraw2D = transform.CanDraw2D(&transform2d);

   363   if (!canDraw2D) {

   364     return gfxSize();

   365   }

   367   return transform2d.ScaleFactors(true);

   368 }

   370 float

   371 GetSuitableScale(float aMaxScale, float aMinScale)

   372 {

   373   // If the minimum scale >= 1.0f, use it; if the maximum <= 1.0f, use it;

   374   // otherwise use 1.0f.

   375   if (aMinScale >= 1.0f) {

   376     return aMinScale;

   377   }

   378   else if (aMaxScale <= 1.0f) {

   379     return aMaxScale;

   380   }

   382   return 1.0f;

   383 }

   385 gfxSize

   386 nsLayoutUtils::ComputeSuitableScaleForAnimation(nsIContent* aContent)

   387 {

   388   gfxSize maxScale(1.0f, 1.0f);

   389   gfxSize minScale(1.0f, 1.0f);

   391   ElementAnimations* animations = HasAnimationOrTransitionForCompositor<ElementAnimations>

   392     (aContent, nsGkAtoms::animationsProperty, eCSSProperty_transform);

   393   if (animations) {

   394     for (uint32_t animIdx = animations->mAnimations.Length(); animIdx-- != 0; ) {

   395       mozilla::StyleAnimation& anim = animations->mAnimations[animIdx];

   396       for (uint32_t propIdx = anim.mProperties.Length(); propIdx-- != 0; ) {

   397         AnimationProperty& prop = anim.mProperties[propIdx];

   398         if (prop.mProperty == eCSSProperty_transform) {

   399           for (uint32_t segIdx = prop.mSegments.Length(); segIdx-- != 0; ) {

   400             AnimationPropertySegment& segment = prop.mSegments[segIdx];

   401             gfxSize from = GetScaleForValue(segment.mFromValue,

   402                                             aContent->GetPrimaryFrame());

   403             maxScale.width = std::max<float>(maxScale.width, from.width);

   404             maxScale.height = std::max<float>(maxScale.height, from.height);

   405             minScale.width = std::min<float>(minScale.width, from.width);

   406             minScale.height = std::min<float>(minScale.height, from.height);

   407             gfxSize to = GetScaleForValue(segment.mToValue,

   408                                           aContent->GetPrimaryFrame());

   409             maxScale.width = std::max<float>(maxScale.width, to.width);

   410             maxScale.height = std::max<float>(maxScale.height, to.height);

   411             minScale.width = std::min<float>(minScale.width, to.width);

   412             minScale.height = std::min<float>(minScale.height, to.height);

   413           }

   414         }

   415       }

   416     }

   417   }

   419   ElementTransitions* transitions = HasAnimationOrTransitionForCompositor<ElementTransitions>

   420     (aContent, nsGkAtoms::transitionsProperty, eCSSProperty_transform);

   421   if (transitions) {

   422     for (uint32_t i = 0, i_end = transitions->mPropertyTransitions.Length();

   423          i < i_end; ++i){

   424       ElementPropertyTransition &pt = transitions->mPropertyTransitions[i];

   425       if (pt.IsRemovedSentinel()) {

   426         continue;

   427       }

   428       MOZ_ASSERT(pt.mProperties.Length() == 1,

   429         "Should have one animation property for a transition");

   430       MOZ_ASSERT(pt.mProperties[0].mSegments.Length() == 1,

   431         "Animation property should have one segment for a transition");

   432       const AnimationPropertySegment& segment = pt.mProperties[0].mSegments[0];

   434       if (pt.mProperties[0].mProperty == eCSSProperty_transform) {

   435         gfxSize start = GetScaleForValue(segment.mFromValue,

   436                                          aContent->GetPrimaryFrame());

   437         maxScale.width = std::max<float>(maxScale.width, start.width);

   438         maxScale.height = std::max<float>(maxScale.height, start.height);

   439         minScale.width = std::min<float>(minScale.width, start.width);

   440         minScale.height = std::min<float>(minScale.height, start.height);

   441         gfxSize end = GetScaleForValue(segment.mToValue,

   442                                        aContent->GetPrimaryFrame());

   443         maxScale.width = std::max<float>(maxScale.width, end.width);

   444         maxScale.height = std::max<float>(maxScale.height, end.height);

   445         minScale.width = std::min<float>(minScale.width, end.width);

   446         minScale.height = std::min<float>(minScale.height, end.height);

   447       }

   448     }

   449   }

   451   return gfxSize(GetSuitableScale(maxScale.width, minScale.width),

   452       GetSuitableScale(maxScale.height, minScale.height));

   453 }

   455 bool

   456 nsLayoutUtils::AreAsyncAnimationsEnabled()

   457 {

   458   static bool sAreAsyncAnimationsEnabled;

   459   static bool sAsyncPrefCached = false;

   461   if (!sAsyncPrefCached) {

   462     sAsyncPrefCached = true;

   463     Preferences::AddBoolVarCache(&sAreAsyncAnimationsEnabled,

   464                                  "layers.offmainthreadcomposition.async-animations");

   465   }

   467   return sAreAsyncAnimationsEnabled &&

   468     gfxPlatform::OffMainThreadCompositingEnabled();

   469 }

   471 bool

   472 nsLayoutUtils::IsAnimationLoggingEnabled()

   473 {

   474   static bool sShouldLog;

   475   static bool sShouldLogPrefCached;

   477   if (!sShouldLogPrefCached) {

   478     sShouldLogPrefCached = true;

   479     Preferences::AddBoolVarCache(&sShouldLog,

   480                                  "layers.offmainthreadcomposition.log-animations");

   481   }

   483   return sShouldLog;

   484 }

   486 bool

   487 nsLayoutUtils::UseBackgroundNearestFiltering()

   488 {

   489   static bool sUseBackgroundNearestFilteringEnabled;

   490   static bool sUseBackgroundNearestFilteringPrefInitialised = false;

   492   if (!sUseBackgroundNearestFilteringPrefInitialised) {

   493     sUseBackgroundNearestFilteringPrefInitialised = true;

   494     sUseBackgroundNearestFilteringEnabled =

   495       Preferences::GetBool("gfx.filter.nearest.force-enabled", false);

   496   }

   498   return sUseBackgroundNearestFilteringEnabled;

   499 }

   501 bool

   502 nsLayoutUtils::GPUImageScalingEnabled()

   503 {

   504   static bool sGPUImageScalingEnabled;

   505   static bool sGPUImageScalingPrefInitialised = false;

   507   if (!sGPUImageScalingPrefInitialised) {

   508     sGPUImageScalingPrefInitialised = true;

   509     sGPUImageScalingEnabled =

   510       Preferences::GetBool("layout.gpu-image-scaling.enabled", false);

   511   }

   513   return sGPUImageScalingEnabled;

   514 }

   516 bool

   517 nsLayoutUtils::AnimatedImageLayersEnabled()

   518 {

   519   static bool sAnimatedImageLayersEnabled;

   520   static bool sAnimatedImageLayersPrefCached = false;

   522   if (!sAnimatedImageLayersPrefCached) {

   523     sAnimatedImageLayersPrefCached = true;

   524     Preferences::AddBoolVarCache(&sAnimatedImageLayersEnabled,

   525                                  "layout.animated-image-layers.enabled",

   526                                  false);

   527   }

   529   return sAnimatedImageLayersEnabled;

   530 }

   532 bool

   533 nsLayoutUtils::CSSFiltersEnabled()

   534 {

   535   static bool sCSSFiltersEnabled;

   536   static bool sCSSFiltersPrefCached = false;

   538   if (!sCSSFiltersPrefCached) {

   539     sCSSFiltersPrefCached = true;

   540     Preferences::AddBoolVarCache(&sCSSFiltersEnabled,

   541                                  "layout.css.filters.enabled",

   542                                  false);

   543   }

   545   return sCSSFiltersEnabled;

   546 }

   548 bool

   549 nsLayoutUtils::UnsetValueEnabled()

   550 {

   551   static bool sUnsetValueEnabled;

   552   static bool sUnsetValuePrefCached = false;

   554   if (!sUnsetValuePrefCached) {

   555     sUnsetValuePrefCached = true;

   556     Preferences::AddBoolVarCache(&sUnsetValueEnabled,

   557                                  "layout.css.unset-value.enabled",

   558                                  false);

   559   }

   561   return sUnsetValueEnabled;

   562 }

   564 bool

   565 nsLayoutUtils::IsTextAlignTrueValueEnabled()

   566 {

   567   static bool sTextAlignTrueValueEnabled;

   568   static bool sTextAlignTrueValueEnabledPrefCached = false;

   570   if (!sTextAlignTrueValueEnabledPrefCached) {

   571     sTextAlignTrueValueEnabledPrefCached = true;

   572     Preferences::AddBoolVarCache(&sTextAlignTrueValueEnabled,

   573                                  TEXT_ALIGN_TRUE_ENABLED_PREF_NAME,

   574                                  false);

   575   }

   577   return sTextAlignTrueValueEnabled;

   578 }

   580 void

   581 nsLayoutUtils::UnionChildOverflow(nsIFrame* aFrame,

   582                                   nsOverflowAreas& aOverflowAreas,

   583                                   FrameChildListIDs aSkipChildLists)

   584 {

   585   // Iterate over all children except pop-ups.

   586   FrameChildListIDs skip = aSkipChildLists |

   587       nsIFrame::kSelectPopupList | nsIFrame::kPopupList;

   588   for (nsIFrame::ChildListIterator childLists(aFrame);

   589        !childLists.IsDone(); childLists.Next()) {

   590     if (skip.Contains(childLists.CurrentID())) {

   591       continue;

   592     }

   594     nsFrameList children = childLists.CurrentList();

   595     for (nsFrameList::Enumerator e(children); !e.AtEnd(); e.Next()) {

   596       nsIFrame* child = e.get();

   597       nsOverflowAreas childOverflow =

   598         child->GetOverflowAreas() + child->GetPosition();

   599       aOverflowAreas.UnionWith(childOverflow);

   600     }

   601   }

   602 }

   604 static void DestroyViewID(void* aObject, nsIAtom* aPropertyName,

   605                           void* aPropertyValue, void* aData)

   606 {

   607   ViewID* id = static_cast<ViewID*>(aPropertyValue);

   608   GetContentMap().Remove(*id);

   609   delete id;

   610 }

   612 /**

   613  * A namespace class for static layout utilities.

   614  */

   616 bool

   617 nsLayoutUtils::FindIDFor(const nsIContent* aContent, ViewID* aOutViewId)

   618 {

   619   void* scrollIdProperty = aContent->GetProperty(nsGkAtoms::RemoteId);

   620   if (scrollIdProperty) {

   621     *aOutViewId = *static_cast<ViewID*>(scrollIdProperty);

   622     return true;

   623   }

   624   return false;

   625 }

   627 ViewID

   628 nsLayoutUtils::FindOrCreateIDFor(nsIContent* aContent)

   629 {

   630   ViewID scrollId;

   632   if (!FindIDFor(aContent, &scrollId)) {

   633     scrollId = sScrollIdCounter++;

   634     aContent->SetProperty(nsGkAtoms::RemoteId, new ViewID(scrollId),

   635                           DestroyViewID);

   636     GetContentMap().Put(scrollId, aContent);

   637   }

   639   return scrollId;

   640 }

   642 nsIContent*

   643 nsLayoutUtils::FindContentFor(ViewID aId)

   644 {

   645   NS_ABORT_IF_FALSE(aId != FrameMetrics::NULL_SCROLL_ID,

   646                     "Cannot find a content element in map for null IDs.");

   647   nsIContent* content;

   648   bool exists = GetContentMap().Get(aId, &content);

   650   if (exists) {

   651     return content;

   652   } else {

   653     return nullptr;

   654   }

   655 }

   657 nsIScrollableFrame*

   658 nsLayoutUtils::FindScrollableFrameFor(ViewID aId)

   659 {

   660   nsIContent* content = FindContentFor(aId);

   661   if (!content) {

   662     return nullptr;

   663   }

   665   nsIFrame* scrolledFrame = content->GetPrimaryFrame();

   666   if (scrolledFrame && content->OwnerDoc()->GetRootElement() == content) {

   667     // The content is the root element of a subdocument, so return the root scrollable

   668     // for the subdocument.

   669     scrolledFrame = scrolledFrame->PresContext()->PresShell()->GetRootScrollFrame();

   670   }

   671   return scrolledFrame ? scrolledFrame->GetScrollTargetFrame() : nullptr;

   672 }

   674 bool

   675 nsLayoutUtils::GetDisplayPort(nsIContent* aContent, nsRect *aResult)

   676 {

   677   DisplayPortPropertyData* rectData =

   678     static_cast<DisplayPortPropertyData*>(aContent->GetProperty(nsGkAtoms::DisplayPort));

   679   DisplayPortMarginsPropertyData* marginsData =

   680     static_cast<DisplayPortMarginsPropertyData*>(aContent->GetProperty(nsGkAtoms::DisplayPortMargins));

   681   if (!rectData && !marginsData) {

   682     return false;

   683   }

   685   if (aResult) {

   686     if (rectData && marginsData) {

   687       // choose margins if equal priority

   688       if (rectData->mPriority > marginsData->mPriority) {

   689         marginsData = nullptr;

   690       } else {

   691         rectData = nullptr;

   692       }

   693     }

   695     if (rectData) {

   696       *aResult = rectData->mRect;

   697     } else {

   698       nsRect* baseData =

   699         static_cast<nsRect*>(aContent->GetProperty(nsGkAtoms::DisplayPortBase));

   700       nsRect base;

   701       if (baseData) {

   702         base = *baseData;

   703       }

   705       nsIFrame* frame = aContent->GetPrimaryFrame();

   706       if (frame) {

   707         bool isRoot = false;

   708         if (aContent->OwnerDoc()->GetRootElement() == aContent) {

   709           // We want the scroll frame, the root scroll frame differs from all

   710           // others in that the primary frame is not the scroll frame.

   711           frame = frame->PresContext()->PresShell()->GetRootScrollFrame();

   712           isRoot = true;

   713         }

   715         // first convert the base rect to layer pixels

   716         nsPresContext* presContext = frame->PresContext();

   717         int32_t auPerDevPixel = presContext->AppUnitsPerDevPixel();

   718         gfxSize res = presContext->PresShell()->GetCumulativeResolution();

   719         gfxSize parentRes = res;

   720         if (isRoot) {

   721           // the base rect for root scroll frames is specified in the parent document

   722           // coordinate space, so it doesn't include the local resolution.

   723           gfxSize localRes = presContext->PresShell()->GetResolution();

   724           parentRes.width /= localRes.width;

   725           parentRes.height /= localRes.height;

   726         }

   727         LayerRect rect;

   728         rect.x = parentRes.width * NSAppUnitsToFloatPixels(base.x, auPerDevPixel);

   729         rect.y = parentRes.height * NSAppUnitsToFloatPixels(base.y, auPerDevPixel);

   730         rect.width =

   731           parentRes.width * NSAppUnitsToFloatPixels(base.width, auPerDevPixel);

   732         rect.height =

   733           parentRes.height * NSAppUnitsToFloatPixels(base.height, auPerDevPixel);

   735         rect.Inflate(marginsData->mMargins);

   737         nsIScrollableFrame* scrollableFrame = frame->GetScrollTargetFrame();

   738         nsPoint scrollPos(

   739           scrollableFrame ? scrollableFrame->GetScrollPosition() : nsPoint(0,0));

   740         if (marginsData->mAlignmentX > 0 || marginsData->mAlignmentY > 0) {

   741           // Avoid division by zero.

   742           if (marginsData->mAlignmentX == 0) {

   743             marginsData->mAlignmentX = 1;

   744           }

   745           if (marginsData->mAlignmentY == 0) {

   746             marginsData->mAlignmentY = 1;

   747           }

   749           LayerPoint scrollPosLayer(

   750             res.width * NSAppUnitsToFloatPixels(scrollPos.x, auPerDevPixel),

   751             res.height * NSAppUnitsToFloatPixels(scrollPos.y, auPerDevPixel));

   752           rect += scrollPosLayer;

   754           // Inflate the rectangle by 1 so that we always push to the next tile

   755           // boundary. This is desirable to stop from having a rectangle with a

   756           // moving origin occasionally being smaller when it coincidentally lines

   757           // up to tile boundaries.

   758           rect.Inflate(1);

   760           float left =

   761             marginsData->mAlignmentX * floor(rect.x / marginsData->mAlignmentX);

   762           float top =

   763             marginsData->mAlignmentY * floor(rect.y / marginsData->mAlignmentY);

   764           float right =

   765             marginsData->mAlignmentX * ceil(rect.XMost() / marginsData->mAlignmentX);

   766           float bottom =

   767             marginsData->mAlignmentY * ceil(rect.YMost() / marginsData->mAlignmentY);

   768           rect = LayerRect(left, top, right - left, bottom - top);

   769           rect -= scrollPosLayer;

   770         }

   772         nsRect result;

   773         result.x = NSFloatPixelsToAppUnits(rect.x / res.width, auPerDevPixel);

   774         result.y = NSFloatPixelsToAppUnits(rect.y / res.height, auPerDevPixel);

   775         result.width =

   776           NSFloatPixelsToAppUnits(rect.width / res.width, auPerDevPixel);

   777         result.height =

   778           NSFloatPixelsToAppUnits(rect.height / res.height, auPerDevPixel);

   780         // Finally, clamp the display port to the expanded scrollable rect.

   781         nsRect expandedScrollableRect = CalculateExpandedScrollableRect(frame);

   782         result = expandedScrollableRect.Intersect(result + scrollPos) - scrollPos;

   784         *aResult = result;

   785       }

   786     }

   787   }

   789   return true;

   790 }

   792 void

   793 nsLayoutUtils::SetDisplayPortMargins(nsIContent* aContent,

   794                                      nsIPresShell* aPresShell,

   795                                      const LayerMargin& aMargins,

   796                                      uint32_t aAlignmentX,

   797                                      uint32_t aAlignmentY,

   798                                      uint32_t aPriority,

   799                                      RepaintMode aRepaintMode)

   800 {

   801   DisplayPortMarginsPropertyData* currentData =

   802     static_cast<DisplayPortMarginsPropertyData*>(aContent->GetProperty(nsGkAtoms::DisplayPortMargins));

   803   if (currentData && currentData->mPriority > aPriority) {

   804     return;

   805   }

   807   aContent->SetProperty(nsGkAtoms::DisplayPortMargins,

   808                         new DisplayPortMarginsPropertyData(

   809                             aMargins, aAlignmentX, aAlignmentY, aPriority),

   810                         nsINode::DeleteProperty<DisplayPortMarginsPropertyData>);

   812   nsIFrame* rootScrollFrame = aPresShell->GetRootScrollFrame();

   813   if (rootScrollFrame && aContent == rootScrollFrame->GetContent()) {

   814     // We are setting a root displayport for a document.

   815     // The pres shell needs a special flag set.

   816     aPresShell->SetIgnoreViewportScrolling(true);

   817   }

   819   if (aRepaintMode == RepaintMode::Repaint) {

   820     nsIFrame* rootFrame = aPresShell->FrameManager()->GetRootFrame();

   821     if (rootFrame) {

   822       rootFrame->SchedulePaint();

   823     }

   824   }

   825 }

   827 void

   828 nsLayoutUtils::SetDisplayPortBase(nsIContent* aContent, const nsRect& aBase)

   829 {

   830   aContent->SetProperty(nsGkAtoms::DisplayPortBase, new nsRect(aBase),

   831                         nsINode::DeleteProperty<nsRect>);

   832 }

   834 void

   835 nsLayoutUtils::SetDisplayPortBaseIfNotSet(nsIContent* aContent, const nsRect& aBase)

   836 {

   837   if (!aContent->GetProperty(nsGkAtoms::DisplayPortBase)) {

   838     SetDisplayPortBase(aContent, aBase);

   839   }

   840 }

   842 bool

   843 nsLayoutUtils::GetCriticalDisplayPort(nsIContent* aContent, nsRect* aResult)

   844 {

   845   void* property = aContent->GetProperty(nsGkAtoms::CriticalDisplayPort);

   846   if (!property) {

   847     return false;

   848   }

   850   if (aResult) {

   851     *aResult = *static_cast<nsRect*>(property);

   852   }

   853   return true;

   854 }

   856 nsIFrame*

   857 nsLayoutUtils::LastContinuationWithChild(nsIFrame* aFrame)

   858 {

   859   NS_PRECONDITION(aFrame, "NULL frame pointer");

   860   aFrame = aFrame->LastContinuation();

   861   while (!aFrame->GetFirstPrincipalChild() &&

   862          aFrame->GetPrevContinuation()) {

   863     aFrame = aFrame->GetPrevContinuation();

   864   }

   865   return aFrame;

   866 }

   868 /**

   869  * GetFirstChildFrame returns the first "real" child frame of a

   870  * given frame.  It will descend down into pseudo-frames (unless the

   871  * pseudo-frame is the :before generated frame).

   872  * @param aFrame the frame

   873  * @param aFrame the frame's content node

   874  */

   875 static nsIFrame*

   876 GetFirstChildFrame(nsIFrame*       aFrame,

   877                    nsIContent*     aContent)

   878 {

   879   NS_PRECONDITION(aFrame, "NULL frame pointer");

   881   // Get the first child frame

   882   nsIFrame* childFrame = aFrame->GetFirstPrincipalChild();

   884   // If the child frame is a pseudo-frame, then return its first child.

   885   // Note that the frame we create for the generated content is also a

   886   // pseudo-frame and so don't drill down in that case

   887   if (childFrame &&

   888       childFrame->IsPseudoFrame(aContent) &&

   889       !childFrame->IsGeneratedContentFrame()) {

   890     return GetFirstChildFrame(childFrame, aContent);

   891   }

   893   return childFrame;

   894 }

   896 /**

   897  * GetLastChildFrame returns the last "real" child frame of a

   898  * given frame.  It will descend down into pseudo-frames (unless the

   899  * pseudo-frame is the :after generated frame).

   900  * @param aFrame the frame

   901  * @param aFrame the frame's content node

   902  */

   903 static nsIFrame*

   904 GetLastChildFrame(nsIFrame*       aFrame,

   905                   nsIContent*     aContent)

   906 {

   907   NS_PRECONDITION(aFrame, "NULL frame pointer");

   909   // Get the last continuation frame that's a parent

   910   nsIFrame* lastParentContinuation =

   911     nsLayoutUtils::LastContinuationWithChild(aFrame);

   912   nsIFrame* lastChildFrame =

   913     lastParentContinuation->GetLastChild(nsIFrame::kPrincipalList);

   914   if (lastChildFrame) {

   915     // Get the frame's first continuation. This matters in case the frame has

   916     // been continued across multiple lines or split by BiDi resolution.

   917     lastChildFrame = lastChildFrame->FirstContinuation();

   919     // If the last child frame is a pseudo-frame, then return its last child.

   920     // Note that the frame we create for the generated content is also a

   921     // pseudo-frame and so don't drill down in that case

   922     if (lastChildFrame &&

   923         lastChildFrame->IsPseudoFrame(aContent) &&

   924         !lastChildFrame->IsGeneratedContentFrame()) {

   925       return GetLastChildFrame(lastChildFrame, aContent);

   926     }

   928     return lastChildFrame;

   929   }

   931   return nullptr;

   932 }

   934 //static

   935 FrameChildListID

   936 nsLayoutUtils::GetChildListNameFor(nsIFrame* aChildFrame)

   937 {

   938   nsIFrame::ChildListID id = nsIFrame::kPrincipalList;

   940   if (aChildFrame->GetStateBits() & NS_FRAME_IS_OVERFLOW_CONTAINER) {

   941     nsIFrame* pif = aChildFrame->GetPrevInFlow();

   942     if (pif->GetParent() == aChildFrame->GetParent()) {

   943       id = nsIFrame::kExcessOverflowContainersList;

   944     }

   945     else {

   946       id = nsIFrame::kOverflowContainersList;

   947     }

   948   }

   949   // See if the frame is moved out of the flow

   950   else if (aChildFrame->GetStateBits() & NS_FRAME_OUT_OF_FLOW) {

   951     // Look at the style information to tell

   952     const nsStyleDisplay* disp = aChildFrame->StyleDisplay();

   954     if (NS_STYLE_POSITION_ABSOLUTE == disp->mPosition) {

   955       id = nsIFrame::kAbsoluteList;

   956     } else if (NS_STYLE_POSITION_FIXED == disp->mPosition) {

   957       if (nsLayoutUtils::IsReallyFixedPos(aChildFrame)) {

   958         id = nsIFrame::kFixedList;

   959       } else {

   960         id = nsIFrame::kAbsoluteList;

   961       }

   962 #ifdef MOZ_XUL

   963     } else if (NS_STYLE_DISPLAY_POPUP == disp->mDisplay) {

   964       // Out-of-flows that are DISPLAY_POPUP must be kids of the root popup set

   965 #ifdef DEBUG

   966       nsIFrame* parent = aChildFrame->GetParent();

   967       NS_ASSERTION(parent && parent->GetType() == nsGkAtoms::popupSetFrame,

   968                    "Unexpected parent");

   969 #endif // DEBUG

   971       id = nsIFrame::kPopupList;

   972 #endif // MOZ_XUL

   973     } else {

   974       NS_ASSERTION(aChildFrame->IsFloating(), "not a floated frame");

   975       id = nsIFrame::kFloatList;

   976     }

   978   } else {

   979     nsIAtom* childType = aChildFrame->GetType();

   980     if (nsGkAtoms::menuPopupFrame == childType) {

   981       nsIFrame* parent = aChildFrame->GetParent();

   982       MOZ_ASSERT(parent, "nsMenuPopupFrame can't be the root frame");

   983       if (parent) {

   984         if (parent->GetType() == nsGkAtoms::popupSetFrame) {

   985           id = nsIFrame::kPopupList;

   986         } else {

   987           nsIFrame* firstPopup = parent->GetFirstChild(nsIFrame::kPopupList);

   988           MOZ_ASSERT(!firstPopup || !firstPopup->GetNextSibling(),

   989                      "We assume popupList only has one child, but it has more.");

   990           id = firstPopup == aChildFrame

   991                  ? nsIFrame::kPopupList

   992                  : nsIFrame::kPrincipalList;

   993         }

   994       } else {

   995         id = nsIFrame::kPrincipalList;

   996       }

   997     } else if (nsGkAtoms::tableColGroupFrame == childType) {

   998       id = nsIFrame::kColGroupList;

   999     } else if (nsGkAtoms::tableCaptionFrame == childType) {

  1000       id = nsIFrame::kCaptionList;

  1001     } else {

  1002       id = nsIFrame::kPrincipalList;

  1003     }

  1004   }

  1006 #ifdef DEBUG

  1007   // Verify that the frame is actually in that child list or in the

  1008   // corresponding overflow list.

  1009   nsIFrame* parent = aChildFrame->GetParent();

  1010   bool found = parent->GetChildList(id).ContainsFrame(aChildFrame);

  1011   if (!found) {

  1012     if (!(aChildFrame->GetStateBits() & NS_FRAME_OUT_OF_FLOW)) {

  1013       found = parent->GetChildList(nsIFrame::kOverflowList)

  1014                 .ContainsFrame(aChildFrame);

  1015     }

  1016     else if (aChildFrame->IsFloating()) {

  1017       found = parent->GetChildList(nsIFrame::kOverflowOutOfFlowList)

  1018                 .ContainsFrame(aChildFrame);

  1019       if (!found) {

  1020         found = parent->GetChildList(nsIFrame::kPushedFloatsList)

  1021                   .ContainsFrame(aChildFrame);

  1022       }

  1023     }

  1024     // else it's positioned and should have been on the 'id' child list.

  1025     NS_POSTCONDITION(found, "not in child list");

  1026   }

  1027 #endif

  1029   return id;

  1030 }

  1032 // static

  1033 nsIFrame*

  1034 nsLayoutUtils::GetBeforeFrame(nsIFrame* aFrame)

  1035 {

  1036   NS_PRECONDITION(aFrame, "NULL frame pointer");

  1037   NS_ASSERTION(!aFrame->GetPrevContinuation(),

  1038                "aFrame must be first continuation");

  1040   nsIFrame* cif = aFrame->GetContentInsertionFrame();

  1041   nsIFrame* firstFrame = GetFirstChildFrame(cif, aFrame->GetContent());

  1043   if (firstFrame && IsGeneratedContentFor(nullptr, firstFrame,

  1044                                           nsCSSPseudoElements::before)) {

  1045     return firstFrame;

  1046   }

  1048   return nullptr;

  1049 }

  1051 // static

  1052 nsIFrame*

  1053 nsLayoutUtils::GetAfterFrame(nsIFrame* aFrame)

  1054 {

  1055   NS_PRECONDITION(aFrame, "NULL frame pointer");

  1057   nsIFrame* cif = aFrame->GetContentInsertionFrame();

  1058   nsIFrame* lastFrame = GetLastChildFrame(cif, aFrame->GetContent());

  1060   if (lastFrame && IsGeneratedContentFor(nullptr, lastFrame,

  1061                                          nsCSSPseudoElements::after)) {

  1062     return lastFrame;

  1063   }

  1065   return nullptr;

  1066 }

  1068 // static

  1069 nsIFrame*

  1070 nsLayoutUtils::GetClosestFrameOfType(nsIFrame* aFrame, nsIAtom* aFrameType)

  1071 {

  1072   for (nsIFrame* frame = aFrame; frame; frame = frame->GetParent()) {

  1073     if (frame->GetType() == aFrameType) {

  1074       return frame;

  1075     }

  1076   }

  1077   return nullptr;

  1078 }

  1080 // static

  1081 nsIFrame*

  1082 nsLayoutUtils::GetStyleFrame(nsIFrame* aFrame)

  1083 {

  1084   if (aFrame->GetType() == nsGkAtoms::tableOuterFrame) {

  1085     nsIFrame* inner = aFrame->GetFirstPrincipalChild();

  1086     NS_ASSERTION(inner, "Outer table must have an inner");

  1087     return inner;

  1088   }

  1090   return aFrame;

  1091 }

  1093 nsIFrame*

  1094 nsLayoutUtils::GetStyleFrame(const nsIContent* aContent)

  1095 {

  1096   nsIFrame *frame = aContent->GetPrimaryFrame();

  1097   if (!frame) {

  1098     return nullptr;

  1099   }

  1101   return nsLayoutUtils::GetStyleFrame(frame);

  1102 }

  1104 nsIFrame*

  1105 nsLayoutUtils::GetFloatFromPlaceholder(nsIFrame* aFrame) {

  1106   NS_ASSERTION(nsGkAtoms::placeholderFrame == aFrame->GetType(),

  1107                "Must have a placeholder here");

  1108   if (aFrame->GetStateBits() & PLACEHOLDER_FOR_FLOAT) {

  1109     nsIFrame *outOfFlowFrame =

  1110       nsPlaceholderFrame::GetRealFrameForPlaceholder(aFrame);

  1111     NS_ASSERTION(outOfFlowFrame->IsFloating(),

  1112                  "How did that happen?");

  1113     return outOfFlowFrame;

  1114   }

  1116   return nullptr;

  1117 }

  1119 // static

  1120 bool

  1121 nsLayoutUtils::IsGeneratedContentFor(nsIContent* aContent,

  1122                                      nsIFrame* aFrame,

  1123                                      nsIAtom* aPseudoElement)

  1124 {

  1125   NS_PRECONDITION(aFrame, "Must have a frame");

  1126   NS_PRECONDITION(aPseudoElement, "Must have a pseudo name");

  1128   if (!aFrame->IsGeneratedContentFrame()) {

  1129     return false;

  1130   }

  1131   nsIFrame* parent = aFrame->GetParent();

  1132   NS_ASSERTION(parent, "Generated content can't be root frame");

  1133   if (parent->IsGeneratedContentFrame()) {

  1134     // Not the root of the generated content

  1135     return false;

  1136   }

  1138   if (aContent && parent->GetContent() != aContent) {

  1139     return false;

  1140   }

  1142   return (aFrame->GetContent()->Tag() == nsGkAtoms::mozgeneratedcontentbefore) ==

  1143     (aPseudoElement == nsCSSPseudoElements::before);

  1144 }

  1146 // static

  1147 nsIFrame*

  1148 nsLayoutUtils::GetCrossDocParentFrame(const nsIFrame* aFrame,

  1149                                       nsPoint* aExtraOffset)

  1150 {

  1151   nsIFrame* p = aFrame->GetParent();

  1152   if (p)

  1153     return p;

  1155   nsView* v = aFrame->GetView();

  1156   if (!v)

  1157     return nullptr;

  1158   v = v->GetParent(); // anonymous inner view

  1159   if (!v)

  1160     return nullptr;

  1161   if (aExtraOffset) {

  1162     *aExtraOffset += v->GetPosition();

  1163   }

  1164   v = v->GetParent(); // subdocumentframe's view

  1165   return v ? v->GetFrame() : nullptr;

  1166 }

  1168 // static

  1169 bool

  1170 nsLayoutUtils::IsProperAncestorFrameCrossDoc(nsIFrame* aAncestorFrame, nsIFrame* aFrame,

  1171                                              nsIFrame* aCommonAncestor)

  1172 {

  1173   if (aFrame == aAncestorFrame)

  1174     return false;

  1175   return IsAncestorFrameCrossDoc(aAncestorFrame, aFrame, aCommonAncestor);

  1176 }

  1178 // static

  1179 bool

  1180 nsLayoutUtils::IsAncestorFrameCrossDoc(const nsIFrame* aAncestorFrame, const nsIFrame* aFrame,

  1181                                        const nsIFrame* aCommonAncestor)

  1182 {

  1183   for (const nsIFrame* f = aFrame; f != aCommonAncestor;

  1184        f = GetCrossDocParentFrame(f)) {

  1185     if (f == aAncestorFrame)

  1186       return true;

  1187   }

  1188   return aCommonAncestor == aAncestorFrame;

  1189 }

  1191 // static

  1192 bool

  1193 nsLayoutUtils::IsProperAncestorFrame(nsIFrame* aAncestorFrame, nsIFrame* aFrame,

  1194                                      nsIFrame* aCommonAncestor)

  1195 {

  1196   if (aFrame == aAncestorFrame)

  1197     return false;

  1198   for (nsIFrame* f = aFrame; f != aCommonAncestor; f = f->GetParent()) {

  1199     if (f == aAncestorFrame)

  1200       return true;

  1201   }

  1202   return aCommonAncestor == aAncestorFrame;

  1203 }

  1205 // static

  1206 int32_t

  1207 nsLayoutUtils::DoCompareTreePosition(nsIContent* aContent1,

  1208                                      nsIContent* aContent2,

  1209                                      int32_t aIf1Ancestor,

  1210                                      int32_t aIf2Ancestor,

  1211                                      const nsIContent* aCommonAncestor)

  1212 {

  1213   NS_PRECONDITION(aContent1, "aContent1 must not be null");

  1214   NS_PRECONDITION(aContent2, "aContent2 must not be null");

  1216   nsAutoTArray<nsINode*, 32> content1Ancestors;

  1217   nsINode* c1;

  1218   for (c1 = aContent1; c1 && c1 != aCommonAncestor; c1 = c1->GetParentNode()) {

  1219     content1Ancestors.AppendElement(c1);

  1220   }

  1221   if (!c1 && aCommonAncestor) {

  1222     // So, it turns out aCommonAncestor was not an ancestor of c1. Oops.

  1223     // Never mind. We can continue as if aCommonAncestor was null.

  1224     aCommonAncestor = nullptr;

  1225   }

  1227   nsAutoTArray<nsINode*, 32> content2Ancestors;

  1228   nsINode* c2;

  1229   for (c2 = aContent2; c2 && c2 != aCommonAncestor; c2 = c2->GetParentNode()) {

  1230     content2Ancestors.AppendElement(c2);

  1231   }

  1232   if (!c2 && aCommonAncestor) {

  1233     // So, it turns out aCommonAncestor was not an ancestor of c2.

  1234     // We need to retry with no common ancestor hint.

