The Tor Browser: comparison layout/base/nsDisplayList.cpp

--1:000000000000
+:d7b065b59920
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+* vim: set ts=2 sw=2 et tw=78:
+* This Source Code Form is subject to the terms of the Mozilla Public
+* License, v. 2.0. If a copy of the MPL was not distributed with this
+* file, You can obtain one at http://mozilla.org/MPL/2.0/.
+*/
+/*
+* structures that represent things to be painted (ordered in z-order),
+* used during painting and hit testing
+*/
+#include "mozilla/dom/TabChild.h"
+#include "mozilla/layers/PLayerTransaction.h"
+#include "nsDisplayList.h"
+#include "nsCSSRendering.h"
+#include "nsRenderingContext.h"
+#include "nsISelectionController.h"
+#include "nsIPresShell.h"
+#include "nsRegion.h"
+#include "nsStyleStructInlines.h"
+#include "nsStyleTransformMatrix.h"
+#include "gfxMatrix.h"
+#include "nsSVGIntegrationUtils.h"
+#include "nsLayoutUtils.h"
+#include "nsIScrollableFrame.h"
+#include "nsIFrameInlines.h"
+#include "nsThemeConstants.h"
+#include "LayerTreeInvalidation.h"
+#include "imgIContainer.h"
+#include "BasicLayers.h"
+#include "nsBoxFrame.h"
+#include "nsViewportFrame.h"
+#include "nsSubDocumentFrame.h"
+#include "nsSVGEffects.h"
+#include "nsSVGElement.h"
+#include "nsSVGClipPathFrame.h"
+#include "GeckoProfiler.h"
+#include "nsAnimationManager.h"
+#include "nsTransitionManager.h"
+#include "nsViewManager.h"
+#include "ImageLayers.h"
+#include "ImageContainer.h"
+#include "nsCanvasFrame.h"
+#include "StickyScrollContainer.h"
+#include "mozilla/EventStates.h"
+#include "mozilla/LookAndFeel.h"
+#include "mozilla/Preferences.h"
+#include "ActiveLayerTracker.h"
+#include "nsContentUtils.h"
+#include "nsPrintfCString.h"
+#include "UnitTransforms.h"
+#include <stdint.h>
+#include <algorithm>
+using namespace mozilla;
+using namespace mozilla::css;
+using namespace mozilla::layers;
+using namespace mozilla::dom;
+typedef FrameMetrics::ViewID ViewID;
+static inline nsIFrame*
+GetTransformRootFrame(nsIFrame* aFrame)
+{
+return nsLayoutUtils::GetTransformRootFrame(aFrame);
+}
+static void AddTransformFunctions(nsCSSValueList* aList,
+nsStyleContext* aContext,
+nsPresContext* aPresContext,
+nsRect& aBounds,
+float aAppUnitsPerPixel,
+InfallibleTArray<TransformFunction>& aFunctions)
+{
+if (aList->mValue.GetUnit() == eCSSUnit_None) {
+return;
+}
+for (const nsCSSValueList* curr = aList; curr; curr = curr->mNext) {
+const nsCSSValue& currElem = curr->mValue;
+NS_ASSERTION(currElem.GetUnit() == eCSSUnit_Function,
+"Stream should consist solely of functions!");
+nsCSSValue::Array* array = currElem.GetArrayValue();
+bool canStoreInRuleTree = true;
+switch (nsStyleTransformMatrix::TransformFunctionOf(array)) {
+case eCSSKeyword_rotatex:
+{
+double theta = array->Item(1).GetAngleValueInRadians();
+aFunctions.AppendElement(RotationX(theta));
+break;
+}
+case eCSSKeyword_rotatey:
+{
+double theta = array->Item(1).GetAngleValueInRadians();
+aFunctions.AppendElement(RotationY(theta));
+break;
+}
+case eCSSKeyword_rotatez:
+{
+double theta = array->Item(1).GetAngleValueInRadians();
+aFunctions.AppendElement(RotationZ(theta));
+break;
+}
+case eCSSKeyword_rotate:
+{
+double theta = array->Item(1).GetAngleValueInRadians();
+aFunctions.AppendElement(Rotation(theta));
+break;
+}
+case eCSSKeyword_rotate3d:
+{
+double x = array->Item(1).GetFloatValue();
+double y = array->Item(2).GetFloatValue();
+double z = array->Item(3).GetFloatValue();
+double theta = array->Item(4).GetAngleValueInRadians();
+aFunctions.AppendElement(Rotation3D(x, y, z, theta));
+break;
+}
+case eCSSKeyword_scalex:
+{
+double x = array->Item(1).GetFloatValue();
+aFunctions.AppendElement(Scale(x, 1, 1));
+break;
+}
+case eCSSKeyword_scaley:
+{
+double y = array->Item(1).GetFloatValue();
+aFunctions.AppendElement(Scale(1, y, 1));
+break;
+}
+case eCSSKeyword_scalez:
+{
+double z = array->Item(1).GetFloatValue();
+aFunctions.AppendElement(Scale(1, 1, z));
+break;
+}
+case eCSSKeyword_scale:
+{
+double x = array->Item(1).GetFloatValue();
+// scale(x) is shorthand for scale(x, x);
+double y = array->Count() == 2 ? x : array->Item(2).GetFloatValue();
+aFunctions.AppendElement(Scale(x, y, 1));
+break;
+}
+case eCSSKeyword_scale3d:
+{
+double x = array->Item(1).GetFloatValue();
+double y = array->Item(2).GetFloatValue();
+double z = array->Item(3).GetFloatValue();
+aFunctions.AppendElement(Scale(x, y, z));
+break;
+}
+case eCSSKeyword_translatex:
+{
+double x = nsStyleTransformMatrix::ProcessTranslatePart(
+array->Item(1), aContext, aPresContext, canStoreInRuleTree,
+aBounds.Width(), aAppUnitsPerPixel);
+aFunctions.AppendElement(Translation(x, 0, 0));
+break;
+}
+case eCSSKeyword_translatey:
+{
+double y = nsStyleTransformMatrix::ProcessTranslatePart(
+array->Item(1), aContext, aPresContext, canStoreInRuleTree,
+aBounds.Height(), aAppUnitsPerPixel);
+aFunctions.AppendElement(Translation(0, y, 0));
+break;
+}
+case eCSSKeyword_translatez:
+{
+double z = nsStyleTransformMatrix::ProcessTranslatePart(
+array->Item(1), aContext, aPresContext, canStoreInRuleTree,
+0, aAppUnitsPerPixel);
+aFunctions.AppendElement(Translation(0, 0, z));
+break;
+}
+case eCSSKeyword_translate:
+{
+double x = nsStyleTransformMatrix::ProcessTranslatePart(
+array->Item(1), aContext, aPresContext, canStoreInRuleTree,
+aBounds.Width(), aAppUnitsPerPixel);
+// translate(x) is shorthand for translate(x, 0)
+double y = 0;
+if (array->Count() == 3) {
+y = nsStyleTransformMatrix::ProcessTranslatePart(
+array->Item(2), aContext, aPresContext, canStoreInRuleTree,
+aBounds.Height(), aAppUnitsPerPixel);
+}
+aFunctions.AppendElement(Translation(x, y, 0));
+break;
+}
+case eCSSKeyword_translate3d:
+{
+double x = nsStyleTransformMatrix::ProcessTranslatePart(
+array->Item(1), aContext, aPresContext, canStoreInRuleTree,
+aBounds.Width(), aAppUnitsPerPixel);
+double y = nsStyleTransformMatrix::ProcessTranslatePart(
+array->Item(2), aContext, aPresContext, canStoreInRuleTree,
+aBounds.Height(), aAppUnitsPerPixel);
+double z = nsStyleTransformMatrix::ProcessTranslatePart(
+array->Item(3), aContext, aPresContext, canStoreInRuleTree,
+0, aAppUnitsPerPixel);
+aFunctions.AppendElement(Translation(x, y, z));
+break;
+}
+case eCSSKeyword_skewx:
+{
+double x = array->Item(1).GetAngleValueInRadians();
+aFunctions.AppendElement(SkewX(x));
+break;
+}
+case eCSSKeyword_skewy:
+{
+double y = array->Item(1).GetAngleValueInRadians();
+aFunctions.AppendElement(SkewY(y));
+break;
+}
+case eCSSKeyword_skew:
+{
+double x = array->Item(1).GetAngleValueInRadians();
+// skew(x) is shorthand for skew(x, 0)
+double y = 0;
+if (array->Count() == 3) {
+y = array->Item(2).GetAngleValueInRadians();
+}
+aFunctions.AppendElement(Skew(x, y));
+break;
+}
+case eCSSKeyword_matrix:
+{
+gfx::Matrix4x4 matrix;
+matrix._11 = array->Item(1).GetFloatValue();
+matrix._12 = array->Item(2).GetFloatValue();
+matrix._13 = 0;
+matrix._14 = 0;
+matrix._21 = array->Item(3).GetFloatValue();
+matrix._22 = array->Item(4).GetFloatValue();
+matrix._23 = 0;
+matrix._24 = 0;
+matrix._31 = 0;
+matrix._32 = 0;
+matrix._33 = 1;
+matrix._34 = 0;
+matrix._41 = array->Item(5).GetFloatValue();
+matrix._42 = array->Item(6).GetFloatValue();
+matrix._43 = 0;
+matrix._44 = 1;
+aFunctions.AppendElement(TransformMatrix(matrix));
+break;
+}
+case eCSSKeyword_matrix3d:
+{
+gfx::Matrix4x4 matrix;
+matrix._11 = array->Item(1).GetFloatValue();
+matrix._12 = array->Item(2).GetFloatValue();
+matrix._13 = array->Item(3).GetFloatValue();
+matrix._14 = array->Item(4).GetFloatValue();
+matrix._21 = array->Item(5).GetFloatValue();
+matrix._22 = array->Item(6).GetFloatValue();
+matrix._23 = array->Item(7).GetFloatValue();
+matrix._24 = array->Item(8).GetFloatValue();
+matrix._31 = array->Item(9).GetFloatValue();
+matrix._32 = array->Item(10).GetFloatValue();
+matrix._33 = array->Item(11).GetFloatValue();
+matrix._34 = array->Item(12).GetFloatValue();
+matrix._41 = array->Item(13).GetFloatValue();
+matrix._42 = array->Item(14).GetFloatValue();
+matrix._43 = array->Item(15).GetFloatValue();
+matrix._44 = array->Item(16).GetFloatValue();
+aFunctions.AppendElement(TransformMatrix(matrix));
+break;
+}
+case eCSSKeyword_interpolatematrix:
+{
+gfx3DMatrix matrix;
+nsStyleTransformMatrix::ProcessInterpolateMatrix(matrix, array,
+aContext,
+aPresContext,
+canStoreInRuleTree,
+aBounds,
+aAppUnitsPerPixel);
+gfx::Matrix4x4 transform;
+gfx::ToMatrix4x4(matrix, transform);
+aFunctions.AppendElement(TransformMatrix(transform));
+break;
+}
+case eCSSKeyword_perspective:
+{
+aFunctions.AppendElement(Perspective(array->Item(1).GetFloatValue()));
+break;
+}
+default:
+NS_ERROR("Function not handled yet!");
+}
+}
+}
+static TimingFunction
+ToTimingFunction(css::ComputedTimingFunction& aCTF)
+{
+if (aCTF.GetType() == nsTimingFunction::Function) {
+const nsSMILKeySpline* spline = aCTF.GetFunction();
+return TimingFunction(CubicBezierFunction(spline->X1(), spline->Y1(),
+spline->X2(), spline->Y2()));
+}
+uint32_t type = aCTF.GetType() == nsTimingFunction::StepStart ? 1 : 2;
+return TimingFunction(StepFunction(aCTF.GetSteps(), type));
+}
+static void
+AddAnimationForProperty(nsIFrame* aFrame, nsCSSProperty aProperty,
+mozilla::StyleAnimation* ea, Layer* aLayer,
+AnimationData& aData, bool aPending)
+{
+NS_ASSERTION(aLayer->AsContainerLayer(), "Should only animate ContainerLayer");
+nsStyleContext* styleContext = aFrame->StyleContext();
+nsPresContext* presContext = aFrame->PresContext();
+nsRect bounds = nsDisplayTransform::GetFrameBoundsForTransform(aFrame);
+// all data passed directly to the compositor should be in css pixels
+float scale = nsDeviceContext::AppUnitsPerCSSPixel();
+mozilla::layers::Animation* animation =
+aPending ?
+aLayer->AddAnimationForNextTransaction() :
+aLayer->AddAnimation();
+animation->startTime() = ea->mStartTime + ea->mDelay;
+animation->duration() = ea->mIterationDuration;
+animation->numIterations() =
+ea->mIterationCount != NS_IEEEPositiveInfinity() ? ea->mIterationCount : -1;
+animation->direction() = ea->mDirection;
+animation->property() = aProperty;
+animation->data() = aData;
+for (uint32_t propIdx = 0; propIdx < ea->mProperties.Length(); propIdx++) {
+AnimationProperty* property = &ea->mProperties[propIdx];
+if (aProperty != property->mProperty) {
+continue;
+}
+for (uint32_t segIdx = 0; segIdx < property->mSegments.Length(); segIdx++) {
+AnimationPropertySegment* segment = &property->mSegments[segIdx];
+AnimationSegment* animSegment = animation->segments().AppendElement();
+if (aProperty == eCSSProperty_transform) {
+animSegment->startState() = InfallibleTArray<TransformFunction>();
+animSegment->endState() = InfallibleTArray<TransformFunction>();
+nsCSSValueSharedList* list = segment->mFromValue.GetCSSValueSharedListValue();
+AddTransformFunctions(list->mHead, styleContext, presContext, bounds, scale,
+animSegment->startState().get_ArrayOfTransformFunction());
+list = segment->mToValue.GetCSSValueSharedListValue();
+AddTransformFunctions(list->mHead, styleContext, presContext, bounds, scale,
+animSegment->endState().get_ArrayOfTransformFunction());
+} else if (aProperty == eCSSProperty_opacity) {
+animSegment->startState() = segment->mFromValue.GetFloatValue();
+animSegment->endState() = segment->mToValue.GetFloatValue();
+}
+animSegment->startPortion() = segment->mFromKey;
+animSegment->endPortion() = segment->mToKey;
+animSegment->sampleFn() = ToTimingFunction(segment->mTimingFunction);
+}
+}
+}
+template<class T>
+static void
+AddAnimationsForProperty(nsIFrame* aFrame, nsCSSProperty aProperty,
+nsTArray<T>& aAnimations,
+Layer* aLayer, AnimationData& aData,
+bool aPending) {
+mozilla::TimeStamp currentTime =
+aFrame->PresContext()->RefreshDriver()->MostRecentRefresh();
+for (uint32_t animIdx = 0; animIdx < aAnimations.Length(); animIdx++) {
+mozilla::StyleAnimation* anim = &aAnimations[animIdx];
+if (!(anim->HasAnimationOfProperty(aProperty) &&
+anim->IsRunningAt(currentTime))) {
+continue;
+}
+AddAnimationForProperty(aFrame, aProperty, anim, aLayer, aData, aPending);
+anim->mIsRunningOnCompositor = true;
+}
+}
+/* static */ void
+nsDisplayListBuilder::AddAnimationsAndTransitionsToLayer(Layer* aLayer,
+nsDisplayListBuilder* aBuilder,
+nsDisplayItem* aItem,
+nsIFrame* aFrame,
+nsCSSProperty aProperty)
+{
+// This function can be called in two ways:  from
+// nsDisplay*::BuildLayer while constructing a layer (with all
+// pointers non-null), or from RestyleManager's handling of
+// UpdateOpacityLayer/UpdateTransformLayer hints.
+MOZ_ASSERT(!aBuilder == !aItem,
+"should only be called in two configurations, with both "
+"aBuilder and aItem, or with neither");
+MOZ_ASSERT(!aItem || aFrame == aItem->Frame(), "frame mismatch");
+bool pending = !aBuilder;
+if (pending) {
+aLayer->ClearAnimationsForNextTransaction();
+} else {
+aLayer->ClearAnimations();
+}
+nsIContent* content = aFrame->GetContent();
+if (!content) {
+return;
+}
+ElementTransitions* et =
+nsTransitionManager::GetTransitionsForCompositor(content, aProperty);
+ElementAnimations* ea =
+nsAnimationManager::GetAnimationsForCompositor(content, aProperty);
+if (!ea && !et) {
+return;
+}
+// If the frame is not prerendered, bail out.
+// Do this check only during layer construction; during updating the
+// caller is required to check it appropriately.
+if (aItem && !aItem->CanUseAsyncAnimations(aBuilder)) {
+// AnimationManager or TransitionManager need to know that we refused to
+// run this animation asynchronously so that they will not throttle the
+// main thread animation.
+aFrame->Properties().Set(nsIFrame::RefusedAsyncAnimation(),
+reinterpret_cast<void*>(intptr_t(true)));
+// We need to schedule another refresh driver run so that AnimationManager
+// or TransitionManager get a chance to unthrottle the animation.
+aFrame->SchedulePaint();
+return;
+}
+AnimationData data;
+if (aProperty == eCSSProperty_transform) {
+nsRect bounds = nsDisplayTransform::GetFrameBoundsForTransform(aFrame);
+// all data passed directly to the compositor should be in css pixels
+float scale = nsDeviceContext::AppUnitsPerCSSPixel();
+gfxPoint3D offsetToTransformOrigin =
+nsDisplayTransform::GetDeltaToTransformOrigin(aFrame, scale, &bounds);
+gfxPoint3D offsetToPerspectiveOrigin =
+nsDisplayTransform::GetDeltaToPerspectiveOrigin(aFrame, scale);
+nscoord perspective = 0.0;
+nsStyleContext* parentStyleContext = aFrame->StyleContext()->GetParent();
+if (parentStyleContext) {
+const nsStyleDisplay* disp = parentStyleContext->StyleDisplay();
+if (disp && disp->mChildPerspective.GetUnit() == eStyleUnit_Coord) {
+perspective = disp->mChildPerspective.GetCoordValue();
+}
+}
+nsPoint origin;
+if (aItem) {
+origin = aItem->ToReferenceFrame();
+} else {
+// transform display items used a reference frame computed from
+// their GetTransformRootFrame().
+nsIFrame* referenceFrame =
+nsLayoutUtils::GetReferenceFrame(GetTransformRootFrame(aFrame));
+origin = aFrame->GetOffsetToCrossDoc(referenceFrame);
+}
+data = TransformData(origin, offsetToTransformOrigin,
+offsetToPerspectiveOrigin, bounds, perspective,
+aFrame->PresContext()->AppUnitsPerDevPixel());
+} else if (aProperty == eCSSProperty_opacity) {
+data = null_t();
+}
+if (et) {
+AddAnimationsForProperty(aFrame, aProperty, et->mPropertyTransitions,
+aLayer, data, pending);
+aLayer->SetAnimationGeneration(et->mAnimationGeneration);
+}
+if (ea) {
+AddAnimationsForProperty(aFrame, aProperty, ea->mAnimations,
+aLayer, data, pending);
+aLayer->SetAnimationGeneration(ea->mAnimationGeneration);
+}
+}
+nsDisplayListBuilder::nsDisplayListBuilder(nsIFrame* aReferenceFrame,
+Mode aMode, bool aBuildCaret)
+: mReferenceFrame(aReferenceFrame),
+mIgnoreScrollFrame(nullptr),
+mLayerEventRegions(nullptr),
+mCurrentTableItem(nullptr),
+mFinalTransparentRegion(nullptr),
+mCachedOffsetFrame(aReferenceFrame),
+mCachedReferenceFrame(aReferenceFrame),
+mCachedOffset(0, 0),
+mGlassDisplayItem(nullptr),
+mMode(aMode),
+mCurrentScrollParentId(FrameMetrics::NULL_SCROLL_ID),
+mBuildCaret(aBuildCaret),
+mIgnoreSuppression(false),
+mHadToIgnoreSuppression(false),
+mIsAtRootOfPseudoStackingContext(false),
+mIncludeAllOutOfFlows(false),
+mDescendIntoSubdocuments(true),
+mSelectedFramesOnly(false),
+mAccurateVisibleRegions(false),
+mAllowMergingAndFlattening(true),
+mWillComputePluginGeometry(false),
+mInTransform(false),
+mInFixedPos(false),
+mSyncDecodeImages(false),
+mIsPaintingToWindow(false),
+mIsCompositingCheap(false),
+mContainsPluginItem(false),
+mContainsBlendMode(false),
+mAncestorHasTouchEventHandler(false),
+mHaveScrollableDisplayPort(false)
+{
+MOZ_COUNT_CTOR(nsDisplayListBuilder);
+PL_InitArenaPool(&mPool, "displayListArena", 1024,
+std::max(NS_ALIGNMENT_OF(void*),NS_ALIGNMENT_OF(double))-1);
+nsPresContext* pc = aReferenceFrame->PresContext();
+nsIPresShell *shell = pc->PresShell();
+if (pc->IsRenderingOnlySelection()) {
+nsCOMPtr<nsISelectionController> selcon(do_QueryInterface(shell));
+if (selcon) {
+selcon->GetSelection(nsISelectionController::SELECTION_NORMAL,
+getter_AddRefs(mBoundingSelection));
+}
+}
+nsCSSRendering::BeginFrameTreesLocked();
+PR_STATIC_ASSERT(nsDisplayItem::TYPE_MAX < (1 << nsDisplayItem::TYPE_BITS));
+}
+static void MarkFrameForDisplay(nsIFrame* aFrame, nsIFrame* aStopAtFrame) {
+for (nsIFrame* f = aFrame; f;
+f = nsLayoutUtils::GetParentOrPlaceholderFor(f)) {
+if (f->GetStateBits() & NS_FRAME_FORCE_DISPLAY_LIST_DESCEND_INTO)
+return;
+f->AddStateBits(NS_FRAME_FORCE_DISPLAY_LIST_DESCEND_INTO);
+if (f == aStopAtFrame) {
+// we've reached a frame that we know will be painted, so we can stop.
+break;
+}
+}
+}
+void nsDisplayListBuilder::MarkOutOfFlowFrameForDisplay(nsIFrame* aDirtyFrame,
+nsIFrame* aFrame,
+const nsRect& aDirtyRect)
+{
+nsRect dirtyRectRelativeToDirtyFrame = aDirtyRect;
+if (nsLayoutUtils::IsFixedPosFrameInDisplayPort(aFrame)) {
+NS_ASSERTION(aDirtyFrame == aFrame->GetParent(), "Dirty frame should be viewport frame");
+// position: fixed items are reflowed into and only drawn inside the
+// viewport, or the scroll position clamping scrollport size, if one is
+// set.
+nsIPresShell* ps = aFrame->PresContext()->PresShell();
+dirtyRectRelativeToDirtyFrame.MoveTo(0, 0);
+if (ps->IsScrollPositionClampingScrollPortSizeSet()) {
+dirtyRectRelativeToDirtyFrame.SizeTo(ps->GetScrollPositionClampingScrollPortSize());
+} else {
+dirtyRectRelativeToDirtyFrame.SizeTo(aDirtyFrame->GetSize());
+}
+}
+nsRect dirty = dirtyRectRelativeToDirtyFrame - aFrame->GetOffsetTo(aDirtyFrame);
+nsRect overflowRect = aFrame->GetVisualOverflowRect();
+if (aFrame->IsTransformed() &&
+nsLayoutUtils::HasAnimationsForCompositor(aFrame->GetContent(),
+eCSSProperty_transform)) {
+/**
+* Add a fuzz factor to the overflow rectangle so that elements only just
+* out of view are pulled into the display list, so they can be
+* prerendered if necessary.
+*/
+overflowRect.Inflate(nsPresContext::CSSPixelsToAppUnits(32));
+}
+if (!dirty.IntersectRect(dirty, overflowRect))
+return;
+const DisplayItemClip* clip = mClipState.GetClipForContainingBlockDescendants();
+OutOfFlowDisplayData* data = clip ? new OutOfFlowDisplayData(*clip, dirty)
+: new OutOfFlowDisplayData(dirty);
+aFrame->Properties().Set(nsDisplayListBuilder::OutOfFlowDisplayDataProperty(), data);
+MarkFrameForDisplay(aFrame, aDirtyFrame);
+}
+static void UnmarkFrameForDisplay(nsIFrame* aFrame) {
+nsPresContext* presContext = aFrame->PresContext();
+presContext->PropertyTable()->
+Delete(aFrame, nsDisplayListBuilder::OutOfFlowDisplayDataProperty());
+for (nsIFrame* f = aFrame; f;
+f = nsLayoutUtils::GetParentOrPlaceholderFor(f)) {
+if (!(f->GetStateBits() & NS_FRAME_FORCE_DISPLAY_LIST_DESCEND_INTO))
+return;
+f->RemoveStateBits(NS_FRAME_FORCE_DISPLAY_LIST_DESCEND_INTO);
+}
+}
+static bool gPrintApzcTree = false;
+static bool GetApzcTreePrintPref() {
+static bool initialized = false;
+if (!initialized) {
+Preferences::AddBoolVarCache(&gPrintApzcTree, "apz.printtree", gPrintApzcTree);
+initialized = true;
+}
+return gPrintApzcTree;
+}
+static void RecordFrameMetrics(nsIFrame* aForFrame,
+nsIFrame* aScrollFrame,
+const nsIFrame* aReferenceFrame,
+ContainerLayer* aRoot,
+const nsRect& aVisibleRect,
+const nsRect& aViewport,
+nsRect* aDisplayPort,
+nsRect* aCriticalDisplayPort,
+ViewID aScrollId,
+bool aIsRoot,
+const ContainerLayerParameters& aContainerParameters) {
+nsPresContext* presContext = aForFrame->PresContext();
+int32_t auPerDevPixel = presContext->AppUnitsPerDevPixel();
+LayoutDeviceToLayerScale resolution(aContainerParameters.mXScale, aContainerParameters.mYScale);
+nsIntRect visible = aVisibleRect.ScaleToNearestPixels(
+resolution.scale, resolution.scale, auPerDevPixel);
+aRoot->SetVisibleRegion(visible);
+FrameMetrics metrics;
+metrics.mViewport = CSSRect::FromAppUnits(aViewport);
+if (aDisplayPort) {
+metrics.mDisplayPort = CSSRect::FromAppUnits(*aDisplayPort);
+if (aCriticalDisplayPort) {
+metrics.mCriticalDisplayPort = CSSRect::FromAppUnits(*aCriticalDisplayPort);
+}
+}
+nsIScrollableFrame* scrollableFrame = nullptr;
+if (aScrollFrame)
+scrollableFrame = aScrollFrame->GetScrollTargetFrame();
+metrics.mScrollableRect = CSSRect::FromAppUnits(
+nsLayoutUtils::CalculateScrollableRectForFrame(scrollableFrame, aForFrame));
+if (scrollableFrame) {
+nsPoint scrollPosition = scrollableFrame->GetScrollPosition();
+metrics.SetScrollOffset(CSSPoint::FromAppUnits(scrollPosition));
+// If the frame was scrolled since the last layers update, and by
+// something other than the APZ code, we want to tell the APZ to update
+// its scroll offset.
+nsIAtom* originOfLastScroll = scrollableFrame->OriginOfLastScroll();
+if (originOfLastScroll && originOfLastScroll != nsGkAtoms::apz) {
+metrics.SetScrollOffsetUpdated(scrollableFrame->CurrentScrollGeneration());
+}
+}
+metrics.SetScrollId(aScrollId);
+metrics.mIsRoot = aIsRoot;
+// Only the root scrollable frame for a given presShell should pick up
+// the presShell's resolution. All the other frames are 1.0.
+nsIPresShell* presShell = presContext->GetPresShell();
+if (aScrollFrame == presShell->GetRootScrollFrame()) {
+metrics.mResolution = ParentLayerToLayerScale(presShell->GetXResolution(),
+presShell->GetYResolution());
+} else {
+metrics.mResolution = ParentLayerToLayerScale(1.0f);
+}
+// For the cumulateive resolution, multiply the resolutions of all the
+// presShells back up to the root
+metrics.mCumulativeResolution = LayoutDeviceToLayerScale(1.0f);
+nsIPresShell* curPresShell = presShell;
+while (curPresShell != nullptr) {
+ParentLayerToLayerScale presShellResolution(curPresShell->GetXResolution(),
+curPresShell->GetYResolution());
+metrics.mCumulativeResolution.scale *= presShellResolution.scale;
+nsPresContext* parentContext = curPresShell->GetPresContext()->GetParentPresContext();
+curPresShell = parentContext ? parentContext->GetPresShell() : nullptr;
+}
+metrics.mDevPixelsPerCSSPixel = CSSToLayoutDeviceScale(
+(float)nsPresContext::AppUnitsPerCSSPixel() / auPerDevPixel);
+// Initially, AsyncPanZoomController should render the content to the screen
+// at the painted resolution.
+const LayerToScreenScale layerToScreenScale(1.0f);
+metrics.SetZoom(metrics.mCumulativeResolution * metrics.mDevPixelsPerCSSPixel
+* layerToScreenScale);
+if (presShell) {
+nsIDocument* document = nullptr;
+document = presShell->GetDocument();
+if (document) {
+nsCOMPtr<nsPIDOMWindow> innerWin(document->GetInnerWindow());
+if (innerWin) {
+metrics.mMayHaveTouchListeners = innerWin->HasTouchEventListeners();
+}
+}
+}
+LayoutDeviceToParentLayerScale layoutToParentLayerScale =
+// The ScreenToParentLayerScale should be mTransformScale which is not calculated yet,
+// but we don't yet handle CSS transforms, so we assume it's 1 here.
+metrics.mCumulativeResolution * LayerToScreenScale(1.0) * ScreenToParentLayerScale(1.0);
+// Calculate the composition bounds as the size of the scroll frame and
+// its origin relative to the reference frame.
+// If aScrollFrame is null, we are in a document without a root scroll frame,
+// so it's a xul document. In this case, use the size of the viewport frame.
+nsIFrame* frameForCompositionBoundsCalculation = aScrollFrame ? aScrollFrame : aForFrame;
+nsRect compositionBounds(frameForCompositionBoundsCalculation->GetOffsetToCrossDoc(aReferenceFrame),
+frameForCompositionBoundsCalculation->GetSize());
+metrics.mCompositionBounds = RoundedToInt(LayoutDeviceRect::FromAppUnits(compositionBounds, auPerDevPixel)
+* layoutToParentLayerScale);
+// For the root scroll frame of the root content document, the above calculation
+// will yield the size of the viewport frame as the composition bounds, which
+// doesn't actually correspond to what is visible when
+// nsIDOMWindowUtils::setCSSViewport has been called to modify the visible area of
+// the prescontext that the viewport frame is reflowed into. In that case if our
+// document has a widget then the widget's bounds will correspond to what is
+// visible. If we don't have a widget the root view's bounds correspond to what
+// would be visible because they don't get modified by setCSSViewport.