  1235     return DoCompareTreePosition(aContent1, aContent2,

  1236                                  aIf1Ancestor, aIf2Ancestor, nullptr);

  1237   }

  1239   int last1 = content1Ancestors.Length() - 1;

  1240   int last2 = content2Ancestors.Length() - 1;

  1241   nsINode* content1Ancestor = nullptr;

  1242   nsINode* content2Ancestor = nullptr;

  1243   while (last1 >= 0 && last2 >= 0

  1244          && ((content1Ancestor = content1Ancestors.ElementAt(last1)) ==

  1245              (content2Ancestor = content2Ancestors.ElementAt(last2)))) {

  1246     last1--;

  1247     last2--;

  1248   }

  1250   if (last1 < 0) {

  1251     if (last2 < 0) {

  1252       NS_ASSERTION(aContent1 == aContent2, "internal error?");

  1253       return 0;

  1254     }

  1255     // aContent1 is an ancestor of aContent2

  1256     return aIf1Ancestor;

  1257   }

  1259   if (last2 < 0) {

  1260     // aContent2 is an ancestor of aContent1

  1261     return aIf2Ancestor;

  1262   }

  1264   // content1Ancestor != content2Ancestor, so they must be siblings with the same parent

  1265   nsINode* parent = content1Ancestor->GetParentNode();

  1266 #ifdef DEBUG

  1267   // TODO: remove the uglyness, see bug 598468.

  1268   NS_ASSERTION(gPreventAssertInCompareTreePosition || parent,

  1269                "no common ancestor at all???");

  1270 #endif // DEBUG

  1271   if (!parent) { // different documents??

  1272     return 0;

  1273   }

  1275   int32_t index1 = parent->IndexOf(content1Ancestor);

  1276   int32_t index2 = parent->IndexOf(content2Ancestor);

  1277   if (index1 < 0 || index2 < 0) {

  1278     // one of them must be anonymous; we can't determine the order

  1279     return 0;

  1280   }

  1282   return index1 - index2;

  1283 }

  1285 // static

  1286 nsIFrame*

  1287 nsLayoutUtils::FillAncestors(nsIFrame* aFrame,

  1288                              nsIFrame* aStopAtAncestor,

  1289                              nsTArray<nsIFrame*>* aAncestors)

  1290 {

  1291   while (aFrame && aFrame != aStopAtAncestor) {

  1292     aAncestors->AppendElement(aFrame);

  1293     aFrame = nsLayoutUtils::GetParentOrPlaceholderFor(aFrame);

  1294   }

  1295   return aFrame;

  1296 }

  1298 // Return true if aFrame1 is after aFrame2

  1299 static bool IsFrameAfter(nsIFrame* aFrame1, nsIFrame* aFrame2)

  1300 {

  1301   nsIFrame* f = aFrame2;

  1302   do {

  1303     f = f->GetNextSibling();

  1304     if (f == aFrame1)

  1305       return true;

  1306   } while (f);

  1307   return false;

  1308 }

  1310 // static

  1311 int32_t

  1312 nsLayoutUtils::DoCompareTreePosition(nsIFrame* aFrame1,

  1313                                      nsIFrame* aFrame2,

  1314                                      int32_t aIf1Ancestor,

  1315                                      int32_t aIf2Ancestor,

  1316                                      nsIFrame* aCommonAncestor)

  1317 {

  1318   NS_PRECONDITION(aFrame1, "aFrame1 must not be null");

  1319   NS_PRECONDITION(aFrame2, "aFrame2 must not be null");

  1321   nsAutoTArray<nsIFrame*,20> frame2Ancestors;

  1322   nsIFrame* nonCommonAncestor =

  1323     FillAncestors(aFrame2, aCommonAncestor, &frame2Ancestors);

  1325   return DoCompareTreePosition(aFrame1, aFrame2, frame2Ancestors,

  1326                                aIf1Ancestor, aIf2Ancestor,

  1327                                nonCommonAncestor ? aCommonAncestor : nullptr);

  1328 }

  1330 // static

  1331 int32_t

  1332 nsLayoutUtils::DoCompareTreePosition(nsIFrame* aFrame1,

  1333                                      nsIFrame* aFrame2,

  1334                                      nsTArray<nsIFrame*>& aFrame2Ancestors,

  1335                                      int32_t aIf1Ancestor,

  1336                                      int32_t aIf2Ancestor,

  1337                                      nsIFrame* aCommonAncestor)

  1338 {

  1339   NS_PRECONDITION(aFrame1, "aFrame1 must not be null");

  1340   NS_PRECONDITION(aFrame2, "aFrame2 must not be null");

  1342   nsPresContext* presContext = aFrame1->PresContext();

  1343   if (presContext != aFrame2->PresContext()) {

  1344     NS_ERROR("no common ancestor at all, different documents");

  1345     return 0;

  1346   }

  1348   nsAutoTArray<nsIFrame*,20> frame1Ancestors;

  1349   if (aCommonAncestor &&

  1350       !FillAncestors(aFrame1, aCommonAncestor, &frame1Ancestors)) {

  1351     // We reached the root of the frame tree ... if aCommonAncestor was set,

  1352     // it is wrong

  1353     return DoCompareTreePosition(aFrame1, aFrame2,

  1354                                  aIf1Ancestor, aIf2Ancestor, nullptr);

  1355   }

  1357   int32_t last1 = int32_t(frame1Ancestors.Length()) - 1;

  1358   int32_t last2 = int32_t(aFrame2Ancestors.Length()) - 1;

  1359   while (last1 >= 0 && last2 >= 0 &&

  1360          frame1Ancestors[last1] == aFrame2Ancestors[last2]) {

  1361     last1--;

  1362     last2--;

  1363   }

  1365   if (last1 < 0) {

  1366     if (last2 < 0) {

  1367       NS_ASSERTION(aFrame1 == aFrame2, "internal error?");

  1368       return 0;

  1369     }

  1370     // aFrame1 is an ancestor of aFrame2

  1371     return aIf1Ancestor;

  1372   }

  1374   if (last2 < 0) {

  1375     // aFrame2 is an ancestor of aFrame1

  1376     return aIf2Ancestor;

  1377   }

  1379   nsIFrame* ancestor1 = frame1Ancestors[last1];

  1380   nsIFrame* ancestor2 = aFrame2Ancestors[last2];

  1381   // Now we should be able to walk sibling chains to find which one is first

  1382   if (IsFrameAfter(ancestor2, ancestor1))

  1383     return -1;

  1384   if (IsFrameAfter(ancestor1, ancestor2))

  1385     return 1;

  1386   NS_WARNING("Frames were in different child lists???");

  1387   return 0;

  1388 }

  1390 // static

  1391 nsIFrame* nsLayoutUtils::GetLastSibling(nsIFrame* aFrame) {

  1392   if (!aFrame) {

  1393     return nullptr;

  1394   }

  1396   nsIFrame* next;

  1397   while ((next = aFrame->GetNextSibling()) != nullptr) {

  1398     aFrame = next;

  1399   }

  1400   return aFrame;

  1401 }

  1403 // static

  1404 nsView*

  1405 nsLayoutUtils::FindSiblingViewFor(nsView* aParentView, nsIFrame* aFrame) {

  1406   nsIFrame* parentViewFrame = aParentView->GetFrame();

  1407   nsIContent* parentViewContent = parentViewFrame ? parentViewFrame->GetContent() : nullptr;

  1408   for (nsView* insertBefore = aParentView->GetFirstChild(); insertBefore;

  1409        insertBefore = insertBefore->GetNextSibling()) {

  1410     nsIFrame* f = insertBefore->GetFrame();

  1411     if (!f) {

  1412       // this view could be some anonymous view attached to a meaningful parent

  1413       for (nsView* searchView = insertBefore->GetParent(); searchView;

  1414            searchView = searchView->GetParent()) {

  1415         f = searchView->GetFrame();

  1416         if (f) {

  1417           break;

  1418         }

  1419       }

  1420       NS_ASSERTION(f, "Can't find a frame anywhere!");

  1421     }

  1422     if (!f || !aFrame->GetContent() || !f->GetContent() ||

  1423         CompareTreePosition(aFrame->GetContent(), f->GetContent(), parentViewContent) > 0) {

  1424       // aFrame's content is after f's content (or we just don't know),

  1425       // so put our view before f's view

  1426       return insertBefore;

  1427     }

  1428   }

  1429   return nullptr;

  1430 }

  1432 //static

  1433 nsIScrollableFrame*

  1434 nsLayoutUtils::GetScrollableFrameFor(const nsIFrame *aScrolledFrame)

  1435 {

  1436   nsIFrame *frame = aScrolledFrame->GetParent();

  1437   nsIScrollableFrame *sf = do_QueryFrame(frame);

  1438   return sf;

  1439 }

  1441 /* static */ void

  1442 nsLayoutUtils::SetFixedPositionLayerData(Layer* aLayer,

  1443                                          const nsIFrame* aViewportFrame,

  1444                                          const nsRect& aAnchorRect,

  1445                                          const nsIFrame* aFixedPosFrame,

  1446                                          nsPresContext* aPresContext,

  1447                                          const ContainerLayerParameters& aContainerParameters) {

  1448   // Find out the rect of the viewport frame relative to the reference frame.

  1449   // This, in conjunction with the container scale, will correspond to the

  1450   // coordinate-space of the built layer.

  1451   float factor = aPresContext->AppUnitsPerDevPixel();

  1452   Rect anchorRect(NSAppUnitsToFloatPixels(aAnchorRect.x, factor) *

  1453                     aContainerParameters.mXScale,

  1454                   NSAppUnitsToFloatPixels(aAnchorRect.y, factor) *

  1455                     aContainerParameters.mYScale,

  1456                   NSAppUnitsToFloatPixels(aAnchorRect.width, factor) *

  1457                     aContainerParameters.mXScale,

  1458                   NSAppUnitsToFloatPixels(aAnchorRect.height, factor) *

  1459                     aContainerParameters.mYScale);

  1460   // Need to transform anchorRect from the container layer's coordinate system

  1461   // into aLayer's coordinate system.

  1462   Matrix transform2d;

  1463   if (aLayer->GetTransform().Is2D(&transform2d)) {

  1464     transform2d.Invert();

  1465     anchorRect = transform2d.TransformBounds(anchorRect);

  1466   } else {

  1467     NS_ERROR("3D transform found between fixedpos content and its viewport (should never happen)");

  1468     anchorRect = Rect(0,0,0,0);

  1469   }

  1471   // Work out the anchor point for this fixed position layer. We assume that

  1472   // any positioning set (left/top/right/bottom) indicates that the

  1473   // corresponding side of its container should be the anchor point,

  1474   // defaulting to top-left.

  1475   LayerPoint anchor(anchorRect.x, anchorRect.y);

  1476   // Make sure the layer is aware of any fixed position margins that have

  1477   // been set.

  1478   nsMargin fixedMargins = aPresContext->PresShell()->GetContentDocumentFixedPositionMargins();

  1479   LayerMargin fixedLayerMargins(NSAppUnitsToFloatPixels(fixedMargins.top, factor) *

  1480                                   aContainerParameters.mYScale,

  1481                                 NSAppUnitsToFloatPixels(fixedMargins.right, factor) *

  1482                                   aContainerParameters.mXScale,

  1483                                 NSAppUnitsToFloatPixels(fixedMargins.bottom, factor) *

  1484                                   aContainerParameters.mYScale,

  1485                                 NSAppUnitsToFloatPixels(fixedMargins.left, factor) *

  1486                                   aContainerParameters.mXScale);

  1488   if (aFixedPosFrame != aViewportFrame) {

  1489     const nsStylePosition* position = aFixedPosFrame->StylePosition();

  1490     if (position->mOffset.GetRightUnit() != eStyleUnit_Auto) {

  1491       if (position->mOffset.GetLeftUnit() != eStyleUnit_Auto) {

  1492         anchor.x = anchorRect.x + anchorRect.width / 2.f;

  1493       } else {

  1494         anchor.x = anchorRect.XMost();

  1495       }

  1496     }

  1497     if (position->mOffset.GetBottomUnit() != eStyleUnit_Auto) {

  1498       if (position->mOffset.GetTopUnit() != eStyleUnit_Auto) {

  1499         anchor.y = anchorRect.y + anchorRect.height / 2.f;

  1500       } else {

  1501         anchor.y = anchorRect.YMost();

  1502       }

  1503     }

  1505     // If the frame is auto-positioned on either axis, set the top/left layer

  1506     // margins to -1, to indicate to the compositor that this layer is

  1507     // unaffected by fixed margins.

  1508     if (position->mOffset.GetLeftUnit() == eStyleUnit_Auto &&

  1509         position->mOffset.GetRightUnit() == eStyleUnit_Auto) {

  1510       fixedLayerMargins.left = -1;

  1511     }

  1512     if (position->mOffset.GetTopUnit() == eStyleUnit_Auto &&

  1513         position->mOffset.GetBottomUnit() == eStyleUnit_Auto) {

  1514       fixedLayerMargins.top = -1;

  1515     }

  1516   }

  1518   aLayer->SetFixedPositionAnchor(anchor);

  1519   aLayer->SetFixedPositionMargins(fixedLayerMargins);

  1520 }

  1522 bool

  1523 nsLayoutUtils::ViewportHasDisplayPort(nsPresContext* aPresContext, nsRect* aDisplayPort)

  1524 {

  1525   nsIFrame* rootScrollFrame =

  1526     aPresContext->PresShell()->GetRootScrollFrame();

  1527   return rootScrollFrame &&

  1528     nsLayoutUtils::GetDisplayPort(rootScrollFrame->GetContent(), aDisplayPort);

  1529 }

  1531 bool

  1532 nsLayoutUtils::IsFixedPosFrameInDisplayPort(const nsIFrame* aFrame, nsRect* aDisplayPort)

  1533 {

  1534   // Fixed-pos frames are parented by the viewport frame or the page content frame.

  1535   // We'll assume that printing/print preview don't have displayports for their

  1536   // pages!

  1537   nsIFrame* parent = aFrame->GetParent();

  1538   if (!parent || parent->GetParent() ||

  1539       aFrame->StyleDisplay()->mPosition != NS_STYLE_POSITION_FIXED) {

  1540     return false;

  1541   }

  1542   return ViewportHasDisplayPort(aFrame->PresContext(), aDisplayPort);

  1543 }

  1545 static nsIFrame*

  1546 GetAnimatedGeometryRootForFrame(nsIFrame* aFrame,

  1547                                 const nsIFrame* aStopAtAncestor)

  1548 {

  1549   nsIFrame* f = aFrame;

  1550   nsIFrame* stickyFrame = nullptr;

  1551   while (f != aStopAtAncestor) {

  1552     if (nsLayoutUtils::IsPopup(f))

  1553       break;

  1554     if (ActiveLayerTracker::IsOffsetOrMarginStyleAnimated(f))

  1555       break;

  1556     if (!f->GetParent() &&

  1557         nsLayoutUtils::ViewportHasDisplayPort(f->PresContext())) {

  1558       // Viewport frames in a display port need to be animated geometry roots

  1559       // for background-attachment:fixed elements.

  1560       break;

  1561     }

  1562     nsIFrame* parent = nsLayoutUtils::GetCrossDocParentFrame(f);

  1563     if (!parent)

  1564       break;

  1565     nsIAtom* parentType = parent->GetType();

  1566 #ifdef ANDROID

  1567     // Treat the slider thumb as being as an active scrolled root

  1568     // on mobile so that it can move without repainting.

  1569     if (parentType == nsGkAtoms::sliderFrame)

  1570       break;

  1571 #endif

  1572     // Sticky frames are active if their nearest scrollable frame

  1573     // is also active, just keep a record of sticky frames that we

  1574     // encounter for now.

  1575     if (f->StyleDisplay()->mPosition == NS_STYLE_POSITION_STICKY &&

  1576         !stickyFrame) {

  1577       stickyFrame = f;

  1578     }

  1579     if (parentType == nsGkAtoms::scrollFrame) {

  1580       nsIScrollableFrame* sf = do_QueryFrame(parent);

  1581       if (sf->IsScrollingActive() && sf->GetScrolledFrame() == f) {

  1582         // If we found a sticky frame inside this active scroll frame,

  1583         // then use that. Otherwise use the scroll frame.

  1584         if (stickyFrame) {

  1585           return stickyFrame;

  1586         }

  1587         return f;

  1588       } else {

  1589         stickyFrame = nullptr;

  1590       }

  1591     }

  1592     // Fixed-pos frames are parented by the viewport frame, which has no parent

  1593     if (nsLayoutUtils::IsFixedPosFrameInDisplayPort(f)) {

  1594       return f;

  1595     }

  1596     f = parent;

  1597   }

  1598   return f;

  1599 }

  1601 nsIFrame*

  1602 nsLayoutUtils::GetAnimatedGeometryRootFor(nsDisplayItem* aItem,

  1603                                           nsDisplayListBuilder* aBuilder)

  1604 {

  1605   nsIFrame* f = aItem->Frame();

  1606   if (aItem->GetType() == nsDisplayItem::TYPE_SCROLL_LAYER) {

  1607     nsDisplayScrollLayer* scrollLayerItem =

  1608       static_cast<nsDisplayScrollLayer*>(aItem);

  1609     nsIFrame* scrolledFrame = scrollLayerItem->GetScrolledFrame();

  1610     return GetAnimatedGeometryRootForFrame(scrolledFrame,

  1611         aBuilder->FindReferenceFrameFor(scrolledFrame));

  1612   }

  1613   if (aItem->ShouldFixToViewport(aBuilder)) {

  1614     // Make its active scrolled root be the active scrolled root of

  1615     // the enclosing viewport, since it shouldn't be scrolled by scrolled

  1616     // frames in its document. InvalidateFixedBackgroundFramesFromList in

  1617     // nsGfxScrollFrame will not repaint this item when scrolling occurs.

  1618     nsIFrame* viewportFrame =

  1619       nsLayoutUtils::GetClosestFrameOfType(f, nsGkAtoms::viewportFrame);

  1620     NS_ASSERTION(viewportFrame, "no viewport???");

  1621     return GetAnimatedGeometryRootForFrame(viewportFrame,

  1622         aBuilder->FindReferenceFrameFor(viewportFrame));

  1623   }

  1624   return GetAnimatedGeometryRootForFrame(f, aItem->ReferenceFrame());

  1625 }

  1627 // static

  1628 nsIScrollableFrame*

  1629 nsLayoutUtils::GetNearestScrollableFrameForDirection(nsIFrame* aFrame,

  1630                                                      Direction aDirection)

  1631 {

  1632   NS_ASSERTION(aFrame, "GetNearestScrollableFrameForDirection expects a non-null frame");

  1633   for (nsIFrame* f = aFrame; f; f = nsLayoutUtils::GetCrossDocParentFrame(f)) {

  1634     nsIScrollableFrame* scrollableFrame = do_QueryFrame(f);

  1635     if (scrollableFrame) {

  1636       ScrollbarStyles ss = scrollableFrame->GetScrollbarStyles();

  1637       uint32_t directions = scrollableFrame->GetPerceivedScrollingDirections();

  1638       if (aDirection == eVertical ?

  1639           (ss.mVertical != NS_STYLE_OVERFLOW_HIDDEN &&

  1640            (directions & nsIScrollableFrame::VERTICAL)) :

  1641           (ss.mHorizontal != NS_STYLE_OVERFLOW_HIDDEN &&

  1642            (directions & nsIScrollableFrame::HORIZONTAL)))

  1643         return scrollableFrame;

  1644     }

  1645   }

  1646   return nullptr;

  1647 }

  1649 // static

  1650 nsIScrollableFrame*

  1651 nsLayoutUtils::GetNearestScrollableFrame(nsIFrame* aFrame, uint32_t aFlags)

  1652 {

  1653   NS_ASSERTION(aFrame, "GetNearestScrollableFrame expects a non-null frame");

  1654   for (nsIFrame* f = aFrame; f; f = (aFlags & SCROLLABLE_SAME_DOC) ?

  1655        f->GetParent() : nsLayoutUtils::GetCrossDocParentFrame(f)) {

  1656     nsIScrollableFrame* scrollableFrame = do_QueryFrame(f);

  1657     if (scrollableFrame) {

  1658       ScrollbarStyles ss = scrollableFrame->GetScrollbarStyles();

  1659       if ((aFlags & SCROLLABLE_INCLUDE_HIDDEN) ||

  1660           ss.mVertical != NS_STYLE_OVERFLOW_HIDDEN ||

  1661           ss.mHorizontal != NS_STYLE_OVERFLOW_HIDDEN)

  1662         return scrollableFrame;

  1663     }

  1664   }

  1665   return nullptr;

  1666 }

  1668 // static

  1669 nsRect

  1670 nsLayoutUtils::GetScrolledRect(nsIFrame* aScrolledFrame,

  1671                                const nsRect& aScrolledFrameOverflowArea,

  1672                                const nsSize& aScrollPortSize,

  1673                                uint8_t aDirection)

  1674 {

  1675   nscoord x1 = aScrolledFrameOverflowArea.x,

  1676           x2 = aScrolledFrameOverflowArea.XMost(),

  1677           y1 = aScrolledFrameOverflowArea.y,

  1678           y2 = aScrolledFrameOverflowArea.YMost();

  1679   if (y1 < 0) {

  1680     y1 = 0;

  1681   }

  1682   if (aDirection != NS_STYLE_DIRECTION_RTL) {

  1683     if (x1 < 0) {

  1684       x1 = 0;

  1685     }

  1686   } else {

  1687     if (x2 > aScrollPortSize.width) {

  1688       x2 = aScrollPortSize.width;

  1689     }

  1690     // When the scrolled frame chooses a size larger than its available width (because

  1691     // its padding alone is larger than the available width), we need to keep the

  1692     // start-edge of the scroll frame anchored to the start-edge of the scrollport.

  1693     // When the scrolled frame is RTL, this means moving it in our left-based

  1694     // coordinate system, so we need to compensate for its extra width here by

  1695     // effectively repositioning the frame.

  1696     nscoord extraWidth = std::max(0, aScrolledFrame->GetSize().width - aScrollPortSize.width);

  1697     x2 += extraWidth;

  1698   }

  1699   return nsRect(x1, y1, x2 - x1, y2 - y1);

  1700 }

  1702 //static

  1703 bool

  1704 nsLayoutUtils::HasPseudoStyle(nsIContent* aContent,

  1705                               nsStyleContext* aStyleContext,

  1706                               nsCSSPseudoElements::Type aPseudoElement,

  1707                               nsPresContext* aPresContext)

  1708 {

  1709   NS_PRECONDITION(aPresContext, "Must have a prescontext");

  1711   nsRefPtr<nsStyleContext> pseudoContext;

  1712   if (aContent) {

  1713     pseudoContext = aPresContext->StyleSet()->

  1714       ProbePseudoElementStyle(aContent->AsElement(), aPseudoElement,

  1715                               aStyleContext);

  1716   }

  1717   return pseudoContext != nullptr;

  1718 }

  1720 nsPoint

  1721 nsLayoutUtils::GetDOMEventCoordinatesRelativeTo(nsIDOMEvent* aDOMEvent, nsIFrame* aFrame)

  1722 {

  1723   if (!aDOMEvent)

  1724     return nsPoint(NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE);

  1725   WidgetEvent* event = aDOMEvent->GetInternalNSEvent();

  1726   if (!event)

  1727     return nsPoint(NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE);

  1728   return GetEventCoordinatesRelativeTo(event, aFrame);

  1729 }

  1731 nsPoint

  1732 nsLayoutUtils::GetEventCoordinatesRelativeTo(const WidgetEvent* aEvent,

  1733                                              nsIFrame* aFrame)

  1734 {

  1735   if (!aEvent || (aEvent->eventStructType != NS_MOUSE_EVENT &&

  1736                   aEvent->eventStructType != NS_MOUSE_SCROLL_EVENT &&

  1737                   aEvent->eventStructType != NS_WHEEL_EVENT &&

  1738                   aEvent->eventStructType != NS_DRAG_EVENT &&

  1739                   aEvent->eventStructType != NS_SIMPLE_GESTURE_EVENT &&

  1740                   aEvent->eventStructType != NS_POINTER_EVENT &&

  1741                   aEvent->eventStructType != NS_GESTURENOTIFY_EVENT &&

  1742                   aEvent->eventStructType != NS_TOUCH_EVENT &&

  1743                   aEvent->eventStructType != NS_QUERY_CONTENT_EVENT))

  1744     return nsPoint(NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE);

  1746   return GetEventCoordinatesRelativeTo(aEvent,

  1747            LayoutDeviceIntPoint::ToUntyped(aEvent->AsGUIEvent()->refPoint),

  1748            aFrame);

  1749 }

  1751 nsPoint

  1752 nsLayoutUtils::GetEventCoordinatesRelativeTo(const WidgetEvent* aEvent,

  1753                                              const nsIntPoint aPoint,

  1754                                              nsIFrame* aFrame)

  1755 {

  1756   if (!aFrame) {

  1757     return nsPoint(NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE);

  1758   }

  1760   nsIWidget* widget = aEvent->AsGUIEvent()->widget;

  1761   if (!widget) {

  1762     return nsPoint(NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE);

  1763   }

  1765   return GetEventCoordinatesRelativeTo(widget, aPoint, aFrame);

  1766 }

  1768 nsPoint

  1769 nsLayoutUtils::GetEventCoordinatesRelativeTo(nsIWidget* aWidget,

  1770                                              const nsIntPoint aPoint,

  1771                                              nsIFrame* aFrame)

  1772 {

  1773   if (!aFrame || !aWidget) {

  1774     return nsPoint(NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE);

  1775   }

  1777   nsView* view = aFrame->GetView();

  1778   if (view) {

  1779     nsIWidget* frameWidget = view->GetWidget();

  1780     if (frameWidget && frameWidget == aWidget) {

  1781       // Special case this cause it happens a lot.

  1782       // This also fixes bug 664707, events in the extra-special case of select

  1783       // dropdown popups that are transformed.

  1784       nsPresContext* presContext = aFrame->PresContext();

  1785       nsPoint pt(presContext->DevPixelsToAppUnits(aPoint.x),

  1786                  presContext->DevPixelsToAppUnits(aPoint.y));

  1787       return pt - view->ViewToWidgetOffset();

  1788     }

  1789   }

  1791   /* If we walk up the frame tree and discover that any of the frames are

  1792    * transformed, we need to do extra work to convert from the global

  1793    * space to the local space.

  1794    */

  1795   nsIFrame* rootFrame = aFrame;

  1796   bool transformFound = false;

  1797   for (nsIFrame* f = aFrame; f; f = GetCrossDocParentFrame(f)) {

  1798     if (f->IsTransformed()) {

  1799       transformFound = true;

  1800     }

  1802     rootFrame = f;

  1803   }

  1805   nsView* rootView = rootFrame->GetView();

  1806   if (!rootView) {

  1807     return nsPoint(NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE);

  1808   }

  1810   nsPoint widgetToView = TranslateWidgetToView(rootFrame->PresContext(),

  1811                                                aWidget, aPoint, rootView);

  1813   if (widgetToView == nsPoint(NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE)) {

  1814     return nsPoint(NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE);

  1815   }

  1817   // Convert from root document app units to app units of the document aFrame

  1818   // is in.

  1819   int32_t rootAPD = rootFrame->PresContext()->AppUnitsPerDevPixel();

  1820   int32_t localAPD = aFrame->PresContext()->AppUnitsPerDevPixel();

  1821   widgetToView = widgetToView.ConvertAppUnits(rootAPD, localAPD);

  1823   /* If we encountered a transform, we can't do simple arithmetic to figure

  1824    * out how to convert back to aFrame's coordinates and must use the CTM.

  1825    */

  1826   if (transformFound || aFrame->IsSVGText()) {

  1827     return TransformRootPointToFrame(aFrame, widgetToView);

  1828   }

  1830   /* Otherwise, all coordinate systems are translations of one another,

  1831    * so we can just subtract out the difference.

  1832    */

  1833   return widgetToView - aFrame->GetOffsetToCrossDoc(rootFrame);

  1834 }

  1836 nsIFrame*

  1837 nsLayoutUtils::GetPopupFrameForEventCoordinates(nsPresContext* aPresContext,

  1838                                                 const WidgetEvent* aEvent)

  1839 {

  1840 #ifdef MOZ_XUL

  1841   nsXULPopupManager* pm = nsXULPopupManager::GetInstance();

  1842   if (!pm) {

  1843     return nullptr;

  1844   }

  1845   nsTArray<nsIFrame*> popups;

  1846   pm->GetVisiblePopups(popups);

  1847   uint32_t i;

  1848   // Search from top to bottom

  1849   for (i = 0; i < popups.Length(); i++) {

  1850     nsIFrame* popup = popups[i];

  1851     if (popup->PresContext()->GetRootPresContext() == aPresContext &&

  1852         popup->GetScrollableOverflowRect().Contains(

  1853           GetEventCoordinatesRelativeTo(aEvent, popup))) {

  1854       return popup;

  1855     }

  1856   }

  1857 #endif

  1858   return nullptr;

  1859 }

  1861 gfx3DMatrix

  1862 nsLayoutUtils::ChangeMatrixBasis(const gfxPoint3D &aOrigin,

  1863                                  const gfx3DMatrix &aMatrix)

  1864 {

  1865   gfx3DMatrix result = aMatrix;

  1867   /* Translate to the origin before aMatrix */

  1868   result.Translate(-aOrigin);

  1870   /* Translate back into position after aMatrix */

  1871   result.TranslatePost(aOrigin);

  1873   return result;

  1874 }

  1876 static void ConstrainToCoordValues(float& aStart, float& aSize)

  1877 {

  1878   MOZ_ASSERT(aSize >= 0);

  1880   // Here we try to make sure that the resulting nsRect will continue to cover

  1881   // as much of the area that was covered by the original gfx Rect as possible.

  1883   // We clamp the bounds of the rect to {nscoord_MIN,nscoord_MAX} since

  1884   // nsRect::X/Y() and nsRect::XMost/YMost() can't return values outwith this

  1885   // range:

  1886   float end = aStart + aSize;

  1887   aStart = clamped(aStart, float(nscoord_MIN), float(nscoord_MAX));

  1888   end = clamped(end, float(nscoord_MIN), float(nscoord_MAX));

  1890   aSize = end - aStart;

  1892   // We must also clamp aSize to {0,nscoord_MAX} since nsRect::Width/Height()

  1893   // can't return a value greater than nscoord_MAX. If aSize is greater than

  1894   // nscoord_MAX then we reduce it to nscoord_MAX while keeping the rect

  1895   // centered:

  1896   if (aSize > nscoord_MAX) {

  1897     float excess = aSize - nscoord_MAX;

  1898     excess /= 2;

  1899     aStart += excess;

  1900     aSize = nscoord_MAX;

  1901   }

  1902 }

  1904 /**

  1905  * Given a gfxFloat, constrains its value to be between nscoord_MIN and nscoord_MAX.

  1906  *

  1907  * @param aVal The value to constrain (in/out)

  1908  */

  1909 static void ConstrainToCoordValues(gfxFloat& aVal)

  1910 {

  1911   if (aVal <= nscoord_MIN)

  1912     aVal = nscoord_MIN;

  1913   else if (aVal >= nscoord_MAX)

  1914     aVal = nscoord_MAX;

  1915 }

  1917 static void ConstrainToCoordValues(gfxFloat& aStart, gfxFloat& aSize)

  1918 {

  1919   gfxFloat max = aStart + aSize;

  1921   // Clamp the end points to within nscoord range

  1922   ConstrainToCoordValues(aStart);

  1923   ConstrainToCoordValues(max);

  1925   aSize = max - aStart;

  1926   // If the width if still greater than the max nscoord, then bring both

  1927   // endpoints in by the same amount until it fits.

  1928   if (aSize > nscoord_MAX) {

  1929     gfxFloat excess = aSize - nscoord_MAX;

  1930     excess /= 2;

  1932     aStart += excess;

  1933     aSize = nscoord_MAX;

  1934   } else if (aSize < nscoord_MIN) {

  1935     gfxFloat excess = aSize - nscoord_MIN;

  1936     excess /= 2;

  1938     aStart -= excess;

  1939     aSize = nscoord_MIN;

  1940   }

  1941 }

  1943 nsRect

  1944 nsLayoutUtils::RoundGfxRectToAppRect(const Rect &aRect, float aFactor)

  1945 {

  1946   /* Get a new Rect whose units are app units by scaling by the specified factor. */

  1947   Rect scaledRect = aRect;

  1948   scaledRect.ScaleRoundOut(aFactor);

  1950   /* We now need to constrain our results to the max and min values for coords. */

  1951   ConstrainToCoordValues(scaledRect.x, scaledRect.width);

  1952   ConstrainToCoordValues(scaledRect.y, scaledRect.height);

  1954   /* Now typecast everything back.  This is guaranteed to be safe. */

  1955   return nsRect(nscoord(scaledRect.X()), nscoord(scaledRect.Y()),

  1956                 nscoord(scaledRect.Width()), nscoord(scaledRect.Height()));

  1957 }

  1959 nsRect

  1960 nsLayoutUtils::RoundGfxRectToAppRect(const gfxRect &aRect, float aFactor)

  1961 {

  1962   /* Get a new gfxRect whose units are app units by scaling by the specified factor. */

  1963   gfxRect scaledRect = aRect;

  1964   scaledRect.ScaleRoundOut(aFactor);

  1966   /* We now need to constrain our results to the max and min values for coords. */

  1967   ConstrainToCoordValues(scaledRect.x, scaledRect.width);

  1968   ConstrainToCoordValues(scaledRect.y, scaledRect.height);

  1970   /* Now typecast everything back.  This is guaranteed to be safe. */

  1971   return nsRect(nscoord(scaledRect.X()), nscoord(scaledRect.Y()),

  1972                 nscoord(scaledRect.Width()), nscoord(scaledRect.Height()));

  1973 }

  1976 nsRegion

  1977 nsLayoutUtils::RoundedRectIntersectRect(const nsRect& aRoundedRect,

  1978                                         const nscoord aRadii[8],

  1979                                         const nsRect& aContainedRect)

  1980 {

  1981   // rectFullHeight and rectFullWidth together will approximately contain

  1982   // the total area of the frame minus the rounded corners.

  1983   nsRect rectFullHeight = aRoundedRect;

  1984   nscoord xDiff = std::max(aRadii[NS_CORNER_TOP_LEFT_X], aRadii[NS_CORNER_BOTTOM_LEFT_X]);

  1985   rectFullHeight.x += xDiff;

  1986   rectFullHeight.width -= std::max(aRadii[NS_CORNER_TOP_RIGHT_X],

  1987                                  aRadii[NS_CORNER_BOTTOM_RIGHT_X]) + xDiff;

  1988   nsRect r1;

  1989   r1.IntersectRect(rectFullHeight, aContainedRect);

  1991   nsRect rectFullWidth = aRoundedRect;

  1992   nscoord yDiff = std::max(aRadii[NS_CORNER_TOP_LEFT_Y], aRadii[NS_CORNER_TOP_RIGHT_Y]);

  1993   rectFullWidth.y += yDiff;

  1994   rectFullWidth.height -= std::max(aRadii[NS_CORNER_BOTTOM_LEFT_Y],

  1995                                  aRadii[NS_CORNER_BOTTOM_RIGHT_Y]) + yDiff;

  1996   nsRect r2;

  1997   r2.IntersectRect(rectFullWidth, aContainedRect);

  1999   nsRegion result;

  2000   result.Or(r1, r2);

  2001   return result;

  2002 }

  2004 // Helper for RoundedRectIntersectsRect.

  2005 static bool

  2006 CheckCorner(nscoord aXOffset, nscoord aYOffset,

  2007             nscoord aXRadius, nscoord aYRadius)

  2008 {

  2009   NS_ABORT_IF_FALSE(aXOffset > 0 && aYOffset > 0,

  2010                     "must not pass nonpositives to CheckCorner");

  2011   NS_ABORT_IF_FALSE(aXRadius >= 0 && aYRadius >= 0,

  2012                     "must not pass negatives to CheckCorner");

  2014   // Avoid floating point math unless we're either (1) within the

  2015   // quarter-ellipse area at the rounded corner or (2) outside the

  2016   // rounding.