+bool isRootContentDocRootScrollFrame = presContext->IsRootContentDocument()
+&& aScrollFrame == presShell->GetRootScrollFrame();
+if (isRootContentDocRootScrollFrame) {
+if (nsIFrame* rootFrame = presShell->GetRootFrame()) {
+if (nsView* view = rootFrame->GetView()) {
+nsRect viewBoundsAppUnits = view->GetBounds() + rootFrame->GetOffsetToCrossDoc(aReferenceFrame);
+ParentLayerIntRect viewBounds = RoundedToInt(LayoutDeviceRect::FromAppUnits(viewBoundsAppUnits, auPerDevPixel)
+* layoutToParentLayerScale);
+// On Android, we need to do things a bit differently to get things
+// right (see bug 983208, bug 988882). We use the bounds of the nearest
+// widget, but clamp the height to the view bounds height. This clamping
+// is done to get correct results for a page where the page is sized to
+// the screen and thus the dynamic toolbar never disappears. In such a
+// case, we want the composition bounds to exclude the toolbar height,
+// but the widget bounds includes it. We don't currently have a good way
+// of knowing about the toolbar height, but clamping to the view bounds
+// height gives the correct answer in the cases we care about.
+nsIWidget* widget =
+#ifdef MOZ_WIDGET_ANDROID
+rootFrame->GetNearestWidget();
+#else
+view->GetWidget();
+#endif
+if (widget) {
+nsIntRect widgetBounds;
+widget->GetBounds(widgetBounds);
+metrics.mCompositionBounds = ViewAs<ParentLayerPixel>(widgetBounds);
+#ifdef MOZ_WIDGET_ANDROID
+if (viewBounds.height < metrics.mCompositionBounds.height) {
+metrics.mCompositionBounds.height = viewBounds.height;
+}
+#endif
+} else {
+metrics.mCompositionBounds = viewBounds;
+}
+}
+}
+}
+// Adjust composition bounds for the size of scroll bars.
+if (scrollableFrame && !LookAndFeel::GetInt(LookAndFeel::eIntID_UseOverlayScrollbars)) {
+nsMargin sizes = scrollableFrame->GetActualScrollbarSizes();
+// Scrollbars are not subject to scaling, so CSS pixels = layer pixels for them.
+ParentLayerIntMargin boundMargins = RoundedToInt(CSSMargin::FromAppUnits(sizes) * CSSToParentLayerScale(1.0f));
+metrics.mCompositionBounds.Deflate(boundMargins);
+}
+metrics.SetRootCompositionSize(
+nsLayoutUtils::CalculateRootCompositionSize(aScrollFrame ? aScrollFrame : aForFrame,
+isRootContentDocRootScrollFrame, metrics));
+if (GetApzcTreePrintPref()) {
+if (nsIContent* content = frameForCompositionBoundsCalculation->GetContent()) {
+nsAutoString contentDescription;
+content->Describe(contentDescription);
+metrics.SetContentDescription(NS_LossyConvertUTF16toASCII(contentDescription).get());
+}
+}
+metrics.mPresShellId = presShell->GetPresShellId();
+// If the scroll frame's content is marked 'scrollgrab', record this
+// in the FrameMetrics so APZ knows to provide the scroll grabbing
+// behaviour.
+if (aScrollFrame && nsContentUtils::HasScrollgrab(aScrollFrame->GetContent())) {
+metrics.mHasScrollgrab = true;
+}
+aRoot->SetFrameMetrics(metrics);
+}
+nsDisplayListBuilder::~nsDisplayListBuilder() {
+NS_ASSERTION(mFramesMarkedForDisplay.Length() == 0,
+"All frames should have been unmarked");
+NS_ASSERTION(mPresShellStates.Length() == 0,
+"All presshells should have been exited");
+NS_ASSERTION(!mCurrentTableItem, "No table item should be active");
+nsCSSRendering::EndFrameTreesLocked();
+for (uint32_t i = 0; i < mDisplayItemClipsToDestroy.Length(); ++i) {
+mDisplayItemClipsToDestroy[i]->DisplayItemClip::~DisplayItemClip();
+}
+PL_FinishArenaPool(&mPool);
+MOZ_COUNT_DTOR(nsDisplayListBuilder);
+}
+uint32_t
+nsDisplayListBuilder::GetBackgroundPaintFlags() {
+uint32_t flags = 0;
+if (mSyncDecodeImages) {
+flags |= nsCSSRendering::PAINTBG_SYNC_DECODE_IMAGES;
+}
+if (mIsPaintingToWindow) {
+flags |= nsCSSRendering::PAINTBG_TO_WINDOW;
+}
+return flags;
+}
+void
+nsDisplayListBuilder::SubtractFromVisibleRegion(nsRegion* aVisibleRegion,
+const nsRegion& aRegion)
+{
+if (aRegion.IsEmpty())
+return;
+nsRegion tmp;
+tmp.Sub(*aVisibleRegion, aRegion);
+// Don't let *aVisibleRegion get too complex, but don't let it fluff out
+// to its bounds either, which can be very bad (see bug 516740).
+// Do let aVisibleRegion get more complex if by doing so we reduce its
+// area by at least half.
+if (GetAccurateVisibleRegions() || tmp.GetNumRects() <= 15 ||
+tmp.Area() <= aVisibleRegion->Area()/2) {
+*aVisibleRegion = tmp;
+}
+}
+nsCaret *
+nsDisplayListBuilder::GetCaret() {
+nsRefPtr<nsCaret> caret = CurrentPresShellState()->mPresShell->GetCaret();
+return caret;
+}
+void
+nsDisplayListBuilder::EnterPresShell(nsIFrame* aReferenceFrame,
+const nsRect& aDirtyRect) {
+PresShellState* state = mPresShellStates.AppendElement();
+if (!state)
+return;
+state->mPresShell = aReferenceFrame->PresContext()->PresShell();
+state->mCaretFrame = nullptr;
+state->mFirstFrameMarkedForDisplay = mFramesMarkedForDisplay.Length();
+state->mPresShell->UpdateCanvasBackground();
+if (mIsPaintingToWindow) {
+mReferenceFrame->AddPaintedPresShell(state->mPresShell);
+state->mPresShell->IncrementPaintCount();
+}
+bool buildCaret = mBuildCaret;
+if (mIgnoreSuppression || !state->mPresShell->IsPaintingSuppressed()) {
+if (state->mPresShell->IsPaintingSuppressed()) {
+mHadToIgnoreSuppression = true;
+}
+state->mIsBackgroundOnly = false;
+} else {
+state->mIsBackgroundOnly = true;
+buildCaret = false;
+}
+if (!buildCaret)
+return;
+nsRefPtr<nsCaret> caret = state->mPresShell->GetCaret();
+state->mCaretFrame = caret->GetCaretFrame();
+NS_ASSERTION(state->mCaretFrame == caret->GetCaretFrame(),
+"GetCaretFrame() is unstable");
+if (state->mCaretFrame) {
+// Check if the dirty rect intersects with the caret's dirty rect.
+nsRect caretRect =
+caret->GetCaretRect() + state->mCaretFrame->GetOffsetTo(aReferenceFrame);
+if (caretRect.Intersects(aDirtyRect)) {
+// Okay, our rects intersect, let's mark the frame and all of its ancestors.
+mFramesMarkedForDisplay.AppendElement(state->mCaretFrame);
+MarkFrameForDisplay(state->mCaretFrame, nullptr);
+}
+}
+}
+void
+nsDisplayListBuilder::LeavePresShell(nsIFrame* aReferenceFrame,
+const nsRect& aDirtyRect) {
+if (CurrentPresShellState()->mPresShell != aReferenceFrame->PresContext()->PresShell()) {
+// Must have not allocated a state for this presshell, presumably due
+// to OOM.
+return;
+}
+ResetMarkedFramesForDisplayList();
+mPresShellStates.SetLength(mPresShellStates.Length() - 1);
+}
+void
+nsDisplayListBuilder::ResetMarkedFramesForDisplayList()
+{
+// Unmark and pop off the frames marked for display in this pres shell.
+uint32_t firstFrameForShell = CurrentPresShellState()->mFirstFrameMarkedForDisplay;
+for (uint32_t i = firstFrameForShell;
+i < mFramesMarkedForDisplay.Length(); ++i) {
+UnmarkFrameForDisplay(mFramesMarkedForDisplay[i]);
+}
+mFramesMarkedForDisplay.SetLength(firstFrameForShell);
+}
+void
+nsDisplayListBuilder::MarkFramesForDisplayList(nsIFrame* aDirtyFrame,
+const nsFrameList& aFrames,
+const nsRect& aDirtyRect) {
+mFramesMarkedForDisplay.SetCapacity(mFramesMarkedForDisplay.Length() + aFrames.GetLength());
+for (nsFrameList::Enumerator e(aFrames); !e.AtEnd(); e.Next()) {
+mFramesMarkedForDisplay.AppendElement(e.get());
+MarkOutOfFlowFrameForDisplay(aDirtyFrame, e.get(), aDirtyRect);
+}
+}
+void
+nsDisplayListBuilder::MarkPreserve3DFramesForDisplayList(nsIFrame* aDirtyFrame, const nsRect& aDirtyRect)
+{
+nsAutoTArray<nsIFrame::ChildList,4> childListArray;
+aDirtyFrame->GetChildLists(&childListArray);
+nsIFrame::ChildListArrayIterator lists(childListArray);
+for (; !lists.IsDone(); lists.Next()) {
+nsFrameList::Enumerator childFrames(lists.CurrentList());
+for (; !childFrames.AtEnd(); childFrames.Next()) {
+nsIFrame *child = childFrames.get();
+if (child->Preserves3D()) {
+mFramesMarkedForDisplay.AppendElement(child);
+nsRect dirty = aDirtyRect - child->GetOffsetTo(aDirtyFrame);
+child->Properties().Set(nsDisplayListBuilder::Preserve3DDirtyRectProperty(),
+new nsRect(dirty));
+MarkFrameForDisplay(child, aDirtyFrame);
+}
+}
+}
+}
+void*
+nsDisplayListBuilder::Allocate(size_t aSize) {
+void *tmp;
+PL_ARENA_ALLOCATE(tmp, &mPool, aSize);
+if (!tmp) {
+NS_RUNTIMEABORT("out of memory");
+}
+return tmp;
+}
+const DisplayItemClip*
+nsDisplayListBuilder::AllocateDisplayItemClip(const DisplayItemClip& aOriginal)
+{
+void* p = Allocate(sizeof(DisplayItemClip));
+if (!aOriginal.GetRoundedRectCount()) {
+memcpy(p, &aOriginal, sizeof(DisplayItemClip));
+return static_cast<DisplayItemClip*>(p);
+}
+DisplayItemClip* c = new (p) DisplayItemClip(aOriginal);
+mDisplayItemClipsToDestroy.AppendElement(c);
+return c;
+}
+void nsDisplayListSet::MoveTo(const nsDisplayListSet& aDestination) const
+{
+aDestination.BorderBackground()->AppendToTop(BorderBackground());
+aDestination.BlockBorderBackgrounds()->AppendToTop(BlockBorderBackgrounds());
+aDestination.Floats()->AppendToTop(Floats());
+aDestination.Content()->AppendToTop(Content());
+aDestination.PositionedDescendants()->AppendToTop(PositionedDescendants());
+aDestination.Outlines()->AppendToTop(Outlines());
+}
+void
+nsDisplayList::FlattenTo(nsTArray<nsDisplayItem*>* aElements) {
+nsDisplayItem* item;
+while ((item = RemoveBottom()) != nullptr) {
+if (item->GetType() == nsDisplayItem::TYPE_WRAP_LIST) {
+item->GetSameCoordinateSystemChildren()->FlattenTo(aElements);
+item->~nsDisplayItem();
+} else {
+aElements->AppendElement(item);
+}
+}
+}
+nsRect
+nsDisplayList::GetBounds(nsDisplayListBuilder* aBuilder) const {
+nsRect bounds;
+for (nsDisplayItem* i = GetBottom(); i != nullptr; i = i->GetAbove()) {
+bounds.UnionRect(bounds, i->GetClippedBounds(aBuilder));
+}
+return bounds;
+}
+bool
+nsDisplayList::ComputeVisibilityForRoot(nsDisplayListBuilder* aBuilder,
+nsRegion* aVisibleRegion,
+nsIFrame* aDisplayPortFrame) {
+PROFILER_LABEL("nsDisplayList", "ComputeVisibilityForRoot");
+nsRegion r;
+r.And(*aVisibleRegion, GetBounds(aBuilder));
+return ComputeVisibilityForSublist(aBuilder, aVisibleRegion,
+r.GetBounds(), r.GetBounds(),
+aDisplayPortFrame);
+}
+static nsRegion
+TreatAsOpaque(nsDisplayItem* aItem, nsDisplayListBuilder* aBuilder)
+{
+bool snap;
+nsRegion opaque = aItem->GetOpaqueRegion(aBuilder, &snap);
+if (aBuilder->IsForPluginGeometry()) {
+// Treat all leaf chrome items as opaque, unless their frames are opacity:0.
+// Since opacity:0 frames generate an nsDisplayOpacity, that item will
+// not be treated as opaque here, so opacity:0 chrome content will be
+// effectively ignored, as it should be.
+// We treat leaf chrome items as opaque to ensure that they cover
+// content plugins, for security reasons.
+// Non-leaf chrome items don't render contents of their own so shouldn't
+// be treated as opaque (and their bounds is just the union of their
+// children, which might be a large area their contents don't really cover).
+nsIFrame* f = aItem->Frame();
+if (f->PresContext()->IsChrome() && !aItem->GetChildren() &&
+f->StyleDisplay()->mOpacity != 0.0) {
+opaque = aItem->GetBounds(aBuilder, &snap);
+}
+}
+if (opaque.IsEmpty()) {
+return opaque;
+}
+nsRegion opaqueClipped;
+nsRegionRectIterator iter(opaque);
+for (const nsRect* r = iter.Next(); r; r = iter.Next()) {
+opaqueClipped.Or(opaqueClipped, aItem->GetClip().ApproximateIntersectInward(*r));
+}
+return opaqueClipped;
+}
+/* Checks if aPotentialScrollItem is a scroll layer item and aPotentialScrollbarItem
+* is an overlay scrollbar item for the same scroll frame.
+*/
+static bool
+IsScrollLayerItemAndOverlayScrollbarForScrollFrame(
+nsDisplayItem* aPotentialScrollItem, nsDisplayItem* aPotentialScrollbarItem)
+{
+if (aPotentialScrollItem->GetType() == nsDisplayItem::TYPE_SCROLL_LAYER &&
+aPotentialScrollbarItem &&
+aPotentialScrollbarItem->GetType() == nsDisplayItem::TYPE_OWN_LAYER &&
+LookAndFeel::GetInt(LookAndFeel::eIntID_UseOverlayScrollbars)) {
+nsDisplayScrollLayer* scrollItem =
+static_cast<nsDisplayScrollLayer*>(aPotentialScrollItem);
+nsDisplayOwnLayer* layerItem =
+static_cast<nsDisplayOwnLayer*>(aPotentialScrollbarItem);
+if ((layerItem->GetFlags() &
+(nsDisplayOwnLayer::VERTICAL_SCROLLBAR |
+nsDisplayOwnLayer::HORIZONTAL_SCROLLBAR)) &&
+layerItem->Frame()->GetParent() == scrollItem->GetScrollFrame()) {
+return true;
+}
+}
+return false;
+}
+bool
+nsDisplayList::ComputeVisibilityForSublist(nsDisplayListBuilder* aBuilder,
+nsRegion* aVisibleRegion,
+const nsRect& aListVisibleBounds,
+const nsRect& aAllowVisibleRegionExpansion,
+nsIFrame* aDisplayPortFrame) {
+#ifdef DEBUG
+nsRegion r;
+r.And(*aVisibleRegion, GetBounds(aBuilder));
+NS_ASSERTION(r.GetBounds().IsEqualInterior(aListVisibleBounds),
+"bad aListVisibleBounds");
+#endif
+mVisibleRect = aListVisibleBounds;
+bool anyVisible = false;
+nsAutoTArray<nsDisplayItem*, 512> elements;
+FlattenTo(&elements);
+bool forceTransparentSurface = false;
+for (int32_t i = elements.Length() - 1; i >= 0; --i) {
+nsDisplayItem* item = elements[i];
+nsDisplayItem* belowItem = i < 1 ? nullptr : elements[i - 1];
+nsDisplayList* list = item->GetSameCoordinateSystemChildren();
+if (aBuilder->AllowMergingAndFlattening()) {
+if (belowItem && item->TryMerge(aBuilder, belowItem)) {
+belowItem->~nsDisplayItem();
+elements.ReplaceElementsAt(i - 1, 1, item);
+continue;
+}
+// If an overlay scrollbar item is between a scroll layer item and the
+// other scroll layer items that we need to merge with just move the
+// scrollbar item up, that way it will be on top of the scrolled content
+// and we can try to merge all the scroll layer items.
+if (IsScrollLayerItemAndOverlayScrollbarForScrollFrame(item, belowItem)) {
+elements[i] = belowItem;
+elements[i-1] = item;
+i++;
+continue;
+}
+if (list && item->ShouldFlattenAway(aBuilder)) {
+// The elements on the list >= i no longer serve any use.
+elements.SetLength(i);
+list->FlattenTo(&elements);
+i = elements.Length();
+item->~nsDisplayItem();
+continue;
+}
+}
+nsRect bounds = item->GetClippedBounds(aBuilder);
+nsRegion itemVisible;
+itemVisible.And(*aVisibleRegion, bounds);
+item->mVisibleRect = itemVisible.GetBounds();
+if (item->ComputeVisibility(aBuilder, aVisibleRegion,
+aAllowVisibleRegionExpansion.Intersect(bounds))) {
+anyVisible = true;
+// If we're in a displayport, we need to make sure that fixed position
+// items do not subtract from the visible region, as async scrolling
+// may expose these occluded areas.
+// If the item is fixed pos in the same document as the displayport
+// then don't let it occlude this list. The only other case possible
+// is that the fixed pos content is in a child document, in which it
+// would scroll with the rest of the content.
+bool occlude = true;
+if (aDisplayPortFrame && item->IsInFixedPos()) {
+if (item->Frame()->PresContext() == aDisplayPortFrame->PresContext()) {
+occlude = false;
+}
+}
+if (occlude) {
+nsRegion opaque = TreatAsOpaque(item, aBuilder);
+// Subtract opaque item from the visible region
+aBuilder->SubtractFromVisibleRegion(aVisibleRegion, opaque);
+}
+if (aBuilder->NeedToForceTransparentSurfaceForItem(item) ||
+(list && list->NeedsTransparentSurface())) {
+forceTransparentSurface = true;
+}
+}
+AppendToBottom(item);
+}
+mIsOpaque = !aVisibleRegion->Intersects(mVisibleRect);
+mForceTransparentSurface = forceTransparentSurface;
+#if defined(DEBUG) || defined(MOZ_DUMP_PAINTING)
+mDidComputeVisibility = true;
+#endif
+return anyVisible;
+}
+void nsDisplayList::PaintRoot(nsDisplayListBuilder* aBuilder,
+nsRenderingContext* aCtx,
+uint32_t aFlags) const {
+PROFILER_LABEL("nsDisplayList", "PaintRoot");
+PaintForFrame(aBuilder, aCtx, aBuilder->RootReferenceFrame(), aFlags);
+}
+/**
+* We paint by executing a layer manager transaction, constructing a
+* single layer representing the display list, and then making it the
+* root of the layer manager, drawing into the ThebesLayers.
+*/
+void nsDisplayList::PaintForFrame(nsDisplayListBuilder* aBuilder,
+nsRenderingContext* aCtx,
+nsIFrame* aForFrame,
+uint32_t aFlags) const {
+NS_ASSERTION(mDidComputeVisibility,
+"Must call ComputeVisibility before calling Paint");
+nsRefPtr<LayerManager> layerManager;
+bool widgetTransaction = false;
+bool allowRetaining = false;
+bool doBeginTransaction = true;
+nsView *view = nullptr;
+if (aFlags & PAINT_USE_WIDGET_LAYERS) {
+nsIFrame* rootReferenceFrame = aBuilder->RootReferenceFrame();
+view = rootReferenceFrame->GetView();
+NS_ASSERTION(rootReferenceFrame == nsLayoutUtils::GetDisplayRootFrame(rootReferenceFrame),
+"Reference frame must be a display root for us to use the layer manager");
+nsIWidget* window = rootReferenceFrame->GetNearestWidget();
+if (window) {
+layerManager = window->GetLayerManager(&allowRetaining);
+if (layerManager) {
+doBeginTransaction = !(aFlags & PAINT_EXISTING_TRANSACTION);
+widgetTransaction = true;
+}
+}
+}
+if (!layerManager) {
+if (!aCtx) {
+NS_WARNING("Nowhere to paint into");
+return;
+}
+layerManager = new BasicLayerManager();
+}
+// Store the existing layer builder to reinstate it on return.
+FrameLayerBuilder *oldBuilder = layerManager->GetLayerBuilder();
+FrameLayerBuilder *layerBuilder = new FrameLayerBuilder();
+layerBuilder->Init(aBuilder, layerManager);
+if (aFlags & PAINT_COMPRESSED) {
+layerBuilder->SetLayerTreeCompressionMode();
+}
+if (aFlags & PAINT_FLUSH_LAYERS) {
+FrameLayerBuilder::InvalidateAllLayers(layerManager);
+}
+if (doBeginTransaction) {
+if (aCtx) {
+layerManager->BeginTransactionWithTarget(aCtx->ThebesContext());
+} else {
+layerManager->BeginTransaction();
+}
+}
+if (widgetTransaction) {
+layerBuilder->DidBeginRetainedLayerTransaction(layerManager);
+}
+nsPresContext* presContext = aForFrame->PresContext();
+nsIPresShell* presShell = presContext->GetPresShell();
+NotifySubDocInvalidationFunc computeInvalidFunc =
+presContext->MayHavePaintEventListenerInSubDocument() ? nsPresContext::NotifySubDocInvalidation : 0;
+bool computeInvalidRect = (computeInvalidFunc ||
+(!layerManager->IsCompositingCheap() && layerManager->NeedsWidgetInvalidation())) &&
+widgetTransaction;
+nsAutoPtr<LayerProperties> props(computeInvalidRect ?
+LayerProperties::CloneFrom(layerManager->GetRoot()) :
+nullptr);
+ContainerLayerParameters containerParameters
+(presShell->GetXResolution(), presShell->GetYResolution());
+nsRefPtr<ContainerLayer> root = layerBuilder->
+BuildContainerLayerFor(aBuilder, layerManager, aForFrame, nullptr, *this,
+containerParameters, nullptr);
+nsIDocument* document = nullptr;
+if (presShell) {
+document = presShell->GetDocument();
+}
+if (widgetTransaction ||
+// SVG-as-an-image docs don't paint as part of the retained layer tree,
+// but they still need the invalidation state bits cleared in order for
+// invalidation for CSS/SMIL animation to work properly.
+(document && document->IsBeingUsedAsImage())) {
+aForFrame->ClearInvalidationStateBits();
+}
+if (!root) {
+layerManager->SetUserData(&gLayerManagerLayerBuilder, oldBuilder);
+return;
+}
+// Root is being scaled up by the X/Y resolution. Scale it back down.
+root->SetPostScale(1.0f/containerParameters.mXScale,
+1.0f/containerParameters.mYScale);
+ViewID id = FrameMetrics::NULL_SCROLL_ID;
+bool isRoot = presContext->IsRootContentDocument();
+nsIFrame* rootScrollFrame = presShell->GetRootScrollFrame();
+nsRect displayport, criticalDisplayport;
+bool usingDisplayport = false;
+bool usingCriticalDisplayport = false;
+if (rootScrollFrame) {
+nsIContent* content = rootScrollFrame->GetContent();
+if (content) {
+usingDisplayport = nsLayoutUtils::GetDisplayPort(content, &displayport);
+usingCriticalDisplayport =
+nsLayoutUtils::GetCriticalDisplayPort(content, &criticalDisplayport);
+// If this is the root content document, we want it to have a scroll id.
+if (isRoot) {
+id = nsLayoutUtils::FindOrCreateIDFor(content);
+}
+}
+}
+nsRect viewport(aBuilder->ToReferenceFrame(aForFrame), aForFrame->GetSize());
+RecordFrameMetrics(aForFrame, rootScrollFrame,
+aBuilder->FindReferenceFrameFor(aForFrame),
+root, mVisibleRect, viewport,
+(usingDisplayport ? &displayport : nullptr),
+(usingCriticalDisplayport ? &criticalDisplayport : nullptr),
+id, isRoot, containerParameters);
+if (usingDisplayport &&
+!(root->GetContentFlags() & Layer::CONTENT_OPAQUE)) {
+// See bug 693938, attachment 567017
+NS_WARNING("Transparent content with displayports can be expensive.");
+}
+layerManager->SetRoot(root);
+layerBuilder->WillEndTransaction();
+bool temp = aBuilder->SetIsCompositingCheap(layerManager->IsCompositingCheap());
+LayerManager::EndTransactionFlags flags = LayerManager::END_DEFAULT;
+if (layerManager->NeedsWidgetInvalidation()) {
+if (aFlags & PAINT_NO_COMPOSITE) {
+flags = LayerManager::END_NO_COMPOSITE;
+}
+} else {
+// Client layer managers never composite directly, so
+// we don't need to worry about END_NO_COMPOSITE.
+if (aBuilder->WillComputePluginGeometry()) {
+flags = LayerManager::END_NO_REMOTE_COMPOSITE;
+}
+}
+layerManager->EndTransaction(FrameLayerBuilder::DrawThebesLayer,
+aBuilder, flags);
+aBuilder->SetIsCompositingCheap(temp);
+layerBuilder->DidEndTransaction();
+nsIntRegion invalid;
+if (props) {
+invalid = props->ComputeDifferences(root, computeInvalidFunc);
+} else if (widgetTransaction) {
+LayerProperties::ClearInvalidations(root);
+}
+bool shouldInvalidate = layerManager->NeedsWidgetInvalidation();
+if (view) {
+if (props) {
+if (!invalid.IsEmpty()) {
+nsIntRect bounds = invalid.GetBounds();
+nsRect rect(presContext->DevPixelsToAppUnits(bounds.x),
+presContext->DevPixelsToAppUnits(bounds.y),
+presContext->DevPixelsToAppUnits(bounds.width),
+presContext->DevPixelsToAppUnits(bounds.height));
+if (shouldInvalidate) {
+view->GetViewManager()->InvalidateViewNoSuppression(view, rect);
+}
+presContext->NotifyInvalidation(bounds, 0);
+}
+} else if (shouldInvalidate) {
+view->GetViewManager()->InvalidateView(view);
+}
+}
+if (aFlags & PAINT_FLUSH_LAYERS) {
+FrameLayerBuilder::InvalidateAllLayers(layerManager);
+}
+layerManager->SetUserData(&gLayerManagerLayerBuilder, oldBuilder);
+}
+uint32_t nsDisplayList::Count() const {
+uint32_t count = 0;
+for (nsDisplayItem* i = GetBottom(); i; i = i->GetAbove()) {
+++count;
+}
+return count;
+}
+nsDisplayItem* nsDisplayList::RemoveBottom() {
+nsDisplayItem* item = mSentinel.mAbove;
+if (!item)
+return nullptr;
+mSentinel.mAbove = item->mAbove;
+if (item == mTop) {
+// must have been the only item
+mTop = &mSentinel;
+}
+item->mAbove = nullptr;
+return item;
+}
+void nsDisplayList::DeleteAll() {
+nsDisplayItem* item;
+while ((item = RemoveBottom()) != nullptr) {
+item->~nsDisplayItem();
+}
+}
+static bool
+GetMouseThrough(const nsIFrame* aFrame)
+{
+if (!aFrame->IsBoxFrame())
+return false;
+const nsIFrame* frame = aFrame;
+while (frame) {
+if (frame->GetStateBits() & NS_FRAME_MOUSE_THROUGH_ALWAYS) {
+return true;
+} else if (frame->GetStateBits() & NS_FRAME_MOUSE_THROUGH_NEVER) {
+return false;
+}
+frame = frame->GetParentBox();
+}
+return false;
+}
+static bool
+IsFrameReceivingPointerEvents(nsIFrame* aFrame)
+{
+nsSubDocumentFrame* frame = do_QueryFrame(aFrame);
+if (frame && frame->PassPointerEventsToChildren()) {
+return true;
+}
+return NS_STYLE_POINTER_EVENTS_NONE !=
+aFrame->StyleVisibility()->GetEffectivePointerEvents(aFrame);
+}
+// A list of frames, and their z depth. Used for sorting
+// the results of hit testing.
+struct FramesWithDepth
+{
+FramesWithDepth(float aDepth) :
+mDepth(aDepth)
+{}
+bool operator<(const FramesWithDepth& aOther) const {
+if (mDepth != aOther.mDepth) {
+// We want to sort so that the shallowest item (highest depth value) is first
+return mDepth > aOther.mDepth;
+}
+return this < &aOther;
+}
+bool operator==(const FramesWithDepth& aOther) const {
+return this == &aOther;
+}
+float mDepth;
+nsTArray<nsIFrame*> mFrames;
+};
+// Sort the frames by depth and then moves all the contained frames to the destination
+void FlushFramesArray(nsTArray<FramesWithDepth>& aSource, nsTArray<nsIFrame*>* aDest)
+{
+if (aSource.IsEmpty()) {
+return;
+}
+aSource.Sort();
+uint32_t length = aSource.Length();
+for (uint32_t i = 0; i < length; i++) {
+aDest->MoveElementsFrom(aSource[i].mFrames);
+}
+aSource.Clear();
+}
+void nsDisplayList::HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
+nsDisplayItem::HitTestState* aState,
+nsTArray<nsIFrame*> *aOutFrames) const {
+int32_t itemBufferStart = aState->mItemBuffer.Length();
+nsDisplayItem* item;
+for (item = GetBottom(); item; item = item->GetAbove()) {
+aState->mItemBuffer.AppendElement(item);
+}
+nsAutoTArray<FramesWithDepth, 16> temp;
+for (int32_t i = aState->mItemBuffer.Length() - 1; i >= itemBufferStart; --i) {
+// Pop element off the end of the buffer. We want to shorten the buffer
+// so that recursive calls to HitTest have more buffer space.