  2017   if (aXOffset >= aXRadius || aYOffset >= aYRadius)

  2018     return true;

  2020   // Convert coordinates to a unit circle with (0,0) as the center of

  2021   // curvature, and see if we're inside the circle or outside.

  2022   float scaledX = float(aXRadius - aXOffset) / float(aXRadius);

  2023   float scaledY = float(aYRadius - aYOffset) / float(aYRadius);

  2024   return scaledX * scaledX + scaledY * scaledY < 1.0f;

  2025 }

  2027 bool

  2028 nsLayoutUtils::RoundedRectIntersectsRect(const nsRect& aRoundedRect,

  2029                                          const nscoord aRadii[8],

  2030                                          const nsRect& aTestRect)

  2031 {

  2032   if (!aTestRect.Intersects(aRoundedRect))

  2033     return false;

  2035   // distances from this edge of aRoundedRect to opposite edge of aTestRect,

  2036   // which we know are positive due to the Intersects check above.

  2037   nsMargin insets;

  2038   insets.top = aTestRect.YMost() - aRoundedRect.y;

  2039   insets.right = aRoundedRect.XMost() - aTestRect.x;

  2040   insets.bottom = aRoundedRect.YMost() - aTestRect.y;

  2041   insets.left = aTestRect.XMost() - aRoundedRect.x;

  2043   // Check whether the bottom-right corner of aTestRect is inside the

  2044   // top left corner of aBounds when rounded by aRadii, etc.  If any

  2045   // corner is not, then fail; otherwise succeed.

  2046   return CheckCorner(insets.left, insets.top,

  2047                      aRadii[NS_CORNER_TOP_LEFT_X],

  2048                      aRadii[NS_CORNER_TOP_LEFT_Y]) &&

  2049          CheckCorner(insets.right, insets.top,

  2050                      aRadii[NS_CORNER_TOP_RIGHT_X],

  2051                      aRadii[NS_CORNER_TOP_RIGHT_Y]) &&

  2052          CheckCorner(insets.right, insets.bottom,

  2053                      aRadii[NS_CORNER_BOTTOM_RIGHT_X],

  2054                      aRadii[NS_CORNER_BOTTOM_RIGHT_Y]) &&

  2055          CheckCorner(insets.left, insets.bottom,

  2056                      aRadii[NS_CORNER_BOTTOM_LEFT_X],

  2057                      aRadii[NS_CORNER_BOTTOM_LEFT_Y]);

  2058 }

  2060 nsRect

  2061 nsLayoutUtils::MatrixTransformRectOut(const nsRect &aBounds,

  2062                                       const gfx3DMatrix &aMatrix, float aFactor)

  2063 {

  2064   nsRect outside = aBounds;

  2065   outside.ScaleRoundOut(1/aFactor);

  2066   gfxRect image = aMatrix.TransformBounds(gfxRect(outside.x,

  2067                                                   outside.y,

  2068                                                   outside.width,

  2069                                                   outside.height));

  2070   return RoundGfxRectToAppRect(image, aFactor);

  2071 }

  2073 nsRect

  2074 nsLayoutUtils::MatrixTransformRect(const nsRect &aBounds,

  2075                                    const gfx3DMatrix &aMatrix, float aFactor)

  2076 {

  2077   gfxRect image = aMatrix.TransformBounds(gfxRect(NSAppUnitsToDoublePixels(aBounds.x, aFactor),

  2078                                                   NSAppUnitsToDoublePixels(aBounds.y, aFactor),

  2079                                                   NSAppUnitsToDoublePixels(aBounds.width, aFactor),

  2080                                                   NSAppUnitsToDoublePixels(aBounds.height, aFactor)));

  2082   return RoundGfxRectToAppRect(image, aFactor);

  2083 }

  2085 nsPoint

  2086 nsLayoutUtils::MatrixTransformPoint(const nsPoint &aPoint,

  2087                                     const gfx3DMatrix &aMatrix, float aFactor)

  2088 {

  2089   gfxPoint image = aMatrix.Transform(gfxPoint(NSAppUnitsToFloatPixels(aPoint.x, aFactor),

  2090                                               NSAppUnitsToFloatPixels(aPoint.y, aFactor)));

  2091   return nsPoint(NSFloatPixelsToAppUnits(float(image.x), aFactor),

  2092                  NSFloatPixelsToAppUnits(float(image.y), aFactor));

  2093 }

  2095 gfx3DMatrix

  2096 nsLayoutUtils::GetTransformToAncestor(nsIFrame *aFrame, const nsIFrame *aAncestor)

  2097 {

  2098   nsIFrame* parent;

  2099   gfx3DMatrix ctm;

  2100   if (aFrame == aAncestor) {

  2101     return ctm;

  2102   }

  2103   ctm = aFrame->GetTransformMatrix(aAncestor, &parent);

  2104   while (parent && parent != aAncestor) {

  2105     if (!parent->Preserves3DChildren()) {

  2106       ctm.ProjectTo2D();

  2107     }

  2108     ctm = ctm * parent->GetTransformMatrix(aAncestor, &parent);

  2109   }

  2110   return ctm;

  2111 }

  2113 static nsIFrame*

  2114 FindNearestCommonAncestorFrame(nsIFrame* aFrame1, nsIFrame* aFrame2)

  2115 {

  2116   nsAutoTArray<nsIFrame*,100> ancestors1;

  2117   nsAutoTArray<nsIFrame*,100> ancestors2;

  2118   nsIFrame* commonAncestor = nullptr;

  2119   if (aFrame1->PresContext() == aFrame2->PresContext()) {

  2120     commonAncestor = aFrame1->PresContext()->PresShell()->GetRootFrame();

  2121   }

  2122   for (nsIFrame* f = aFrame1; f != commonAncestor;

  2123        f = nsLayoutUtils::GetCrossDocParentFrame(f)) {

  2124     ancestors1.AppendElement(f);

  2125   }

  2126   for (nsIFrame* f = aFrame2; f != commonAncestor;

  2127        f = nsLayoutUtils::GetCrossDocParentFrame(f)) {

  2128     ancestors2.AppendElement(f);

  2129   }

  2130   uint32_t minLengths = std::min(ancestors1.Length(), ancestors2.Length());

  2131   for (uint32_t i = 1; i <= minLengths; ++i) {

  2132     if (ancestors1[ancestors1.Length() - i] == ancestors2[ancestors2.Length() - i]) {

  2133       commonAncestor = ancestors1[ancestors1.Length() - i];

  2134     } else {

  2135       break;

  2136     }

  2137   }

  2138   return commonAncestor;

  2139 }

  2141 nsLayoutUtils::TransformResult

  2142 nsLayoutUtils::TransformPoints(nsIFrame* aFromFrame, nsIFrame* aToFrame,

  2143                                uint32_t aPointCount, CSSPoint* aPoints)

  2144 {

  2145   nsIFrame* nearestCommonAncestor = FindNearestCommonAncestorFrame(aFromFrame, aToFrame);

  2146   if (!nearestCommonAncestor) {

  2147     return NO_COMMON_ANCESTOR;

  2148   }

  2149   gfx3DMatrix downToDest = GetTransformToAncestor(aToFrame, nearestCommonAncestor);

  2150   if (downToDest.IsSingular()) {

  2151     return NONINVERTIBLE_TRANSFORM;

  2152   }

  2153   downToDest.Invert();

  2154   gfx3DMatrix upToAncestor = GetTransformToAncestor(aFromFrame, nearestCommonAncestor);

  2155   CSSToLayoutDeviceScale devPixelsPerCSSPixelFromFrame(

  2156     double(nsPresContext::AppUnitsPerCSSPixel())/

  2157       aFromFrame->PresContext()->AppUnitsPerDevPixel());

  2158   CSSToLayoutDeviceScale devPixelsPerCSSPixelToFrame(

  2159     double(nsPresContext::AppUnitsPerCSSPixel())/

  2160       aToFrame->PresContext()->AppUnitsPerDevPixel());

  2161   for (uint32_t i = 0; i < aPointCount; ++i) {

  2162     LayoutDevicePoint devPixels = aPoints[i] * devPixelsPerCSSPixelFromFrame;

  2163     gfxPoint toDevPixels = downToDest.ProjectPoint(

  2164         upToAncestor.ProjectPoint(gfxPoint(devPixels.x, devPixels.y)));

  2165     // Divide here so that when the devPixelsPerCSSPixels are the same, we get the correct

  2166     // answer instead of some inaccuracy multiplying a number by its reciprocal.

  2167     aPoints[i] = LayoutDevicePoint(toDevPixels.x, toDevPixels.y) /

  2168         devPixelsPerCSSPixelToFrame;

  2169   }

  2170   return TRANSFORM_SUCCEEDED;

  2171 }

  2173 bool

  2174 nsLayoutUtils::GetLayerTransformForFrame(nsIFrame* aFrame,

  2175                                          gfx3DMatrix* aTransform)

  2176 {

  2177   // FIXME/bug 796690: we can sometimes compute a transform in these

  2178   // cases, it just increases complexity considerably.  Punt for now.

  2179   if (aFrame->Preserves3DChildren() || aFrame->HasTransformGetter()) {

  2180     return false;

  2181   }

  2183   nsIFrame* root = nsLayoutUtils::GetDisplayRootFrame(aFrame);

  2184   if (root->HasAnyStateBits(NS_FRAME_UPDATE_LAYER_TREE)) {

  2185     // Content may have been invalidated, so we can't reliably compute

  2186     // the "layer transform" in general.

  2187     return false;

  2188   }

  2189   // If the caller doesn't care about the value, early-return to skip

  2190   // overhead below.

  2191   if (!aTransform) {

  2192     return true;

  2193   }

  2195   nsDisplayListBuilder builder(root, nsDisplayListBuilder::OTHER,

  2196                                false/*don't build caret*/);

  2197   nsDisplayList list;

  2198   nsDisplayTransform* item =

  2199     new (&builder) nsDisplayTransform(&builder, aFrame, &list);

  2201   *aTransform =

  2202     item->GetTransform();

  2203   item->~nsDisplayTransform();

  2205   return true;

  2206 }

  2208 static bool

  2209 TransformGfxPointFromAncestor(nsIFrame *aFrame,

  2210                               const gfxPoint &aPoint,

  2211                               nsIFrame *aAncestor,

  2212                               gfxPoint* aOut)

  2213 {

  2214   gfx3DMatrix ctm = nsLayoutUtils::GetTransformToAncestor(aFrame, aAncestor);

  2216   float factor = aFrame->PresContext()->AppUnitsPerDevPixel();

  2217   nsRect childBounds = aFrame->GetVisualOverflowRectRelativeToSelf();

  2218   gfxRect childGfxBounds(NSAppUnitsToFloatPixels(childBounds.x, factor),

  2219                          NSAppUnitsToFloatPixels(childBounds.y, factor),

  2220                          NSAppUnitsToFloatPixels(childBounds.width, factor),

  2221                          NSAppUnitsToFloatPixels(childBounds.height, factor));

  2222   return ctm.UntransformPoint(aPoint, childGfxBounds, aOut);

  2223 }

  2225 static gfxRect

  2226 TransformGfxRectToAncestor(nsIFrame *aFrame,

  2227                            const gfxRect &aRect,

  2228                            const nsIFrame *aAncestor,

  2229                            bool* aPreservesAxisAlignedRectangles = nullptr)

  2230 {

  2231   gfx3DMatrix ctm = nsLayoutUtils::GetTransformToAncestor(aFrame, aAncestor);

  2232   if (aPreservesAxisAlignedRectangles) {

  2233     gfxMatrix matrix2d;

  2234     *aPreservesAxisAlignedRectangles =

  2235       ctm.Is2D(&matrix2d) && matrix2d.PreservesAxisAlignedRectangles();

  2236   }

  2237   return ctm.TransformBounds(aRect);

  2238 }

  2240 static SVGTextFrame*

  2241 GetContainingSVGTextFrame(nsIFrame* aFrame)

  2242 {

  2243   if (!aFrame->IsSVGText()) {

  2244     return nullptr;

  2245   }

  2247   return static_cast<SVGTextFrame*>

  2248     (nsLayoutUtils::GetClosestFrameOfType(aFrame->GetParent(),

  2249                                           nsGkAtoms::svgTextFrame));

  2250 }

  2252 nsPoint

  2253 nsLayoutUtils::TransformAncestorPointToFrame(nsIFrame* aFrame,

  2254                                              const nsPoint& aPoint,

  2255                                              nsIFrame* aAncestor)

  2256 {

  2257     SVGTextFrame* text = GetContainingSVGTextFrame(aFrame);

  2259     float factor = aFrame->PresContext()->AppUnitsPerDevPixel();

  2260     gfxPoint result(NSAppUnitsToFloatPixels(aPoint.x, factor),

  2261                     NSAppUnitsToFloatPixels(aPoint.y, factor));

  2263     if (text) {

  2264         if (!TransformGfxPointFromAncestor(text, result, aAncestor, &result)) {

  2265             return nsPoint(NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE);

  2266         }

  2267         result = text->TransformFramePointToTextChild(result, aFrame);

  2268     } else {

  2269         if (!TransformGfxPointFromAncestor(aFrame, result, nullptr, &result)) {

  2270             return nsPoint(NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE);

  2271         }

  2272     }

  2274     return nsPoint(NSFloatPixelsToAppUnits(float(result.x), factor),

  2275                    NSFloatPixelsToAppUnits(float(result.y), factor));

  2276 }

  2278 nsRect

  2279 nsLayoutUtils::TransformFrameRectToAncestor(nsIFrame* aFrame,

  2280                                             const nsRect& aRect,

  2281                                             const nsIFrame* aAncestor,

  2282                                             bool* aPreservesAxisAlignedRectangles /* = nullptr */)

  2283 {

  2284   SVGTextFrame* text = GetContainingSVGTextFrame(aFrame);

  2286   float srcAppUnitsPerDevPixel = aFrame->PresContext()->AppUnitsPerDevPixel();

  2287   gfxRect result;

  2289   if (text) {

  2290     result = text->TransformFrameRectFromTextChild(aRect, aFrame);

  2291     result = TransformGfxRectToAncestor(text, result, aAncestor);

  2292     // TransformFrameRectFromTextChild could involve any kind of transform, we

  2293     // could drill down into it to get an answer out of it but we don't yet.

  2294     if (aPreservesAxisAlignedRectangles)

  2295       *aPreservesAxisAlignedRectangles = false;

  2296   } else {

  2297     result = gfxRect(NSAppUnitsToFloatPixels(aRect.x, srcAppUnitsPerDevPixel),

  2298                      NSAppUnitsToFloatPixels(aRect.y, srcAppUnitsPerDevPixel),

  2299                      NSAppUnitsToFloatPixels(aRect.width, srcAppUnitsPerDevPixel),

  2300                      NSAppUnitsToFloatPixels(aRect.height, srcAppUnitsPerDevPixel));

  2301     result = TransformGfxRectToAncestor(aFrame, result, aAncestor, aPreservesAxisAlignedRectangles);

  2302   }

  2304   float destAppUnitsPerDevPixel = aAncestor->PresContext()->AppUnitsPerDevPixel();

  2305   return nsRect(NSFloatPixelsToAppUnits(float(result.x), destAppUnitsPerDevPixel),

  2306                 NSFloatPixelsToAppUnits(float(result.y), destAppUnitsPerDevPixel),

  2307                 NSFloatPixelsToAppUnits(float(result.width), destAppUnitsPerDevPixel),

  2308                 NSFloatPixelsToAppUnits(float(result.height), destAppUnitsPerDevPixel));

  2309 }

  2311 static nsIntPoint GetWidgetOffset(nsIWidget* aWidget, nsIWidget*& aRootWidget) {

  2312   nsIntPoint offset(0, 0);

  2313   nsIWidget* parent = aWidget->GetParent();

  2314   while (parent) {

  2315     nsIntRect bounds;

  2316     aWidget->GetBounds(bounds);

  2317     offset += bounds.TopLeft();

  2318     aWidget = parent;

  2319     parent = aWidget->GetParent();

  2320   }

  2321   aRootWidget = aWidget;

  2322   return offset;

  2323 }

  2325 nsPoint

  2326 nsLayoutUtils::TranslateWidgetToView(nsPresContext* aPresContext,

  2327                                      nsIWidget* aWidget, nsIntPoint aPt,

  2328                                      nsView* aView)

  2329 {

  2330   nsPoint viewOffset;

  2331   nsIWidget* viewWidget = aView->GetNearestWidget(&viewOffset);

  2332   if (!viewWidget) {

  2333     return nsPoint(NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE);

  2334   }

  2336   nsIWidget* fromRoot;

  2337   nsIntPoint fromOffset = GetWidgetOffset(aWidget, fromRoot);

  2338   nsIWidget* toRoot;

  2339   nsIntPoint toOffset = GetWidgetOffset(viewWidget, toRoot);

  2341   nsIntPoint widgetPoint;

  2342   if (fromRoot == toRoot) {

  2343     widgetPoint = aPt + fromOffset - toOffset;

  2344   } else {

  2345     nsIntPoint screenPoint = aWidget->WidgetToScreenOffset();

  2346     widgetPoint = aPt + screenPoint - viewWidget->WidgetToScreenOffset();

  2347   }

  2349   nsPoint widgetAppUnits(aPresContext->DevPixelsToAppUnits(widgetPoint.x),

  2350                          aPresContext->DevPixelsToAppUnits(widgetPoint.y));

  2351   return widgetAppUnits - viewOffset;

  2352 }

  2354 // Combine aNewBreakType with aOrigBreakType, but limit the break types

  2355 // to NS_STYLE_CLEAR_LEFT, RIGHT, BOTH.

  2356 uint8_t

  2357 nsLayoutUtils::CombineBreakType(uint8_t aOrigBreakType,

  2358                                 uint8_t aNewBreakType)

  2359 {

  2360   uint8_t breakType = aOrigBreakType;

  2361   switch(breakType) {

  2362   case NS_STYLE_CLEAR_LEFT:

  2363     if (NS_STYLE_CLEAR_RIGHT == aNewBreakType ||

  2364         NS_STYLE_CLEAR_BOTH == aNewBreakType) {

  2365       breakType = NS_STYLE_CLEAR_BOTH;

  2366     }

  2367     break;

  2368   case NS_STYLE_CLEAR_RIGHT:

  2369     if (NS_STYLE_CLEAR_LEFT == aNewBreakType ||

  2370         NS_STYLE_CLEAR_BOTH == aNewBreakType) {

  2371       breakType = NS_STYLE_CLEAR_BOTH;

  2372     }

  2373     break;

  2374   case NS_STYLE_CLEAR_NONE:

  2375     if (NS_STYLE_CLEAR_LEFT == aNewBreakType ||

  2376         NS_STYLE_CLEAR_RIGHT == aNewBreakType ||

  2377         NS_STYLE_CLEAR_BOTH == aNewBreakType) {

  2378       breakType = aNewBreakType;

  2379     }

  2380   }

  2381   return breakType;

  2382 }

  2384 #ifdef MOZ_DUMP_PAINTING

  2385 #include <stdio.h>

  2387 static bool gDumpEventList = false;

  2388 int gPaintCount = 0;

  2389 #endif

  2391 nsresult

  2392 nsLayoutUtils::GetRemoteContentIds(nsIFrame* aFrame,

  2393                                    const nsRect& aTarget,

  2394                                    nsTArray<ViewID> &aOutIDs,

  2395                                    bool aIgnoreRootScrollFrame)

  2396 {

  2397   nsDisplayListBuilder builder(aFrame, nsDisplayListBuilder::EVENT_DELIVERY,

  2398                                false);

  2399   nsDisplayList list;

  2401   if (aIgnoreRootScrollFrame) {

  2402     nsIFrame* rootScrollFrame =

  2403       aFrame->PresContext()->PresShell()->GetRootScrollFrame();

  2404     if (rootScrollFrame) {

  2405       builder.SetIgnoreScrollFrame(rootScrollFrame);

  2406     }

  2407   }

  2409   builder.EnterPresShell(aFrame, aTarget);

  2410   aFrame->BuildDisplayListForStackingContext(&builder, aTarget, &list);

  2411   builder.LeavePresShell(aFrame, aTarget);

  2413   nsAutoTArray<nsIFrame*,8> outFrames;

  2414   nsDisplayItem::HitTestState hitTestState(&aOutIDs);

  2415   list.HitTest(&builder, aTarget, &hitTestState, &outFrames);

  2416   list.DeleteAll();

  2418   return NS_OK;

  2419 }

  2421 nsIFrame*

  2422 nsLayoutUtils::GetFrameForPoint(nsIFrame* aFrame, nsPoint aPt, uint32_t aFlags)

  2423 {

  2424   PROFILER_LABEL("nsLayoutUtils", "GetFrameForPoint");

  2425   nsresult rv;

  2426   nsAutoTArray<nsIFrame*,8> outFrames;

  2427   rv = GetFramesForArea(aFrame, nsRect(aPt, nsSize(1, 1)), outFrames, aFlags);

  2428   NS_ENSURE_SUCCESS(rv, nullptr);

  2429   return outFrames.Length() ? outFrames.ElementAt(0) : nullptr;

  2430 }

  2432 nsresult

  2433 nsLayoutUtils::GetFramesForArea(nsIFrame* aFrame, const nsRect& aRect,

  2434                                 nsTArray<nsIFrame*> &aOutFrames,

  2435                                 uint32_t aFlags)

  2436 {

  2437   PROFILER_LABEL("nsLayoutUtils","GetFramesForArea");

  2438   nsDisplayListBuilder builder(aFrame, nsDisplayListBuilder::EVENT_DELIVERY,

  2439                                false);

  2440   nsDisplayList list;

  2441   nsRect target(aRect);

  2443   if (aFlags & IGNORE_PAINT_SUPPRESSION) {

  2444     builder.IgnorePaintSuppression();

  2445   }

  2447   if (aFlags & IGNORE_ROOT_SCROLL_FRAME) {

  2448     nsIFrame* rootScrollFrame =

  2449       aFrame->PresContext()->PresShell()->GetRootScrollFrame();

  2450     if (rootScrollFrame) {

  2451       builder.SetIgnoreScrollFrame(rootScrollFrame);

  2452     }

  2453   }

  2454   if (aFlags & IGNORE_CROSS_DOC) {

  2455     builder.SetDescendIntoSubdocuments(false);

  2456   }

  2458   builder.EnterPresShell(aFrame, target);

  2459   aFrame->BuildDisplayListForStackingContext(&builder, target, &list);

  2460   builder.LeavePresShell(aFrame, target);

  2462 #ifdef MOZ_DUMP_PAINTING

  2463   if (gDumpEventList) {

  2464     fprintf_stderr(stderr, "Event handling --- (%d,%d):\n", aRect.x, aRect.y);

  2465     nsFrame::PrintDisplayList(&builder, list);

  2466   }

  2467 #endif

  2469   nsDisplayItem::HitTestState hitTestState;

  2470   list.HitTest(&builder, target, &hitTestState, &aOutFrames);

  2471   list.DeleteAll();

  2472   return NS_OK;

  2473 }

  2475 // This function is only used on B2G, and some compilers complain about

  2476 // unused static functions, so we need to #ifdef it.

  2477 #ifdef MOZ_WIDGET_GONK

  2478 // aScrollFrame and aScrollFrameAsScrollable must be non-nullptr

  2479 static FrameMetrics

  2480 CalculateFrameMetricsForDisplayPort(nsIFrame* aScrollFrame,

  2481                                     nsIScrollableFrame* aScrollFrameAsScrollable) {

  2482   // Calculate the metrics necessary for calculating the displayport.

  2483   // This code has a lot in common with the code in RecordFrameMetrics();

  2484   // we may want to refactor this at some point.

  2485   FrameMetrics metrics;

  2486   nsPresContext* presContext = aScrollFrame->PresContext();

  2487   nsIPresShell* presShell = presContext->PresShell();

  2488   CSSToLayoutDeviceScale deviceScale(float(nsPresContext::AppUnitsPerCSSPixel())

  2489                                      / presContext->AppUnitsPerDevPixel());

  2490   ParentLayerToLayerScale resolution(presShell->GetResolution().width);

  2491   LayoutDeviceToLayerScale cumulativeResolution(presShell->GetCumulativeResolution().width);

  2493   metrics.mDevPixelsPerCSSPixel = deviceScale;

  2494   metrics.mResolution = resolution;

  2495   metrics.mCumulativeResolution = cumulativeResolution;

  2496   metrics.SetZoom(deviceScale * cumulativeResolution * LayerToScreenScale(1));

  2498   // Only the size of the composition bounds is relevant to the

  2499   // displayport calculation, not its origin.

  2500   nsSize compositionSize = nsLayoutUtils::CalculateCompositionSizeForFrame(aScrollFrame);

  2501   metrics.mCompositionBounds

  2502       = RoundedToInt(LayoutDeviceRect::FromAppUnits(nsRect(nsPoint(0, 0), compositionSize),

  2503                                                     presContext->AppUnitsPerDevPixel())

  2504                      * (cumulativeResolution / resolution));

  2506   // This function is used for setting a display port for subframes, so

  2507   // aScrollFrame will not be the root content document's root scroll frame.

  2508   metrics.SetRootCompositionSize(

  2509       nsLayoutUtils::CalculateRootCompositionSize(aScrollFrame, false, metrics));

  2511   metrics.SetScrollOffset(CSSPoint::FromAppUnits(

  2512       aScrollFrameAsScrollable->GetScrollPosition()));

  2514   metrics.mScrollableRect = CSSRect::FromAppUnits(

  2515       nsLayoutUtils::CalculateScrollableRectForFrame(aScrollFrameAsScrollable, nullptr));

  2517   return metrics;

  2518 }

  2519 #endif

  2521 bool

  2522 nsLayoutUtils::GetOrMaybeCreateDisplayPort(nsDisplayListBuilder& aBuilder,

  2523                                            nsIFrame* aScrollFrame,

  2524                                            nsRect aDisplayPortBase,

  2525                                            nsRect* aOutDisplayport) {

  2526   nsIContent* content = aScrollFrame->GetContent();

  2527   nsIScrollableFrame* scrollableFrame = do_QueryFrame(aScrollFrame);

  2528   if (!content || !scrollableFrame) {

  2529     return false;

  2530   }

  2532   // Set the base rect. Note that this will not influence 'haveDisplayPort',

  2533   // which is based on either the whole rect or margins being set, but it

  2534   // will affect what is returned in 'aOutDisplayPort' if margins are set.

  2535   SetDisplayPortBase(content, aDisplayPortBase);

  2537   bool haveDisplayPort = GetDisplayPort(content, aOutDisplayport);

  2539 #ifdef MOZ_WIDGET_GONK

  2540   // On B2G, we perform an optimization where we ensure that at least one

  2541   // async-scrollable frame (i.e. one that WantsAsyncScroll()) has a displayport.

  2542   // If that's not the case yet, and we are async-scrollable, we will get a

  2543   // displayport.

  2544   // Note: we only do this in processes where we do subframe scrolling to

  2545   //       begin with (i.e., not in the parent process on B2G).

  2546   if (WantSubAPZC() &&

  2547       !aBuilder.HaveScrollableDisplayPort() &&

  2548       scrollableFrame->WantAsyncScroll()) {

  2550     // If we don't already have a displayport, calculate and set one.

  2551     if (!haveDisplayPort) {

  2552       FrameMetrics metrics = CalculateFrameMetricsForDisplayPort(aScrollFrame, scrollableFrame);

  2553       LayerMargin displayportMargins = AsyncPanZoomController::CalculatePendingDisplayPort(

  2554           metrics, ScreenPoint(0.0f, 0.0f), 0.0);

  2555       nsIPresShell* presShell = aScrollFrame->PresContext()->GetPresShell();

  2556       gfx::IntSize alignment = gfxPrefs::LayersTilesEnabled()

  2557           ? gfx::IntSize(gfxPrefs::LayersTileWidth(), gfxPrefs::LayersTileHeight()) :

  2558             gfx::IntSize(0, 0);

  2559       nsLayoutUtils::SetDisplayPortMargins(

  2560           content, presShell, displayportMargins, alignment.width,

  2561           alignment.height, 0, nsLayoutUtils::RepaintMode::DoNotRepaint);

  2562       haveDisplayPort = GetDisplayPort(content, aOutDisplayport);

  2563       NS_ASSERTION(haveDisplayPort, "should have a displayport after having just set it");

  2564     }

  2566     // Record that the we now have a scrollable display port.

  2567     aBuilder.SetHaveScrollableDisplayPort();

  2568   }

  2569 #endif

  2571   return haveDisplayPort;

  2572 }

  2574 nsresult

  2575 nsLayoutUtils::PaintFrame(nsRenderingContext* aRenderingContext, nsIFrame* aFrame,

  2576                           const nsRegion& aDirtyRegion, nscolor aBackstop,

  2577                           uint32_t aFlags)

  2578 {

  2579   PROFILER_LABEL("nsLayoutUtils","PaintFrame");

  2580   if (aFlags & PAINT_WIDGET_LAYERS) {

  2581     nsView* view = aFrame->GetView();

  2582     if (!(view && view->GetWidget() && GetDisplayRootFrame(aFrame) == aFrame)) {

  2583       aFlags &= ~PAINT_WIDGET_LAYERS;

  2584       NS_ASSERTION(aRenderingContext, "need a rendering context");

  2585     }

  2586   }

  2588   nsPresContext* presContext = aFrame->PresContext();

  2589   nsIPresShell* presShell = presContext->PresShell();

  2590   nsRootPresContext* rootPresContext = presContext->GetRootPresContext();

  2591   if (!rootPresContext) {

  2592     return NS_OK;

  2593   }

  2595   nsDisplayListBuilder builder(aFrame, nsDisplayListBuilder::PAINTING,

  2596                            !(aFlags & PAINT_HIDE_CARET));

  2598   nsIFrame* rootScrollFrame = presShell->GetRootScrollFrame();

  2599   bool usingDisplayPort = false;

  2600   nsRect displayport;

  2601   if (rootScrollFrame && !aFrame->GetParent()) {

  2602     nsRect displayportBase(

  2603         nsPoint(0,0),

  2604         nsLayoutUtils::CalculateCompositionSizeForFrame(rootScrollFrame));

  2605     usingDisplayPort = nsLayoutUtils::GetOrMaybeCreateDisplayPort(

  2606         builder, rootScrollFrame, displayportBase, &displayport);

  2607   }

  2609   nsRegion visibleRegion;

  2610   if (aFlags & PAINT_WIDGET_LAYERS) {

  2611     // This layer tree will be reused, so we'll need to calculate it

  2612     // for the whole "visible" area of the window

  2613     //

  2614     // |ignoreViewportScrolling| and |usingDisplayPort| are persistent

  2615     // document-rendering state.  We rely on PresShell to flush

  2616     // retained layers as needed when that persistent state changes.

  2617     if (!usingDisplayPort) {

  2618       visibleRegion = aFrame->GetVisualOverflowRectRelativeToSelf();

  2619     } else {

  2620       visibleRegion = displayport;

  2621     }

  2622   } else {

  2623     visibleRegion = aDirtyRegion;

  2624   }

  2626   // If we're going to display something different from what we'd normally

  2627   // paint in a window then we will flush out any retained layer trees before

  2628   // *and after* we draw.

  2629   bool willFlushRetainedLayers = (aFlags & PAINT_HIDE_CARET) != 0;

  2631   nsDisplayList list;

  2632   if (aFlags & PAINT_IN_TRANSFORM) {

  2633     builder.SetInTransform(true);

  2634   }

  2635   if (aFlags & PAINT_SYNC_DECODE_IMAGES) {

  2636     builder.SetSyncDecodeImages(true);

  2637   }

  2638   if (aFlags & (PAINT_WIDGET_LAYERS | PAINT_TO_WINDOW)) {

  2639     builder.SetPaintingToWindow(true);

  2640   }

  2641   if (aFlags & PAINT_IGNORE_SUPPRESSION) {

  2642     builder.IgnorePaintSuppression();

  2643   }

  2644   // Windowed plugins aren't allowed in popups

  2645   if ((aFlags & PAINT_WIDGET_LAYERS) &&

  2646       !willFlushRetainedLayers &&

  2647       !(aFlags & PAINT_DOCUMENT_RELATIVE) &&

  2648       rootPresContext->NeedToComputePluginGeometryUpdates()) {

  2649     builder.SetWillComputePluginGeometry(true);

  2650   }

  2651   nsRect canvasArea(nsPoint(0, 0), aFrame->GetSize());

  2653   bool ignoreViewportScrolling =

  2654     aFrame->GetParent() ? false : presShell->IgnoringViewportScrolling();

  2655   if (ignoreViewportScrolling && rootScrollFrame) {

  2656     nsIScrollableFrame* rootScrollableFrame =

  2657       presShell->GetRootScrollFrameAsScrollable();

  2658     if (aFlags & PAINT_DOCUMENT_RELATIVE) {

  2659       // Make visibleRegion and aRenderingContext relative to the

  2660       // scrolled frame instead of the root frame.

  2661       nsPoint pos = rootScrollableFrame->GetScrollPosition();

  2662       visibleRegion.MoveBy(-pos);

  2663       if (aRenderingContext) {

  2664         aRenderingContext->Translate(pos);

  2665       }

  2666     }

  2667     builder.SetIgnoreScrollFrame(rootScrollFrame);

  2669     nsCanvasFrame* canvasFrame =

  2670       do_QueryFrame(rootScrollableFrame->GetScrolledFrame());

  2671     if (canvasFrame) {

  2672       // Use UnionRect here to ensure that areas where the scrollbars

  2673       // were are still filled with the background color.

  2674       canvasArea.UnionRect(canvasArea,

  2675         canvasFrame->CanvasArea() + builder.ToReferenceFrame(canvasFrame));

  2676     }

  2677   }

  2679   nsRect dirtyRect = visibleRegion.GetBounds();

  2680   builder.EnterPresShell(aFrame, dirtyRect);

  2681   {

  2682     PROFILER_LABEL("nsLayoutUtils","PaintFrame::BuildDisplayList");

  2683     aFrame->BuildDisplayListForStackingContext(&builder, dirtyRect, &list);

  2684   }

  2685   const bool paintAllContinuations = aFlags & PAINT_ALL_CONTINUATIONS;

  2686   NS_ASSERTION(!paintAllContinuations || !aFrame->GetPrevContinuation(),

  2687                "If painting all continuations, the frame must be "

  2688                "first-continuation");

  2690   nsIAtom* frameType = aFrame->GetType();

  2692   if (paintAllContinuations) {

  2693     nsIFrame* currentFrame = aFrame;

  2694     while ((currentFrame = currentFrame->GetNextContinuation()) != nullptr) {

  2695       PROFILER_LABEL("nsLayoutUtils","PaintFrame::ContinuationsBuildDisplayList");

  2696       nsRect frameDirty = dirtyRect - builder.ToReferenceFrame(currentFrame);

  2697       currentFrame->BuildDisplayListForStackingContext(&builder,

  2698                                                        frameDirty, &list);

  2699     }

  2700   }

  2702   // For the viewport frame in print preview/page layout we want to paint

  2703   // the grey background behind the page, not the canvas color.

  2704   if (frameType == nsGkAtoms::viewportFrame &&

  2705       nsLayoutUtils::NeedsPrintPreviewBackground(presContext)) {

  2706     nsRect bounds = nsRect(builder.ToReferenceFrame(aFrame),

  2707                            aFrame->GetSize());

  2708     presShell->AddPrintPreviewBackgroundItem(builder, list, aFrame, bounds);

  2709   } else if (frameType != nsGkAtoms::pageFrame) {

  2710     // For printing, this function is first called on an nsPageFrame, which

  2711     // creates a display list with a PageContent item. The PageContent item's

  2712     // paint function calls this function on the nsPageFrame's child which is

  2713     // an nsPageContentFrame. We only want to add the canvas background color

  2714     // item once, for the nsPageContentFrame.

  2716     // Add the canvas background color to the bottom of the list. This

  2717     // happens after we've built the list so that AddCanvasBackgroundColorItem

  2718     // can monkey with the contents if necessary.