+item = aState->mItemBuffer[i];
+aState->mItemBuffer.SetLength(i);
+bool snap;
+nsRect r = item->GetBounds(aBuilder, &snap).Intersect(aRect);
+if (item->GetClip().MayIntersect(r)) {
+nsAutoTArray<nsIFrame*, 16> outFrames;
+item->HitTest(aBuilder, aRect, aState, &outFrames);
+// For 3d transforms with preserve-3d we add hit frames into the temp list
+// so we can sort them later, otherwise we add them directly to the output list.
+nsTArray<nsIFrame*> *writeFrames = aOutFrames;
+if (item->GetType() == nsDisplayItem::TYPE_TRANSFORM &&
+item->Frame()->Preserves3D()) {
+if (outFrames.Length()) {
+nsDisplayTransform *transform = static_cast<nsDisplayTransform*>(item);
+nsPoint point = aRect.TopLeft();
+// A 1x1 rect means a point, otherwise use the center of the rect
+if (aRect.width != 1 || aRect.height != 1) {
+point = aRect.Center();
+}
+temp.AppendElement(FramesWithDepth(transform->GetHitDepthAtPoint(aBuilder, point)));
+writeFrames = &temp[temp.Length() - 1].mFrames;
+}
+} else {
+// We may have just finished a run of consecutive preserve-3d transforms,
+// so flush these into the destination array before processing our frame list.
+FlushFramesArray(temp, aOutFrames);
+}
+for (uint32_t j = 0; j < outFrames.Length(); j++) {
+nsIFrame *f = outFrames.ElementAt(j);
+// Handle the XUL 'mousethrough' feature and 'pointer-events'.
+if (!GetMouseThrough(f) && IsFrameReceivingPointerEvents(f)) {
+writeFrames->AppendElement(f);
+}
+}
+}
+}
+// Clear any remaining preserve-3d transforms.
+FlushFramesArray(temp, aOutFrames);
+NS_ASSERTION(aState->mItemBuffer.Length() == uint32_t(itemBufferStart),
+"How did we forget to pop some elements?");
+}
+static void Sort(nsDisplayList* aList, int32_t aCount, nsDisplayList::SortLEQ aCmp,
+void* aClosure) {
+if (aCount < 2)
+return;
+nsDisplayList list1;
+nsDisplayList list2;
+int i;
+int32_t half = aCount/2;
+bool sorted = true;
+nsDisplayItem* prev = nullptr;
+for (i = 0; i < aCount; ++i) {
+nsDisplayItem* item = aList->RemoveBottom();
+(i < half ? &list1 : &list2)->AppendToTop(item);
+if (sorted && prev && !aCmp(prev, item, aClosure)) {
+sorted = false;
+}
+prev = item;
+}
+if (sorted) {
+aList->AppendToTop(&list1);
+aList->AppendToTop(&list2);
+return;
+}
+Sort(&list1, half, aCmp, aClosure);
+Sort(&list2, aCount - half, aCmp, aClosure);
+for (i = 0; i < aCount; ++i) {
+if (list1.GetBottom() &&
+(!list2.GetBottom() ||
+aCmp(list1.GetBottom(), list2.GetBottom(), aClosure))) {
+aList->AppendToTop(list1.RemoveBottom());
+} else {
+aList->AppendToTop(list2.RemoveBottom());
+}
+}
+}
+static nsIContent* FindContentInDocument(nsDisplayItem* aItem, nsIDocument* aDoc) {
+nsIFrame* f = aItem->Frame();
+while (f) {
+nsPresContext* pc = f->PresContext();
+if (pc->Document() == aDoc) {
+return f->GetContent();
+}
+f = nsLayoutUtils::GetCrossDocParentFrame(pc->PresShell()->GetRootFrame());
+}
+return nullptr;
+}
+static bool IsContentLEQ(nsDisplayItem* aItem1, nsDisplayItem* aItem2,
+void* aClosure) {
+nsIContent* commonAncestor = static_cast<nsIContent*>(aClosure);
+// It's possible that the nsIContent for aItem1 or aItem2 is in a subdocument
+// of commonAncestor, because display items for subdocuments have been
+// mixed into the same list. Ensure that we're looking at content
+// in commonAncestor's document.
+nsIDocument* commonAncestorDoc = commonAncestor->OwnerDoc();
+nsIContent* content1 = FindContentInDocument(aItem1, commonAncestorDoc);
+nsIContent* content2 = FindContentInDocument(aItem2, commonAncestorDoc);
+if (!content1 || !content2) {
+NS_ERROR("Document trees are mixed up!");
+// Something weird going on
+return true;
+}
+return nsLayoutUtils::CompareTreePosition(content1, content2, commonAncestor) <= 0;
+}
+static bool IsZOrderLEQ(nsDisplayItem* aItem1, nsDisplayItem* aItem2,
+void* aClosure) {
+// Note that we can't just take the difference of the two
+// z-indices here, because that might overflow a 32-bit int.
+return aItem1->ZIndex() <= aItem2->ZIndex();
+}
+void nsDisplayList::SortByZOrder(nsDisplayListBuilder* aBuilder,
+nsIContent* aCommonAncestor) {
+Sort(aBuilder, IsZOrderLEQ, aCommonAncestor);
+}
+void nsDisplayList::SortByContentOrder(nsDisplayListBuilder* aBuilder,
+nsIContent* aCommonAncestor) {
+Sort(aBuilder, IsContentLEQ, aCommonAncestor);
+}
+void nsDisplayList::Sort(nsDisplayListBuilder* aBuilder,
+SortLEQ aCmp, void* aClosure) {
+::Sort(this, Count(), aCmp, aClosure);
+}
+void
+nsDisplayItem::AddInvalidRegionForSyncDecodeBackgroundImages(
+nsDisplayListBuilder* aBuilder,
+const nsDisplayItemGeometry* aGeometry,
+nsRegion* aInvalidRegion)
+{
+if (aBuilder->ShouldSyncDecodeImages()) {
+if (!nsCSSRendering::AreAllBackgroundImagesDecodedForFrame(mFrame)) {
+bool snap;
+aInvalidRegion->Or(*aInvalidRegion, GetBounds(aBuilder, &snap));
+}
+}
+}
+/* static */ bool
+nsDisplayItem::ForceActiveLayers()
+{
+static bool sForce = false;
+static bool sForceCached = false;
+if (!sForceCached) {
+Preferences::AddBoolVarCache(&sForce, "layers.force-active", false);
+sForceCached = true;
+}
+return sForce;
+}
+/* static */ int32_t
+nsDisplayItem::MaxActiveLayers()
+{
+static int32_t sMaxLayers = false;
+static bool sMaxLayersCached = false;
+if (!sMaxLayersCached) {
+Preferences::AddIntVarCache(&sMaxLayers, "layers.max-active", -1);
+sMaxLayersCached = true;
+}
+return sMaxLayers;
+}
+int32_t
+nsDisplayItem::ZIndex() const
+{
+if (!mFrame->IsPositioned() && !mFrame->IsFlexItem())
+return 0;
+const nsStylePosition* position = mFrame->StylePosition();
+if (position->mZIndex.GetUnit() == eStyleUnit_Integer)
+return position->mZIndex.GetIntValue();
+// sort the auto and 0 elements together
+return 0;
+}
+bool
+nsDisplayItem::RecomputeVisibility(nsDisplayListBuilder* aBuilder,
+nsRegion* aVisibleRegion) {
+nsRect bounds = GetClippedBounds(aBuilder);
+nsRegion itemVisible;
+itemVisible.And(*aVisibleRegion, bounds);
+mVisibleRect = itemVisible.GetBounds();
+// When we recompute visibility within layers we don't need to
+// expand the visible region for content behind plugins (the plugin
+// is not in the layer).
+if (!ComputeVisibility(aBuilder, aVisibleRegion, nsRect()))
+return false;
+nsRegion opaque = TreatAsOpaque(this, aBuilder);
+aBuilder->SubtractFromVisibleRegion(aVisibleRegion, opaque);
+return true;
+}
+nsRect
+nsDisplayItem::GetClippedBounds(nsDisplayListBuilder* aBuilder)
+{
+bool snap;
+nsRect r = GetBounds(aBuilder, &snap);
+return GetClip().ApplyNonRoundedIntersection(r);
+}
+nsRect
+nsDisplaySolidColor::GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap)
+{
+*aSnap = true;
+return mBounds;
+}
+void
+nsDisplaySolidColor::Paint(nsDisplayListBuilder* aBuilder,
+nsRenderingContext* aCtx)
+{
+aCtx->SetColor(mColor);
+aCtx->FillRect(mVisibleRect);
+}
+#ifdef MOZ_DUMP_PAINTING
+void
+nsDisplaySolidColor::WriteDebugInfo(nsACString& aTo)
+{
+aTo += nsPrintfCString(" (rgba %d,%d,%d,%d)",
+NS_GET_R(mColor), NS_GET_G(mColor),
+NS_GET_B(mColor), NS_GET_A(mColor));
+}
+#endif
+static void
+RegisterThemeGeometry(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame)
+{
+nsIFrame* displayRoot = nsLayoutUtils::GetDisplayRootFrame(aFrame);
+for (nsIFrame* f = aFrame; f; f = f->GetParent()) {
+// Bail out if we're in a transformed subtree
+if (f->IsTransformed())
+return;
+// Bail out if we're not in the displayRoot's document
+if (!f->GetParent() && f != displayRoot)
+return;
+}
+nsRect borderBox(aFrame->GetOffsetTo(displayRoot), aFrame->GetSize());
+aBuilder->RegisterThemeGeometry(aFrame->StyleDisplay()->mAppearance,
+borderBox.ToNearestPixels(aFrame->PresContext()->AppUnitsPerDevPixel()));
+}
+nsDisplayBackgroundImage::nsDisplayBackgroundImage(nsDisplayListBuilder* aBuilder,
+nsIFrame* aFrame,
+uint32_t aLayer,
+const nsStyleBackground* aBackgroundStyle)
+: nsDisplayImageContainer(aBuilder, aFrame)
+, mBackgroundStyle(aBackgroundStyle)
+, mLayer(aLayer)
+{
+MOZ_COUNT_CTOR(nsDisplayBackgroundImage);
+mBounds = GetBoundsInternal(aBuilder);
+}
+nsDisplayBackgroundImage::~nsDisplayBackgroundImage()
+{
+#ifdef NS_BUILD_REFCNT_LOGGING
+MOZ_COUNT_DTOR(nsDisplayBackgroundImage);
+#endif
+}
+static nsStyleContext* GetBackgroundStyleContext(nsIFrame* aFrame)
+{
+nsStyleContext *sc;
+if (!nsCSSRendering::FindBackground(aFrame, &sc)) {
+// We don't want to bail out if moz-appearance is set on a root
+// node. If it has a parent content node, bail because it's not
+// a root, other wise keep going in order to let the theme stuff
+// draw the background. The canvas really should be drawing the
+// bg, but there's no way to hook that up via css.
+if (!aFrame->StyleDisplay()->mAppearance) {
+return nullptr;
+}
+nsIContent* content = aFrame->GetContent();
+if (!content || content->GetParent()) {
+return nullptr;
+}
+sc = aFrame->StyleContext();
+}
+return sc;
+}
+/*static*/ bool
+nsDisplayBackgroundImage::AppendBackgroundItemsToTop(nsDisplayListBuilder* aBuilder,
+nsIFrame* aFrame,
+nsDisplayList* aList)
+{
+nsStyleContext* bgSC = nullptr;
+const nsStyleBackground* bg = nullptr;
+nsPresContext* presContext = aFrame->PresContext();
+bool isThemed = aFrame->IsThemed();
+if (!isThemed) {
+bgSC = GetBackgroundStyleContext(aFrame);
+if (bgSC) {
+bg = bgSC->StyleBackground();
+}
+}
+bool drawBackgroundColor = false;
+nscolor color;
+if (!nsCSSRendering::IsCanvasFrame(aFrame) && bg) {
+bool drawBackgroundImage;
+color =
+nsCSSRendering::DetermineBackgroundColor(presContext, bgSC, aFrame,
+drawBackgroundImage, drawBackgroundColor);
+}
+// An auxiliary list is necessary in case we have background blending; if that
+// is the case, background items need to be wrapped by a blend container to
+// isolate blending to the background
+nsDisplayList bgItemList;
+// Even if we don't actually have a background color to paint, we may still need
+// to create an item for hit testing.
+if ((drawBackgroundColor && color != NS_RGBA(0,0,0,0)) ||
+aBuilder->IsForEventDelivery()) {
+bgItemList.AppendNewToTop(
+new (aBuilder) nsDisplayBackgroundColor(aBuilder, aFrame, bg,
+drawBackgroundColor ? color : NS_RGBA(0, 0, 0, 0)));
+}
+if (isThemed) {
+nsDisplayThemedBackground* bgItem =
+new (aBuilder) nsDisplayThemedBackground(aBuilder, aFrame);
+bgItemList.AppendNewToTop(bgItem);
+aList->AppendToTop(&bgItemList);
+return true;
+}
+if (!bg) {
+aList->AppendToTop(&bgItemList);
+return false;
+}
+bool needBlendContainer = false;
+// Passing bg == nullptr in this macro will result in one iteration with
+// i = 0.
+NS_FOR_VISIBLE_BACKGROUND_LAYERS_BACK_TO_FRONT(i, bg) {
+if (bg->mLayers[i].mImage.IsEmpty()) {
+continue;
+}
+if (bg->mLayers[i].mBlendMode != NS_STYLE_BLEND_NORMAL) {
+needBlendContainer = true;
+}
+nsDisplayBackgroundImage* bgItem =
+new (aBuilder) nsDisplayBackgroundImage(aBuilder, aFrame, i, bg);
+bgItemList.AppendNewToTop(bgItem);
+}
+if (needBlendContainer) {
+bgItemList.AppendNewToTop(
+new (aBuilder) nsDisplayBlendContainer(aBuilder, aFrame, &bgItemList));
+}
+aList->AppendToTop(&bgItemList);
+return false;
+}
+// Check that the rounded border of aFrame, added to aToReferenceFrame,
+// intersects aRect.  Assumes that the unrounded border has already
+// been checked for intersection.
+static bool
+RoundedBorderIntersectsRect(nsIFrame* aFrame,
+const nsPoint& aFrameToReferenceFrame,
+const nsRect& aTestRect)
+{
+if (!nsRect(aFrameToReferenceFrame, aFrame->GetSize()).Intersects(aTestRect))
+return false;
+nscoord radii[8];
+return !aFrame->GetBorderRadii(radii) ||
+nsLayoutUtils::RoundedRectIntersectsRect(nsRect(aFrameToReferenceFrame,
+aFrame->GetSize()),
+radii, aTestRect);
+}
+// Returns TRUE if aContainedRect is guaranteed to be contained in
+// the rounded rect defined by aRoundedRect and aRadii. Complex cases are
+// handled conservatively by returning FALSE in some situations where
+// a more thorough analysis could return TRUE.
+//
+// See also RoundedRectIntersectsRect.
+static bool RoundedRectContainsRect(const nsRect& aRoundedRect,
+const nscoord aRadii[8],
+const nsRect& aContainedRect) {
+nsRegion rgn = nsLayoutUtils::RoundedRectIntersectRect(aRoundedRect, aRadii, aContainedRect);
+return rgn.Contains(aContainedRect);
+}
+bool
+nsDisplayBackgroundImage::IsSingleFixedPositionImage(nsDisplayListBuilder* aBuilder,
+const nsRect& aClipRect,
+gfxRect* aDestRect)
+{
+if (!mBackgroundStyle)
+return false;
+if (mBackgroundStyle->mLayers.Length() != 1)
+return false;
+nsPresContext* presContext = mFrame->PresContext();
+uint32_t flags = aBuilder->GetBackgroundPaintFlags();
+nsRect borderArea = nsRect(ToReferenceFrame(), mFrame->GetSize());
+const nsStyleBackground::Layer &layer = mBackgroundStyle->mLayers[mLayer];
+if (layer.mAttachment != NS_STYLE_BG_ATTACHMENT_FIXED)
+return false;
+nsBackgroundLayerState state =
+nsCSSRendering::PrepareBackgroundLayer(presContext,
+mFrame,
+flags,
+borderArea,
+aClipRect,
+*mBackgroundStyle,
+layer);
+nsImageRenderer* imageRenderer = &state.mImageRenderer;
+// We only care about images here, not gradients.
+if (!imageRenderer->IsRasterImage())
+return false;
+int32_t appUnitsPerDevPixel = presContext->AppUnitsPerDevPixel();
+*aDestRect = nsLayoutUtils::RectToGfxRect(state.mFillArea, appUnitsPerDevPixel);
+return true;
+}
+bool
+nsDisplayBackgroundImage::TryOptimizeToImageLayer(LayerManager* aManager,
+nsDisplayListBuilder* aBuilder)
+{
+if (!mBackgroundStyle)
+return false;
+nsPresContext* presContext = mFrame->PresContext();
+uint32_t flags = aBuilder->GetBackgroundPaintFlags();
+nsRect borderArea = nsRect(ToReferenceFrame(), mFrame->GetSize());
+const nsStyleBackground::Layer &layer = mBackgroundStyle->mLayers[mLayer];
+if (layer.mClip != NS_STYLE_BG_CLIP_BORDER) {
+return false;
+}
+nscoord radii[8];
+if (mFrame->GetBorderRadii(radii)) {
+return false;
+}
+nsBackgroundLayerState state =
+nsCSSRendering::PrepareBackgroundLayer(presContext,
+mFrame,
+flags,
+borderArea,
+borderArea,
+*mBackgroundStyle,
+layer);
+nsImageRenderer* imageRenderer = &state.mImageRenderer;
+// We only care about images here, not gradients.
+if (!imageRenderer->IsRasterImage())
+return false;
+nsRefPtr<ImageContainer> imageContainer = imageRenderer->GetContainer(aManager);
+// Image is not ready to be made into a layer yet
+if (!imageContainer)
+return false;
+// We currently can't handle tiled or partial backgrounds.
+if (!state.mDestArea.IsEqualEdges(state.mFillArea)) {
+return false;
+}
+// XXX Ignoring state.mAnchor. ImageLayer drawing snaps mDestArea edges to
+// layer pixel boundaries. This should be OK for now.
+int32_t appUnitsPerDevPixel = presContext->AppUnitsPerDevPixel();
+mDestRect = nsLayoutUtils::RectToGfxRect(state.mDestArea, appUnitsPerDevPixel);
+mImageContainer = imageContainer;
+// Ok, we can turn this into a layer if needed.
+return true;
+}
+already_AddRefed<ImageContainer>
+nsDisplayBackgroundImage::GetContainer(LayerManager* aManager,
+nsDisplayListBuilder *aBuilder)
+{
+if (!TryOptimizeToImageLayer(aManager, aBuilder)) {
+return nullptr;
+}
+nsRefPtr<ImageContainer> container = mImageContainer;
+return container.forget();
+}
+LayerState
+nsDisplayBackgroundImage::GetLayerState(nsDisplayListBuilder* aBuilder,
+LayerManager* aManager,
+const ContainerLayerParameters& aParameters)
+{
+bool animated = false;
+if (mBackgroundStyle) {
+const nsStyleBackground::Layer &layer = mBackgroundStyle->mLayers[mLayer];
+const nsStyleImage* image = &layer.mImage;
+if (image->GetType() == eStyleImageType_Image) {
+imgIRequest* imgreq = image->GetImageData();
+nsCOMPtr<imgIContainer> image;
+if (NS_SUCCEEDED(imgreq->GetImage(getter_AddRefs(image))) && image) {
+if (NS_FAILED(image->GetAnimated(&animated))) {
+animated = false;
+}
+}
+}
+}
+if (!animated ||
+!nsLayoutUtils::AnimatedImageLayersEnabled()) {
+if (!aManager->IsCompositingCheap() ||
+!nsLayoutUtils::GPUImageScalingEnabled()) {
+return LAYER_NONE;
+}
+}
+if (!TryOptimizeToImageLayer(aManager, aBuilder)) {
+return LAYER_NONE;
+}
+if (!animated) {
+mozilla::gfx::IntSize imageSize = mImageContainer->GetCurrentSize();
+NS_ASSERTION(imageSize.width != 0 && imageSize.height != 0, "Invalid image size!");
+gfxRect destRect = mDestRect;
+destRect.width *= aParameters.mXScale;
+destRect.height *= aParameters.mYScale;
+// Calculate the scaling factor for the frame.
+gfxSize scale = gfxSize(destRect.width / imageSize.width, destRect.height / imageSize.height);
+// If we are not scaling at all, no point in separating this into a layer.
+if (scale.width == 1.0f && scale.height == 1.0f) {
+return LAYER_NONE;
+}
+// If the target size is pretty small, no point in using a layer.
+if (destRect.width * destRect.height < 64 * 64) {
+return LAYER_NONE;
+}
+}
+return LAYER_ACTIVE;
+}
+already_AddRefed<Layer>
+nsDisplayBackgroundImage::BuildLayer(nsDisplayListBuilder* aBuilder,
+LayerManager* aManager,
+const ContainerLayerParameters& aParameters)
+{
+nsRefPtr<ImageLayer> layer = static_cast<ImageLayer*>
+(aManager->GetLayerBuilder()->GetLeafLayerFor(aBuilder, this));
+if (!layer) {
+layer = aManager->CreateImageLayer();
+if (!layer)
+return nullptr;
+}
+layer->SetContainer(mImageContainer);
+ConfigureLayer(layer, aParameters.mOffset);
+return layer.forget();
+}
+void
+nsDisplayBackgroundImage::ConfigureLayer(ImageLayer* aLayer, const nsIntPoint& aOffset)
+{
+aLayer->SetFilter(nsLayoutUtils::GetGraphicsFilterForFrame(mFrame));
+mozilla::gfx::IntSize imageSize = mImageContainer->GetCurrentSize();
+NS_ASSERTION(imageSize.width != 0 && imageSize.height != 0, "Invalid image size!");
+gfxPoint p = mDestRect.TopLeft() + aOffset;
+gfx::Matrix transform;
+transform.Translate(p.x, p.y);
+transform.Scale(mDestRect.width/imageSize.width,
+mDestRect.height/imageSize.height);
+aLayer->SetBaseTransform(gfx::Matrix4x4::From2D(transform));
+aLayer->SetVisibleRegion(nsIntRect(0, 0, imageSize.width, imageSize.height));
+}
+void
+nsDisplayBackgroundImage::HitTest(nsDisplayListBuilder* aBuilder,
+const nsRect& aRect,
+HitTestState* aState,
+nsTArray<nsIFrame*> *aOutFrames)
+{
+if (RoundedBorderIntersectsRect(mFrame, ToReferenceFrame(), aRect)) {
+aOutFrames->AppendElement(mFrame);
+}
+}
+bool
+nsDisplayBackgroundImage::ComputeVisibility(nsDisplayListBuilder* aBuilder,
+nsRegion* aVisibleRegion,
+const nsRect& aAllowVisibleRegionExpansion)
+{
+if (!nsDisplayItem::ComputeVisibility(aBuilder, aVisibleRegion,
+aAllowVisibleRegionExpansion)) {
+return false;
+}
+// Return false if the background was propagated away from this
+// frame. We don't want this display item to show up and confuse
+// anything.
+return mBackgroundStyle;
+}
+/* static */ nsRegion
+nsDisplayBackgroundImage::GetInsideClipRegion(nsDisplayItem* aItem,
+nsPresContext* aPresContext,
+uint8_t aClip, const nsRect& aRect,
+bool* aSnap)
+{
+nsRegion result;
+if (aRect.IsEmpty())
+return result;
+nsIFrame *frame = aItem->Frame();
+nscoord radii[8];
+nsRect clipRect;
+bool haveRadii;
+switch (aClip) {
+case NS_STYLE_BG_CLIP_BORDER:
+haveRadii = frame->GetBorderRadii(radii);
+clipRect = nsRect(aItem->ToReferenceFrame(), frame->GetSize());
+break;
+case NS_STYLE_BG_CLIP_PADDING:
+haveRadii = frame->GetPaddingBoxBorderRadii(radii);
+clipRect = frame->GetPaddingRect() - frame->GetPosition() + aItem->ToReferenceFrame();
+break;
+case NS_STYLE_BG_CLIP_CONTENT:
+haveRadii = frame->GetContentBoxBorderRadii(radii);
+clipRect = frame->GetContentRect() - frame->GetPosition() + aItem->ToReferenceFrame();
+break;
+default:
+NS_NOTREACHED("Unknown clip type");
+return result;
+}
+if (haveRadii) {
+*aSnap = false;
+result = nsLayoutUtils::RoundedRectIntersectRect(clipRect, radii, aRect);
+} else {
+result = clipRect.Intersect(aRect);
+}
+return result;
+}
+nsRegion
+nsDisplayBackgroundImage::GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
+bool* aSnap) {
+nsRegion result;
+*aSnap = false;
+if (!mBackgroundStyle)
+return result;
+*aSnap = true;
+// For policies other than EACH_BOX, don't try to optimize here, since
+// this could easily lead to O(N^2) behavior inside InlineBackgroundData,
+// which expects frames to be sent to it in content order, not reverse
+// content order which we'll produce here.
+// Of course, if there's only one frame in the flow, it doesn't matter.
+if (mBackgroundStyle->mBackgroundInlinePolicy == NS_STYLE_BG_INLINE_POLICY_EACH_BOX ||
+(!mFrame->GetPrevContinuation() && !mFrame->GetNextContinuation())) {
+const nsStyleBackground::Layer& layer = mBackgroundStyle->mLayers[mLayer];
+if (layer.mImage.IsOpaque() && layer.mBlendMode == NS_STYLE_BLEND_NORMAL) {
+nsPresContext* presContext = mFrame->PresContext();
+result = GetInsideClipRegion(this, presContext, layer.mClip, mBounds, aSnap);
+}
+}
+return result;
+}
+bool
+nsDisplayBackgroundImage::IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColor) {
+if (!mBackgroundStyle) {
+*aColor = NS_RGBA(0,0,0,0);
+return true;
+}
+return false;
+}
+bool
+nsDisplayBackgroundImage::IsVaryingRelativeToMovingFrame(nsDisplayListBuilder* aBuilder,
+nsIFrame* aFrame)
+{
+if (!mBackgroundStyle)
+return false;
+if (!mBackgroundStyle->HasFixedBackground())
+return false;
+// If aFrame is mFrame or an ancestor in this document, and aFrame is
+// not the viewport frame, then moving aFrame will move mFrame
+// relative to the viewport, so our fixed-pos background will change.
+return aFrame->GetParent() &&
+(aFrame == mFrame ||
+nsLayoutUtils::IsProperAncestorFrame(aFrame, mFrame));
+}
+nsRect
+nsDisplayBackgroundImage::GetPositioningArea()
+{
+if (!mBackgroundStyle) {
+return nsRect();
+}
+nsIFrame* attachedToFrame;
+return nsCSSRendering::ComputeBackgroundPositioningArea(
+mFrame->PresContext(), mFrame,
+nsRect(ToReferenceFrame(), mFrame->GetSize()),
+*mBackgroundStyle, mBackgroundStyle->mLayers[mLayer],
+&attachedToFrame) + ToReferenceFrame();
+}
+bool
+nsDisplayBackgroundImage::RenderingMightDependOnPositioningAreaSizeChange()
+{
+if (!mBackgroundStyle)
+return false;
+nscoord radii[8];
+if (mFrame->GetBorderRadii(radii)) {
+// A change in the size of the positioning area might change the position
+// of the rounded corners.
+return true;
+}
+const nsStyleBackground::Layer &layer = mBackgroundStyle->mLayers[mLayer];
+if (layer.RenderingMightDependOnPositioningAreaSizeChange()) {
+return true;
+}
+return false;
+}
+static void CheckForBorderItem(nsDisplayItem *aItem, uint32_t& aFlags)
+{
+nsDisplayItem* nextItem = aItem->GetAbove();
+while (nextItem && nextItem->GetType() == nsDisplayItem::TYPE_BACKGROUND) {
+nextItem = nextItem->GetAbove();
+}
+if (nextItem &&
+nextItem->Frame() == aItem->Frame() &&
+nextItem->GetType() == nsDisplayItem::TYPE_BORDER) {
+aFlags |= nsCSSRendering::PAINTBG_WILL_PAINT_BORDER;
+}
+}
+void
+nsDisplayBackgroundImage::Paint(nsDisplayListBuilder* aBuilder,
+nsRenderingContext* aCtx) {
+PaintInternal(aBuilder, aCtx, mVisibleRect, nullptr);
+}
+void
+nsDisplayBackgroundImage::PaintInternal(nsDisplayListBuilder* aBuilder,
+nsRenderingContext* aCtx, const nsRect& aBounds,
+nsRect* aClipRect) {
+nsPoint offset = ToReferenceFrame();
+uint32_t flags = aBuilder->GetBackgroundPaintFlags();
+CheckForBorderItem(this, flags);
+nsCSSRendering::PaintBackground(mFrame->PresContext(), *aCtx, mFrame,
+aBounds,
+nsRect(offset, mFrame->GetSize()),
+flags, aClipRect, mLayer);
+}
+void nsDisplayBackgroundImage::ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
+const nsDisplayItemGeometry* aGeometry,
+nsRegion* aInvalidRegion)
+{
+if (!mBackgroundStyle) {
+return;
+}
+const nsDisplayBackgroundGeometry* geometry = static_cast<const nsDisplayBackgroundGeometry*>(aGeometry);
+bool snap;
+nsRect bounds = GetBounds(aBuilder, &snap);
+nsRect positioningArea = GetPositioningArea();
+if (positioningArea.TopLeft() != geometry->mPositioningArea.TopLeft() ||
+(positioningArea.Size() != geometry->mPositioningArea.Size() &&
+RenderingMightDependOnPositioningAreaSizeChange())) {
+// Positioning area changed in a way that could cause everything to change,
+// so invalidate everything (both old and new painting areas).
+aInvalidRegion->Or(bounds, geometry->mBounds);
+if (positioningArea.Size() != geometry->mPositioningArea.Size()) {
+NotifyRenderingChanged();
+}
+return;
+}
+if (aBuilder->ShouldSyncDecodeImages()) {
+if (mBackgroundStyle &&
+!nsCSSRendering::IsBackgroundImageDecodedForStyleContextAndLayer(mBackgroundStyle, mLayer)) {
+aInvalidRegion->Or(*aInvalidRegion, bounds);
+NotifyRenderingChanged();
+}
+}
+if (!bounds.IsEqualInterior(geometry->mBounds)) {
+// Positioning area is unchanged, so invalidate just the change in the
+// painting area.