  2719     canvasArea.IntersectRect(canvasArea, visibleRegion.GetBounds());

  2720     presShell->AddCanvasBackgroundColorItem(

  2721            builder, list, aFrame, canvasArea, aBackstop);

  2723     // If the passed in backstop color makes us draw something different from

  2724     // normal, we need to flush layers.

  2725     if ((aFlags & PAINT_WIDGET_LAYERS) && !willFlushRetainedLayers) {

  2726       nsView* view = aFrame->GetView();

  2727       if (view) {

  2728         nscolor backstop = presShell->ComputeBackstopColor(view);

  2729         // The PresShell's canvas background color doesn't get updated until

  2730         // EnterPresShell, so this check has to be done after that.

  2731         nscolor canvasColor = presShell->GetCanvasBackground();

  2732         if (NS_ComposeColors(aBackstop, canvasColor) !=

  2733             NS_ComposeColors(backstop, canvasColor)) {

  2734           willFlushRetainedLayers = true;

  2735         }

  2736       }

  2737     }

  2738   }

  2740   builder.LeavePresShell(aFrame, dirtyRect);

  2742   if (builder.GetHadToIgnorePaintSuppression()) {

  2743     willFlushRetainedLayers = true;

  2744   }

  2746 #ifdef MOZ_DUMP_PAINTING

  2747   FILE* savedDumpFile = gfxUtils::sDumpPaintFile;

  2748   if (gfxUtils::sDumpPaintList || gfxUtils::sDumpPainting) {

  2749     if (gfxUtils::sDumpPaintingToFile) {

  2750       nsCString string("dump-");

  2751       string.AppendInt(gPaintCount);

  2752       string.Append(".html");

  2753       gfxUtils::sDumpPaintFile = fopen(string.BeginReading(), "w");

  2754     } else {

  2755       gfxUtils::sDumpPaintFile = stderr;

  2756     }

  2757     if (gfxUtils::sDumpPaintingToFile) {

  2758       fprintf_stderr(gfxUtils::sDumpPaintFile, "<html><head><script>var array = {}; function ViewImage(index) { window.location = array[index]; }</script></head><body>");

  2759     }

  2760     fprintf_stderr(gfxUtils::sDumpPaintFile, "Painting --- before optimization (dirty %d,%d,%d,%d):\n",

  2761             dirtyRect.x, dirtyRect.y, dirtyRect.width, dirtyRect.height);

  2762     nsFrame::PrintDisplayList(&builder, list, gfxUtils::sDumpPaintFile, gfxUtils::sDumpPaintingToFile);

  2763     if (gfxUtils::sDumpPaintingToFile) {

  2764       fprintf_stderr(gfxUtils::sDumpPaintFile, "<script>");

  2765     }

  2766   }

  2767 #endif

  2769   list.ComputeVisibilityForRoot(&builder, &visibleRegion,

  2770                                 usingDisplayPort ? rootScrollFrame : nullptr);

  2772   uint32_t flags = nsDisplayList::PAINT_DEFAULT;

  2773   if (aFlags & PAINT_WIDGET_LAYERS) {

  2774     flags |= nsDisplayList::PAINT_USE_WIDGET_LAYERS;

  2775     if (willFlushRetainedLayers) {

  2776       // The caller wanted to paint from retained layers, but set up

  2777       // the paint in such a way that we can't use them.  We're going

  2778       // to display something different from what we'd normally paint

  2779       // in a window, so make sure we flush out any retained layer

  2780       // trees before *and after* we draw.  Callers should be fixed to

  2781       // not do this.

  2782       NS_WARNING("Flushing retained layers!");

  2783       flags |= nsDisplayList::PAINT_FLUSH_LAYERS;

  2784     } else if (!(aFlags & PAINT_DOCUMENT_RELATIVE)) {

  2785       nsIWidget *widget = aFrame->GetNearestWidget();

  2786       if (widget) {

  2787         builder.SetFinalTransparentRegion(visibleRegion);

  2788         // If we're finished building display list items for painting of the outermost

  2789         // pres shell, notify the widget about any toolbars we've encountered.

  2790         widget->UpdateThemeGeometries(builder.GetThemeGeometries());

  2791       }

  2792     }

  2793   }

  2794   if (aFlags & PAINT_EXISTING_TRANSACTION) {

  2795     flags |= nsDisplayList::PAINT_EXISTING_TRANSACTION;

  2796   }

  2797   if (aFlags & PAINT_NO_COMPOSITE) {

  2798     flags |= nsDisplayList::PAINT_NO_COMPOSITE;

  2799   }

  2800   if (aFlags & PAINT_COMPRESSED) {

  2801     flags |= nsDisplayList::PAINT_COMPRESSED;

  2802   }

  2804   list.PaintRoot(&builder, aRenderingContext, flags);

  2806 #ifdef MOZ_DUMP_PAINTING

  2807   if (gfxUtils::sDumpPaintList || gfxUtils::sDumpPainting) {

  2808     if (gfxUtils::sDumpPaintingToFile) {

  2809       fprintf_stderr(gfxUtils::sDumpPaintFile, "</script>");

  2810     }

  2811     fprintf_stderr(gfxUtils::sDumpPaintFile, "Painting --- after optimization:\n");

  2812     nsFrame::PrintDisplayList(&builder, list, gfxUtils::sDumpPaintFile, gfxUtils::sDumpPaintingToFile);

  2814     fprintf_stderr(gfxUtils::sDumpPaintFile, "Painting --- retained layer tree:\n");

  2815     nsIWidget* widget = aFrame->GetNearestWidget();

  2816     if (widget) {

  2817       nsRefPtr<LayerManager> layerManager = widget->GetLayerManager();

  2818       if (layerManager) {

  2819         FrameLayerBuilder::DumpRetainedLayerTree(layerManager, gfxUtils::sDumpPaintFile,

  2820                                                  gfxUtils::sDumpPaintingToFile);

  2821       }

  2822     }

  2823     if (gfxUtils::sDumpPaintingToFile) {

  2824       fprintf(gfxUtils::sDumpPaintFile, "</body></html>");

  2825       fclose(gfxUtils::sDumpPaintFile);

  2826     }

  2827     gfxUtils::sDumpPaintFile = savedDumpFile;

  2828     gPaintCount++;

  2829   }

  2830 #endif

  2832   // Update the widget's opaque region information. This sets

  2833   // glass boundaries on Windows. Also set up plugin clip regions and bounds.

  2834   if ((aFlags & PAINT_WIDGET_LAYERS) &&

  2835       !willFlushRetainedLayers &&

  2836       !(aFlags & PAINT_DOCUMENT_RELATIVE)) {

  2837     nsIWidget *widget = aFrame->GetNearestWidget();

  2838     if (widget) {

  2839       nsRegion excludedRegion = builder.GetExcludedGlassRegion();

  2840       excludedRegion.Sub(excludedRegion, visibleRegion);

  2841       nsIntRegion windowRegion(excludedRegion.ToNearestPixels(presContext->AppUnitsPerDevPixel()));

  2842       widget->UpdateOpaqueRegion(windowRegion);

  2843     }

  2844   }

  2846   if (builder.WillComputePluginGeometry()) {

  2847     nsRefPtr<LayerManager> layerManager;

  2848     nsIWidget* widget = aFrame->GetNearestWidget();

  2849     if (widget) {

  2850       layerManager = widget->GetLayerManager();

  2851     }

  2853     rootPresContext->ComputePluginGeometryUpdates(aFrame, &builder, &list);

  2855     // We're not going to get a WillPaintWindow event here if we didn't do

  2856     // widget invalidation, so just apply the plugin geometry update here instead.

  2857     // We could instead have the compositor send back an equivalent to WillPaintWindow,

  2858     // but it should be close enough to now not to matter.

  2859     if (layerManager && !layerManager->NeedsWidgetInvalidation()) {

  2860       rootPresContext->ApplyPluginGeometryUpdates();

  2861     }

  2863     // We told the compositor thread not to composite when it received the transaction because

  2864     // we wanted to update plugins first. Schedule the composite now.

  2865     if (layerManager) {

  2866       layerManager->Composite();

  2867     }

  2868   }

  2871   // Flush the list so we don't trigger the IsEmpty-on-destruction assertion

  2872   list.DeleteAll();

  2873   return NS_OK;

  2874 }

  2876 /**

  2877  * Uses a binary search for find where the cursor falls in the line of text

  2878  * It also keeps track of the part of the string that has already been measured

  2879  * so it doesn't have to keep measuring the same text over and over

  2880  *

  2881  * @param "aBaseWidth" contains the width in twips of the portion

  2882  * of the text that has already been measured, and aBaseInx contains

  2883  * the index of the text that has already been measured.

  2884  *

  2885  * @param aTextWidth returns the (in twips) the length of the text that falls

  2886  * before the cursor aIndex contains the index of the text where the cursor falls

  2887  */

  2888 bool

  2889 nsLayoutUtils::BinarySearchForPosition(nsRenderingContext* aRendContext,

  2890                         const char16_t* aText,

  2891                         int32_t    aBaseWidth,

  2892                         int32_t    aBaseInx,

  2893                         int32_t    aStartInx,

  2894                         int32_t    aEndInx,

  2895                         int32_t    aCursorPos,

  2896                         int32_t&   aIndex,

  2897                         int32_t&   aTextWidth)

  2898 {

  2899   int32_t range = aEndInx - aStartInx;

  2900   if ((range == 1) || (range == 2 && NS_IS_HIGH_SURROGATE(aText[aStartInx]))) {

  2901     aIndex   = aStartInx + aBaseInx;

  2902     aTextWidth = aRendContext->GetWidth(aText, aIndex);

  2903     return true;

  2904   }

  2906   int32_t inx = aStartInx + (range / 2);

  2908   // Make sure we don't leave a dangling low surrogate

  2909   if (NS_IS_HIGH_SURROGATE(aText[inx-1]))

  2910     inx++;

  2912   int32_t textWidth = aRendContext->GetWidth(aText, inx);

  2914   int32_t fullWidth = aBaseWidth + textWidth;

  2915   if (fullWidth == aCursorPos) {

  2916     aTextWidth = textWidth;

  2917     aIndex = inx;

  2918     return true;

  2919   } else if (aCursorPos < fullWidth) {

  2920     aTextWidth = aBaseWidth;

  2921     if (BinarySearchForPosition(aRendContext, aText, aBaseWidth, aBaseInx, aStartInx, inx, aCursorPos, aIndex, aTextWidth)) {

  2922       return true;

  2923     }

  2924   } else {

  2925     aTextWidth = fullWidth;

  2926     if (BinarySearchForPosition(aRendContext, aText, aBaseWidth, aBaseInx, inx, aEndInx, aCursorPos, aIndex, aTextWidth)) {

  2927       return true;

  2928     }

  2929   }

  2930   return false;

  2931 }

  2933 static void

  2934 AddBoxesForFrame(nsIFrame* aFrame,

  2935                  nsLayoutUtils::BoxCallback* aCallback)

  2936 {

  2937   nsIAtom* pseudoType = aFrame->StyleContext()->GetPseudo();

  2939   if (pseudoType == nsCSSAnonBoxes::tableOuter) {

  2940     AddBoxesForFrame(aFrame->GetFirstPrincipalChild(), aCallback);

  2941     nsIFrame* kid = aFrame->GetFirstChild(nsIFrame::kCaptionList);

  2942     if (kid) {

  2943       AddBoxesForFrame(kid, aCallback);

  2944     }

  2945   } else if (pseudoType == nsCSSAnonBoxes::mozAnonymousBlock ||

  2946              pseudoType == nsCSSAnonBoxes::mozAnonymousPositionedBlock ||

  2947              pseudoType == nsCSSAnonBoxes::mozMathMLAnonymousBlock ||

  2948              pseudoType == nsCSSAnonBoxes::mozXULAnonymousBlock) {

  2949     for (nsIFrame* kid = aFrame->GetFirstPrincipalChild(); kid; kid = kid->GetNextSibling()) {

  2950       AddBoxesForFrame(kid, aCallback);

  2951     }

  2952   } else {

  2953     aCallback->AddBox(aFrame);

  2954   }

  2955 }

  2957 void

  2958 nsLayoutUtils::GetAllInFlowBoxes(nsIFrame* aFrame, BoxCallback* aCallback)

  2959 {

  2960   while (aFrame) {

  2961     AddBoxesForFrame(aFrame, aCallback);

  2962     aFrame = nsLayoutUtils::GetNextContinuationOrIBSplitSibling(aFrame);

  2963   }

  2964 }

  2966 nsIFrame*

  2967 nsLayoutUtils::GetFirstNonAnonymousFrame(nsIFrame* aFrame)

  2968 {

  2969   while (aFrame) {

  2970     nsIAtom* pseudoType = aFrame->StyleContext()->GetPseudo();

  2972     if (pseudoType == nsCSSAnonBoxes::tableOuter) {

  2973       nsIFrame* f = GetFirstNonAnonymousFrame(aFrame->GetFirstPrincipalChild());

  2974       if (f) {

  2975         return f;

  2976       }

  2977       nsIFrame* kid = aFrame->GetFirstChild(nsIFrame::kCaptionList);

  2978       if (kid) {

  2979         f = GetFirstNonAnonymousFrame(kid);

  2980         if (f) {

  2981           return f;

  2982         }

  2983       }

  2984     } else if (pseudoType == nsCSSAnonBoxes::mozAnonymousBlock ||

  2985                pseudoType == nsCSSAnonBoxes::mozAnonymousPositionedBlock ||

  2986                pseudoType == nsCSSAnonBoxes::mozMathMLAnonymousBlock ||

  2987                pseudoType == nsCSSAnonBoxes::mozXULAnonymousBlock) {

  2988       for (nsIFrame* kid = aFrame->GetFirstPrincipalChild(); kid; kid = kid->GetNextSibling()) {

  2989         nsIFrame* f = GetFirstNonAnonymousFrame(kid);

  2990         if (f) {

  2991           return f;

  2992         }

  2993       }

  2994     } else {

  2995       return aFrame;

  2996     }

  2998     aFrame = nsLayoutUtils::GetNextContinuationOrIBSplitSibling(aFrame);

  2999   }

  3000   return nullptr;

  3001 }

  3003 struct BoxToRect : public nsLayoutUtils::BoxCallback {

  3004   nsIFrame* mRelativeTo;

  3005   nsLayoutUtils::RectCallback* mCallback;

  3006   uint32_t mFlags;

  3008   BoxToRect(nsIFrame* aRelativeTo, nsLayoutUtils::RectCallback* aCallback,

  3009             uint32_t aFlags)

  3010     : mRelativeTo(aRelativeTo), mCallback(aCallback), mFlags(aFlags) {}

  3012   virtual void AddBox(nsIFrame* aFrame) MOZ_OVERRIDE {

  3013     nsRect r;

  3014     nsIFrame* outer = nsSVGUtils::GetOuterSVGFrameAndCoveredRegion(aFrame, &r);

  3015     if (!outer) {

  3016       outer = aFrame;

  3017       switch (mFlags & nsLayoutUtils::RECTS_WHICH_BOX_MASK) {

  3018         case nsLayoutUtils::RECTS_USE_CONTENT_BOX:

  3019           r = aFrame->GetContentRectRelativeToSelf();

  3020           break;

  3021         case nsLayoutUtils::RECTS_USE_PADDING_BOX:

  3022           r = aFrame->GetPaddingRectRelativeToSelf();

  3023           break;

  3024         case nsLayoutUtils::RECTS_USE_MARGIN_BOX:

  3025           r = aFrame->GetMarginRectRelativeToSelf();

  3026           break;

  3027         default: // Use the border box

  3028           r = aFrame->GetRectRelativeToSelf();

  3029       }

  3030     }

  3031     if (mFlags & nsLayoutUtils::RECTS_ACCOUNT_FOR_TRANSFORMS) {

  3032       r = nsLayoutUtils::TransformFrameRectToAncestor(outer, r, mRelativeTo);

  3033     } else {

  3034       r += outer->GetOffsetTo(mRelativeTo);

  3035     }

  3036     mCallback->AddRect(r);

  3037   }

  3038 };

  3040 void

  3041 nsLayoutUtils::GetAllInFlowRects(nsIFrame* aFrame, nsIFrame* aRelativeTo,

  3042                                  RectCallback* aCallback, uint32_t aFlags)

  3043 {

  3044   BoxToRect converter(aRelativeTo, aCallback, aFlags);

  3045   GetAllInFlowBoxes(aFrame, &converter);

  3046 }

  3048 nsLayoutUtils::RectAccumulator::RectAccumulator() : mSeenFirstRect(false) {}

  3050 void nsLayoutUtils::RectAccumulator::AddRect(const nsRect& aRect) {

  3051   mResultRect.UnionRect(mResultRect, aRect);

  3052   if (!mSeenFirstRect) {

  3053     mSeenFirstRect = true;

  3054     mFirstRect = aRect;

  3055   }

  3056 }

  3058 nsLayoutUtils::RectListBuilder::RectListBuilder(DOMRectList* aList)

  3059   : mRectList(aList)

  3060 {

  3061 }

  3063 void nsLayoutUtils::RectListBuilder::AddRect(const nsRect& aRect) {

  3064   nsRefPtr<DOMRect> rect = new DOMRect(mRectList);

  3066   rect->SetLayoutRect(aRect);

  3067   mRectList->Append(rect);

  3068 }

  3070 nsIFrame* nsLayoutUtils::GetContainingBlockForClientRect(nsIFrame* aFrame)

  3071 {

  3072   return aFrame->PresContext()->PresShell()->GetRootFrame();

  3073 }

  3075 nsRect

  3076 nsLayoutUtils::GetAllInFlowRectsUnion(nsIFrame* aFrame, nsIFrame* aRelativeTo,

  3077                                       uint32_t aFlags) {

  3078   RectAccumulator accumulator;

  3079   GetAllInFlowRects(aFrame, aRelativeTo, &accumulator, aFlags);

  3080   return accumulator.mResultRect.IsEmpty() ? accumulator.mFirstRect

  3081           : accumulator.mResultRect;

  3082 }

  3084 nsRect

  3085 nsLayoutUtils::GetTextShadowRectsUnion(const nsRect& aTextAndDecorationsRect,

  3086                                        nsIFrame* aFrame,

  3087                                        uint32_t aFlags)

  3088 {

  3089   const nsStyleText* textStyle = aFrame->StyleText();

  3090   if (!textStyle->HasTextShadow())

  3091     return aTextAndDecorationsRect;

  3093   nsRect resultRect = aTextAndDecorationsRect;

  3094   int32_t A2D = aFrame->PresContext()->AppUnitsPerDevPixel();

  3095   for (uint32_t i = 0; i < textStyle->mTextShadow->Length(); ++i) {

  3096     nsCSSShadowItem* shadow = textStyle->mTextShadow->ShadowAt(i);

  3097     nsMargin blur = nsContextBoxBlur::GetBlurRadiusMargin(shadow->mRadius, A2D);

  3098     if ((aFlags & EXCLUDE_BLUR_SHADOWS) && blur != nsMargin(0, 0, 0, 0))

  3099       continue;

  3101     nsRect tmpRect(aTextAndDecorationsRect);

  3103     tmpRect.MoveBy(nsPoint(shadow->mXOffset, shadow->mYOffset));

  3104     tmpRect.Inflate(blur);

  3106     resultRect.UnionRect(resultRect, tmpRect);

  3107   }

  3108   return resultRect;

  3109 }

  3111 nsresult

  3112 nsLayoutUtils::GetFontMetricsForFrame(const nsIFrame* aFrame,

  3113                                       nsFontMetrics** aFontMetrics,

  3114                                       float aInflation)

  3115 {

  3116   return nsLayoutUtils::GetFontMetricsForStyleContext(aFrame->StyleContext(),

  3117                                                       aFontMetrics,

  3118                                                       aInflation);

  3119 }

  3121 nsresult

  3122 nsLayoutUtils::GetFontMetricsForStyleContext(nsStyleContext* aStyleContext,

  3123                                              nsFontMetrics** aFontMetrics,

  3124                                              float aInflation)

  3125 {

  3126   // pass the user font set object into the device context to pass along to CreateFontGroup

  3127   nsPresContext* pc = aStyleContext->PresContext();

  3128   gfxUserFontSet* fs = pc->GetUserFontSet();

  3129   gfxTextPerfMetrics* tp = pc->GetTextPerfMetrics();

  3131   nsFont font = aStyleContext->StyleFont()->mFont;

  3132   // We need to not run font.size through floats when it's large since

  3133   // doing so would be lossy.  Fortunately, in such cases, aInflation is

  3134   // guaranteed to be 1.0f.

  3135   if (aInflation != 1.0f) {

  3136     font.size = NSToCoordRound(font.size * aInflation);

  3137   }

  3138   return pc->DeviceContext()->GetMetricsFor(

  3139                   font, aStyleContext->StyleFont()->mLanguage,

  3140                   fs, tp, *aFontMetrics);

  3141 }

  3143 nsIFrame*

  3144 nsLayoutUtils::FindChildContainingDescendant(nsIFrame* aParent, nsIFrame* aDescendantFrame)

  3145 {

  3146   nsIFrame* result = aDescendantFrame;

  3148   while (result) {

  3149     nsIFrame* parent = result->GetParent();

  3150     if (parent == aParent) {

  3151       break;

  3152     }

  3154     // The frame is not an immediate child of aParent so walk up another level

  3155     result = parent;

  3156   }

  3158   return result;

  3159 }

  3161 nsBlockFrame*

  3162 nsLayoutUtils::GetAsBlock(nsIFrame* aFrame)

  3163 {

  3164   nsBlockFrame* block = do_QueryFrame(aFrame);

  3165   return block;

  3166 }

  3168 nsBlockFrame*

  3169 nsLayoutUtils::FindNearestBlockAncestor(nsIFrame* aFrame)

  3170 {

  3171   nsIFrame* nextAncestor;

  3172   for (nextAncestor = aFrame->GetParent(); nextAncestor;

  3173        nextAncestor = nextAncestor->GetParent()) {

  3174     nsBlockFrame* block = GetAsBlock(nextAncestor);

  3175     if (block)

  3176       return block;

  3177   }

  3178   return nullptr;

  3179 }

  3181 nsIFrame*

  3182 nsLayoutUtils::GetNonGeneratedAncestor(nsIFrame* aFrame)

  3183 {

  3184   if (!(aFrame->GetStateBits() & NS_FRAME_GENERATED_CONTENT))

  3185     return aFrame;

  3187   nsIFrame* f = aFrame;

  3188   do {

  3189     f = GetParentOrPlaceholderFor(f);

  3190   } while (f->GetStateBits() & NS_FRAME_GENERATED_CONTENT);

  3191   return f;

  3192 }

  3194 nsIFrame*

  3195 nsLayoutUtils::GetParentOrPlaceholderFor(nsIFrame* aFrame)

  3196 {

  3197   if ((aFrame->GetStateBits() & NS_FRAME_OUT_OF_FLOW)

  3198       && !aFrame->GetPrevInFlow()) {

  3199     return aFrame->PresContext()->PresShell()->FrameManager()->

  3200       GetPlaceholderFrameFor(aFrame);

  3201   }

  3202   return aFrame->GetParent();

  3203 }

  3205 nsIFrame*

  3206 nsLayoutUtils::GetParentOrPlaceholderForCrossDoc(nsIFrame* aFrame)

  3207 {

  3208   nsIFrame* f = GetParentOrPlaceholderFor(aFrame);

  3209   if (f)

  3210     return f;

  3211   return GetCrossDocParentFrame(aFrame);

  3212 }

  3214 nsIFrame*

  3215 nsLayoutUtils::GetNextContinuationOrIBSplitSibling(nsIFrame *aFrame)

  3216 {

  3217   nsIFrame *result = aFrame->GetNextContinuation();

  3218   if (result)

  3219     return result;

  3221   if ((aFrame->GetStateBits() & NS_FRAME_PART_OF_IBSPLIT) != 0) {

  3222     // We only store the ib-split sibling annotation with the first

  3223     // frame in the continuation chain. Walk back to find that frame now.

  3224     aFrame = aFrame->FirstContinuation();

  3226     void* value = aFrame->Properties().Get(nsIFrame::IBSplitSibling());

  3227     return static_cast<nsIFrame*>(value);

  3228   }

  3230   return nullptr;

  3231 }

  3233 nsIFrame*

  3234 nsLayoutUtils::FirstContinuationOrIBSplitSibling(nsIFrame *aFrame)

  3235 {

  3236   nsIFrame *result = aFrame->FirstContinuation();

  3237   if (result->GetStateBits() & NS_FRAME_PART_OF_IBSPLIT) {

  3238     while (true) {

  3239       nsIFrame *f = static_cast<nsIFrame*>

  3240         (result->Properties().Get(nsIFrame::IBSplitPrevSibling()));

  3241       if (!f)

  3242         break;

  3243       result = f;

  3244     }

  3245   }

  3247   return result;

  3248 }

  3250 bool

  3251 nsLayoutUtils::IsFirstContinuationOrIBSplitSibling(nsIFrame *aFrame)

  3252 {

  3253   if (aFrame->GetPrevContinuation()) {

  3254     return false;

  3255   }

  3256   if ((aFrame->GetStateBits() & NS_FRAME_PART_OF_IBSPLIT) &&

  3257       aFrame->Properties().Get(nsIFrame::IBSplitPrevSibling())) {

  3258     return false;

  3259   }

  3261   return true;

  3262 }

  3264 bool

  3265 nsLayoutUtils::IsViewportScrollbarFrame(nsIFrame* aFrame)

  3266 {

  3267   if (!aFrame)

  3268     return false;

  3270   nsIFrame* rootScrollFrame =

  3271     aFrame->PresContext()->PresShell()->GetRootScrollFrame();

  3272   if (!rootScrollFrame)

  3273     return false;

  3275   nsIScrollableFrame* rootScrollableFrame = do_QueryFrame(rootScrollFrame);

  3276   NS_ASSERTION(rootScrollableFrame, "The root scorollable frame is null");

  3278   if (!IsProperAncestorFrame(rootScrollFrame, aFrame))

  3279     return false;

  3281   nsIFrame* rootScrolledFrame = rootScrollableFrame->GetScrolledFrame();

  3282   return !(rootScrolledFrame == aFrame ||

  3283            IsProperAncestorFrame(rootScrolledFrame, aFrame));

  3284 }

  3286 static nscoord AddPercents(nsLayoutUtils::IntrinsicWidthType aType,

  3287                            nscoord aCurrent, float aPercent)

  3288 {

  3289   nscoord result = aCurrent;

  3290   if (aPercent > 0.0f && aType == nsLayoutUtils::PREF_WIDTH) {

  3291     // XXX Should we also consider percentages for min widths, up to a

  3292     // limit?

  3293     if (aPercent >= 1.0f)

  3294       result = nscoord_MAX;

  3295     else

  3296       result = NSToCoordRound(float(result) / (1.0f - aPercent));

  3297   }

  3298   return result;

  3299 }

  3301 // Use only for widths/heights (or their min/max), since it clamps

  3302 // negative calc() results to 0.

  3303 static bool GetAbsoluteCoord(const nsStyleCoord& aStyle, nscoord& aResult)

  3304 {

  3305   if (aStyle.IsCalcUnit()) {

  3306     if (aStyle.CalcHasPercent()) {

  3307       return false;

  3308     }

  3309     // If it has no percents, we can pass 0 for the percentage basis.

  3310     aResult = nsRuleNode::ComputeComputedCalc(aStyle, 0);

  3311     if (aResult < 0)

  3312       aResult = 0;

  3313     return true;

  3314   }

  3316   if (eStyleUnit_Coord != aStyle.GetUnit())

  3317     return false;

  3319   aResult = aStyle.GetCoordValue();

  3320   NS_ASSERTION(aResult >= 0, "negative widths not allowed");

  3321   return true;

  3322 }

  3324 // Only call on style coords for which GetAbsoluteCoord returned false.

  3325 static bool

  3326 GetPercentHeight(const nsStyleCoord& aStyle,

  3327                  nsIFrame* aFrame,

  3328                  nscoord& aResult)

  3329 {

  3330   if (eStyleUnit_Percent != aStyle.GetUnit() &&

  3331       !aStyle.IsCalcUnit())

  3332     return false;

  3334   MOZ_ASSERT(!aStyle.IsCalcUnit() || aStyle.CalcHasPercent(),

  3335              "GetAbsoluteCoord should have handled this");

  3337   nsIFrame *f = aFrame->GetContainingBlock();

  3338   if (!f) {

  3339     NS_NOTREACHED("top of frame tree not a containing block");

  3340     return false;

  3341   }

  3343   // During reflow, nsHTMLScrollFrame::ReflowScrolledFrame uses

  3344   // SetComputedHeight on the reflow state for its child to propagate its

  3345   // computed height to the scrolled content. So here we skip to the scroll

  3346   // frame that contains this scrolled content in order to get the same

  3347   // behavior as layout when computing percentage heights.

  3348   if (f->StyleContext()->GetPseudo() == nsCSSAnonBoxes::scrolledContent) {

  3349     f = f->GetParent();

  3350   }

  3352   const nsStylePosition *pos = f->StylePosition();

  3353   nscoord h;

  3354   if (!GetAbsoluteCoord(pos->mHeight, h) &&

  3355       !GetPercentHeight(pos->mHeight, f, h)) {

  3356     NS_ASSERTION(pos->mHeight.GetUnit() == eStyleUnit_Auto ||

  3357                  pos->mHeight.HasPercent(),

  3358                  "unknown height unit");

  3359     nsIAtom* fType = f->GetType();

  3360     if (fType != nsGkAtoms::viewportFrame && fType != nsGkAtoms::canvasFrame &&

  3361         fType != nsGkAtoms::pageContentFrame) {

  3362       // There's no basis for the percentage height, so it acts like auto.

  3363       // Should we consider a max-height < min-height pair a basis for

  3364       // percentage heights?  The spec is somewhat unclear, and not doing

  3365       // so is simpler and avoids troubling discontinuities in behavior,

  3366       // so I'll choose not to. -LDB

  3367       return false;

  3368     }

  3370     NS_ASSERTION(pos->mHeight.GetUnit() == eStyleUnit_Auto,

  3371                  "Unexpected height unit for viewport or canvas or page-content");

  3372     // For the viewport, canvas, and page-content kids, the percentage

  3373     // basis is just the parent height.

  3374     h = f->GetSize().height;

  3375     if (h == NS_UNCONSTRAINEDSIZE) {

  3376       // We don't have a percentage basis after all

  3377       return false;

  3378     }

  3379   }

  3381   nscoord maxh;

  3382   if (GetAbsoluteCoord(pos->mMaxHeight, maxh) ||

  3383       GetPercentHeight(pos->mMaxHeight, f, maxh)) {

  3384     if (maxh < h)

  3385       h = maxh;

  3386   } else {

  3387     NS_ASSERTION(pos->mMaxHeight.GetUnit() == eStyleUnit_None ||

  3388                  pos->mMaxHeight.HasPercent(),

  3389                  "unknown max-height unit");

  3390   }

  3392   nscoord minh;

  3393   if (GetAbsoluteCoord(pos->mMinHeight, minh) ||

  3394       GetPercentHeight(pos->mMinHeight, f, minh)) {

  3395     if (minh > h)

  3396       h = minh;

  3397   } else {

  3398     NS_ASSERTION(pos->mMinHeight.HasPercent(),

  3399                  "unknown min-height unit");

  3400   }

  3402   if (aStyle.IsCalcUnit()) {

  3403     aResult = std::max(nsRuleNode::ComputeComputedCalc(aStyle, h), 0);

  3404     return true;

  3405   }

  3407   aResult = NSToCoordRound(aStyle.GetPercentValue() * h);

  3408   return true;

  3409 }

  3411 // Handles only -moz-max-content and -moz-min-content, and

  3412 // -moz-fit-content for min-width and max-width, since the others

  3413 // (-moz-fit-content for width, and -moz-available) have no effect on

  3414 // intrinsic widths.

  3415 enum eWidthProperty { PROP_WIDTH, PROP_MAX_WIDTH, PROP_MIN_WIDTH };

  3416 static bool

  3417 GetIntrinsicCoord(const nsStyleCoord& aStyle,

  3418                   nsRenderingContext* aRenderingContext,

  3419                   nsIFrame* aFrame,

  3420                   eWidthProperty aProperty,

  3421                   nscoord& aResult)

  3422 {

  3423   NS_PRECONDITION(aProperty == PROP_WIDTH || aProperty == PROP_MAX_WIDTH ||

  3424                   aProperty == PROP_MIN_WIDTH, "unexpected property");

  3425   if (aStyle.GetUnit() != eStyleUnit_Enumerated)

  3426     return false;

  3427   int32_t val = aStyle.GetIntValue();

  3428   NS_ASSERTION(val == NS_STYLE_WIDTH_MAX_CONTENT ||

  3429                val == NS_STYLE_WIDTH_MIN_CONTENT ||

  3430                val == NS_STYLE_WIDTH_FIT_CONTENT ||

  3431                val == NS_STYLE_WIDTH_AVAILABLE,

  3432                "unexpected enumerated value for width property");

  3433   if (val == NS_STYLE_WIDTH_AVAILABLE)

  3434     return false;

  3435   if (val == NS_STYLE_WIDTH_FIT_CONTENT) {

  3436     if (aProperty == PROP_WIDTH)

  3437       return false; // handle like 'width: auto'

  3438     if (aProperty == PROP_MAX_WIDTH)

  3439       // constrain large 'width' values down to -moz-max-content

  3440       val = NS_STYLE_WIDTH_MAX_CONTENT;

  3441     else

  3442       // constrain small 'width' or 'max-width' values up to -moz-min-content

  3443       val = NS_STYLE_WIDTH_MIN_CONTENT;

  3444   }

  3446   NS_ASSERTION(val == NS_STYLE_WIDTH_MAX_CONTENT ||

  3447                val == NS_STYLE_WIDTH_MIN_CONTENT,

  3448                "should have reduced everything remaining to one of these");

  3450   // If aFrame is a container for font size inflation, then shrink

  3451   // wrapping inside of it should not apply font size inflation.

  3452   AutoMaybeDisableFontInflation an(aFrame);

  3454   if (val == NS_STYLE_WIDTH_MAX_CONTENT)

  3455     aResult = aFrame->GetPrefWidth(aRenderingContext);

  3456   else

  3457     aResult = aFrame->GetMinWidth(aRenderingContext);

  3458   return true;

  3459 }

  3461 #undef  DEBUG_INTRINSIC_WIDTH

  3463 #ifdef DEBUG_INTRINSIC_WIDTH

  3464 static int32_t gNoiseIndent = 0;

  3465 #endif

  3467 /* static */ nscoord

  3468 nsLayoutUtils::IntrinsicForContainer(nsRenderingContext *aRenderingContext,

  3469                                      nsIFrame *aFrame,

  3470                                      IntrinsicWidthType aType,

  3471                                      uint32_t aFlags)

  3472 {

  3473   NS_PRECONDITION(aFrame, "null frame");

  3474   NS_PRECONDITION(aType == MIN_WIDTH || aType == PREF_WIDTH, "bad type");

  3476 #ifdef DEBUG_INTRINSIC_WIDTH

  3477   nsFrame::IndentBy(stderr, gNoiseIndent);

  3478   static_cast<nsFrame*>(aFrame)->ListTag(stderr);

  3479   printf_stderr(" %s intrinsic width for container:\n",

  3480          aType == MIN_WIDTH ? "min" : "pref");

  3481 #endif

  3483   // If aFrame is a container for font size inflation, then shrink

  3484   // wrapping inside of it should not apply font size inflation.