+aInvalidRegion->Xor(bounds, geometry->mBounds);
+NotifyRenderingChanged();
+}
+}
+nsRect
+nsDisplayBackgroundImage::GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) {
+*aSnap = true;
+return mBounds;
+}
+nsRect
+nsDisplayBackgroundImage::GetBoundsInternal(nsDisplayListBuilder* aBuilder) {
+nsPresContext* presContext = mFrame->PresContext();
+if (!mBackgroundStyle) {
+return nsRect();
+}
+nsRect borderBox = nsRect(ToReferenceFrame(), mFrame->GetSize());
+nsRect clipRect = borderBox;
+if (mFrame->GetType() == nsGkAtoms::canvasFrame) {
+nsCanvasFrame* frame = static_cast<nsCanvasFrame*>(mFrame);
+clipRect = frame->CanvasArea() + ToReferenceFrame();
+}
+const nsStyleBackground::Layer& layer = mBackgroundStyle->mLayers[mLayer];
+return nsCSSRendering::GetBackgroundLayerRect(presContext, mFrame,
+borderBox, clipRect,
+*mBackgroundStyle, layer,
+aBuilder->GetBackgroundPaintFlags());
+}
+uint32_t
+nsDisplayBackgroundImage::GetPerFrameKey()
+{
+return (mLayer << nsDisplayItem::TYPE_BITS) |
+nsDisplayItem::GetPerFrameKey();
+}
+nsDisplayThemedBackground::nsDisplayThemedBackground(nsDisplayListBuilder* aBuilder,
+nsIFrame* aFrame)
+: nsDisplayItem(aBuilder, aFrame)
+{
+MOZ_COUNT_CTOR(nsDisplayThemedBackground);
+const nsStyleDisplay* disp = mFrame->StyleDisplay();
+mAppearance = disp->mAppearance;
+mFrame->IsThemed(disp, &mThemeTransparency);
+// Perform necessary RegisterThemeGeometry
+switch (disp->mAppearance) {
+case NS_THEME_MOZ_MAC_UNIFIED_TOOLBAR:
+case NS_THEME_TOOLBAR:
+case NS_THEME_WINDOW_TITLEBAR:
+case NS_THEME_WINDOW_BUTTON_BOX:
+case NS_THEME_MOZ_MAC_FULLSCREEN_BUTTON:
+case NS_THEME_WINDOW_BUTTON_BOX_MAXIMIZED:
+RegisterThemeGeometry(aBuilder, aFrame);
+break;
+case NS_THEME_WIN_BORDERLESS_GLASS:
+case NS_THEME_WIN_GLASS:
+aBuilder->SetGlassDisplayItem(this);
+break;
+}
+mBounds = GetBoundsInternal();
+}
+nsDisplayThemedBackground::~nsDisplayThemedBackground()
+{
+#ifdef NS_BUILD_REFCNT_LOGGING
+MOZ_COUNT_DTOR(nsDisplayThemedBackground);
+#endif
+}
+#ifdef MOZ_DUMP_PAINTING
+void
+nsDisplayThemedBackground::WriteDebugInfo(nsACString& aTo)
+{
+aTo += nsPrintfCString(" (themed, appearance:%d)", mAppearance);
+}
+#endif
+void
+nsDisplayThemedBackground::HitTest(nsDisplayListBuilder* aBuilder,
+const nsRect& aRect,
+HitTestState* aState,
+nsTArray<nsIFrame*> *aOutFrames)
+{
+// Assume that any point in our border rect is a hit.
+if (nsRect(ToReferenceFrame(), mFrame->GetSize()).Intersects(aRect)) {
+aOutFrames->AppendElement(mFrame);
+}
+}
+nsRegion
+nsDisplayThemedBackground::GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
+bool* aSnap) {
+nsRegion result;
+*aSnap = false;
+if (mThemeTransparency == nsITheme::eOpaque) {
+result = nsRect(ToReferenceFrame(), mFrame->GetSize());
+}
+return result;
+}
+bool
+nsDisplayThemedBackground::IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColor) {
+if (mAppearance == NS_THEME_WIN_BORDERLESS_GLASS ||
+mAppearance == NS_THEME_WIN_GLASS) {
+*aColor = NS_RGBA(0,0,0,0);
+return true;
+}
+return false;
+}
+nsRect
+nsDisplayThemedBackground::GetPositioningArea()
+{
+return nsRect(ToReferenceFrame(), mFrame->GetSize());
+}
+void
+nsDisplayThemedBackground::Paint(nsDisplayListBuilder* aBuilder,
+nsRenderingContext* aCtx)
+{
+PaintInternal(aBuilder, aCtx, mVisibleRect, nullptr);
+}
+void
+nsDisplayThemedBackground::PaintInternal(nsDisplayListBuilder* aBuilder,
+nsRenderingContext* aCtx, const nsRect& aBounds,
+nsRect* aClipRect)
+{
+// XXXzw this ignores aClipRect.
+nsPresContext* presContext = mFrame->PresContext();
+nsITheme *theme = presContext->GetTheme();
+nsRect borderArea(ToReferenceFrame(), mFrame->GetSize());
+nsRect drawing(borderArea);
+theme->GetWidgetOverflow(presContext->DeviceContext(), mFrame, mAppearance,
+&drawing);
+drawing.IntersectRect(drawing, aBounds);
+theme->DrawWidgetBackground(aCtx, mFrame, mAppearance, borderArea, drawing);
+}
+bool nsDisplayThemedBackground::IsWindowActive()
+{
+EventStates docState = mFrame->GetContent()->OwnerDoc()->GetDocumentState();
+return !docState.HasState(NS_DOCUMENT_STATE_WINDOW_INACTIVE);
+}
+void nsDisplayThemedBackground::ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
+const nsDisplayItemGeometry* aGeometry,
+nsRegion* aInvalidRegion)
+{
+const nsDisplayThemedBackgroundGeometry* geometry = static_cast<const nsDisplayThemedBackgroundGeometry*>(aGeometry);
+bool snap;
+nsRect bounds = GetBounds(aBuilder, &snap);
+nsRect positioningArea = GetPositioningArea();
+if (!positioningArea.IsEqualInterior(geometry->mPositioningArea)) {
+// Invalidate everything (both old and new painting areas).
+aInvalidRegion->Or(bounds, geometry->mBounds);
+return;
+}
+if (!bounds.IsEqualInterior(geometry->mBounds)) {
+// Positioning area is unchanged, so invalidate just the change in the
+// painting area.
+aInvalidRegion->Xor(bounds, geometry->mBounds);
+}
+nsITheme* theme = mFrame->PresContext()->GetTheme();
+if (theme->WidgetAppearanceDependsOnWindowFocus(mAppearance) &&
+IsWindowActive() != geometry->mWindowIsActive) {
+aInvalidRegion->Or(*aInvalidRegion, bounds);
+}
+}
+nsRect
+nsDisplayThemedBackground::GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) {
+*aSnap = true;
+return mBounds;
+}
+nsRect
+nsDisplayThemedBackground::GetBoundsInternal() {
+nsPresContext* presContext = mFrame->PresContext();
+nsRect r(nsPoint(0,0), mFrame->GetSize());
+presContext->GetTheme()->
+GetWidgetOverflow(presContext->DeviceContext(), mFrame,
+mFrame->StyleDisplay()->mAppearance, &r);
+#ifdef XP_MACOSX
+// Bug 748219
+r.Inflate(mFrame->PresContext()->AppUnitsPerDevPixel());
+#endif
+return r + ToReferenceFrame();
+}
+void
+nsDisplayBackgroundColor::Paint(nsDisplayListBuilder* aBuilder,
+nsRenderingContext* aCtx)
+{
+if (mColor == NS_RGBA(0, 0, 0, 0)) {
+return;
+}
+nsPoint offset = ToReferenceFrame();
+uint32_t flags = aBuilder->GetBackgroundPaintFlags();
+CheckForBorderItem(this, flags);
+nsCSSRendering::PaintBackgroundColor(mFrame->PresContext(), *aCtx, mFrame,
+mVisibleRect,
+nsRect(offset, mFrame->GetSize()),
+flags);
+}
+nsRegion
+nsDisplayBackgroundColor::GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
+bool* aSnap)
+{
+if (NS_GET_A(mColor) != 255) {
+return nsRegion();
+}
+if (!mBackgroundStyle)
+return nsRegion();
+*aSnap = true;
+const nsStyleBackground::Layer& bottomLayer = mBackgroundStyle->BottomLayer();
+nsRect borderBox = nsRect(ToReferenceFrame(), mFrame->GetSize());
+nsPresContext* presContext = mFrame->PresContext();
+return nsDisplayBackgroundImage::GetInsideClipRegion(this, presContext, bottomLayer.mClip, borderBox, aSnap);
+}
+bool
+nsDisplayBackgroundColor::IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColor)
+{
+*aColor = mColor;
+if (!mBackgroundStyle)
+return true;
+return (!nsLayoutUtils::HasNonZeroCorner(mFrame->StyleBorder()->mBorderRadius) &&
+mBackgroundStyle->BottomLayer().mClip == NS_STYLE_BG_CLIP_BORDER);
+}
+void
+nsDisplayBackgroundColor::HitTest(nsDisplayListBuilder* aBuilder,
+const nsRect& aRect,
+HitTestState* aState,
+nsTArray<nsIFrame*> *aOutFrames)
+{
+if (!RoundedBorderIntersectsRect(mFrame, ToReferenceFrame(), aRect)) {
+// aRect doesn't intersect our border-radius curve.
+return;
+}
+aOutFrames->AppendElement(mFrame);
+}
+#ifdef MOZ_DUMP_PAINTING
+void
+nsDisplayBackgroundColor::WriteDebugInfo(nsACString& aTo)
+{
+aTo += nsPrintfCString(" (rgba %d,%d,%d,%d)",
+NS_GET_R(mColor), NS_GET_G(mColor),
+NS_GET_B(mColor), NS_GET_A(mColor));
+}
+#endif
+nsRect
+nsDisplayOutline::GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) {
+*aSnap = false;
+return mFrame->GetVisualOverflowRectRelativeToSelf() + ToReferenceFrame();
+}
+void
+nsDisplayOutline::Paint(nsDisplayListBuilder* aBuilder,
+nsRenderingContext* aCtx) {
+// TODO join outlines together
+nsPoint offset = ToReferenceFrame();
+nsCSSRendering::PaintOutline(mFrame->PresContext(), *aCtx, mFrame,
+mVisibleRect,
+nsRect(offset, mFrame->GetSize()),
+mFrame->StyleContext());
+}
+bool
+nsDisplayOutline::ComputeVisibility(nsDisplayListBuilder* aBuilder,
+nsRegion* aVisibleRegion,
+const nsRect& aAllowVisibleRegionExpansion) {
+if (!nsDisplayItem::ComputeVisibility(aBuilder, aVisibleRegion,
+aAllowVisibleRegionExpansion)) {
+return false;
+}
+const nsStyleOutline* outline = mFrame->StyleOutline();
+nsRect borderBox(ToReferenceFrame(), mFrame->GetSize());
+if (borderBox.Contains(aVisibleRegion->GetBounds()) &&
+!nsLayoutUtils::HasNonZeroCorner(outline->mOutlineRadius)) {
+if (outline->mOutlineOffset >= 0) {
+// the visible region is entirely inside the border-rect, and the outline
+// isn't rendered inside the border-rect, so the outline is not visible
+return false;
+}
+}
+return true;
+}
+void
+nsDisplayEventReceiver::HitTest(nsDisplayListBuilder* aBuilder,
+const nsRect& aRect,
+HitTestState* aState,
+nsTArray<nsIFrame*> *aOutFrames)
+{
+if (!RoundedBorderIntersectsRect(mFrame, ToReferenceFrame(), aRect)) {
+// aRect doesn't intersect our border-radius curve.
+return;
+}
+aOutFrames->AppendElement(mFrame);
+}
+void
+nsDisplayLayerEventRegions::AddFrame(nsDisplayListBuilder* aBuilder,
+nsIFrame* aFrame)
+{
+NS_ASSERTION(aBuilder->FindReferenceFrameFor(aFrame) == aBuilder->FindReferenceFrameFor(mFrame),
+"Reference frame mismatch");
+uint8_t pointerEvents = aFrame->StyleVisibility()->mPointerEvents;
+if (pointerEvents == NS_STYLE_POINTER_EVENTS_NONE) {
+return;
+}
+// XXX handle other pointerEvents values for SVG
+// XXX Do something clever here for the common case where the border box
+// is obviously entirely inside mHitRegion.
+nsRect borderBox(aBuilder->ToReferenceFrame(aFrame), aFrame->GetSize());
+const DisplayItemClip* clip = aBuilder->ClipState().GetCurrentCombinedClip(aBuilder);
+bool borderBoxHasRoundedCorners =
+nsLayoutUtils::HasNonZeroCorner(aFrame->StyleBorder()->mBorderRadius);
+if (clip) {
+borderBox = clip->ApplyNonRoundedIntersection(borderBox);
+if (clip->GetRoundedRectCount() > 0) {
+borderBoxHasRoundedCorners = true;
+}
+}
+if (borderBoxHasRoundedCorners ||
+(aFrame->GetStateBits() & NS_FRAME_SVG_LAYOUT)) {
+mMaybeHitRegion.Or(mMaybeHitRegion, borderBox);
+} else {
+mHitRegion.Or(mHitRegion, borderBox);
+}
+if (aBuilder->GetAncestorHasTouchEventHandler()) {
+mDispatchToContentHitRegion.Or(mDispatchToContentHitRegion, borderBox);
+}
+}
+void
+nsDisplayCaret::Paint(nsDisplayListBuilder* aBuilder,
+nsRenderingContext* aCtx) {
+// Note: Because we exist, we know that the caret is visible, so we don't
+// need to check for the caret's visibility.
+mCaret->PaintCaret(aBuilder, aCtx, mFrame, ToReferenceFrame());
+}
+bool
+nsDisplayBorder::ComputeVisibility(nsDisplayListBuilder* aBuilder,
+nsRegion* aVisibleRegion,
+const nsRect& aAllowVisibleRegionExpansion) {
+if (!nsDisplayItem::ComputeVisibility(aBuilder, aVisibleRegion,
+aAllowVisibleRegionExpansion)) {
+return false;
+}
+nsRect paddingRect = mFrame->GetPaddingRect() - mFrame->GetPosition() +
+ToReferenceFrame();
+const nsStyleBorder *styleBorder;
+if (paddingRect.Contains(aVisibleRegion->GetBounds()) &&
+!(styleBorder = mFrame->StyleBorder())->IsBorderImageLoaded() &&
+!nsLayoutUtils::HasNonZeroCorner(styleBorder->mBorderRadius)) {
+// the visible region is entirely inside the content rect, and no part
+// of the border is rendered inside the content rect, so we are not
+// visible
+// Skip this if there's a border-image (which draws a background
+// too) or if there is a border-radius (which makes the border draw
+// further in).