  3485   AutoMaybeDisableFontInflation an(aFrame);

  3487   nsIFrame::IntrinsicWidthOffsetData offsets =

  3488     aFrame->IntrinsicWidthOffsets(aRenderingContext);

  3490   const nsStylePosition *stylePos = aFrame->StylePosition();

  3491   uint8_t boxSizing = stylePos->mBoxSizing;

  3492   const nsStyleCoord &styleWidth = stylePos->mWidth;

  3493   const nsStyleCoord &styleMinWidth = stylePos->mMinWidth;

  3494   const nsStyleCoord &styleMaxWidth = stylePos->mMaxWidth;

  3496   // We build up two values starting with the content box, and then

  3497   // adding padding, border and margin.  The result is normally

  3498   // |result|.  Then, when we handle 'width', 'min-width', and

  3499   // 'max-width', we use the results we've been building in |min| as a

  3500   // minimum, overriding 'min-width'.  This ensures two things:

  3501   //   * that we don't let a value of 'box-sizing' specifying a width

  3502   //     smaller than the padding/border inside the box-sizing box give

  3503   //     a content width less than zero

  3504   //   * that we prevent tables from becoming smaller than their

  3505   //     intrinsic minimum width

  3506   nscoord result = 0, min = 0;

  3508   nscoord maxw;

  3509   bool haveFixedMaxWidth = GetAbsoluteCoord(styleMaxWidth, maxw);

  3510   nscoord minw;

  3511   bool haveFixedMinWidth = GetAbsoluteCoord(styleMinWidth, minw);

  3513   // If we have a specified width (or a specified 'min-width' greater

  3514   // than the specified 'max-width', which works out to the same thing),

  3515   // don't even bother getting the frame's intrinsic width, because in

  3516   // this case GetAbsoluteCoord(styleWidth, w) will always succeed, so

  3517   // we'll never need the intrinsic dimensions.

  3518   if (styleWidth.GetUnit() == eStyleUnit_Enumerated &&

  3519       (styleWidth.GetIntValue() == NS_STYLE_WIDTH_MAX_CONTENT ||

  3520        styleWidth.GetIntValue() == NS_STYLE_WIDTH_MIN_CONTENT)) {

  3521     // -moz-fit-content and -moz-available enumerated widths compute intrinsic

  3522     // widths just like auto.

  3523     // For -moz-max-content and -moz-min-content, we handle them like

  3524     // specified widths, but ignore box-sizing.

  3525     boxSizing = NS_STYLE_BOX_SIZING_CONTENT;

  3526   } else if (!styleWidth.ConvertsToLength() &&

  3527              !(haveFixedMinWidth && haveFixedMaxWidth && maxw <= minw)) {

  3528 #ifdef DEBUG_INTRINSIC_WIDTH

  3529     ++gNoiseIndent;

  3530 #endif

  3531     if (aType == MIN_WIDTH)

  3532       result = aFrame->GetMinWidth(aRenderingContext);

  3533     else

  3534       result = aFrame->GetPrefWidth(aRenderingContext);

  3535 #ifdef DEBUG_INTRINSIC_WIDTH

  3536     --gNoiseIndent;

  3537     nsFrame::IndentBy(stderr, gNoiseIndent);

  3538     static_cast<nsFrame*>(aFrame)->ListTag(stderr);

  3539     printf_stderr(" %s intrinsic width from frame is %d.\n",

  3540            aType == MIN_WIDTH ? "min" : "pref", result);

  3541 #endif

  3543     // Handle elements with an intrinsic ratio (or size) and a specified

  3544     // height, min-height, or max-height.

  3545     const nsStyleCoord &styleHeight = stylePos->mHeight;

  3546     const nsStyleCoord &styleMinHeight = stylePos->mMinHeight;

  3547     const nsStyleCoord &styleMaxHeight = stylePos->mMaxHeight;

  3548     if (styleHeight.GetUnit() != eStyleUnit_Auto ||

  3549         !(styleMinHeight.GetUnit() == eStyleUnit_Coord &&

  3550           styleMinHeight.GetCoordValue() == 0) ||

  3551         styleMaxHeight.GetUnit() != eStyleUnit_None) {

  3553       nsSize ratio = aFrame->GetIntrinsicRatio();

  3555       if (ratio.height != 0) {

  3556         nscoord heightTakenByBoxSizing = 0;

  3557         switch (boxSizing) {

  3558         case NS_STYLE_BOX_SIZING_BORDER: {

  3559           const nsStyleBorder* styleBorder = aFrame->StyleBorder();

  3560           heightTakenByBoxSizing +=

  3561             styleBorder->GetComputedBorder().TopBottom();

  3562           // fall through

  3563         }

  3564         case NS_STYLE_BOX_SIZING_PADDING: {

  3565           if (!(aFlags & IGNORE_PADDING)) {

  3566             const nsStylePadding* stylePadding = aFrame->StylePadding();

  3567             nscoord pad;

  3568             if (GetAbsoluteCoord(stylePadding->mPadding.GetTop(), pad) ||

  3569                 GetPercentHeight(stylePadding->mPadding.GetTop(), aFrame, pad)) {

  3570               heightTakenByBoxSizing += pad;

  3571             }

  3572             if (GetAbsoluteCoord(stylePadding->mPadding.GetBottom(), pad) ||

  3573                 GetPercentHeight(stylePadding->mPadding.GetBottom(), aFrame, pad)) {

  3574               heightTakenByBoxSizing += pad;

  3575             }

  3576           }

  3577           // fall through

  3578         }

  3579         case NS_STYLE_BOX_SIZING_CONTENT:

  3580         default:

  3581           break;

  3582         }

  3584         nscoord h;

  3585         if (GetAbsoluteCoord(styleHeight, h) ||

  3586             GetPercentHeight(styleHeight, aFrame, h)) {

  3587           h = std::max(0, h - heightTakenByBoxSizing);

  3588           result =

  3589             NSToCoordRound(h * (float(ratio.width) / float(ratio.height)));

  3590         }

  3592         if (GetAbsoluteCoord(styleMaxHeight, h) ||

  3593             GetPercentHeight(styleMaxHeight, aFrame, h)) {

  3594           h = std::max(0, h - heightTakenByBoxSizing);

  3595           nscoord maxWidth =

  3596             NSToCoordRound(h * (float(ratio.width) / float(ratio.height)));

  3597           if (maxWidth < result)

  3598             result = maxWidth;

  3599         }

  3601         if (GetAbsoluteCoord(styleMinHeight, h) ||

  3602             GetPercentHeight(styleMinHeight, aFrame, h)) {

  3603           h = std::max(0, h - heightTakenByBoxSizing);

  3604           nscoord minWidth =

  3605             NSToCoordRound(h * (float(ratio.width) / float(ratio.height)));

  3606           if (minWidth > result)

  3607             result = minWidth;

  3608         }

  3609       }

  3610     }

  3611   }

  3613   if (aFrame->GetType() == nsGkAtoms::tableFrame) {

  3614     // Tables can't shrink smaller than their intrinsic minimum width,

  3615     // no matter what.

  3616     min = aFrame->GetMinWidth(aRenderingContext);

  3617   }

  3619   // We also need to track what has been added on outside of the box

  3620   // (controlled by 'box-sizing') where 'width', 'min-width' and

  3621   // 'max-width' are applied.  We have to account for these properties

  3622   // after getting all the offsets (margin, border, padding) because

  3623   // percentages do not operate linearly.

  3624   // Doing this is ok because although percentages aren't handled

  3625   // linearly, they are handled monotonically.

  3626   nscoord coordOutsideWidth = 0;

  3627   float pctOutsideWidth = 0;

  3628   float pctTotal = 0.0f;

  3630   if (!(aFlags & IGNORE_PADDING)) {

  3631     coordOutsideWidth += offsets.hPadding;

  3632     pctOutsideWidth += offsets.hPctPadding;

  3634     if (boxSizing == NS_STYLE_BOX_SIZING_PADDING) {

  3635       min += coordOutsideWidth;

  3636       result = NSCoordSaturatingAdd(result, coordOutsideWidth);

  3637       pctTotal += pctOutsideWidth;

  3639       coordOutsideWidth = 0;

  3640       pctOutsideWidth = 0.0f;

  3641     }

  3642   }

  3644   coordOutsideWidth += offsets.hBorder;

  3646   if (boxSizing == NS_STYLE_BOX_SIZING_BORDER) {

  3647     min += coordOutsideWidth;

  3648     result = NSCoordSaturatingAdd(result, coordOutsideWidth);

  3649     pctTotal += pctOutsideWidth;

  3651     coordOutsideWidth = 0;

  3652     pctOutsideWidth = 0.0f;

  3653   }

  3655   coordOutsideWidth += offsets.hMargin;

  3656   pctOutsideWidth += offsets.hPctMargin;

  3658   min += coordOutsideWidth;

  3659   result = NSCoordSaturatingAdd(result, coordOutsideWidth);

  3660   pctTotal += pctOutsideWidth;

  3662   nscoord w;

  3663   if (GetAbsoluteCoord(styleWidth, w) ||

  3664       GetIntrinsicCoord(styleWidth, aRenderingContext, aFrame,

  3665                         PROP_WIDTH, w)) {

  3666     result = AddPercents(aType, w + coordOutsideWidth, pctOutsideWidth);

  3667   }

  3668   else if (aType == MIN_WIDTH &&

  3669            // The only cases of coord-percent-calc() units that

  3670            // GetAbsoluteCoord didn't handle are percent and calc()s

  3671            // containing percent.

  3672            styleWidth.IsCoordPercentCalcUnit() &&

  3673            aFrame->IsFrameOfType(nsIFrame::eReplaced)) {

  3674     // A percentage width on replaced elements means they can shrink to 0.

  3675     result = 0; // let |min| handle padding/border/margin

  3676   }

  3677   else {

  3678     // NOTE: We could really do a lot better for percents and for some

  3679     // cases of calc() containing percent (certainly including any where

  3680     // the coefficient on the percent is positive and there are no max()

  3681     // expressions).  However, doing better for percents wouldn't be

  3682     // backwards compatible.

  3683     result = AddPercents(aType, result, pctTotal);

  3684   }

  3686   if (haveFixedMaxWidth ||

  3687       GetIntrinsicCoord(styleMaxWidth, aRenderingContext, aFrame,

  3688                         PROP_MAX_WIDTH, maxw)) {

  3689     maxw = AddPercents(aType, maxw + coordOutsideWidth, pctOutsideWidth);

  3690     if (result > maxw)

  3691       result = maxw;

  3692   }

  3694   if (haveFixedMinWidth ||

  3695       GetIntrinsicCoord(styleMinWidth, aRenderingContext, aFrame,

  3696                         PROP_MIN_WIDTH, minw)) {

  3697     minw = AddPercents(aType, minw + coordOutsideWidth, pctOutsideWidth);

  3698     if (result < minw)

  3699       result = minw;

  3700   }

  3702   min = AddPercents(aType, min, pctTotal);

  3703   if (result < min)

  3704     result = min;

  3706   const nsStyleDisplay *disp = aFrame->StyleDisplay();

  3707   if (aFrame->IsThemed(disp)) {

  3708     nsIntSize size(0, 0);

  3709     bool canOverride = true;

  3710     nsPresContext *presContext = aFrame->PresContext();

  3711     presContext->GetTheme()->

  3712       GetMinimumWidgetSize(aRenderingContext, aFrame, disp->mAppearance,

  3713                            &size, &canOverride);

  3715     nscoord themeWidth = presContext->DevPixelsToAppUnits(size.width);

  3717     // GMWS() returns a border-box width

  3718     themeWidth += offsets.hMargin;

  3719     themeWidth = AddPercents(aType, themeWidth, offsets.hPctMargin);

  3721     if (themeWidth > result || !canOverride)

  3722       result = themeWidth;

  3723   }

  3725 #ifdef DEBUG_INTRINSIC_WIDTH

  3726   nsFrame::IndentBy(stderr, gNoiseIndent);

  3727   static_cast<nsFrame*>(aFrame)->ListTag(stderr);

  3728   printf_stderr(" %s intrinsic width for container is %d twips.\n",

  3729          aType == MIN_WIDTH ? "min" : "pref", result);

  3730 #endif

  3732   return result;

  3733 }

  3735 /* static */ nscoord

  3736 nsLayoutUtils::ComputeCBDependentValue(nscoord aPercentBasis,

  3737                                        const nsStyleCoord& aCoord)

  3738 {

  3739   NS_WARN_IF_FALSE(aPercentBasis != NS_UNCONSTRAINEDSIZE,

  3740                    "have unconstrained width or height; this should only "

  3741                    "result from very large sizes, not attempts at intrinsic "

  3742                    "size calculation");

  3744   if (aCoord.IsCoordPercentCalcUnit()) {

  3745     return nsRuleNode::ComputeCoordPercentCalc(aCoord, aPercentBasis);

  3746   }

  3747   NS_ASSERTION(aCoord.GetUnit() == eStyleUnit_None ||

  3748                aCoord.GetUnit() == eStyleUnit_Auto,

  3749                "unexpected width value");

  3750   return 0;

  3751 }

  3753 /* static */ nscoord

  3754 nsLayoutUtils::ComputeWidthValue(

  3755                  nsRenderingContext* aRenderingContext,

  3756                  nsIFrame*            aFrame,

  3757                  nscoord              aContainingBlockWidth,

  3758                  nscoord              aContentEdgeToBoxSizing,

  3759                  nscoord              aBoxSizingToMarginEdge,

  3760                  const nsStyleCoord&  aCoord)

  3761 {

  3762   NS_PRECONDITION(aFrame, "non-null frame expected");

  3763   NS_PRECONDITION(aRenderingContext, "non-null rendering context expected");

  3764   NS_WARN_IF_FALSE(aContainingBlockWidth != NS_UNCONSTRAINEDSIZE,

  3765                    "have unconstrained width; this should only result from "

  3766                    "very large sizes, not attempts at intrinsic width "

  3767                    "calculation");

  3768   NS_PRECONDITION(aContainingBlockWidth >= 0,

  3769                   "width less than zero");

  3771   nscoord result;

  3772   if (aCoord.IsCoordPercentCalcUnit()) {

  3773     result = nsRuleNode::ComputeCoordPercentCalc(aCoord,

  3774                                                  aContainingBlockWidth);

  3775     // The result of a calc() expression might be less than 0; we

  3776     // should clamp at runtime (below).  (Percentages and coords that

  3777     // are less than 0 have already been dropped by the parser.)

  3778     result -= aContentEdgeToBoxSizing;

  3779   } else {

  3780     MOZ_ASSERT(eStyleUnit_Enumerated == aCoord.GetUnit());

  3781     // If aFrame is a container for font size inflation, then shrink

  3782     // wrapping inside of it should not apply font size inflation.

  3783     AutoMaybeDisableFontInflation an(aFrame);

  3785     int32_t val = aCoord.GetIntValue();

  3786     switch (val) {

  3787       case NS_STYLE_WIDTH_MAX_CONTENT:

  3788         result = aFrame->GetPrefWidth(aRenderingContext);

  3789         NS_ASSERTION(result >= 0, "width less than zero");

  3790         break;

  3791       case NS_STYLE_WIDTH_MIN_CONTENT:

  3792         result = aFrame->GetMinWidth(aRenderingContext);

  3793         NS_ASSERTION(result >= 0, "width less than zero");

  3794         break;

  3795       case NS_STYLE_WIDTH_FIT_CONTENT:

  3796         {

  3797           nscoord pref = aFrame->GetPrefWidth(aRenderingContext),

  3798                    min = aFrame->GetMinWidth(aRenderingContext),

  3799                   fill = aContainingBlockWidth -

  3800                          (aBoxSizingToMarginEdge + aContentEdgeToBoxSizing);

  3801           result = std::max(min, std::min(pref, fill));

  3802           NS_ASSERTION(result >= 0, "width less than zero");

  3803         }

  3804         break;

  3805       case NS_STYLE_WIDTH_AVAILABLE:

  3806         result = aContainingBlockWidth -

  3807                  (aBoxSizingToMarginEdge + aContentEdgeToBoxSizing);

  3808     }

  3809   }

  3811   return std::max(0, result);

  3812 }

  3814 /* static */ nscoord

  3815 nsLayoutUtils::ComputeHeightDependentValue(

  3816                  nscoord              aContainingBlockHeight,

  3817                  const nsStyleCoord&  aCoord)

  3818 {

  3819   // XXXldb Some callers explicitly check aContainingBlockHeight

  3820   // against NS_AUTOHEIGHT *and* unit against eStyleUnit_Percent or

  3821   // calc()s containing percents before calling this function.

  3822   // However, it would be much more likely to catch problems without

  3823   // the unit conditions.

  3824   // XXXldb Many callers pass a non-'auto' containing block height when

  3825   // according to CSS2.1 they should be passing 'auto'.

  3826   NS_PRECONDITION(NS_AUTOHEIGHT != aContainingBlockHeight ||

  3827                   !aCoord.HasPercent(),

  3828                   "unexpected containing block height");

  3830   if (aCoord.IsCoordPercentCalcUnit()) {

  3831     return nsRuleNode::ComputeCoordPercentCalc(aCoord, aContainingBlockHeight);

  3832   }

  3834   NS_ASSERTION(aCoord.GetUnit() == eStyleUnit_None ||

  3835                aCoord.GetUnit() == eStyleUnit_Auto,

  3836                "unexpected height value");

  3837   return 0;

  3838 }

  3840 /* static */ void

  3841 nsLayoutUtils::MarkDescendantsDirty(nsIFrame *aSubtreeRoot)

  3842 {

  3843   nsAutoTArray<nsIFrame*, 4> subtrees;

  3844   subtrees.AppendElement(aSubtreeRoot);

  3846   // dirty descendants, iterating over subtrees that may include

  3847   // additional subtrees associated with placeholders

  3848   do {

  3849     nsIFrame *subtreeRoot = subtrees.ElementAt(subtrees.Length() - 1);

  3850     subtrees.RemoveElementAt(subtrees.Length() - 1);

  3852     // Mark all descendants dirty (using an nsTArray stack rather than

  3853     // recursion).

  3854     // Note that nsHTMLReflowState::InitResizeFlags has some similar

  3855     // code; see comments there for how and why it differs.

  3856     nsAutoTArray<nsIFrame*, 32> stack;

  3857     stack.AppendElement(subtreeRoot);

  3859     do {

  3860       nsIFrame *f = stack.ElementAt(stack.Length() - 1);

  3861       stack.RemoveElementAt(stack.Length() - 1);

  3863       f->MarkIntrinsicWidthsDirty();

  3865       if (f->GetType() == nsGkAtoms::placeholderFrame) {

  3866         nsIFrame *oof = nsPlaceholderFrame::GetRealFrameForPlaceholder(f);

  3867         if (!nsLayoutUtils::IsProperAncestorFrame(subtreeRoot, oof)) {

  3868           // We have another distinct subtree we need to mark.

  3869           subtrees.AppendElement(oof);

  3870         }

  3871       }

  3873       nsIFrame::ChildListIterator lists(f);

  3874       for (; !lists.IsDone(); lists.Next()) {

  3875         nsFrameList::Enumerator childFrames(lists.CurrentList());

  3876         for (; !childFrames.AtEnd(); childFrames.Next()) {

  3877           nsIFrame* kid = childFrames.get();

  3878           stack.AppendElement(kid);

  3879         }

  3880       }

  3881     } while (stack.Length() != 0);

  3882   } while (subtrees.Length() != 0);

  3883 }

  3885 #define MULDIV(a,b,c) (nscoord(int64_t(a) * int64_t(b) / int64_t(c)))

  3887 /* static */ nsSize

  3888 nsLayoutUtils::ComputeSizeWithIntrinsicDimensions(

  3889                    nsRenderingContext* aRenderingContext, nsIFrame* aFrame,

  3890                    const IntrinsicSize& aIntrinsicSize,

  3891                    nsSize aIntrinsicRatio, nsSize aCBSize,

  3892                    nsSize aMargin, nsSize aBorder, nsSize aPadding)

  3893 {

  3894   const nsStylePosition* stylePos = aFrame->StylePosition();

  3896   // If we're a flex item, we'll compute our size a bit differently.

  3897   const nsStyleCoord* widthStyleCoord = &(stylePos->mWidth);

  3898   const nsStyleCoord* heightStyleCoord = &(stylePos->mHeight);

  3900   bool isFlexItem = aFrame->IsFlexItem();

  3901   bool isHorizontalFlexItem = false;

  3903   if (isFlexItem) {

  3904     // Flex items use their "flex-basis" property in place of their main-size

  3905     // property (e.g. "width") for sizing purposes, *unless* they have

  3906     // "flex-basis:auto", in which case they use their main-size property after

  3907     // all.

  3908     uint32_t flexDirection =

  3909       aFrame->GetParent()->StylePosition()->mFlexDirection;

  3910     isHorizontalFlexItem =

  3911       flexDirection == NS_STYLE_FLEX_DIRECTION_ROW ||

  3912       flexDirection == NS_STYLE_FLEX_DIRECTION_ROW_REVERSE;

  3914     // NOTE: The logic here should match the similar chunk for determining

  3915     // widthStyleCoord and heightStyleCoord in nsFrame::ComputeSize().

  3916     const nsStyleCoord* flexBasis = &(stylePos->mFlexBasis);

  3917     if (flexBasis->GetUnit() != eStyleUnit_Auto) {

  3918       if (isHorizontalFlexItem) {

  3919         widthStyleCoord = flexBasis;

  3920       } else {

  3921         // One caveat for vertical flex items: We don't support enumerated

  3922         // values (e.g. "max-content") for height properties yet. So, if our

  3923         // computed flex-basis is an enumerated value, we'll just behave as if

  3924         // it were "auto", which means "use the main-size property after all"

  3925         // (which is "height", in this case).

  3926         // NOTE: Once we support intrinsic sizing keywords for "height",

  3927         // we should remove this check.

  3928         if (flexBasis->GetUnit() != eStyleUnit_Enumerated) {

  3929           heightStyleCoord = flexBasis;

  3930         }

  3931       }

  3932     }

  3933   }

  3935   // Handle intrinsic sizes and their interaction with

  3936   // {min-,max-,}{width,height} according to the rules in

  3937   // http://www.w3.org/TR/CSS21/visudet.html#min-max-widths

  3939   // Note: throughout the following section of the function, I avoid

  3940   // a * (b / c) because of its reduced accuracy relative to a * b / c

  3941   // or (a * b) / c (which are equivalent).

  3943   const bool isAutoWidth = widthStyleCoord->GetUnit() == eStyleUnit_Auto;

  3944   const bool isAutoHeight = IsAutoHeight(*heightStyleCoord, aCBSize.height);

  3946   nsSize boxSizingAdjust(0,0);

  3947   switch (stylePos->mBoxSizing) {

  3948     case NS_STYLE_BOX_SIZING_BORDER:

  3949       boxSizingAdjust += aBorder;

  3950       // fall through

  3951     case NS_STYLE_BOX_SIZING_PADDING:

  3952       boxSizingAdjust += aPadding;

  3953   }

  3954   nscoord boxSizingToMarginEdgeWidth =

  3955     aMargin.width + aBorder.width + aPadding.width - boxSizingAdjust.width;

  3957   nscoord width, minWidth, maxWidth, height, minHeight, maxHeight;

  3959   if (!isAutoWidth) {

  3960     width = nsLayoutUtils::ComputeWidthValue(aRenderingContext,

  3961               aFrame, aCBSize.width, boxSizingAdjust.width,

  3962               boxSizingToMarginEdgeWidth, *widthStyleCoord);

  3963   }

  3965   if (stylePos->mMaxWidth.GetUnit() != eStyleUnit_None &&

  3966       !(isFlexItem && isHorizontalFlexItem)) {

  3967     maxWidth = nsLayoutUtils::ComputeWidthValue(aRenderingContext,

  3968                  aFrame, aCBSize.width, boxSizingAdjust.width,

  3969                  boxSizingToMarginEdgeWidth, stylePos->mMaxWidth);

  3970   } else {

  3971     // NOTE: Flex items ignore their min & max sizing properties in their

  3972     // flex container's main-axis.  (Those properties get applied later in

  3973     // the flexbox algorithm.)

  3974     maxWidth = nscoord_MAX;

  3975   }

  3977   if (!(isFlexItem && isHorizontalFlexItem)) {

  3978     minWidth = nsLayoutUtils::ComputeWidthValue(aRenderingContext,

  3979                  aFrame, aCBSize.width, boxSizingAdjust.width,

  3980                  boxSizingToMarginEdgeWidth, stylePos->mMinWidth);

  3981   } else {

  3982     // NOTE: Flex items ignore their min & max sizing properties in their

  3983     // flex container's main-axis.  (Those properties get applied later in

  3984     // the flexbox algorithm.)

  3985     minWidth = 0;

  3986   }

  3988   if (!isAutoHeight) {

  3989     height = nsLayoutUtils::ComputeHeightValue(aCBSize.height,

  3990                 boxSizingAdjust.height,

  3991                 *heightStyleCoord);

  3992   }

  3994   if (!IsAutoHeight(stylePos->mMaxHeight, aCBSize.height) &&

  3995       !(isFlexItem && !isHorizontalFlexItem)) {

  3996     maxHeight = nsLayoutUtils::ComputeHeightValue(aCBSize.height,

  3997                   boxSizingAdjust.height,

  3998                   stylePos->mMaxHeight);

  3999   } else {

  4000     maxHeight = nscoord_MAX;

  4001   }

  4003   if (!IsAutoHeight(stylePos->mMinHeight, aCBSize.height) &&

  4004       !(isFlexItem && !isHorizontalFlexItem)) {

  4005     minHeight = nsLayoutUtils::ComputeHeightValue(aCBSize.height,

  4006                   boxSizingAdjust.height,

  4007                   stylePos->mMinHeight);

  4008   } else {

  4009     minHeight = 0;

  4010   }

  4012   // Resolve percentage intrinsic width/height as necessary:

  4014   NS_ASSERTION(aCBSize.width != NS_UNCONSTRAINEDSIZE,

  4015                "Our containing block must not have unconstrained width!");

  4017   bool hasIntrinsicWidth, hasIntrinsicHeight;

  4018   nscoord intrinsicWidth, intrinsicHeight;

  4020   if (aIntrinsicSize.width.GetUnit() == eStyleUnit_Coord) {

  4021     hasIntrinsicWidth = true;

  4022     intrinsicWidth = aIntrinsicSize.width.GetCoordValue();

  4023     if (intrinsicWidth < 0)

  4024       intrinsicWidth = 0;

  4025   } else {

  4026     NS_ASSERTION(aIntrinsicSize.width.GetUnit() == eStyleUnit_None,

  4027                  "unexpected unit");

  4028     hasIntrinsicWidth = false;

  4029     intrinsicWidth = 0;

  4030   }

  4032   if (aIntrinsicSize.height.GetUnit() == eStyleUnit_Coord) {

  4033     hasIntrinsicHeight = true;

  4034     intrinsicHeight = aIntrinsicSize.height.GetCoordValue();

  4035     if (intrinsicHeight < 0)

  4036       intrinsicHeight = 0;

  4037   } else {

  4038     NS_ASSERTION(aIntrinsicSize.height.GetUnit() == eStyleUnit_None,

  4039                  "unexpected unit");

  4040     hasIntrinsicHeight = false;

  4041     intrinsicHeight = 0;

  4042   }

  4044   NS_ASSERTION(aIntrinsicRatio.width >= 0 && aIntrinsicRatio.height >= 0,

  4045                "Intrinsic ratio has a negative component!");

  4047   // Now calculate the used values for width and height:

  4049   if (isAutoWidth) {

  4050     if (isAutoHeight) {

  4052       // 'auto' width, 'auto' height

  4054       // Get tentative values - CSS 2.1 sections 10.3.2 and 10.6.2:

  4056       nscoord tentWidth, tentHeight;

  4058       if (hasIntrinsicWidth) {

  4059         tentWidth = intrinsicWidth;

  4060       } else if (hasIntrinsicHeight && aIntrinsicRatio.height > 0) {

  4061         tentWidth = MULDIV(intrinsicHeight, aIntrinsicRatio.width, aIntrinsicRatio.height);

  4062       } else if (aIntrinsicRatio.width > 0) {

  4063         tentWidth = aCBSize.width - boxSizingToMarginEdgeWidth; // XXX scrollbar?

  4064         if (tentWidth < 0) tentWidth = 0;

  4065       } else {

  4066         tentWidth = nsPresContext::CSSPixelsToAppUnits(300);

  4067       }

  4069       if (hasIntrinsicHeight) {

  4070         tentHeight = intrinsicHeight;

  4071       } else if (aIntrinsicRatio.width > 0) {

  4072         tentHeight = MULDIV(tentWidth, aIntrinsicRatio.height, aIntrinsicRatio.width);

  4073       } else {

  4074         tentHeight = nsPresContext::CSSPixelsToAppUnits(150);

  4075       }

  4077       return ComputeAutoSizeWithIntrinsicDimensions(minWidth, minHeight,

  4078                                                     maxWidth, maxHeight,

  4079                                                     tentWidth, tentHeight);

  4080     } else {

  4082       // 'auto' width, non-'auto' height

  4083       height = NS_CSS_MINMAX(height, minHeight, maxHeight);

  4084       if (aIntrinsicRatio.height > 0) {

  4085         width = MULDIV(height, aIntrinsicRatio.width, aIntrinsicRatio.height);

  4086       } else if (hasIntrinsicWidth) {

  4087         width = intrinsicWidth;

  4088       } else {

  4089         width = nsPresContext::CSSPixelsToAppUnits(300);

  4090       }

  4091       width = NS_CSS_MINMAX(width, minWidth, maxWidth);

  4093     }

  4094   } else {

  4095     if (isAutoHeight) {

  4097       // non-'auto' width, 'auto' height

  4098       width = NS_CSS_MINMAX(width, minWidth, maxWidth);

  4099       if (aIntrinsicRatio.width > 0) {

  4100         height = MULDIV(width, aIntrinsicRatio.height, aIntrinsicRatio.width);

  4101       } else if (hasIntrinsicHeight) {

  4102         height = intrinsicHeight;

  4103       } else {

  4104         height = nsPresContext::CSSPixelsToAppUnits(150);

  4105       }

  4106       height = NS_CSS_MINMAX(height, minHeight, maxHeight);

  4108     } else {

  4110       // non-'auto' width, non-'auto' height

  4111       width = NS_CSS_MINMAX(width, minWidth, maxWidth);

  4112       height = NS_CSS_MINMAX(height, minHeight, maxHeight);

  4114     }

  4115   }

  4117   return nsSize(width, height);

  4118 }

  4120 nsSize

  4121 nsLayoutUtils::ComputeAutoSizeWithIntrinsicDimensions(nscoord minWidth, nscoord minHeight,

  4122                                                       nscoord maxWidth, nscoord maxHeight,

  4123                                                       nscoord tentWidth, nscoord tentHeight)

  4124 {

  4125   // Now apply min/max-width/height - CSS 2.1 sections 10.4 and 10.7:

  4127   if (minWidth > maxWidth)

  4128     maxWidth = minWidth;

  4129   if (minHeight > maxHeight)

  4130     maxHeight = minHeight;

  4132   nscoord heightAtMaxWidth, heightAtMinWidth,

  4133           widthAtMaxHeight, widthAtMinHeight;

  4135   if (tentWidth > 0) {

  4136     heightAtMaxWidth = MULDIV(maxWidth, tentHeight, tentWidth);

  4137     if (heightAtMaxWidth < minHeight)

  4138       heightAtMaxWidth = minHeight;

  4139     heightAtMinWidth = MULDIV(minWidth, tentHeight, tentWidth);

  4140     if (heightAtMinWidth > maxHeight)

  4141       heightAtMinWidth = maxHeight;

  4142   } else {

  4143     heightAtMaxWidth = heightAtMinWidth = NS_CSS_MINMAX(tentHeight, minHeight, maxHeight);

  4144   }

  4146   if (tentHeight > 0) {

  4147     widthAtMaxHeight = MULDIV(maxHeight, tentWidth, tentHeight);

  4148     if (widthAtMaxHeight < minWidth)

  4149       widthAtMaxHeight = minWidth;

  4150     widthAtMinHeight = MULDIV(minHeight, tentWidth, tentHeight);

  4151     if (widthAtMinHeight > maxWidth)

  4152       widthAtMinHeight = maxWidth;

  4153   } else {

  4154     widthAtMaxHeight = widthAtMinHeight = NS_CSS_MINMAX(tentWidth, minWidth, maxWidth);

  4155   }

  4157   // The table at http://www.w3.org/TR/CSS21/visudet.html#min-max-widths :

  4159   nscoord width, height;

  4161   if (tentWidth > maxWidth) {

  4162     if (tentHeight > maxHeight) {

  4163       if (int64_t(maxWidth) * int64_t(tentHeight) <=

  4164           int64_t(maxHeight) * int64_t(tentWidth)) {

  4165         width = maxWidth;

  4166         height = heightAtMaxWidth;

  4167       } else {

  4168         width = widthAtMaxHeight;

  4169         height = maxHeight;

  4170       }

  4171     } else {

  4172       // This also covers "(w > max-width) and (h < min-height)" since in

  4173       // that case (max-width/w < 1), and with (h < min-height):

  4174       //   max(max-width * h/w, min-height) == min-height

  4175       width = maxWidth;

  4176       height = heightAtMaxWidth;

  4177     }

  4178   } else if (tentWidth < minWidth) {

  4179     if (tentHeight < minHeight) {

  4180       if (int64_t(minWidth) * int64_t(tentHeight) <=

  4181           int64_t(minHeight) * int64_t(tentWidth)) {

  4182         width = widthAtMinHeight;

  4183         height = minHeight;

  4184       } else {

  4185         width = minWidth;

  4186         height = heightAtMinWidth;

  4187       }

  4188     } else {

  4189       // This also covers "(w < min-width) and (h > max-height)" since in

  4190       // that case (min-width/w > 1), and with (h > max-height):

  4191       //   min(min-width * h/w, max-height) == max-height

  4192       width = minWidth;

  4193       height = heightAtMinWidth;

  4194     }

  4195   } else {

  4196     if (tentHeight > maxHeight) {

  4197       width = widthAtMaxHeight;

  4198       height = maxHeight;

  4199     } else if (tentHeight < minHeight) {

  4200       width = widthAtMinHeight;

  4201       height = minHeight;

  4202     } else {

  4203       width = tentWidth;

  4204       height = tentHeight;

  4205     }

  4206   }

  4208   return nsSize(width, height);

  4209 }

  4211 /* static */ nscoord

  4212 nsLayoutUtils::MinWidthFromInline(nsIFrame* aFrame,

  4213                                   nsRenderingContext* aRenderingContext)

  4214 {

  4215   NS_ASSERTION(!aFrame->IsContainerForFontSizeInflation(),

  4216                "should not be container for font size inflation");

  4218   nsIFrame::InlineMinWidthData data;

  4219   DISPLAY_MIN_WIDTH(aFrame, data.prevLines);

  4220   aFrame->AddInlineMinWidth(aRenderingContext, &data);

  4221   data.ForceBreak(aRenderingContext);

  4222   return data.prevLines;

  4223 }

  4225 /* static */ nscoord

  4226 nsLayoutUtils::PrefWidthFromInline(nsIFrame* aFrame,

  4227                                    nsRenderingContext* aRenderingContext)

  4228 {

  4229   NS_ASSERTION(!aFrame->IsContainerForFontSizeInflation(),

  4230                "should not be container for font size inflation");

  4232   nsIFrame::InlinePrefWidthData data;

  4233   DISPLAY_PREF_WIDTH(aFrame, data.prevLines);

  4234   aFrame->AddInlinePrefWidth(aRenderingContext, &data);

  4235   data.ForceBreak(aRenderingContext);

  4236   return data.prevLines;

  4237 }

  4239 static nscolor

  4240 DarkenColor(nscolor aColor)

  4241 {

  4242   uint16_t  hue, sat, value;

  4243   uint8_t alpha;

  4245   // convert the RBG to HSV so we can get the lightness (which is the v)

  4246   NS_RGB2HSV(aColor, hue, sat, value, alpha);

  4248   // The goal here is to send white to black while letting colored

  4249   // stuff stay colored... So we adopt the following approach.

  4250   // Something with sat = 0 should end up with value = 0.  Something

  4251   // with a high sat can end up with a high value and it's ok.... At

  4252   // the same time, we don't want to make things lighter.  Do

  4253   // something simple, since it seems to work.

  4254   if (value > sat) {

  4255     value = sat;

  4256     // convert this color back into the RGB color space.

  4257     NS_HSV2RGB(aColor, hue, sat, value, alpha);

  4258   }

  4259   return aColor;

  4260 }

  4262 // Check whether we should darken text/decoration colors. We need to do this if

  4263 // background images and colors are being suppressed, because that means

  4264 // light text will not be visible against the (presumed light-colored) background.

  4265 static bool

  4266 ShouldDarkenColors(nsPresContext* aPresContext)

  4267 {

  4268   return !aPresContext->GetBackgroundColorDraw() &&

  4269          !aPresContext->GetBackgroundImageDraw();

  4270 }

  4272 nscolor

  4273 nsLayoutUtils::GetColor(nsIFrame* aFrame, nsCSSProperty aProperty)

  4274 {

  4275   if (aProperty == eCSSProperty_color)

  4276   {

  4277     nscolor nativeColor = NS_RGB(0, 0, 0);

  4278     if (GetNativeTextColor(aFrame, nativeColor))

  4279       return nativeColor;

  4280   }

  4282   nscolor color = aFrame->GetVisitedDependentColor(aProperty);

  4283   if (ShouldDarkenColors(aFrame->PresContext())) {

  4284     color = DarkenColor(color);

  4285   }

  4287   return color;

  4288 }

  4290 bool

  4291 nsLayoutUtils::GetNativeTextColor(nsIFrame* aFrame, nscolor& aColor)

  4292 {

  4293   nsPresContext *presContext = aFrame->PresContext();

  4294   if (!presContext->IsChrome()) {

  4295     // If native appearance was used to draw the background of the containing

  4296     // frame, return a contrasting native foreground color instead of the

  4297     // color from the element's style.  This avoids a problem where black

  4298     // text was displayed on a black background when a Windows theme such as

  4299     // "High Contrast Black" was used.  The background is drawn inside

  4300     // nsNativeThemeWin::ClassicDrawWidgetBackground().

  4301     //

  4302     // Because both the background color and this foreground color are used

  4303     // directly without exposing the colors via CSS computed styles, the

  4304     // native colors are not leaked to content.

  4305     nsIFrame* bgFrame =

  4306                     nsCSSRendering::FindNonTransparentBackgroundFrame(aFrame);

  4307     if (bgFrame) {

  4308       const nsStyleDisplay* displayData = bgFrame->StyleDisplay();

  4309       uint8_t widgetType = displayData->mAppearance;

  4310       nsITheme *theme = presContext->GetTheme();

  4311       if (theme && widgetType && theme->ThemeSupportsWidget(presContext,

  4312                                                             bgFrame,

  4313                                                             widgetType)) {

  4314         bool isDisabled = false;

  4315         nsIContent* frameContent = bgFrame->GetContent();

  4316         if (frameContent && frameContent->IsElement()) {

  4317           EventStates es = frameContent->AsElement()->State();

  4318           isDisabled = es.HasState(NS_EVENT_STATE_DISABLED);

  4319         }

  4321         if (NS_SUCCEEDED(LookAndFeel::GetColorForNativeAppearance(widgetType,

  4322                                                        isDisabled, &aColor))) {

  4323             return true;

  4324         }

  4325       }

  4326     }

  4327   }

  4329   return false;

  4330 }

  4332 gfxFloat

  4333 nsLayoutUtils::GetSnappedBaselineY(nsIFrame* aFrame, gfxContext* aContext,

  4334                                    nscoord aY, nscoord aAscent)

  4335 {

  4336   gfxFloat appUnitsPerDevUnit = aFrame->PresContext()->AppUnitsPerDevPixel();

  4337   gfxFloat baseline = gfxFloat(aY) + aAscent;

  4338   gfxRect putativeRect(0, baseline/appUnitsPerDevUnit, 1, 1);

  4339   if (!aContext->UserToDevicePixelSnapped(putativeRect, true))

  4340     return baseline;

  4341   return aContext->DeviceToUser(putativeRect.TopLeft()).y * appUnitsPerDevUnit;

  4342 }

  4344 void

  4345 nsLayoutUtils::DrawString(const nsIFrame*       aFrame,

  4346                           nsRenderingContext*   aContext,

  4347                           const char16_t*      aString,

  4348                           int32_t               aLength,

  4349                           nsPoint               aPoint,

  4350                           nsStyleContext*       aStyleContext)

  4351 {

  4352   nsresult rv = NS_ERROR_FAILURE;

  4353   nsPresContext* presContext = aFrame->PresContext();

  4354   if (presContext->BidiEnabled()) {

  4355     nsBidiLevel level =

  4356       nsBidiPresUtils::BidiLevelFromStyle(aStyleContext ?

  4357                                           aStyleContext : aFrame->StyleContext());

  4358     rv = nsBidiPresUtils::RenderText(aString, aLength, level,

  4359                                      presContext, *aContext, *aContext,

  4360                                      aPoint.x, aPoint.y);

  4361   }

  4362   if (NS_FAILED(rv))

  4363   {

  4364     aContext->SetTextRunRTL(false);

  4365     aContext->DrawString(aString, aLength, aPoint.x, aPoint.y);

  4366   }

  4367 }

  4369 nscoord

  4370 nsLayoutUtils::GetStringWidth(const nsIFrame*      aFrame,

  4371                               nsRenderingContext* aContext,

  4372                               const char16_t*     aString,

  4373                               int32_t              aLength)

  4374 {

  4375   nsPresContext* presContext = aFrame->PresContext();

  4376   if (presContext->BidiEnabled()) {

  4377     nsBidiLevel level =

  4378       nsBidiPresUtils::BidiLevelFromStyle(aFrame->StyleContext());

  4379     return nsBidiPresUtils::MeasureTextWidth(aString, aLength,

  4380                                              level, presContext, *aContext);

  4381   }

  4382   aContext->SetTextRunRTL(false);

  4383   return aContext->GetWidth(aString, aLength);

  4384 }

  4386 /* static */ void

  4387 nsLayoutUtils::PaintTextShadow(const nsIFrame* aFrame,

  4388                                nsRenderingContext* aContext,

  4389                                const nsRect& aTextRect,

  4390                                const nsRect& aDirtyRect,

  4391                                const nscolor& aForegroundColor,

  4392                                TextShadowCallback aCallback,

  4393                                void* aCallbackData)

  4394 {

  4395   const nsStyleText* textStyle = aFrame->StyleText();

  4396   if (!textStyle->HasTextShadow())

  4397     return;

  4399   // Text shadow happens with the last value being painted at the back,

  4400   // ie. it is painted first.

  4401   gfxContext* aDestCtx = aContext->ThebesContext();

  4402   for (uint32_t i = textStyle->mTextShadow->Length(); i > 0; --i) {

  4403     nsCSSShadowItem* shadowDetails = textStyle->mTextShadow->ShadowAt(i - 1);

  4404     nsPoint shadowOffset(shadowDetails->mXOffset,

  4405                          shadowDetails->mYOffset);

  4406     nscoord blurRadius = std::max(shadowDetails->mRadius, 0);

  4408     nsRect shadowRect(aTextRect);

  4409     shadowRect.MoveBy(shadowOffset);

  4411     nsPresContext* presCtx = aFrame->PresContext();

  4412     nsContextBoxBlur contextBoxBlur;

  4413     gfxContext* shadowContext = contextBoxBlur.Init(shadowRect, 0, blurRadius,

  4414                                                     presCtx->AppUnitsPerDevPixel(),

  4415                                                     aDestCtx, aDirtyRect, nullptr);

  4416     if (!shadowContext)

  4417       continue;

  4419     nscolor shadowColor;

  4420     if (shadowDetails->mHasColor)

  4421       shadowColor = shadowDetails->mColor;

  4422     else

  4423       shadowColor = aForegroundColor;

  4425     // Conjure an nsRenderingContext from a gfxContext for drawing the text

  4426     // to blur.

  4427     nsRefPtr<nsRenderingContext> renderingContext = new nsRenderingContext();

  4428     renderingContext->Init(presCtx->DeviceContext(), shadowContext);

  4430     aDestCtx->Save();

  4431     aDestCtx->NewPath();

  4432     aDestCtx->SetColor(gfxRGBA(shadowColor));

  4434     // The callback will draw whatever we want to blur as a shadow.

  4435     aCallback(renderingContext, shadowOffset, shadowColor, aCallbackData);

  4437     contextBoxBlur.DoPaint();

  4438     aDestCtx->Restore();

  4439   }

  4440 }

  4442 /* static */ nscoord

  4443 nsLayoutUtils::GetCenteredFontBaseline(nsFontMetrics* aFontMetrics,

  4444                                        nscoord         aLineHeight)

  4445 {

  4446   nscoord fontAscent = aFontMetrics->MaxAscent();

  4447   nscoord fontHeight = aFontMetrics->MaxHeight();

  4449   nscoord leading = aLineHeight - fontHeight;

  4450   return fontAscent + leading/2;

  4451 }

  4454 /* static */ bool

  4455 nsLayoutUtils::GetFirstLineBaseline(const nsIFrame* aFrame, nscoord* aResult)

  4456 {

  4457   LinePosition position;

  4458   if (!GetFirstLinePosition(aFrame, &position))

  4459     return false;

  4460   *aResult = position.mBaseline;

  4461   return true;

  4462 }

  4464 /* static */ bool

  4465 nsLayoutUtils::GetFirstLinePosition(const nsIFrame* aFrame,

  4466                                     LinePosition* aResult)

  4467 {

  4468   const nsBlockFrame* block = nsLayoutUtils::GetAsBlock(const_cast<nsIFrame*>(aFrame));

  4469   if (!block) {

  4470     // For the first-line baseline we also have to check for a table, and if

  4471     // so, use the baseline of its first row.

  4472     nsIAtom* fType = aFrame->GetType();

  4473     if (fType == nsGkAtoms::tableOuterFrame) {

  4474       aResult->mTop = 0;

  4475       aResult->mBaseline = aFrame->GetBaseline();

  4476       // This is what we want for the list bullet caller; not sure if

  4477       // other future callers will want the same.

  4478       aResult->mBottom = aFrame->GetSize().height;

  4479       return true;

  4480     }

  4482     // For first-line baselines, we have to consider scroll frames.

  4483     if (fType == nsGkAtoms::scrollFrame) {

  4484       nsIScrollableFrame *sFrame = do_QueryFrame(const_cast<nsIFrame*>(aFrame));

  4485       if (!sFrame) {

  4486         NS_NOTREACHED("not scroll frame");

  4487       }

  4488       LinePosition kidPosition;

  4489       if (GetFirstLinePosition(sFrame->GetScrolledFrame(), &kidPosition)) {

  4490         // Consider only the border and padding that contributes to the

  4491         // kid's position, not the scrolling, so we get the initial

  4492         // position.

  4493         *aResult = kidPosition + aFrame->GetUsedBorderAndPadding().top;

  4494         return true;

  4495       }

  4496       return false;

  4497     }

  4499     if (fType == nsGkAtoms::fieldSetFrame) {

  4500       LinePosition kidPosition;

  4501       nsIFrame* kid = aFrame->GetFirstPrincipalChild();

  4502       // kid might be a legend frame here, but that's ok.

  4503       if (GetFirstLinePosition(kid, &kidPosition)) {

  4504         *aResult = kidPosition + kid->GetNormalPosition().y;

  4505         return true;

  4506       }

  4507       return false;

  4508     }

  4510     // No baseline.

  4511     return false;

  4512   }

  4514   for (nsBlockFrame::const_line_iterator line = block->begin_lines(),

  4515                                      line_end = block->end_lines();

  4516        line != line_end; ++line) {

  4517     if (line->IsBlock()) {

  4518       nsIFrame *kid = line->mFirstChild;

  4519       LinePosition kidPosition;

  4520       if (GetFirstLinePosition(kid, &kidPosition)) {

  4521         *aResult = kidPosition + kid->GetNormalPosition().y;

  4522         return true;

  4523       }

  4524     } else {

  4525       // XXX Is this the right test?  We have some bogus empty lines

  4526       // floating around, but IsEmpty is perhaps too weak.

  4527       if (line->BSize() != 0 || !line->IsEmpty()) {

  4528         nscoord top = line->BStart();

  4529         aResult->mTop = top;

  4530         aResult->mBaseline = top + line->GetAscent();

  4531         aResult->mBottom = top + line->BSize();

  4532         return true;

  4533       }

  4534     }

  4535   }

  4536   return false;

  4537 }

  4539 /* static */ bool

  4540 nsLayoutUtils::GetLastLineBaseline(const nsIFrame* aFrame, nscoord* aResult)

  4541 {

  4542   const nsBlockFrame* block = nsLayoutUtils::GetAsBlock(const_cast<nsIFrame*>(aFrame));

  4543   if (!block)

  4544     // No baseline.  (We intentionally don't descend into scroll frames.)

  4545     return false;

  4547   for (nsBlockFrame::const_reverse_line_iterator line = block->rbegin_lines(),

  4548                                              line_end = block->rend_lines();

  4549        line != line_end; ++line) {

  4550     if (line->IsBlock()) {

  4551       nsIFrame *kid = line->mFirstChild;

  4552       nscoord kidBaseline;

  4553       if (GetLastLineBaseline(kid, &kidBaseline)) {

  4554         // Ignore relative positioning for baseline calculations

  4555         *aResult = kidBaseline + kid->GetNormalPosition().y;

  4556         return true;

  4557       } else if (kid->GetType() == nsGkAtoms::scrollFrame) {

  4558         // Use the bottom of the scroll frame.

  4559         // XXX CSS2.1 really doesn't say what to do here.

  4560         *aResult = kid->GetNormalPosition().y + kid->GetRect().height;

  4561         return true;

  4562       }

  4563     } else {

  4564       // XXX Is this the right test?  We have some bogus empty lines

  4565       // floating around, but IsEmpty is perhaps too weak.

  4566       if (line->BSize() != 0 || !line->IsEmpty()) {

  4567         *aResult = line->BStart() + line->GetAscent();

  4568         return true;

  4569       }

  4570     }

  4571   }

  4572   return false;

  4573 }

  4575 static nscoord

  4576 CalculateBlockContentBottom(nsBlockFrame* aFrame)

  4577 {

  4578   NS_PRECONDITION(aFrame, "null ptr");

  4580   nscoord contentBottom = 0;

  4582   for (nsBlockFrame::line_iterator line = aFrame->begin_lines(),

  4583                                    line_end = aFrame->end_lines();

  4584        line != line_end; ++line) {

  4585     if (line->IsBlock()) {

  4586       nsIFrame* child = line->mFirstChild;

  4587       nscoord offset = child->GetNormalPosition().y;

  4588       contentBottom = std::max(contentBottom,

  4589                         nsLayoutUtils::CalculateContentBottom(child) + offset);

  4590     }

  4591     else {

  4592       contentBottom = std::max(contentBottom, line->BEnd());

  4593     }

  4594   }

  4595   return contentBottom;

  4596 }

  4598 /* static */ nscoord

  4599 nsLayoutUtils::CalculateContentBottom(nsIFrame* aFrame)

  4600 {

  4601   NS_PRECONDITION(aFrame, "null ptr");

  4603   nscoord contentBottom = aFrame->GetRect().height;

  4605   // We want scrollable overflow rather than visual because this

  4606   // calculation is intended to affect layout.

  4607   if (aFrame->GetScrollableOverflowRect().height > contentBottom) {

  4608     nsIFrame::ChildListIDs skip(nsIFrame::kOverflowList |

  4609                                 nsIFrame::kExcessOverflowContainersList |

  4610                                 nsIFrame::kOverflowOutOfFlowList);

  4611     nsBlockFrame* blockFrame = GetAsBlock(aFrame);

  4612     if (blockFrame) {

  4613       contentBottom =

  4614         std::max(contentBottom, CalculateBlockContentBottom(blockFrame));

  4615       skip |= nsIFrame::kPrincipalList;

  4616     }

  4617     nsIFrame::ChildListIterator lists(aFrame);

  4618     for (; !lists.IsDone(); lists.Next()) {

  4619       if (!skip.Contains(lists.CurrentID())) {

  4620         nsFrameList::Enumerator childFrames(lists.CurrentList());

  4621         for (; !childFrames.AtEnd(); childFrames.Next()) {

  4622           nsIFrame* child = childFrames.get();

  4623           nscoord offset = child->GetNormalPosition().y;

  4624           contentBottom = std::max(contentBottom,

  4625                                  CalculateContentBottom(child) + offset);

  4626         }

  4627       }

  4628     }

  4629   }

  4630   return contentBottom;

  4631 }

  4633 /* static */ nsIFrame*

  4634 nsLayoutUtils::GetClosestLayer(nsIFrame* aFrame)

  4635 {

  4636   nsIFrame* layer;

  4637   for (layer = aFrame; layer; layer = layer->GetParent()) {

  4638     if (layer->IsPositioned() ||

  4639         (layer->GetParent() &&

  4640           layer->GetParent()->GetType() == nsGkAtoms::scrollFrame))

  4641       break;

  4642   }

  4643   if (layer)

  4644     return layer;

  4645   return aFrame->PresContext()->PresShell()->FrameManager()->GetRootFrame();

  4646 }

  4648 GraphicsFilter

  4649 nsLayoutUtils::GetGraphicsFilterForFrame(nsIFrame* aForFrame)

  4650 {

  4651   GraphicsFilter defaultFilter = GraphicsFilter::FILTER_GOOD;

  4652   nsStyleContext *sc;

  4653   if (nsCSSRendering::IsCanvasFrame(aForFrame)) {

  4654     nsCSSRendering::FindBackground(aForFrame, &sc);

  4655   } else {

  4656     sc = aForFrame->StyleContext();

  4657   }

  4659   switch (sc->StyleSVG()->mImageRendering) {

  4660   case NS_STYLE_IMAGE_RENDERING_OPTIMIZESPEED:

  4661     return GraphicsFilter::FILTER_FAST;

  4662   case NS_STYLE_IMAGE_RENDERING_OPTIMIZEQUALITY:

  4663     return GraphicsFilter::FILTER_BEST;

  4664   case NS_STYLE_IMAGE_RENDERING_CRISPEDGES:

  4665     return GraphicsFilter::FILTER_NEAREST;

  4666   default:

  4667     return defaultFilter;

  4668   }

  4669 }

  4671 /**

  4672  * Given an image being drawn into an appunit coordinate system, and

  4673  * a point in that coordinate system, map the point back into image

  4674  * pixel space.

  4675  * @param aSize the size of the image, in pixels

  4676  * @param aDest the rectangle that the image is being mapped into

  4677  * @param aPt a point in the same coordinate system as the rectangle

  4678  */

  4679 static gfxPoint

  4680 MapToFloatImagePixels(const gfxSize& aSize,

  4681                       const gfxRect& aDest, const gfxPoint& aPt)

  4682 {

  4683   return gfxPoint(((aPt.x - aDest.X())*aSize.width)/aDest.Width(),

  4684                   ((aPt.y - aDest.Y())*aSize.height)/aDest.Height());

  4685 }

  4687 /**

  4688  * Given an image being drawn into an pixel-based coordinate system, and

  4689  * a point in image space, map the point into the pixel-based coordinate

  4690  * system.

  4691  * @param aSize the size of the image, in pixels

  4692  * @param aDest the rectangle that the image is being mapped into

  4693  * @param aPt a point in image space

  4694  */

  4695 static gfxPoint

  4696 MapToFloatUserPixels(const gfxSize& aSize,

  4697                      const gfxRect& aDest, const gfxPoint& aPt)

  4698 {

  4699   return gfxPoint(aPt.x*aDest.Width()/aSize.width + aDest.X(),

  4700                   aPt.y*aDest.Height()/aSize.height + aDest.Y());

  4701 }

  4703 /* static */ gfxRect

  4704 nsLayoutUtils::RectToGfxRect(const nsRect& aRect, int32_t aAppUnitsPerDevPixel)

  4705 {

  4706   return gfxRect(gfxFloat(aRect.x) / aAppUnitsPerDevPixel,

  4707                  gfxFloat(aRect.y) / aAppUnitsPerDevPixel,

  4708                  gfxFloat(aRect.width) / aAppUnitsPerDevPixel,

  4709                  gfxFloat(aRect.height) / aAppUnitsPerDevPixel);

  4710 }

  4712 struct SnappedImageDrawingParameters {

  4713   // A transform from either device space or user space (depending on mResetCTM)

  4714   // to image space

  4715   gfxMatrix mUserSpaceToImageSpace;

  4716   // A device-space, pixel-aligned rectangle to fill

  4717   gfxRect mFillRect;

  4718   // A pixel rectangle in tiled image space outside of which gfx should not

  4719   // sample (using EXTEND_PAD as necessary)

  4720   nsIntRect mSubimage;

  4721   // Whether there's anything to draw at all

  4722   bool mShouldDraw;

  4723   // true iff the CTM of the rendering context needs to be reset to the

  4724   // identity matrix before drawing

  4725   bool mResetCTM;

  4727   SnappedImageDrawingParameters()

  4728    : mShouldDraw(false)

  4729    , mResetCTM(false)

  4730   {}

  4732   SnappedImageDrawingParameters(const gfxMatrix& aUserSpaceToImageSpace,

  4733                                 const gfxRect&   aFillRect,

  4734                                 const nsIntRect& aSubimage,

  4735                                 bool             aResetCTM)

  4736    : mUserSpaceToImageSpace(aUserSpaceToImageSpace)

  4737    , mFillRect(aFillRect)

  4738    , mSubimage(aSubimage)

  4739    , mShouldDraw(true)

  4740    , mResetCTM(aResetCTM)

  4741   {}

  4742 };

  4744 /**

  4745  * Given a set of input parameters, compute certain output parameters

  4746  * for drawing an image with the image snapping algorithm.

  4747  * See https://wiki.mozilla.org/Gecko:Image_Snapping_and_Rendering

  4748  *

  4749  *  @see nsLayoutUtils::DrawImage() for the descriptions of input parameters

  4750  */

  4751 static SnappedImageDrawingParameters

  4752 ComputeSnappedImageDrawingParameters(gfxContext*     aCtx,

  4753                                      int32_t         aAppUnitsPerDevPixel,

  4754                                      const nsRect    aDest,

  4755                                      const nsRect    aFill,

  4756                                      const nsPoint   aAnchor,

  4757                                      const nsRect    aDirty,

  4758                                      const nsIntSize aImageSize)

  4760 {

  4761   if (aDest.IsEmpty() || aFill.IsEmpty() || !aImageSize.width || !aImageSize.height)

  4762     return SnappedImageDrawingParameters();

  4764   gfxRect devPixelDest =

  4765     nsLayoutUtils::RectToGfxRect(aDest, aAppUnitsPerDevPixel);

  4766   gfxRect devPixelFill =

  4767     nsLayoutUtils::RectToGfxRect(aFill, aAppUnitsPerDevPixel);

  4768   gfxRect devPixelDirty =

  4769     nsLayoutUtils::RectToGfxRect(aDirty, aAppUnitsPerDevPixel);

  4771   gfxMatrix currentMatrix = aCtx->CurrentMatrix();

  4772   gfxRect fill = devPixelFill;

  4773   bool didSnap;

  4774   // Snap even if we have a scale in the context. But don't snap if

  4775   // we have something that's not translation+scale, or if the scale flips in

  4776   // the X or Y direction, because snapped image drawing can't handle that yet.

  4777   if (!currentMatrix.HasNonAxisAlignedTransform() &&

  4778       currentMatrix.xx > 0.0 && currentMatrix.yy > 0.0 &&

  4779       aCtx->UserToDevicePixelSnapped(fill, true)) {

  4780     didSnap = true;

  4781     if (fill.IsEmpty()) {

  4782       return SnappedImageDrawingParameters();

  4783     }

  4784   } else {

  4785     didSnap = false;

  4786     fill = devPixelFill;

  4787   }

  4789   gfxSize imageSize(aImageSize.width, aImageSize.height);

  4791   // Compute the set of pixels that would be sampled by an ideal rendering

  4792   gfxPoint subimageTopLeft =

  4793     MapToFloatImagePixels(imageSize, devPixelDest, devPixelFill.TopLeft());

  4794   gfxPoint subimageBottomRight =

  4795     MapToFloatImagePixels(imageSize, devPixelDest, devPixelFill.BottomRight());

  4796   nsIntRect intSubimage;

  4797   intSubimage.MoveTo(NSToIntFloor(subimageTopLeft.x),

  4798                      NSToIntFloor(subimageTopLeft.y));

  4799   intSubimage.SizeTo(NSToIntCeil(subimageBottomRight.x) - intSubimage.x,

  4800                      NSToIntCeil(subimageBottomRight.y) - intSubimage.y);

  4802   // Compute the anchor point and compute final fill rect.

  4803   // This code assumes that pixel-based devices have one pixel per

  4804   // device unit!

  4805   gfxPoint anchorPoint(gfxFloat(aAnchor.x)/aAppUnitsPerDevPixel,

  4806                        gfxFloat(aAnchor.y)/aAppUnitsPerDevPixel);

  4807   gfxPoint imageSpaceAnchorPoint =

  4808     MapToFloatImagePixels(imageSize, devPixelDest, anchorPoint);

  4810   if (didSnap) {

  4811     imageSpaceAnchorPoint.Round();

  4812     anchorPoint = imageSpaceAnchorPoint;

  4813     anchorPoint = MapToFloatUserPixels(imageSize, devPixelDest, anchorPoint);

  4814     anchorPoint = currentMatrix.Transform(anchorPoint);

  4815     anchorPoint.Round();

  4817     // This form of Transform is safe to call since non-axis-aligned

  4818     // transforms wouldn't be snapped.

  4819     devPixelDirty = currentMatrix.Transform(devPixelDirty);

  4820   }

  4822   gfxFloat scaleX = imageSize.width*aAppUnitsPerDevPixel/aDest.width;

  4823   gfxFloat scaleY = imageSize.height*aAppUnitsPerDevPixel/aDest.height;

  4824   if (didSnap) {

  4825     // We'll reset aCTX to the identity matrix before drawing, so we need to

  4826     // adjust our scales to match.

  4827     scaleX /= currentMatrix.xx;

  4828     scaleY /= currentMatrix.yy;

  4829   }

  4830   gfxFloat translateX = imageSpaceAnchorPoint.x - anchorPoint.x*scaleX;

  4831   gfxFloat translateY = imageSpaceAnchorPoint.y - anchorPoint.y*scaleY;

  4832   gfxMatrix transform(scaleX, 0, 0, scaleY, translateX, translateY);

  4834   gfxRect finalFillRect = fill;

  4835   // If the user-space-to-image-space transform is not a straight

  4836   // translation by integers, then filtering will occur, and

  4837   // restricting the fill rect to the dirty rect would change the values

  4838   // computed for edge pixels, which we can't allow.

  4839   // Also, if didSnap is false then rounding out 'devPixelDirty' might not

  4840   // produce pixel-aligned coordinates, which would also break the values

  4841   // computed for edge pixels.

  4842   if (didSnap && !transform.HasNonIntegerTranslation()) {

  4843     devPixelDirty.RoundOut();

  4844     finalFillRect = fill.Intersect(devPixelDirty);

  4845   }

  4846   if (finalFillRect.IsEmpty())

  4847     return SnappedImageDrawingParameters();

  4849   return SnappedImageDrawingParameters(transform, finalFillRect, intSubimage,

  4850                                        didSnap);

  4851 }

  4854 static nsresult

  4855 DrawImageInternal(nsRenderingContext*    aRenderingContext,

  4856                   imgIContainer*         aImage,

  4857                   GraphicsFilter         aGraphicsFilter,

  4858                   const nsRect&          aDest,

  4859                   const nsRect&          aFill,

  4860                   const nsPoint&         aAnchor,

  4861                   const nsRect&          aDirty,

  4862                   const nsIntSize&       aImageSize,

  4863                   const SVGImageContext* aSVGContext,

  4864                   uint32_t               aImageFlags)

  4865 {

  4866   if (aDest.Contains(aFill)) {

  4867     aImageFlags |= imgIContainer::FLAG_CLAMP;

  4868   }

  4869   int32_t appUnitsPerDevPixel = aRenderingContext->AppUnitsPerDevPixel();

  4870   gfxContext* ctx = aRenderingContext->ThebesContext();

  4872   SnappedImageDrawingParameters drawingParams =

  4873     ComputeSnappedImageDrawingParameters(ctx, appUnitsPerDevPixel, aDest, aFill,

  4874                                          aAnchor, aDirty, aImageSize);

  4876   if (!drawingParams.mShouldDraw)

  4877     return NS_OK;

  4879   gfxContextMatrixAutoSaveRestore saveMatrix(ctx);

  4880   if (drawingParams.mResetCTM) {

  4881     ctx->IdentityMatrix();

  4882   }

  4884   aImage->Draw(ctx, aGraphicsFilter, drawingParams.mUserSpaceToImageSpace,

  4885                drawingParams.mFillRect, drawingParams.mSubimage, aImageSize,

  4886                aSVGContext, imgIContainer::FRAME_CURRENT, aImageFlags);

  4887   return NS_OK;

  4888 }

  4890 /* static */ void

  4891 nsLayoutUtils::DrawPixelSnapped(nsRenderingContext* aRenderingContext,

  4892                                 gfxDrawable*         aDrawable,

  4893                                 GraphicsFilter       aFilter,

  4894                                 const nsRect&        aDest,

  4895                                 const nsRect&        aFill,

  4896                                 const nsPoint&       aAnchor,

  4897                                 const nsRect&        aDirty)

  4898 {

  4899   int32_t appUnitsPerDevPixel = aRenderingContext->AppUnitsPerDevPixel();

  4900   gfxContext* ctx = aRenderingContext->ThebesContext();

  4901   gfxIntSize drawableSize = aDrawable->Size();

  4902   nsIntSize imageSize(drawableSize.width, drawableSize.height);

  4904   SnappedImageDrawingParameters drawingParams =

  4905     ComputeSnappedImageDrawingParameters(ctx, appUnitsPerDevPixel, aDest, aFill,

  4906                                          aAnchor, aDirty, imageSize);

  4908   if (!drawingParams.mShouldDraw)

  4909     return;

  4911   gfxContextMatrixAutoSaveRestore saveMatrix(ctx);

  4912   if (drawingParams.mResetCTM) {

  4913     ctx->IdentityMatrix();

  4914   }

  4916   gfxRect sourceRect =

  4917     drawingParams.mUserSpaceToImageSpace.Transform(drawingParams.mFillRect);

  4918   gfxRect imageRect(0, 0, imageSize.width, imageSize.height);

  4919   gfxRect subimage(drawingParams.mSubimage.x, drawingParams.mSubimage.y,

  4920                    drawingParams.mSubimage.width, drawingParams.mSubimage.height);

  4922   NS_ASSERTION(!sourceRect.Intersect(subimage).IsEmpty(),

  4923                "We must be allowed to sample *some* source pixels!");

  4925   gfxUtils::DrawPixelSnapped(ctx, aDrawable,

  4926                              drawingParams.mUserSpaceToImageSpace, subimage,

  4927                              sourceRect, imageRect, drawingParams.mFillRect,

  4928                              gfxImageFormat::ARGB32, aFilter);

  4929 }

  4931 /* static */ nsresult

  4932 nsLayoutUtils::DrawSingleUnscaledImage(nsRenderingContext* aRenderingContext,

  4933                                        imgIContainer*       aImage,

  4934                                        GraphicsFilter       aGraphicsFilter,

  4935                                        const nsPoint&       aDest,

  4936                                        const nsRect*        aDirty,

  4937                                        uint32_t             aImageFlags,

  4938                                        const nsRect*        aSourceArea)

  4939 {

  4940   nsIntSize imageSize;

  4941   aImage->GetWidth(&imageSize.width);

  4942   aImage->GetHeight(&imageSize.height);

  4943   NS_ENSURE_TRUE(imageSize.width > 0 && imageSize.height > 0, NS_ERROR_FAILURE);

  4945   nscoord appUnitsPerCSSPixel = nsDeviceContext::AppUnitsPerCSSPixel();

  4946   nsSize size(imageSize.width*appUnitsPerCSSPixel,

  4947               imageSize.height*appUnitsPerCSSPixel);

  4949   nsRect source;

  4950   if (aSourceArea) {

  4951     source = *aSourceArea;

  4952   } else {

  4953     source.SizeTo(size);

  4954   }

  4956   nsRect dest(aDest - source.TopLeft(), size);

  4957   nsRect fill(aDest, source.Size());

  4958   // Ensure that only a single image tile is drawn. If aSourceArea extends

  4959   // outside the image bounds, we want to honor the aSourceArea-to-aDest

  4960   // translation but we don't want to actually tile the image.

  4961   fill.IntersectRect(fill, dest);

  4962   return DrawImageInternal(aRenderingContext, aImage, aGraphicsFilter,

  4963                            dest, fill, aDest, aDirty ? *aDirty : dest,

  4964                            imageSize, nullptr, aImageFlags);

  4965 }

  4967 /* static */ nsresult

  4968 nsLayoutUtils::DrawSingleImage(nsRenderingContext*    aRenderingContext,

  4969                                imgIContainer*         aImage,

  4970                                GraphicsFilter         aGraphicsFilter,

  4971                                const nsRect&          aDest,

  4972                                const nsRect&          aDirty,

  4973                                const SVGImageContext* aSVGContext,

  4974                                uint32_t               aImageFlags,

  4975                                const nsRect*          aSourceArea)

  4976 {

  4977   nsIntSize imageSize;

  4978   if (aImage->GetType() == imgIContainer::TYPE_VECTOR) {

  4979     // We choose a size for vector images that emulates a raster image which

  4980     // is perfectly sized for the destination rect: each pixel in the image

  4981     // maps exactly to a single pixel on-screen.

  4982     nscoord appUnitsPerDevPx = aRenderingContext->AppUnitsPerDevPixel();

  4983     imageSize.width = NSAppUnitsToIntPixels(aDest.width, appUnitsPerDevPx);

  4984     imageSize.height = NSAppUnitsToIntPixels(aDest.height, appUnitsPerDevPx);

  4985   } else {

  4986     // Raster images have an intrinsic size, so we just use that.

  4987     aImage->GetWidth(&imageSize.width);

  4988     aImage->GetHeight(&imageSize.height);

  4989   }

  4990   NS_ENSURE_TRUE(imageSize.width > 0 && imageSize.height > 0, NS_ERROR_FAILURE);

  4992   nsRect source;

  4993   if (aSourceArea) {

  4994     source = *aSourceArea;

  4995   } else {

  4996     nscoord appUnitsPerCSSPixel = nsDeviceContext::AppUnitsPerCSSPixel();

  4997     source.SizeTo(imageSize.width*appUnitsPerCSSPixel,

  4998                   imageSize.height*appUnitsPerCSSPixel);

  4999   }

  5001   nsRect dest = nsLayoutUtils::GetWholeImageDestination(imageSize, source,

  5002                                                         aDest);

  5003   // Ensure that only a single image tile is drawn. If aSourceArea extends

  5004   // outside the image bounds, we want to honor the aSourceArea-to-aDest

  5005   // transform but we don't want to actually tile the image.

  5006   nsRect fill;

  5007   fill.IntersectRect(aDest, dest);

  5008   return DrawImageInternal(aRenderingContext, aImage, aGraphicsFilter, dest, fill,

  5009                            fill.TopLeft(), aDirty, imageSize, aSVGContext, aImageFlags);

  5010 }

  5012 /* static */ void

  5013 nsLayoutUtils::ComputeSizeForDrawing(imgIContainer *aImage,

  5014                                      nsIntSize&     aImageSize, /*outparam*/

  5015                                      nsSize&        aIntrinsicRatio, /*outparam*/

  5016                                      bool&          aGotWidth,  /*outparam*/

  5017                                      bool&          aGotHeight  /*outparam*/)

  5018 {

  5019   aGotWidth  = NS_SUCCEEDED(aImage->GetWidth(&aImageSize.width));

  5020   aGotHeight = NS_SUCCEEDED(aImage->GetHeight(&aImageSize.height));

  5021   bool gotRatio = NS_SUCCEEDED(aImage->GetIntrinsicRatio(&aIntrinsicRatio));

  5023   if (!(aGotWidth && aGotHeight) && !gotRatio) {

  5024     // We hit an error (say, because the image failed to load or couldn't be

  5025     // decoded) and should return zero size.

  5026     aGotWidth = aGotHeight = true;

  5027     aImageSize = nsIntSize(0, 0);

  5028     aIntrinsicRatio = nsSize(0, 0);

  5029   }

  5030 }

  5033 /* static */ nsresult

  5034 nsLayoutUtils::DrawBackgroundImage(nsRenderingContext* aRenderingContext,

  5035                                    imgIContainer*      aImage,

  5036                                    const nsIntSize&    aImageSize,

  5037                                    GraphicsFilter      aGraphicsFilter,

  5038                                    const nsRect&       aDest,

  5039                                    const nsRect&       aFill,

  5040                                    const nsPoint&      aAnchor,

  5041                                    const nsRect&       aDirty,

  5042                                    uint32_t            aImageFlags)

  5043 {

  5044   PROFILER_LABEL("layout", "nsLayoutUtils::DrawBackgroundImage");

  5046   if (UseBackgroundNearestFiltering()) {

  5047     aGraphicsFilter = GraphicsFilter::FILTER_NEAREST;

  5048   }

  5050   return DrawImageInternal(aRenderingContext, aImage, aGraphicsFilter,

  5051                            aDest, aFill, aAnchor, aDirty,

  5052                            aImageSize, nullptr, aImageFlags);

  5053 }

  5055 /* static */ nsresult

  5056 nsLayoutUtils::DrawImage(nsRenderingContext* aRenderingContext,

  5057                          imgIContainer*       aImage,

  5058                          GraphicsFilter       aGraphicsFilter,

  5059                          const nsRect&        aDest,

  5060                          const nsRect&        aFill,

  5061                          const nsPoint&       aAnchor,

  5062                          const nsRect&        aDirty,

  5063                          uint32_t             aImageFlags)

  5064 {

  5065   nsIntSize imageSize;

  5066   nsSize imageRatio;

  5067   bool gotHeight, gotWidth;

  5068   ComputeSizeForDrawing(aImage, imageSize, imageRatio, gotWidth, gotHeight);

  5070   // XXX Dimensionless images shouldn't fall back to filled-area size -- the

  5071   //     caller should provide the image size, a la DrawBackgroundImage.

  5072   if (gotWidth != gotHeight) {

  5073     if (!gotWidth) {

  5074       if (imageRatio.height != 0) {

  5075         imageSize.width =

  5076           NSCoordSaturatingNonnegativeMultiply(imageSize.height,

  5077                                                float(imageRatio.width) /

  5078                                                float(imageRatio.height));

  5079         gotWidth = true;

  5080       }

  5081     } else {

  5082       if (imageRatio.width != 0) {

  5083         imageSize.height =

  5084           NSCoordSaturatingNonnegativeMultiply(imageSize.width,

  5085                                                float(imageRatio.height) /

  5086                                                float(imageRatio.width));

  5087         gotHeight = true;

  5088       }

  5089     }

  5090   }

  5092   if (!gotWidth) {

  5093     imageSize.width = nsPresContext::AppUnitsToIntCSSPixels(aFill.width);

  5094   }

  5095   if (!gotHeight) {

  5096     imageSize.height = nsPresContext::AppUnitsToIntCSSPixels(aFill.height);

  5097   }

  5099   return DrawImageInternal(aRenderingContext, aImage, aGraphicsFilter,

  5100                            aDest, aFill, aAnchor, aDirty,

  5101                            imageSize, nullptr, aImageFlags);

  5102 }

  5104 /* static */ nsRect

  5105 nsLayoutUtils::GetWholeImageDestination(const nsIntSize& aWholeImageSize,

  5106                                         const nsRect& aImageSourceArea,

  5107                                         const nsRect& aDestArea)

  5108 {

  5109   double scaleX = double(aDestArea.width)/aImageSourceArea.width;

  5110   double scaleY = double(aDestArea.height)/aImageSourceArea.height;

  5111   nscoord destOffsetX = NSToCoordRound(aImageSourceArea.x*scaleX);

  5112   nscoord destOffsetY = NSToCoordRound(aImageSourceArea.y*scaleY);

  5113   nscoord appUnitsPerCSSPixel = nsDeviceContext::AppUnitsPerCSSPixel();

  5114   nscoord wholeSizeX = NSToCoordRound(aWholeImageSize.width*appUnitsPerCSSPixel*scaleX);

  5115   nscoord wholeSizeY = NSToCoordRound(aWholeImageSize.height*appUnitsPerCSSPixel*scaleY);

  5116   return nsRect(aDestArea.TopLeft() - nsPoint(destOffsetX, destOffsetY),

  5117                 nsSize(wholeSizeX, wholeSizeY));

  5118 }

  5120 /* static */ already_AddRefed<imgIContainer>

  5121 nsLayoutUtils::OrientImage(imgIContainer* aContainer,

  5122                            const nsStyleImageOrientation& aOrientation)

  5123 {

  5124   MOZ_ASSERT(aContainer, "Should have an image container");

  5125   nsCOMPtr<imgIContainer> img(aContainer);

  5127   if (aOrientation.IsFromImage()) {

  5128     img = ImageOps::Orient(img, img->GetOrientation());

  5129   } else if (!aOrientation.IsDefault()) {

  5130     Angle angle = aOrientation.Angle();

  5131     Flip flip  = aOrientation.IsFlipped() ? Flip::Horizontal

  5132                                           : Flip::Unflipped;

  5133     img = ImageOps::Orient(img, Orientation(angle, flip));

  5134   }

  5136   return img.forget();

  5137 }

  5139 static bool NonZeroStyleCoord(const nsStyleCoord& aCoord)

  5140 {

  5141   if (aCoord.IsCoordPercentCalcUnit()) {

  5142     // Since negative results are clamped to 0, check > 0.

  5143     return nsRuleNode::ComputeCoordPercentCalc(aCoord, nscoord_MAX) > 0 ||

  5144            nsRuleNode::ComputeCoordPercentCalc(aCoord, 0) > 0;

  5145   }

  5147   return true;

  5148 }

  5150 /* static */ bool

  5151 nsLayoutUtils::HasNonZeroCorner(const nsStyleCorners& aCorners)

  5152 {

  5153   NS_FOR_CSS_HALF_CORNERS(corner) {

  5154     if (NonZeroStyleCoord(aCorners.Get(corner)))

  5155       return true;

  5156   }

  5157   return false;

  5158 }

  5160 // aCorner is a "full corner" value, i.e. NS_CORNER_TOP_LEFT etc

  5161 static bool IsCornerAdjacentToSide(uint8_t aCorner, css::Side aSide)

  5162 {

  5163   PR_STATIC_ASSERT((int)NS_SIDE_TOP == NS_CORNER_TOP_LEFT);

  5164   PR_STATIC_ASSERT((int)NS_SIDE_RIGHT == NS_CORNER_TOP_RIGHT);

  5165   PR_STATIC_ASSERT((int)NS_SIDE_BOTTOM == NS_CORNER_BOTTOM_RIGHT);

  5166   PR_STATIC_ASSERT((int)NS_SIDE_LEFT == NS_CORNER_BOTTOM_LEFT);

  5167   PR_STATIC_ASSERT((int)NS_SIDE_TOP == ((NS_CORNER_TOP_RIGHT - 1)&3));

  5168   PR_STATIC_ASSERT((int)NS_SIDE_RIGHT == ((NS_CORNER_BOTTOM_RIGHT - 1)&3));

  5169   PR_STATIC_ASSERT((int)NS_SIDE_BOTTOM == ((NS_CORNER_BOTTOM_LEFT - 1)&3));

  5170   PR_STATIC_ASSERT((int)NS_SIDE_LEFT == ((NS_CORNER_TOP_LEFT - 1)&3));

  5172   return aSide == aCorner || aSide == ((aCorner - 1)&3);

  5173 }

  5175 /* static */ bool

  5176 nsLayoutUtils::HasNonZeroCornerOnSide(const nsStyleCorners& aCorners,

  5177                                       css::Side aSide)

  5178 {

  5179   PR_STATIC_ASSERT(NS_CORNER_TOP_LEFT_X/2 == NS_CORNER_TOP_LEFT);

  5180   PR_STATIC_ASSERT(NS_CORNER_TOP_LEFT_Y/2 == NS_CORNER_TOP_LEFT);

  5181   PR_STATIC_ASSERT(NS_CORNER_TOP_RIGHT_X/2 == NS_CORNER_TOP_RIGHT);

  5182   PR_STATIC_ASSERT(NS_CORNER_TOP_RIGHT_Y/2 == NS_CORNER_TOP_RIGHT);

  5183   PR_STATIC_ASSERT(NS_CORNER_BOTTOM_RIGHT_X/2 == NS_CORNER_BOTTOM_RIGHT);

  5184   PR_STATIC_ASSERT(NS_CORNER_BOTTOM_RIGHT_Y/2 == NS_CORNER_BOTTOM_RIGHT);

  5185   PR_STATIC_ASSERT(NS_CORNER_BOTTOM_LEFT_X/2 == NS_CORNER_BOTTOM_LEFT);

  5186   PR_STATIC_ASSERT(NS_CORNER_BOTTOM_LEFT_Y/2 == NS_CORNER_BOTTOM_LEFT);

  5188   NS_FOR_CSS_HALF_CORNERS(corner) {

  5189     // corner is a "half corner" value, so dividing by two gives us a

  5190     // "full corner" value.

  5191     if (NonZeroStyleCoord(aCorners.Get(corner)) &&

  5192         IsCornerAdjacentToSide(corner/2, aSide))

  5193       return true;

  5194   }

  5195   return false;

  5196 }

  5198 /* static */ nsTransparencyMode

  5199 nsLayoutUtils::GetFrameTransparency(nsIFrame* aBackgroundFrame,

  5200                                     nsIFrame* aCSSRootFrame) {

  5201   if (aCSSRootFrame->StyleDisplay()->mOpacity < 1.0f)

  5202     return eTransparencyTransparent;

  5204   if (HasNonZeroCorner(aCSSRootFrame->StyleBorder()->mBorderRadius))

  5205     return eTransparencyTransparent;

  5207   if (aCSSRootFrame->StyleDisplay()->mAppearance == NS_THEME_WIN_GLASS)

  5208     return eTransparencyGlass;

  5210   if (aCSSRootFrame->StyleDisplay()->mAppearance == NS_THEME_WIN_BORDERLESS_GLASS)

  5211     return eTransparencyBorderlessGlass;

  5213   nsITheme::Transparency transparency;

  5214   if (aCSSRootFrame->IsThemed(&transparency))

  5215     return transparency == nsITheme::eTransparent

  5216          ? eTransparencyTransparent

  5217          : eTransparencyOpaque;

  5219   // We need an uninitialized window to be treated as opaque because

  5220   // doing otherwise breaks window display effects on some platforms,

  5221   // specifically Vista. (bug 450322)

  5222   if (aBackgroundFrame->GetType() == nsGkAtoms::viewportFrame &&

  5223       !aBackgroundFrame->GetFirstPrincipalChild()) {

  5224     return eTransparencyOpaque;

  5225   }

  5227   nsStyleContext* bgSC;

  5228   if (!nsCSSRendering::FindBackground(aBackgroundFrame, &bgSC)) {

  5229     return eTransparencyTransparent;

  5230   }

  5231   const nsStyleBackground* bg = bgSC->StyleBackground();

  5232   if (NS_GET_A(bg->mBackgroundColor) < 255 ||

  5233       // bottom layer's clip is used for the color

  5234       bg->BottomLayer().mClip != NS_STYLE_BG_CLIP_BORDER)

  5235     return eTransparencyTransparent;

  5236   return eTransparencyOpaque;

  5237 }

  5239 static bool IsPopupFrame(nsIFrame* aFrame)

  5240 {

  5241   // aFrame is a popup it's the list control frame dropdown for a combobox.

  5242   nsIAtom* frameType = aFrame->GetType();

  5243   if (frameType == nsGkAtoms::listControlFrame) {

  5244     nsListControlFrame* lcf = static_cast<nsListControlFrame*>(aFrame);

  5245     return lcf->IsInDropDownMode();

  5246   }

  5248   // ... or if it's a XUL menupopup frame.

  5249   return frameType == nsGkAtoms::menuPopupFrame;

  5250 }

  5252 /* static */ bool

  5253 nsLayoutUtils::IsPopup(nsIFrame* aFrame)

  5254 {

  5255   // Optimization: the frame can't possibly be a popup if it has no view.

  5256   if (!aFrame->HasView()) {

  5257     NS_ASSERTION(!IsPopupFrame(aFrame), "popup frame must have a view");

  5258     return false;

  5259   }

  5260   return IsPopupFrame(aFrame);

  5261 }

  5263 /* static */ nsIFrame*

  5264 nsLayoutUtils::GetDisplayRootFrame(nsIFrame* aFrame)

  5265 {

  5266   // We could use GetRootPresContext() here if the

  5267   // NS_FRAME_IN_POPUP frame bit is set.

  5268   nsIFrame* f = aFrame;

  5269   for (;;) {

  5270     if (!f->HasAnyStateBits(NS_FRAME_IN_POPUP)) {

  5271       f = f->PresContext()->FrameManager()->GetRootFrame();

  5272     } else if (IsPopup(f)) {

  5273       return f;

  5274     }

  5275     nsIFrame* parent = GetCrossDocParentFrame(f);

  5276     if (!parent)

  5277       return f;

  5278     f = parent;

  5279   }

  5280 }

  5282 /* static */ nsIFrame*

  5283 nsLayoutUtils::GetReferenceFrame(nsIFrame* aFrame)

  5284 {

  5285   nsIFrame *f = aFrame;

  5286   for (;;) {

  5287     if (f->IsTransformed() || IsPopup(f)) {

  5288       return f;

  5289     }

  5290     nsIFrame* parent = GetCrossDocParentFrame(f);

  5291     if (!parent) {

  5292       return f;

  5293     }

  5294     f = parent;

  5295   }

  5296 }

  5298 /* static */ nsIFrame*

  5299 nsLayoutUtils::GetTransformRootFrame(nsIFrame* aFrame)

  5300 {

  5301   nsIFrame *parent = nsLayoutUtils::GetCrossDocParentFrame(aFrame);

  5302   while (parent && parent->Preserves3DChildren()) {

  5303     parent = nsLayoutUtils::GetCrossDocParentFrame(parent);

  5304   }

  5305   return parent;

  5306 }

  5308 /* static */ uint32_t

  5309 nsLayoutUtils::GetTextRunFlagsForStyle(nsStyleContext* aStyleContext,

  5310                                        const nsStyleFont* aStyleFont,

  5311                                        const nsStyleText* aStyleText,

  5312                                        nscoord aLetterSpacing)

  5313 {

  5314   uint32_t result = 0;

  5315   if (aLetterSpacing != 0) {

  5316     result |= gfxTextRunFactory::TEXT_DISABLE_OPTIONAL_LIGATURES;

  5317   }

  5318   if (aStyleText->mControlCharacterVisibility == NS_STYLE_CONTROL_CHARACTER_VISIBILITY_HIDDEN) {

  5319     result |= gfxTextRunFactory::TEXT_HIDE_CONTROL_CHARACTERS;

  5320   }

  5321   switch (aStyleContext->StyleSVG()->mTextRendering) {

  5322   case NS_STYLE_TEXT_RENDERING_OPTIMIZESPEED:

  5323     result |= gfxTextRunFactory::TEXT_OPTIMIZE_SPEED;

  5324     break;

  5325   case NS_STYLE_TEXT_RENDERING_AUTO:

  5326     if (aStyleFont->mFont.size <

  5327         aStyleContext->PresContext()->GetAutoQualityMinFontSize()) {

  5328       result |= gfxTextRunFactory::TEXT_OPTIMIZE_SPEED;

  5329     }

  5330     break;

  5331   default:

  5332     break;

  5333   }

  5334   return result;

  5335 }

  5337 /* static */ void

  5338 nsLayoutUtils::GetRectDifferenceStrips(const nsRect& aR1, const nsRect& aR2,

  5339                                        nsRect* aHStrip, nsRect* aVStrip) {

  5340   NS_ASSERTION(aR1.TopLeft() == aR2.TopLeft(),

  5341                "expected rects at the same position");

  5342   nsRect unionRect(aR1.x, aR1.y, std::max(aR1.width, aR2.width),

  5343                    std::max(aR1.height, aR2.height));

  5344   nscoord VStripStart = std::min(aR1.width, aR2.width);

  5345   nscoord HStripStart = std::min(aR1.height, aR2.height);

  5346   *aVStrip = unionRect;

  5347   aVStrip->x += VStripStart;

  5348   aVStrip->width -= VStripStart;

  5349   *aHStrip = unionRect;

  5350   aHStrip->y += HStripStart;

  5351   aHStrip->height -= HStripStart;

  5352 }

  5354 nsDeviceContext*

  5355 nsLayoutUtils::GetDeviceContextForScreenInfo(nsPIDOMWindow* aWindow)

  5356 {

  5357   if (!aWindow) {

  5358     return nullptr;

  5359   }

  5361   nsCOMPtr<nsIDocShell> docShell = aWindow->GetDocShell();

  5362   while (docShell) {

  5363     // Now make sure our size is up to date.  That will mean that the device

  5364     // context does the right thing on multi-monitor systems when we return it to

  5365     // the caller.  It will also make sure that our prescontext has been created,

  5366     // if we're supposed to have one.

  5367     nsCOMPtr<nsPIDOMWindow> win = do_GetInterface(docShell);

  5368     if (!win) {

  5369       // No reason to go on

  5370       return nullptr;

  5371     }

  5373     win->EnsureSizeUpToDate();

  5375     nsRefPtr<nsPresContext> presContext;

  5376     docShell->GetPresContext(getter_AddRefs(presContext));

  5377     if (presContext) {

  5378       nsDeviceContext* context = presContext->DeviceContext();

  5379       if (context) {

  5380         return context;

  5381       }

  5382     }

  5384     nsCOMPtr<nsIDocShellTreeItem> parentItem;

  5385     docShell->GetParent(getter_AddRefs(parentItem));

  5386     docShell = do_QueryInterface(parentItem);

  5387   }

  5389   return nullptr;

  5390 }

  5392 /* static */ bool

  5393 nsLayoutUtils::IsReallyFixedPos(nsIFrame* aFrame)

  5394 {

  5395   NS_PRECONDITION(aFrame->GetParent(),

  5396                   "IsReallyFixedPos called on frame not in tree");

  5397   NS_PRECONDITION(aFrame->StyleDisplay()->mPosition ==

  5398                     NS_STYLE_POSITION_FIXED,

  5399                   "IsReallyFixedPos called on non-'position:fixed' frame");

  5401   nsIAtom *parentType = aFrame->GetParent()->GetType();

  5402   return parentType == nsGkAtoms::viewportFrame ||

  5403          parentType == nsGkAtoms::pageContentFrame;

  5404 }

  5406 nsLayoutUtils::SurfaceFromElementResult

  5407 nsLayoutUtils::SurfaceFromElement(nsIImageLoadingContent* aElement,

  5408                                   uint32_t aSurfaceFlags,

  5409                                   DrawTarget* aTarget)

  5410 {

  5411   SurfaceFromElementResult result;

  5412   nsresult rv;

  5414   nsCOMPtr<imgIRequest> imgRequest;

  5415   rv = aElement->GetRequest(nsIImageLoadingContent::CURRENT_REQUEST,

  5416                             getter_AddRefs(imgRequest));

  5417   if (NS_FAILED(rv) || !imgRequest)

  5418     return result;

  5420   uint32_t status;

  5421   imgRequest->GetImageStatus(&status);

  5422   if ((status & imgIRequest::STATUS_LOAD_COMPLETE) == 0) {

  5423     // Spec says to use GetComplete, but that only works on

  5424     // nsIDOMHTMLImageElement, and we support all sorts of other stuff

  5425     // here.  Do this for now pending spec clarification.

  5426     result.mIsStillLoading = (status & imgIRequest::STATUS_ERROR) == 0;

  5427     return result;

  5428   }

  5430   nsCOMPtr<nsIPrincipal> principal;

  5431   rv = imgRequest->GetImagePrincipal(getter_AddRefs(principal));

  5432   if (NS_FAILED(rv))

  5433     return result;

  5435   nsCOMPtr<imgIContainer> imgContainer;

  5436   rv = imgRequest->GetImage(getter_AddRefs(imgContainer));

  5437   if (NS_FAILED(rv))

  5438     return result;

  5440   uint32_t noRasterize = aSurfaceFlags & SFE_NO_RASTERIZING_VECTORS;

  5442   uint32_t whichFrame = (aSurfaceFlags & SFE_WANT_FIRST_FRAME)

  5443                         ? (uint32_t) imgIContainer::FRAME_FIRST

  5444                         : (uint32_t) imgIContainer::FRAME_CURRENT;

  5445   uint32_t frameFlags = imgIContainer::FLAG_SYNC_DECODE;

  5446   if (aSurfaceFlags & SFE_NO_COLORSPACE_CONVERSION)

  5447     frameFlags |= imgIContainer::FLAG_DECODE_NO_COLORSPACE_CONVERSION;

  5448   if (aSurfaceFlags & SFE_PREFER_NO_PREMULTIPLY_ALPHA) {

  5449     frameFlags |= imgIContainer::FLAG_DECODE_NO_PREMULTIPLY_ALPHA;

  5450     result.mIsPremultiplied = false;

  5451   }

  5453   int32_t imgWidth, imgHeight;

  5454   rv = imgContainer->GetWidth(&imgWidth);

  5455   nsresult rv2 = imgContainer->GetHeight(&imgHeight);

  5456   if (NS_FAILED(rv) || NS_FAILED(rv2))

  5457     return result;

  5459   if (!noRasterize || imgContainer->GetType() == imgIContainer::TYPE_RASTER) {

  5460     if (aSurfaceFlags & SFE_WANT_IMAGE_SURFACE) {

  5461       frameFlags |= imgIContainer::FLAG_WANT_DATA_SURFACE;

  5462     }

  5463     result.mSourceSurface = imgContainer->GetFrame(whichFrame, frameFlags);

  5464     if (!result.mSourceSurface) {

  5465       return result;

  5466     }

  5467     // The surface we return is likely to be cached. We don't want to have to

  5468     // convert to a surface that's compatible with aTarget each time it's used

  5469     // (that would result in terrible performance), so we convert once here

  5470     // upfront if aTarget is specified.

  5471     if (aTarget) {

  5472       RefPtr<SourceSurface> optSurface =

  5473         aTarget->OptimizeSourceSurface(result.mSourceSurface);

  5474       if (optSurface) {

  5475         result.mSourceSurface = optSurface;

  5476       }

  5477     }

  5478   } else {

  5479     result.mDrawInfo.mImgContainer = imgContainer;

  5480     result.mDrawInfo.mWhichFrame = whichFrame;

  5481     result.mDrawInfo.mDrawingFlags = frameFlags;

  5482   }

  5484   int32_t corsmode;

  5485   if (NS_SUCCEEDED(imgRequest->GetCORSMode(&corsmode))) {

  5486     result.mCORSUsed = (corsmode != imgIRequest::CORS_NONE);

  5487   }

  5489   result.mSize = gfxIntSize(imgWidth, imgHeight);

  5490   result.mPrincipal = principal.forget();

  5491   // no images, including SVG images, can load content from another domain.

  5492   result.mIsWriteOnly = false;

  5493   result.mImageRequest = imgRequest.forget();

  5495   return result;

  5496 }

  5498 nsLayoutUtils::SurfaceFromElementResult

  5499 nsLayoutUtils::SurfaceFromElement(HTMLImageElement *aElement,

  5500                                   uint32_t aSurfaceFlags,

  5501                                   DrawTarget* aTarget)

  5502 {

  5503   return SurfaceFromElement(static_cast<nsIImageLoadingContent*>(aElement),

  5504                             aSurfaceFlags, aTarget);

  5505 }

  5507 nsLayoutUtils::SurfaceFromElementResult

  5508 nsLayoutUtils::SurfaceFromElement(HTMLCanvasElement* aElement,

  5509                                   uint32_t aSurfaceFlags,

  5510                                   DrawTarget* aTarget)

  5511 {

  5512   SurfaceFromElementResult result;

  5514   bool* isPremultiplied = nullptr;

  5515   if (aSurfaceFlags & SFE_PREFER_NO_PREMULTIPLY_ALPHA) {

  5516     isPremultiplied = &result.mIsPremultiplied;

  5517   }

  5519   gfxIntSize size = aElement->GetSize();

  5521   result.mSourceSurface = aElement->GetSurfaceSnapshot(isPremultiplied);

  5522   if (!result.mSourceSurface) {

  5523      // If the element doesn't have a context then we won't get a snapshot. The canvas spec wants us to not error and just

  5524      // draw nothing, so return an empty surface.

  5525      DrawTarget *ref = aTarget ? aTarget : gfxPlatform::GetPlatform()->ScreenReferenceDrawTarget();

  5526      RefPtr<DrawTarget> dt = ref->CreateSimilarDrawTarget(IntSize(size.width, size.height),

  5527                                                           SurfaceFormat::B8G8R8A8);

  5528      if (dt) {

  5529        result.mSourceSurface = dt->Snapshot();

  5530      }

  5531   } else if (aTarget) {

  5532     RefPtr<SourceSurface> opt = aTarget->OptimizeSourceSurface(result.mSourceSurface);

  5533     if (opt) {

  5534       result.mSourceSurface = opt;

  5535     }

  5536   }

  5538   // Ensure that any future changes to the canvas trigger proper invalidation,

  5539   // in case this is being used by -moz-element()

  5540   aElement->MarkContextClean();

  5542   result.mSize = size;

  5543   result.mPrincipal = aElement->NodePrincipal();

  5544   result.mIsWriteOnly = aElement->IsWriteOnly();

  5546   return result;

  5547 }

  5549 nsLayoutUtils::SurfaceFromElementResult

  5550 nsLayoutUtils::SurfaceFromElement(HTMLVideoElement* aElement,

  5551                                   uint32_t aSurfaceFlags,

  5552                                   DrawTarget* aTarget)

  5553 {

  5554   SurfaceFromElementResult result;

  5556   NS_WARN_IF_FALSE((aSurfaceFlags & SFE_PREFER_NO_PREMULTIPLY_ALPHA) == 0, "We can't support non-premultiplied alpha for video!");

  5558   uint16_t readyState;

  5559   if (NS_SUCCEEDED(aElement->GetReadyState(&readyState)) &&

  5560       (readyState == nsIDOMHTMLMediaElement::HAVE_NOTHING ||

  5561        readyState == nsIDOMHTMLMediaElement::HAVE_METADATA)) {

  5562     result.mIsStillLoading = true;

  5563     return result;

  5564   }

  5566   // If it doesn't have a principal, just bail

  5567   nsCOMPtr<nsIPrincipal> principal = aElement->GetCurrentPrincipal();

  5568   if (!principal)

  5569     return result;

  5571   ImageContainer *container = aElement->GetImageContainer();

  5572   if (!container)

  5573     return result;

  5575   mozilla::gfx::IntSize size;

  5576   result.mSourceSurface = container->GetCurrentAsSourceSurface(&size);

  5577   if (!result.mSourceSurface)

  5578     return result;

  5580   if (aTarget) {

  5581     RefPtr<SourceSurface> opt = aTarget->OptimizeSourceSurface(result.mSourceSurface);

  5582     if (opt) {

  5583       result.mSourceSurface = opt;

  5584     }

  5585   }

  5587   result.mCORSUsed = aElement->GetCORSMode() != CORS_NONE;

  5588   result.mSize = ThebesIntSize(size);

  5589   result.mPrincipal = principal.forget();

  5590   result.mIsWriteOnly = false;

  5592   return result;

  5593 }

  5595 nsLayoutUtils::SurfaceFromElementResult

  5596 nsLayoutUtils::SurfaceFromElement(dom::Element* aElement,

  5597                                   uint32_t aSurfaceFlags,

  5598                                   DrawTarget* aTarget)

  5599 {

  5600   // If it's a <canvas>, we may be able to just grab its internal surface

  5601   if (HTMLCanvasElement* canvas =

  5602         HTMLCanvasElement::FromContentOrNull(aElement)) {

  5603     return SurfaceFromElement(canvas, aSurfaceFlags, aTarget);

  5604   }

  5606   // Maybe it's <video>?

  5607   if (HTMLVideoElement* video =

  5608         HTMLVideoElement::FromContentOrNull(aElement)) {

  5609     return SurfaceFromElement(video, aSurfaceFlags, aTarget);

  5610   }

  5612   // Finally, check if it's a normal image

  5613   nsCOMPtr<nsIImageLoadingContent> imageLoader = do_QueryInterface(aElement);

  5615   if (!imageLoader) {

  5616     return SurfaceFromElementResult();

  5617   }

  5619   return SurfaceFromElement(imageLoader, aSurfaceFlags, aTarget);

  5620 }

  5622 /* static */

  5623 nsIContent*

  5624 nsLayoutUtils::GetEditableRootContentByContentEditable(nsIDocument* aDocument)

  5625 {

  5626   // If the document is in designMode we should return nullptr.

  5627   if (!aDocument || aDocument->HasFlag(NODE_IS_EDITABLE)) {

  5628     return nullptr;

  5629   }

  5631   // contenteditable only works with HTML document.

  5632   // Note: Use nsIDOMHTMLDocument rather than nsIHTMLDocument for getting the

  5633   //       body node because nsIDOMHTMLDocument::GetBody() does something

  5634   //       additional work for some cases and nsEditor uses them.

  5635   nsCOMPtr<nsIDOMHTMLDocument> domHTMLDoc = do_QueryInterface(aDocument);

  5636   if (!domHTMLDoc) {

  5637     return nullptr;

  5638   }

  5640   Element* rootElement = aDocument->GetRootElement();

  5641   if (rootElement && rootElement->IsEditable()) {

  5642     return rootElement;

  5643   }

  5645   // If there are no editable root element, check its <body> element.

  5646   // Note that the body element could be <frameset> element.

  5647   nsCOMPtr<nsIDOMHTMLElement> body;

  5648   nsresult rv = domHTMLDoc->GetBody(getter_AddRefs(body));

  5649   nsCOMPtr<nsIContent> content = do_QueryInterface(body);

  5650   if (NS_SUCCEEDED(rv) && content && content->IsEditable()) {

  5651     return content;

  5652   }

  5653   return nullptr;

  5654 }

  5656 #ifdef DEBUG

  5657 /* static */ void

  5658 nsLayoutUtils::AssertNoDuplicateContinuations(nsIFrame* aContainer,

  5659                                               const nsFrameList& aFrameList)

  5660 {

  5661   for (nsIFrame* f = aFrameList.FirstChild(); f ; f = f->GetNextSibling()) {

  5662     // Check only later continuations of f; we deal with checking the

  5663     // earlier continuations when we hit those earlier continuations in

  5664     // the frame list.

  5665     for (nsIFrame *c = f; (c = c->GetNextInFlow());) {

  5666       NS_ASSERTION(c->GetParent() != aContainer ||

  5667                    !aFrameList.ContainsFrame(c),

  5668                    "Two continuations of the same frame in the same "

  5669                    "frame list");

  5670     }

  5671   }

  5672 }

  5674 // Is one of aFrame's ancestors a letter frame?

  5675 static bool

  5676 IsInLetterFrame(nsIFrame *aFrame)

  5677 {

  5678   for (nsIFrame *f = aFrame->GetParent(); f; f = f->GetParent()) {

  5679     if (f->GetType() == nsGkAtoms::letterFrame) {

  5680       return true;

  5681     }

  5682   }

  5683   return false;

  5684 }

  5686 /* static */ void

  5687 nsLayoutUtils::AssertTreeOnlyEmptyNextInFlows(nsIFrame *aSubtreeRoot)

  5688 {

  5689   NS_ASSERTION(aSubtreeRoot->GetPrevInFlow(),

  5690                "frame tree not empty, but caller reported complete status");

  5692   // Also assert that text frames map no text.

  5693   int32_t start, end;

  5694   nsresult rv = aSubtreeRoot->GetOffsets(start, end);

  5695   NS_ASSERTION(NS_SUCCEEDED(rv), "GetOffsets failed");

  5696   // In some cases involving :first-letter, we'll partially unlink a

  5697   // continuation in the middle of a continuation chain from its

  5698   // previous and next continuations before destroying it, presumably so

  5699   // that we don't also destroy the later continuations.  Once we've

  5700   // done this, GetOffsets returns incorrect values.

  5701   // For examples, see list of tests in

  5702   // https://bugzilla.mozilla.org/show_bug.cgi?id=619021#c29

  5703   NS_ASSERTION(start == end || IsInLetterFrame(aSubtreeRoot),

  5704                "frame tree not empty, but caller reported complete status");

  5706   nsIFrame::ChildListIterator lists(aSubtreeRoot);

  5707   for (; !lists.IsDone(); lists.Next()) {

  5708     nsFrameList::Enumerator childFrames(lists.CurrentList());

  5709     for (; !childFrames.AtEnd(); childFrames.Next()) {

  5710       nsLayoutUtils::AssertTreeOnlyEmptyNextInFlows(childFrames.get());

  5711     }

  5712   }

  5713 }

  5714 #endif

  5716 static void

  5717 GetFontFacesForFramesInner(nsIFrame* aFrame, nsFontFaceList* aFontFaceList)

  5718 {

  5719   NS_PRECONDITION(aFrame, "NULL frame pointer");

  5721   if (aFrame->GetType() == nsGkAtoms::textFrame) {

  5722     if (!aFrame->GetPrevContinuation()) {

  5723       nsLayoutUtils::GetFontFacesForText(aFrame, 0, INT32_MAX, true,

  5724                                          aFontFaceList);

  5725     }

  5726     return;

  5727   }

  5729   nsIFrame::ChildListID childLists[] = { nsIFrame::kPrincipalList,

  5730                                          nsIFrame::kPopupList };

  5731   for (size_t i = 0; i < ArrayLength(childLists); ++i) {

  5732     nsFrameList children(aFrame->GetChildList(childLists[i]));

  5733     for (nsFrameList::Enumerator e(children); !e.AtEnd(); e.Next()) {

  5734       nsIFrame* child = e.get();

  5735       child = nsPlaceholderFrame::GetRealFrameFor(child);

  5736       GetFontFacesForFramesInner(child, aFontFaceList);

  5737     }

  5738   }

  5739 }

  5741 /* static */

  5742 nsresult

  5743 nsLayoutUtils::GetFontFacesForFrames(nsIFrame* aFrame,

  5744                                      nsFontFaceList* aFontFaceList)

  5745 {

  5746   NS_PRECONDITION(aFrame, "NULL frame pointer");

  5748   while (aFrame) {

  5749     GetFontFacesForFramesInner(aFrame, aFontFaceList);

  5750     aFrame = GetNextContinuationOrIBSplitSibling(aFrame);

  5751   }

  5753   return NS_OK;

  5754 }

  5756 /* static */

  5757 nsresult

  5758 nsLayoutUtils::GetFontFacesForText(nsIFrame* aFrame,

  5759                                    int32_t aStartOffset, int32_t aEndOffset,

  5760                                    bool aFollowContinuations,

  5761                                    nsFontFaceList* aFontFaceList)

  5762 {

  5763   NS_PRECONDITION(aFrame, "NULL frame pointer");

  5765   if (aFrame->GetType() != nsGkAtoms::textFrame) {

  5766     return NS_OK;

  5767   }

  5769   nsTextFrame* curr = static_cast<nsTextFrame*>(aFrame);

  5770   do {

  5771     int32_t fstart = std::max(curr->GetContentOffset(), aStartOffset);

  5772     int32_t fend = std::min(curr->GetContentEnd(), aEndOffset);

  5773     if (fstart >= fend) {

  5774       curr = static_cast<nsTextFrame*>(curr->GetNextContinuation());

  5775       continue;

  5776     }

  5778     // curr is overlapping with the offset we want

  5779     gfxSkipCharsIterator iter = curr->EnsureTextRun(nsTextFrame::eInflated);

  5780     gfxTextRun* textRun = curr->GetTextRun(nsTextFrame::eInflated);

  5781     NS_ENSURE_TRUE(textRun, NS_ERROR_OUT_OF_MEMORY);

  5783     // include continuations in the range that share the same textrun

  5784     nsTextFrame* next = nullptr;

  5785     if (aFollowContinuations && fend < aEndOffset) {

  5786       next = static_cast<nsTextFrame*>(curr->GetNextContinuation());

  5787       while (next && next->GetTextRun(nsTextFrame::eInflated) == textRun) {

  5788         fend = std::min(next->GetContentEnd(), aEndOffset);

  5789         next = fend < aEndOffset ?

  5790           static_cast<nsTextFrame*>(next->GetNextContinuation()) : nullptr;

  5791       }

  5792     }

  5794     uint32_t skipStart = iter.ConvertOriginalToSkipped(fstart);

  5795     uint32_t skipEnd = iter.ConvertOriginalToSkipped(fend);

  5796     aFontFaceList->AddFontsFromTextRun(textRun, skipStart, skipEnd - skipStart);

  5797     curr = next;

  5798   } while (aFollowContinuations && curr);

  5800   return NS_OK;

  5801 }

  5803 /* static */

  5804 size_t

  5805 nsLayoutUtils::SizeOfTextRunsForFrames(nsIFrame* aFrame,

  5806                                        MallocSizeOf aMallocSizeOf,

  5807                                        bool clear)

  5808 {

  5809   NS_PRECONDITION(aFrame, "NULL frame pointer");

  5811   size_t total = 0;

  5813   if (aFrame->GetType() == nsGkAtoms::textFrame) {

  5814     nsTextFrame* textFrame = static_cast<nsTextFrame*>(aFrame);

  5815     for (uint32_t i = 0; i < 2; ++i) {

  5816       gfxTextRun *run = textFrame->GetTextRun(

  5817         (i != 0) ? nsTextFrame::eInflated : nsTextFrame::eNotInflated);

  5818       if (run) {

  5819         if (clear) {

  5820           run->ResetSizeOfAccountingFlags();

  5821         } else {

  5822           total += run->MaybeSizeOfIncludingThis(aMallocSizeOf);

  5823         }

  5824       }

  5825     }

  5826     return total;

  5827   }

  5829   nsAutoTArray<nsIFrame::ChildList,4> childListArray;

  5830   aFrame->GetChildLists(&childListArray);

  5832   for (nsIFrame::ChildListArrayIterator childLists(childListArray);

  5833        !childLists.IsDone(); childLists.Next()) {

  5834     for (nsFrameList::Enumerator e(childLists.CurrentList());

  5835          !e.AtEnd(); e.Next()) {

  5836       total += SizeOfTextRunsForFrames(e.get(), aMallocSizeOf, clear);

  5837     }

  5838   }

  5839   return total;

  5840 }

  5842 /* static */

  5843 void

  5844 nsLayoutUtils::Initialize()

  5845 {

  5846   Preferences::AddUintVarCache(&sFontSizeInflationMaxRatio,

  5847                                "font.size.inflation.maxRatio");

  5848   Preferences::AddUintVarCache(&sFontSizeInflationEmPerLine,

  5849                                "font.size.inflation.emPerLine");

  5850   Preferences::AddUintVarCache(&sFontSizeInflationMinTwips,

  5851                                "font.size.inflation.minTwips");

  5852   Preferences::AddUintVarCache(&sFontSizeInflationLineThreshold,

  5853                                "font.size.inflation.lineThreshold");

  5854   Preferences::AddIntVarCache(&sFontSizeInflationMappingIntercept,

  5855                               "font.size.inflation.mappingIntercept");

  5856   Preferences::AddBoolVarCache(&sFontSizeInflationForceEnabled,

  5857                                "font.size.inflation.forceEnabled");

  5858   Preferences::AddBoolVarCache(&sFontSizeInflationDisabledInMasterProcess,

  5859                                "font.size.inflation.disabledInMasterProcess");

  5860   Preferences::AddBoolVarCache(&sInvalidationDebuggingIsEnabled,

  5861                                "nglayout.debug.invalidation");

  5862   Preferences::AddBoolVarCache(&sCSSVariablesEnabled,

  5863                                "layout.css.variables.enabled");

  5864   Preferences::AddBoolVarCache(&sInterruptibleReflowEnabled,

  5865                                "layout.interruptible-reflow.enabled");

  5867   Preferences::RegisterCallback(GridEnabledPrefChangeCallback,

  5868                                 GRID_ENABLED_PREF_NAME);

  5869   GridEnabledPrefChangeCallback(GRID_ENABLED_PREF_NAME, nullptr);

  5870   Preferences::RegisterCallback(StickyEnabledPrefChangeCallback,

  5871                                 STICKY_ENABLED_PREF_NAME);

  5872   StickyEnabledPrefChangeCallback(STICKY_ENABLED_PREF_NAME, nullptr);

  5873   Preferences::RegisterCallback(TextAlignTrueEnabledPrefChangeCallback,

  5874                                 TEXT_ALIGN_TRUE_ENABLED_PREF_NAME);

  5875   TextAlignTrueEnabledPrefChangeCallback(TEXT_ALIGN_TRUE_ENABLED_PREF_NAME,

  5876                                          nullptr);

  5878   nsComputedDOMStyle::RegisterPrefChangeCallbacks();

  5879 }

  5881 /* static */

  5882 void

  5883 nsLayoutUtils::Shutdown()

  5884 {

  5885   if (sContentMap) {

  5886     delete sContentMap;

  5887     sContentMap = nullptr;

  5888   }

  5890   Preferences::UnregisterCallback(GridEnabledPrefChangeCallback,

  5891                                   GRID_ENABLED_PREF_NAME);

  5892   Preferences::UnregisterCallback(StickyEnabledPrefChangeCallback,

  5893                                   STICKY_ENABLED_PREF_NAME);

  5895   nsComputedDOMStyle::UnregisterPrefChangeCallbacks();

  5896 }

  5898 /* static */

  5899 void

  5900 nsLayoutUtils::RegisterImageRequest(nsPresContext* aPresContext,

  5901                                     imgIRequest* aRequest,

  5902                                     bool* aRequestRegistered)

  5903 {

  5904   if (!aPresContext) {

  5905     return;

  5906   }

  5908   if (aRequestRegistered && *aRequestRegistered) {

  5909     // Our request is already registered with the refresh driver, so

  5910     // no need to register it again.

  5911     return;

  5912   }

  5914   if (aRequest) {

  5915     if (!aPresContext->RefreshDriver()->AddImageRequest(aRequest)) {

  5916       NS_WARNING("Unable to add image request");

  5917       return;

  5918     }

  5920     if (aRequestRegistered) {

  5921       *aRequestRegistered = true;

  5922     }

  5923   }

  5924 }

  5926 /* static */

  5927 void

  5928 nsLayoutUtils::RegisterImageRequestIfAnimated(nsPresContext* aPresContext,

  5929                                               imgIRequest* aRequest,

  5930                                               bool* aRequestRegistered)

  5931 {

  5932   if (!aPresContext) {

  5933     return;

  5934   }

  5936   if (aRequestRegistered && *aRequestRegistered) {

  5937     // Our request is already registered with the refresh driver, so

  5938     // no need to register it again.

  5939     return;

  5940   }

  5942   if (aRequest) {

  5943     nsCOMPtr<imgIContainer> image;

  5944     if (NS_SUCCEEDED(aRequest->GetImage(getter_AddRefs(image)))) {

  5945       // Check to verify that the image is animated. If so, then add it to the

  5946       // list of images tracked by the refresh driver.

  5947       bool isAnimated = false;

  5948       nsresult rv = image->GetAnimated(&isAnimated);

  5949       if (NS_SUCCEEDED(rv) && isAnimated) {

  5950         if (!aPresContext->RefreshDriver()->AddImageRequest(aRequest)) {

  5951           NS_WARNING("Unable to add image request");

  5952           return;

  5953         }

  5955         if (aRequestRegistered) {

  5956           *aRequestRegistered = true;

  5957         }

  5958       }

  5959     }

  5960   }

  5961 }

  5963 /* static */

  5964 void

  5965 nsLayoutUtils::DeregisterImageRequest(nsPresContext* aPresContext,

  5966                                       imgIRequest* aRequest,

  5967                                       bool* aRequestRegistered)

  5968 {

  5969   if (!aPresContext) {

  5970     return;

  5971   }

  5973   // Deregister our imgIRequest with the refresh driver to

  5974   // complete tear-down, but only if it has been registered

  5975   if (aRequestRegistered && !*aRequestRegistered) {

  5976     return;

  5977   }

  5979   if (aRequest) {

  5980     nsCOMPtr<imgIContainer> image;

  5981     if (NS_SUCCEEDED(aRequest->GetImage(getter_AddRefs(image)))) {

  5982       aPresContext->RefreshDriver()->RemoveImageRequest(aRequest);

  5984       if (aRequestRegistered) {

  5985         *aRequestRegistered = false;

  5986       }

  5987     }

  5988   }

  5989 }

  5991 /* static */

  5992 void

  5993 nsLayoutUtils::PostRestyleEvent(Element* aElement,

  5994                                 nsRestyleHint aRestyleHint,

  5995                                 nsChangeHint aMinChangeHint)

  5996 {

  5997   nsIDocument* doc = aElement->GetCurrentDoc();

  5998   if (doc) {

  5999     nsCOMPtr<nsIPresShell> presShell = doc->GetShell();

  6000     if (presShell) {

  6001       presShell->GetPresContext()->RestyleManager()->PostRestyleEvent(

  6002         aElement, aRestyleHint, aMinChangeHint);

  6003     }

  6004   }

  6005 }

  6007 nsSetAttrRunnable::nsSetAttrRunnable(nsIContent* aContent, nsIAtom* aAttrName,

  6008                                      const nsAString& aValue)

  6009   : mContent(aContent),

  6010     mAttrName(aAttrName),

  6011     mValue(aValue)

  6012 {

  6013   NS_ASSERTION(aContent && aAttrName, "Missing stuff, prepare to crash");

  6014 }

  6016 nsSetAttrRunnable::nsSetAttrRunnable(nsIContent* aContent, nsIAtom* aAttrName,

  6017                                      int32_t aValue)

  6018   : mContent(aContent),

  6019     mAttrName(aAttrName)

  6020 {

  6021   NS_ASSERTION(aContent && aAttrName, "Missing stuff, prepare to crash");

  6022   mValue.AppendInt(aValue);

  6023 }

  6025 NS_IMETHODIMP

  6026 nsSetAttrRunnable::Run()

  6027 {

  6028   return mContent->SetAttr(kNameSpaceID_None, mAttrName, mValue, true);

  6029 }

  6031 nsUnsetAttrRunnable::nsUnsetAttrRunnable(nsIContent* aContent,

  6032                                          nsIAtom* aAttrName)

  6033   : mContent(aContent),

  6034     mAttrName(aAttrName)

  6035 {

  6036   NS_ASSERTION(aContent && aAttrName, "Missing stuff, prepare to crash");

  6037 }

  6039 NS_IMETHODIMP

  6040 nsUnsetAttrRunnable::Run()

  6041 {

  6042   return mContent->UnsetAttr(kNameSpaceID_None, mAttrName, true);

  6043 }

  6045 /**

  6046  * Compute the minimum font size inside of a container with the given

  6047  * width, such that **when the user zooms the container to fill the full

  6048  * width of the device**, the fonts satisfy our minima.

  6049  */

  6050 static nscoord

  6051 MinimumFontSizeFor(nsPresContext* aPresContext, nscoord aContainerWidth)

  6052 {

  6053   nsIPresShell* presShell = aPresContext->PresShell();

  6055   uint32_t emPerLine = presShell->FontSizeInflationEmPerLine();

  6056   uint32_t minTwips = presShell->FontSizeInflationMinTwips();

  6057   if (emPerLine == 0 && minTwips == 0) {

  6058     return 0;

  6059   }

  6061   // Clamp the container width to the device dimensions

  6062   nscoord iFrameWidth = aPresContext->GetVisibleArea().width;

  6063   nscoord effectiveContainerWidth = std::min(iFrameWidth, aContainerWidth);

  6065   nscoord byLine = 0, byInch = 0;

  6066   if (emPerLine != 0) {

  6067     byLine = effectiveContainerWidth / emPerLine;

  6068   }

  6069   if (minTwips != 0) {

  6070     // REVIEW: Is this giving us app units and sizes *not* counting

  6071     // viewport scaling?

  6072     float deviceWidthInches =

  6073       aPresContext->ScreenWidthInchesForFontInflation();

  6074     byInch = NSToCoordRound(effectiveContainerWidth /

  6075                             (deviceWidthInches * 1440 /

  6076                              minTwips ));

  6077   }

  6078   return std::max(byLine, byInch);

  6079 }

  6081 /* static */ float

  6082 nsLayoutUtils::FontSizeInflationInner(const nsIFrame *aFrame,

  6083                                       nscoord aMinFontSize)

  6084 {

  6085   // Note that line heights should be inflated by the same ratio as the

  6086   // font size of the same text; thus we operate only on the font size

  6087   // even when we're scaling a line height.

  6088   nscoord styleFontSize = aFrame->StyleFont()->mFont.size;

  6089   if (styleFontSize <= 0) {

  6090     // Never scale zero font size.

  6091     return 1.0;

  6092   }

  6094   if (aMinFontSize <= 0) {

  6095     // No need to scale.

  6096     return 1.0;

  6097   }

  6099   // If between this current frame and its font inflation container there is a

  6100   // non-inline element with fixed width or height, then we should not inflate

  6101   // fonts for this frame.

  6102   for (const nsIFrame* f = aFrame;

  6103        f && !f->IsContainerForFontSizeInflation();

  6104        f = f->GetParent()) {

  6105     nsIContent* content = f->GetContent();

  6106     nsIAtom* fType = f->GetType();

  6107     // Also, if there is more than one frame corresponding to a single

  6108     // content node, we want the outermost one.

  6109     if (!(f->GetParent() && f->GetParent()->GetContent() == content) &&

  6110         // ignore width/height on inlines since they don't apply

  6111         fType != nsGkAtoms::inlineFrame &&

  6112         // ignore width on radios and checkboxes since we enlarge them and

  6113         // they have width/height in ua.css

  6114         fType != nsGkAtoms::formControlFrame) {

  6115       nsStyleCoord stylePosWidth = f->StylePosition()->mWidth;

  6116       nsStyleCoord stylePosHeight = f->StylePosition()->mHeight;

  6117       if (stylePosWidth.GetUnit() != eStyleUnit_Auto ||

  6118           stylePosHeight.GetUnit() != eStyleUnit_Auto) {

  6120         return 1.0;

  6121       }

  6122     }

  6123   }

  6125   int32_t interceptParam = nsLayoutUtils::FontSizeInflationMappingIntercept();

  6126   float maxRatio = (float)nsLayoutUtils::FontSizeInflationMaxRatio() / 100.0f;

  6128   float ratio = float(styleFontSize) / float(aMinFontSize);

  6129   float inflationRatio;

  6131   // Given a minimum inflated font size m, a specified font size s, we want to

  6132   // find the inflated font size i and then return the ratio of i to s (i/s).

  6133   if (interceptParam >= 0) {

  6134     // Since the mapping intercept parameter P is greater than zero, we use it

  6135     // to determine the point where our mapping function intersects the i=s

  6136     // line. This means that we have an equation of the form:

  6137     //

  6138     // i = m + s·(P/2)/(1 + P/2), if s <= (1 + P/2)·m

  6139     // i = s, if s >= (1 + P/2)·m

  6141     float intercept = 1 + float(interceptParam)/2.0f;

  6142     if (ratio >= intercept) {

  6143       // If we're already at 1+P/2 or more times the minimum, don't scale.

  6144       return 1.0;

  6145     }

  6147     // The point (intercept, intercept) is where the part of the i vs. s graph

  6148     // that's not slope 1 meets the i=s line.  (This part of the

  6149     // graph is a line from (0, m), to that point). We calculate the

  6150     // intersection point to be ((1+P/2)m, (1+P/2)m), where P is the

  6151     // intercept parameter above. We then need to return i/s.

  6152     inflationRatio = (1.0f + (ratio * (intercept - 1) / intercept)) / ratio;

  6153   } else {

  6154     // This is the case where P is negative. We essentially want to implement

  6155     // the case for P=infinity here, so we make i = s + m, which means that

  6156     // i/s = s/s + m/s = 1 + 1/ratio

  6157     inflationRatio = 1 + 1.0f / ratio;

  6158   }

  6160   if (maxRatio > 1.0 && inflationRatio > maxRatio) {

  6161     return maxRatio;

  6162   } else {

  6163     return inflationRatio;

  6164   }

  6165 }

  6167 static bool

  6168 ShouldInflateFontsForContainer(const nsIFrame *aFrame)

  6169 {

  6170   // We only want to inflate fonts for text that is in a place

  6171   // with room to expand.  The question is what the best heuristic for

  6172   // that is...

  6173   // For now, we're going to use NS_FRAME_IN_CONSTRAINED_HEIGHT, which

  6174   // indicates whether the frame is inside something with a constrained

  6175   // height (propagating down the tree), but the propagation stops when

  6176   // we hit overflow-y: scroll or auto.

  6177   const nsStyleText* styleText = aFrame->StyleText();

  6179   return styleText->mTextSizeAdjust != NS_STYLE_TEXT_SIZE_ADJUST_NONE &&

  6180          !(aFrame->GetStateBits() & NS_FRAME_IN_CONSTRAINED_HEIGHT) &&

  6181          // We also want to disable font inflation for containers that have

  6182          // preformatted text.

  6183          styleText->WhiteSpaceCanWrap(aFrame);

  6184 }

  6186 nscoord

  6187 nsLayoutUtils::InflationMinFontSizeFor(const nsIFrame *aFrame)

  6188 {

  6189   nsPresContext *presContext = aFrame->PresContext();

  6190   if (!FontSizeInflationEnabled(presContext) ||

  6191       presContext->mInflationDisabledForShrinkWrap) {

  6192     return 0;

  6193   }

  6195   for (const nsIFrame *f = aFrame; f; f = f->GetParent()) {

  6196     if (f->IsContainerForFontSizeInflation()) {

  6197       if (!ShouldInflateFontsForContainer(f)) {

  6198         return 0;

  6199       }

  6201       nsFontInflationData *data =

  6202         nsFontInflationData::FindFontInflationDataFor(aFrame);

  6203       // FIXME: The need to null-check here is sort of a bug, and might

  6204       // lead to incorrect results.

  6205       if (!data || !data->InflationEnabled()) {

  6206         return 0;

  6207       }

  6209       return MinimumFontSizeFor(aFrame->PresContext(),

  6210                                 data->EffectiveWidth());

  6211     }

  6212   }

  6214   NS_ABORT_IF_FALSE(false, "root should always be container");

  6216   return 0;

  6217 }

  6219 float

  6220 nsLayoutUtils::FontSizeInflationFor(const nsIFrame *aFrame)

  6221 {

  6222   if (aFrame->IsSVGText()) {

  6223     const nsIFrame* container = aFrame;

  6224     while (container->GetType() != nsGkAtoms::svgTextFrame) {

  6225       container = container->GetParent();

  6226     }

  6227     NS_ASSERTION(container, "expected to find an ancestor SVGTextFrame");

  6228     return

  6229       static_cast<const SVGTextFrame*>(container)->GetFontSizeScaleFactor();

  6230   }

  6232   if (!FontSizeInflationEnabled(aFrame->PresContext())) {

  6233     return 1.0f;

  6234   }

  6236   return FontSizeInflationInner(aFrame, InflationMinFontSizeFor(aFrame));

  6237 }

  6239 /* static */ bool

  6240 nsLayoutUtils::FontSizeInflationEnabled(nsPresContext *aPresContext)

  6241 {

  6242   nsIPresShell* presShell = aPresContext->GetPresShell();

  6244   if (!presShell) {

  6245     return false;

  6246   }

  6248   return presShell->FontSizeInflationEnabled();

  6249 }

  6251 /* static */ nsRect

  6252 nsLayoutUtils::GetBoxShadowRectForFrame(nsIFrame* aFrame,

  6253                                         const nsSize& aFrameSize)

  6254 {

  6255   nsCSSShadowArray* boxShadows = aFrame->StyleBorder()->mBoxShadow;

  6256   if (!boxShadows) {

  6257     return nsRect();

  6258   }

  6260   nsRect shadows;

  6261   int32_t A2D = aFrame->PresContext()->AppUnitsPerDevPixel();

  6262   for (uint32_t i = 0; i < boxShadows->Length(); ++i) {

  6263     nsRect tmpRect(nsPoint(0, 0), aFrameSize);

  6264     nsCSSShadowItem* shadow = boxShadows->ShadowAt(i);

  6266     // inset shadows are never painted outside the frame

  6267     if (shadow->mInset)

  6268       continue;

  6270     tmpRect.MoveBy(nsPoint(shadow->mXOffset, shadow->mYOffset));

  6271     tmpRect.Inflate(shadow->mSpread);

  6272     tmpRect.Inflate(

  6273       nsContextBoxBlur::GetBlurRadiusMargin(shadow->mRadius, A2D));

  6274     shadows.UnionRect(shadows, tmpRect);

  6275   }

  6276   return shadows;

  6277 }

  6279 /* static */ void

  6280 nsLayoutUtils::UpdateImageVisibilityForFrame(nsIFrame* aImageFrame)

  6281 {

  6282 #ifdef DEBUG

  6283   nsIAtom* type = aImageFrame->GetType();

  6284   MOZ_ASSERT(type == nsGkAtoms::imageFrame ||

  6285              type == nsGkAtoms::imageControlFrame ||

  6286              type == nsGkAtoms::svgImageFrame, "wrong type of frame");

  6287 #endif

  6289   nsCOMPtr<nsIImageLoadingContent> content = do_QueryInterface(aImageFrame->GetContent());

  6290   if (!content) {

  6291     return;

  6292   }

  6294   nsIPresShell* presShell = aImageFrame->PresContext()->PresShell();

  6295   if (presShell->AssumeAllImagesVisible()) {

  6296     presShell->EnsureImageInVisibleList(content);

  6297     return;

  6298   }

  6300   bool visible = true;

  6301   nsIFrame* f = aImageFrame->GetParent();

  6302   nsRect rect = aImageFrame->GetContentRectRelativeToSelf();

  6303   nsIFrame* rectFrame = aImageFrame;

  6304   while (f) {

  6305     nsIScrollableFrame* sf = do_QueryFrame(f);

  6306     if (sf) {

  6307       nsRect transformedRect =

  6308         nsLayoutUtils::TransformFrameRectToAncestor(rectFrame, rect, f);

  6309       if (!sf->IsRectNearlyVisible(transformedRect)) {

  6310         visible = false;

  6311         break;

  6312       }

  6313       // Move transformedRect to be contained in the scrollport as best we can

  6314       // (it might not fit) to pretend that it was scrolled into view.

  6315       nsRect scrollPort = sf->GetScrollPortRect();

  6316       if (transformedRect.XMost() > scrollPort.XMost()) {

  6317         transformedRect.x -= transformedRect.XMost() - scrollPort.XMost();

  6318       }

  6319       if (transformedRect.x < scrollPort.x) {

  6320         transformedRect.x = scrollPort.x;

  6321       }

  6322       if (transformedRect.YMost() > scrollPort.YMost()) {

  6323         transformedRect.y -= transformedRect.YMost() - scrollPort.YMost();

  6324       }

  6325       if (transformedRect.y < scrollPort.y) {

  6326         transformedRect.y = scrollPort.y;

  6327       }

  6328       transformedRect.width = std::min(transformedRect.width, scrollPort.width);

  6329       transformedRect.height = std::min(transformedRect.height, scrollPort.height);

  6330       rect = transformedRect;

  6331       rectFrame = f;

  6332     }

  6333     nsIFrame* parent = f->GetParent();

  6334     if (!parent) {

  6335       parent = nsLayoutUtils::GetCrossDocParentFrame(f);

  6336       if (parent && parent->PresContext()->IsChrome()) {

  6337         break;

  6338       }

  6339     }

  6340     f = parent;

  6341   }

  6343   if (visible) {

  6344     presShell->EnsureImageInVisibleList(content);

  6345   } else {

  6346     presShell->RemoveImageFromVisibleList(content);

  6347   }

  6348 }

  6350 /* static */ nsSize

  6351 nsLayoutUtils::CalculateCompositionSizeForFrame(nsIFrame* aFrame)

  6352 {

  6353   nsSize size(aFrame->GetSize());

  6355   nsPresContext* presContext = aFrame->PresContext();

  6356   nsIPresShell* presShell = presContext->PresShell();

  6358   // See the comments in the code that calculates the root

  6359   // composition bounds in RecordFrameMetrics.

  6360   // TODO: Reuse that code here.

  6361   bool isRootContentDocRootScrollFrame = presContext->IsRootContentDocument()

  6362                                       && aFrame == presShell->GetRootScrollFrame();

  6363   if (isRootContentDocRootScrollFrame) {

  6364     if (nsIFrame* rootFrame = presShell->GetRootFrame()) {

  6365       if (nsView* view = rootFrame->GetView()) {

  6366         nsSize viewSize = view->GetBounds().Size();

  6367         nsIWidget* widget =

  6368 #ifdef MOZ_WIDGET_ANDROID

  6369             rootFrame->GetNearestWidget();

  6370 #else

  6371             view->GetWidget();

  6372 #endif

  6373         if (widget) {

  6374           nsIntRect widgetBounds;

  6375           widget->GetBounds(widgetBounds);

  6376           int32_t auPerDevPixel = presContext->AppUnitsPerDevPixel();

  6377           size = nsSize(widgetBounds.width * auPerDevPixel,

  6378                         widgetBounds.height * auPerDevPixel);

  6379 #ifdef MOZ_WIDGET_ANDROID

  6380           if (viewSize.height < size.height) {

  6381             size.height = viewSize.height;

  6382           }

  6383 #endif

  6384         } else {

  6385           size = viewSize;

  6386         }

  6387       }

  6388     }

  6389   }

  6391   // Adjust composition bounds for the size of scroll bars.

  6392   nsIScrollableFrame* scrollableFrame = aFrame->GetScrollTargetFrame();

  6393   if (scrollableFrame && !LookAndFeel::GetInt(LookAndFeel::eIntID_UseOverlayScrollbars)) {

  6394     nsMargin margins = scrollableFrame->GetActualScrollbarSizes();

  6395     size.width -= margins.LeftRight();

  6396     size.height -= margins.TopBottom();

  6397   }

  6399   return size;

  6400 }

  6401 /* static */ CSSSize

  6402 nsLayoutUtils::CalculateRootCompositionSize(nsIFrame* aFrame,

  6403                                             bool aIsRootContentDocRootScrollFrame,

  6404                                             const FrameMetrics& aMetrics)

  6405 {

  6407   if (aIsRootContentDocRootScrollFrame) {

  6408     return ViewAs<LayerPixel>(ParentLayerSize(aMetrics.mCompositionBounds.Size()),

  6409                               PixelCastJustification::ParentLayerToLayerForRootComposition)

  6410            / aMetrics.LayersPixelsPerCSSPixel();

  6411   }

  6412   nsPresContext* presContext = aFrame->PresContext();

  6413   LayerSize rootCompositionSize;

  6414   nsPresContext* rootPresContext =

  6415     presContext->GetToplevelContentDocumentPresContext();

  6416   if (!rootPresContext) {

  6417     rootPresContext = presContext->GetRootPresContext();

  6418   }

  6419   nsIPresShell* rootPresShell = nullptr;

  6420   if (rootPresContext) {

  6421     // See the comments in the code that calculates the root

  6422     // composition bounds in RecordFrameMetrics.

  6423     // TODO: Reuse that code here.

  6424     nsIPresShell* rootPresShell = rootPresContext->PresShell();

  6425     if (nsIFrame* rootFrame = rootPresShell->GetRootFrame()) {

  6426       if (nsView* view = rootFrame->GetView()) {

  6427         LayoutDeviceToParentLayerScale parentResolution(

  6428           rootPresShell->GetCumulativeResolution().width

  6429           / rootPresShell->GetResolution().width);

  6430         int32_t rootAUPerDevPixel = rootPresContext->AppUnitsPerDevPixel();

  6431         nsRect viewBounds = view->GetBounds();

  6432         LayerSize viewSize = ViewAs<LayerPixel>(

  6433           (LayoutDeviceRect::FromAppUnits(viewBounds, rootAUPerDevPixel)

  6434            * parentResolution).Size(), PixelCastJustification::ParentLayerToLayerForRootComposition);

  6435         nsIWidget* widget =

  6436 #ifdef MOZ_WIDGET_ANDROID

  6437             rootFrame->GetNearestWidget();

  6438 #else

  6439             view->GetWidget();

  6440 #endif

  6441         if (widget) {

  6442           nsIntRect widgetBounds;

  6443           widget->GetBounds(widgetBounds);

  6444           rootCompositionSize = LayerSize(ViewAs<LayerPixel>(widgetBounds.Size()));

  6445 #ifdef MOZ_WIDGET_ANDROID

  6446           if (viewSize.height < rootCompositionSize.height) {

  6447             rootCompositionSize.height = viewSize.height;

  6448           }

  6449 #endif

  6450         } else {

  6451           rootCompositionSize = viewSize;

  6452         }

  6453       }

  6454     }

  6455   } else {

  6456     nsIWidget* widget = aFrame->GetNearestWidget();

  6457     nsIntRect widgetBounds;

  6458     widget->GetBounds(widgetBounds);

  6459     rootCompositionSize = LayerSize(ViewAs<LayerPixel>(widgetBounds.Size()));

  6460   }

  6462   // Adjust composition size for the size of scroll bars.

  6463   nsIFrame* rootRootScrollFrame = rootPresShell ? rootPresShell->GetRootScrollFrame() : nullptr;

  6464   nsIScrollableFrame* rootScrollableFrame = nullptr;

  6465   if (rootRootScrollFrame) {

  6466     rootScrollableFrame = rootRootScrollFrame->GetScrollTargetFrame();

  6467   }

  6468   if (rootScrollableFrame && !LookAndFeel::GetInt(LookAndFeel::eIntID_UseOverlayScrollbars)) {

  6469     CSSMargin margins = CSSMargin::FromAppUnits(rootScrollableFrame->GetActualScrollbarSizes());

  6470     // Scrollbars are not subject to scaling, so CSS pixels = layer pixels for them.

  6471     rootCompositionSize.width -= margins.LeftRight();

  6472     rootCompositionSize.height -= margins.TopBottom();

  6473   }

  6475   return rootCompositionSize / aMetrics.LayersPixelsPerCSSPixel();

  6476 }

  6478 /* static */ nsRect

  6479 nsLayoutUtils::CalculateScrollableRectForFrame(nsIScrollableFrame* aScrollableFrame, nsIFrame* aRootFrame)

  6480 {

  6481   nsRect contentBounds;

  6482   if (aScrollableFrame) {

  6483     contentBounds = aScrollableFrame->GetScrollRange();

  6485     // We ifndef the below code for Fennec because it requires special behaviour

  6486     // on the APZC side. Because Fennec has it's own PZC implementation which doesn't

  6487     // provide the special behaviour, this code will cause it to break. We can remove

  6488     // the ifndef once Fennec switches over to APZ or if we add the special handling

  6489     // to Fennec

  6490 #ifndef MOZ_WIDGET_ANDROID

  6491     nsPoint scrollPosition = aScrollableFrame->GetScrollPosition();

  6492     if (aScrollableFrame->GetScrollbarStyles().mVertical == NS_STYLE_OVERFLOW_HIDDEN) {

  6493       contentBounds.y = scrollPosition.y;

  6494       contentBounds.height = 0;

  6495     }

  6496     if (aScrollableFrame->GetScrollbarStyles().mHorizontal == NS_STYLE_OVERFLOW_HIDDEN) {

  6497       contentBounds.x = scrollPosition.x;

  6498       contentBounds.width = 0;

  6499     }

  6500 #endif

  6502     contentBounds.width += aScrollableFrame->GetScrollPortRect().width;

  6503     contentBounds.height += aScrollableFrame->GetScrollPortRect().height;

  6504   } else {

  6505     contentBounds = aRootFrame->GetRect();

  6506   }

  6507   return contentBounds;

  6508 }

  6510 /* static */ nsRect

  6511 nsLayoutUtils::CalculateExpandedScrollableRect(nsIFrame* aFrame)

  6512 {

  6513   nsRect scrollableRect =

  6514     CalculateScrollableRectForFrame(aFrame->GetScrollTargetFrame(),

  6515                                     aFrame->PresContext()->PresShell()->GetRootFrame());

  6516   nsSize compSize = CalculateCompositionSizeForFrame(aFrame);

  6518   if (aFrame == aFrame->PresContext()->PresShell()->GetRootScrollFrame()) {

  6519     // the composition size for the root scroll frame does not include the

  6520     // local resolution, so we adjust.

  6521     gfxSize res = aFrame->PresContext()->PresShell()->GetResolution();

  6522     compSize.width = NSToCoordRound(compSize.width / ((float) res.width));

  6523     compSize.height = NSToCoordRound(compSize.height / ((float) res.height));

  6524   }

  6526   if (scrollableRect.width < compSize.width) {

  6527     scrollableRect.x = std::max(0,

  6528                                 scrollableRect.x - (compSize.width - scrollableRect.width));

  6529     scrollableRect.width = compSize.width;

  6530   }

  6532   if (scrollableRect.height < compSize.height) {

  6533     scrollableRect.y = std::max(0,

  6534                                 scrollableRect.y - (compSize.height - scrollableRect.height));

  6535     scrollableRect.height = compSize.height;

  6536   }

  6537   return scrollableRect;

  6538 }

  6540 /* static */ bool

  6541 nsLayoutUtils::WantSubAPZC()

  6542 {

  6543    // TODO Turn this on for inprocess OMTC on all platforms

  6544    bool wantSubAPZC = gfxPrefs::APZSubframeEnabled();

  6545 #ifdef MOZ_WIDGET_GONK

  6546    if (XRE_GetProcessType() != GeckoProcessType_Content) {

  6547      wantSubAPZC = false;

  6548    }

  6549 #endif

  6550    return wantSubAPZC;

  6551  }

  6553 nsLayoutUtils::SurfaceFromElementResult::SurfaceFromElementResult()

  6554   // Use safe default values here

  6555   : mIsWriteOnly(true)

  6556   , mIsStillLoading(false)

  6557   , mCORSUsed(false)

  6558   , mIsPremultiplied(true)

  6559 {

  6560 }

  6562 bool

  6563 nsLayoutUtils::IsNonWrapperBlock(nsIFrame* aFrame)

  6564 {

  6565   return GetAsBlock(aFrame) && !aFrame->IsBlockWrapper();

  6566 }

  6568 bool

  6569 nsLayoutUtils::NeedsPrintPreviewBackground(nsPresContext* aPresContext)

  6570 {

  6571   return aPresContext->IsRootPaginatedDocument() &&

  6572     (aPresContext->Type() == nsPresContext::eContext_PrintPreview ||

  6573      aPresContext->Type() == nsPresContext::eContext_PageLayout);

  6574 }

  6576 AutoMaybeDisableFontInflation::AutoMaybeDisableFontInflation(nsIFrame *aFrame)

  6577 {

  6578   // FIXME: Now that inflation calculations are based on the flow

  6579   // root's NCA's (nearest common ancestor of its inflatable

  6580   // descendants) width, we could probably disable inflation in

  6581   // fewer cases than we currently do.

  6582   if (aFrame->IsContainerForFontSizeInflation()) {

  6583     mPresContext = aFrame->PresContext();

  6584     mOldValue = mPresContext->mInflationDisabledForShrinkWrap;

  6585     mPresContext->mInflationDisabledForShrinkWrap = true;

  6586   } else {

  6587     // indicate we have nothing to restore

  6588     mPresContext = nullptr;

  6589   }

  6590 }

  6592 AutoMaybeDisableFontInflation::~AutoMaybeDisableFontInflation()

  6593 {

  6594   if (mPresContext) {

  6595     mPresContext->mInflationDisabledForShrinkWrap = mOldValue;

  6596   }

  6597 }

The Tor Browser / file revision

layout/base/nsLayoutUtils.cpp@b8a032363ba2

layout/base/nsLayoutUtils.cpp