+return false;
+}
+return true;
+}
+nsDisplayItemGeometry*
+nsDisplayBorder::AllocateGeometry(nsDisplayListBuilder* aBuilder)
+{
+return new nsDisplayBorderGeometry(this, aBuilder);
+}
+void
+nsDisplayBorder::ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
+const nsDisplayItemGeometry* aGeometry,
+nsRegion* aInvalidRegion)
+{
+const nsDisplayBorderGeometry* geometry = static_cast<const nsDisplayBorderGeometry*>(aGeometry);
+bool snap;
+if (!geometry->mBounds.IsEqualInterior(GetBounds(aBuilder, &snap)) ||
+!geometry->mContentRect.IsEqualInterior(GetContentRect())) {
+// We can probably get away with only invalidating the difference
+// between the border and padding rects, but the XUL ui at least
+// is apparently painting a background with this?
+aInvalidRegion->Or(GetBounds(aBuilder, &snap), geometry->mBounds);
+}
+}
+void
+nsDisplayBorder::Paint(nsDisplayListBuilder* aBuilder,
+nsRenderingContext* aCtx) {
+nsPoint offset = ToReferenceFrame();
+nsCSSRendering::PaintBorder(mFrame->PresContext(), *aCtx, mFrame,
+mVisibleRect,
+nsRect(offset, mFrame->GetSize()),
+mFrame->StyleContext(),
+mFrame->GetSkipSides());
+}
+nsRect
+nsDisplayBorder::GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap)
+{
+*aSnap = true;
+return CalculateBounds(*mFrame->StyleBorder());
+}
+nsRect
+nsDisplayBorder::CalculateBounds(const nsStyleBorder& aStyleBorder)
+{
+nsRect borderBounds(ToReferenceFrame(), mFrame->GetSize());
+if (aStyleBorder.IsBorderImageLoaded()) {
+borderBounds.Inflate(aStyleBorder.GetImageOutset());
+return borderBounds;
+} else {
+nsMargin border = aStyleBorder.GetComputedBorder();
+nsRect result;
+if (border.top > 0) {
+result = nsRect(borderBounds.X(), borderBounds.Y(), borderBounds.Width(), border.top);
+}
+if (border.right > 0) {
+result.UnionRect(result, nsRect(borderBounds.XMost() - border.right, borderBounds.Y(), border.right, borderBounds.Height()));
+}
+if (border.bottom > 0) {
+result.UnionRect(result, nsRect(borderBounds.X(), borderBounds.YMost() - border.bottom, borderBounds.Width(), border.bottom));
+}
+if (border.left > 0) {
+result.UnionRect(result, nsRect(borderBounds.X(), borderBounds.Y(), border.left, borderBounds.Height()));
+}
+return result;
+}
+}
+// Given a region, compute a conservative approximation to it as a list
+// of rectangles that aren't vertically adjacent (i.e., vertically
+// adjacent or overlapping rectangles are combined).
+// Right now this is only approximate, some vertically overlapping rectangles
+// aren't guaranteed to be combined.
+static void
+ComputeDisjointRectangles(const nsRegion& aRegion,
+nsTArray<nsRect>* aRects) {
+nscoord accumulationMargin = nsPresContext::CSSPixelsToAppUnits(25);
+nsRect accumulated;
+nsRegionRectIterator iter(aRegion);
+while (true) {
+const nsRect* r = iter.Next();
+if (r && !accumulated.IsEmpty() &&
+accumulated.YMost() >= r->y - accumulationMargin) {
+accumulated.UnionRect(accumulated, *r);
+continue;
+}
+if (!accumulated.IsEmpty()) {
+aRects->AppendElement(accumulated);
+accumulated.SetEmpty();
+}
+if (!r)
+break;
+accumulated = *r;
+}
+}
+void
+nsDisplayBoxShadowOuter::Paint(nsDisplayListBuilder* aBuilder,
+nsRenderingContext* aCtx) {
+nsPoint offset = ToReferenceFrame();
+nsRect borderRect = mFrame->VisualBorderRectRelativeToSelf() + offset;
+nsPresContext* presContext = mFrame->PresContext();
+nsAutoTArray<nsRect,10> rects;
+ComputeDisjointRectangles(mVisibleRegion, &rects);
+PROFILER_LABEL("nsDisplayBoxShadowOuter", "Paint");
+for (uint32_t i = 0; i < rects.Length(); ++i) {
+aCtx->PushState();
+aCtx->IntersectClip(rects[i]);
+nsCSSRendering::PaintBoxShadowOuter(presContext, *aCtx, mFrame,
+borderRect, rects[i], mOpacity);
+aCtx->PopState();
+}
+}
+nsRect
+nsDisplayBoxShadowOuter::GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) {
+*aSnap = false;
+return mBounds;
+}
+nsRect
+nsDisplayBoxShadowOuter::GetBoundsInternal() {
+return nsLayoutUtils::GetBoxShadowRectForFrame(mFrame, mFrame->GetSize()) +
+ToReferenceFrame();
+}
+bool
+nsDisplayBoxShadowOuter::ComputeVisibility(nsDisplayListBuilder* aBuilder,
+nsRegion* aVisibleRegion,
+const nsRect& aAllowVisibleRegionExpansion) {
+if (!nsDisplayItem::ComputeVisibility(aBuilder, aVisibleRegion,
+aAllowVisibleRegionExpansion)) {
+return false;
+}
+// Store the actual visible region
+mVisibleRegion.And(*aVisibleRegion, mVisibleRect);
+nsPoint origin = ToReferenceFrame();
+nsRect visibleBounds = aVisibleRegion->GetBounds();
+nsRect frameRect(origin, mFrame->GetSize());
+if (!frameRect.Contains(visibleBounds))
+return true;
+// the visible region is entirely inside the border-rect, and box shadows
+// never render within the border-rect (unless there's a border radius).
+nscoord twipsRadii[8];
+bool hasBorderRadii = mFrame->GetBorderRadii(twipsRadii);
+if (!hasBorderRadii)
+return false;
+return !RoundedRectContainsRect(frameRect, twipsRadii, visibleBounds);
+}
+void
+nsDisplayBoxShadowOuter::ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
+const nsDisplayItemGeometry* aGeometry,
+nsRegion* aInvalidRegion)
+{
+const nsDisplayItemGenericGeometry* geometry =
+static_cast<const nsDisplayItemGenericGeometry*>(aGeometry);
+bool snap;
+if (!geometry->mBounds.IsEqualInterior(GetBounds(aBuilder, &snap)) ||
+!geometry->mBorderRect.IsEqualInterior(GetBorderRect())) {
+nsRegion oldShadow, newShadow;
+nscoord dontCare[8];
+bool hasBorderRadius = mFrame->GetBorderRadii(dontCare);
+if (hasBorderRadius) {
+// If we have rounded corners then we need to invalidate the frame area
+// too since we paint into it.
+oldShadow = geometry->mBounds;
+newShadow = GetBounds(aBuilder, &snap);
+} else {
+oldShadow = oldShadow.Sub(geometry->mBounds, geometry->mBorderRect);
+newShadow = newShadow.Sub(GetBounds(aBuilder, &snap), GetBorderRect());
+}
+aInvalidRegion->Or(oldShadow, newShadow);
+}
+}
+void
+nsDisplayBoxShadowInner::Paint(nsDisplayListBuilder* aBuilder,
+nsRenderingContext* aCtx) {
+nsPoint offset = ToReferenceFrame();
+nsRect borderRect = nsRect(offset, mFrame->GetSize());
+nsPresContext* presContext = mFrame->PresContext();
+nsAutoTArray<nsRect,10> rects;
+ComputeDisjointRectangles(mVisibleRegion, &rects);
+PROFILER_LABEL("nsDisplayBoxShadowInner", "Paint");
+for (uint32_t i = 0; i < rects.Length(); ++i) {
+aCtx->PushState();
+aCtx->IntersectClip(rects[i]);
+nsCSSRendering::PaintBoxShadowInner(presContext, *aCtx, mFrame,
+borderRect, rects[i]);
+aCtx->PopState();
+}
+}
+bool
+nsDisplayBoxShadowInner::ComputeVisibility(nsDisplayListBuilder* aBuilder,
+nsRegion* aVisibleRegion,
+const nsRect& aAllowVisibleRegionExpansion) {
+if (!nsDisplayItem::ComputeVisibility(aBuilder, aVisibleRegion,
+aAllowVisibleRegionExpansion)) {
+return false;
+}
+// Store the actual visible region
+mVisibleRegion.And(*aVisibleRegion, mVisibleRect);
+return true;
+}
+nsDisplayWrapList::nsDisplayWrapList(nsDisplayListBuilder* aBuilder,
+nsIFrame* aFrame, nsDisplayList* aList)
+: nsDisplayItem(aBuilder, aFrame)
+, mOverrideZIndex(0)
+{
+mList.AppendToTop(aList);
+UpdateBounds(aBuilder);
+if (!aFrame || !aFrame->IsTransformed()) {
+return;
+}
+// If the frame is a preserve-3d parent, then we will create transforms
+// inside this list afterwards (see WrapPreserve3DList in nsFrame.cpp).
+// In this case we will always be outside of the transform, so share
+// our parents reference frame.
+if (aFrame->Preserves3DChildren()) {
+mReferenceFrame =
+aBuilder->FindReferenceFrameFor(GetTransformRootFrame(aFrame));
+mToReferenceFrame = aFrame->GetOffsetToCrossDoc(mReferenceFrame);
+return;
+}
+// If we're a transformed frame, then we need to find out if we're inside
+// the nsDisplayTransform or outside of it. Frames inside the transform
+// need mReferenceFrame == mFrame, outside needs the next ancestor
+// reference frame.
+// If we're inside the transform, then the nsDisplayItem constructor
+// will have done the right thing.
+// If we're outside the transform, then we should have only one child
+// (since nsDisplayTransform wraps all actual content), and that child
+// will have the correct reference frame set (since nsDisplayTransform
+// handles this explictly).
+//
+// Preserve-3d can cause us to have multiple nsDisplayTransform
+// children.
+nsDisplayItem *i = mList.GetBottom();
+if (i && (!i->GetAbove() || i->GetType() == TYPE_TRANSFORM) &&
+i->Frame() == mFrame) {
+mReferenceFrame = i->ReferenceFrame();
+mToReferenceFrame = i->ToReferenceFrame();
+}
+}
+nsDisplayWrapList::nsDisplayWrapList(nsDisplayListBuilder* aBuilder,
+nsIFrame* aFrame, nsDisplayItem* aItem)
+: nsDisplayItem(aBuilder, aFrame)
+, mOverrideZIndex(0)
+{
+mList.AppendToTop(aItem);
+UpdateBounds(aBuilder);
+if (!aFrame || !aFrame->IsTransformed()) {
+return;
+}
+if (aFrame->Preserves3DChildren()) {
+mReferenceFrame =
+aBuilder->FindReferenceFrameFor(GetTransformRootFrame(aFrame));
+mToReferenceFrame = aFrame->GetOffsetToCrossDoc(mReferenceFrame);
+return;
+}
+// See the previous nsDisplayWrapList constructor
+if (aItem->Frame() == aFrame) {
+mReferenceFrame = aItem->ReferenceFrame();
+mToReferenceFrame = aItem->ToReferenceFrame();
+}
+}
+nsDisplayWrapList::nsDisplayWrapList(nsDisplayListBuilder* aBuilder,
+nsIFrame* aFrame, nsDisplayItem* aItem,
+const nsIFrame* aReferenceFrame,
+const nsPoint& aToReferenceFrame)
+: nsDisplayItem(aBuilder, aFrame, aReferenceFrame, aToReferenceFrame)
+, mOverrideZIndex(0)
+{
+mList.AppendToTop(aItem);
+mBounds = mList.GetBounds(aBuilder);
+}
+nsDisplayWrapList::~nsDisplayWrapList() {
+mList.DeleteAll();
+}
+void
+nsDisplayWrapList::HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
+HitTestState* aState, nsTArray<nsIFrame*> *aOutFrames) {
+mList.HitTest(aBuilder, aRect, aState, aOutFrames);
+}
+nsRect
+nsDisplayWrapList::GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) {
+*aSnap = false;
+return mBounds;
+}
+bool
+nsDisplayWrapList::ComputeVisibility(nsDisplayListBuilder* aBuilder,
+nsRegion* aVisibleRegion,
+const nsRect& aAllowVisibleRegionExpansion) {
+// Convert the passed in visible region to our appunits.
+nsRegion visibleRegion;
+// mVisibleRect has been clipped to GetClippedBounds
+visibleRegion.And(*aVisibleRegion, mVisibleRect);
+nsRegion originalVisibleRegion = visibleRegion;
+bool retval =
+mList.ComputeVisibilityForSublist(aBuilder, &visibleRegion,
+mVisibleRect,
+aAllowVisibleRegionExpansion);
+nsRegion removed;
+// removed = originalVisibleRegion - visibleRegion
+removed.Sub(originalVisibleRegion, visibleRegion);
+// aVisibleRegion = aVisibleRegion - removed (modulo any simplifications
+// SubtractFromVisibleRegion does)
+aBuilder->SubtractFromVisibleRegion(aVisibleRegion, removed);
+return retval;
+}
+nsRegion
+nsDisplayWrapList::GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
+bool* aSnap) {
+*aSnap = false;
+nsRegion result;
+if (mList.IsOpaque()) {
+// Everything within GetBounds that's visible is opaque.
+result = GetBounds(aBuilder, aSnap);
+}
+return result;
+}
+bool nsDisplayWrapList::IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColor) {
+// We could try to do something but let's conservatively just return false.
+return false;
+}
+bool nsDisplayWrapList::IsVaryingRelativeToMovingFrame(nsDisplayListBuilder* aBuilder,
+nsIFrame* aFrame) {
+NS_WARNING("nsDisplayWrapList::IsVaryingRelativeToMovingFrame called unexpectedly");
+// We could try to do something but let's conservatively just return true.
+return true;
+}
+void nsDisplayWrapList::Paint(nsDisplayListBuilder* aBuilder,
+nsRenderingContext* aCtx) {
+NS_ERROR("nsDisplayWrapList should have been flattened away for painting");
+}
+/**
+* Returns true if all descendant display items can be placed in the same
+* ThebesLayer --- GetLayerState returns LAYER_INACTIVE or LAYER_NONE,
+* and they all have the expected animated geometry root.
+*/
+static LayerState
+RequiredLayerStateForChildren(nsDisplayListBuilder* aBuilder,
+LayerManager* aManager,
+const ContainerLayerParameters& aParameters,
+const nsDisplayList& aList,
+nsIFrame* aExpectedAnimatedGeometryRootForChildren)
+{
+LayerState result = LAYER_INACTIVE;
+for (nsDisplayItem* i = aList.GetBottom(); i; i = i->GetAbove()) {
+if (result == LAYER_INACTIVE &&
+nsLayoutUtils::GetAnimatedGeometryRootFor(i, aBuilder) !=
+aExpectedAnimatedGeometryRootForChildren) {
+result = LAYER_ACTIVE;
+}
+LayerState state = i->GetLayerState(aBuilder, aManager, aParameters);
+if ((state == LAYER_ACTIVE || state == LAYER_ACTIVE_FORCE) &&
+state > result) {
+result = state;
+}
+if (state == LAYER_ACTIVE_EMPTY && state > result) {
+result = LAYER_ACTIVE_FORCE;
+}
+if (state == LAYER_NONE) {
+nsDisplayList* list = i->GetSameCoordinateSystemChildren();
+if (list) {
+LayerState childState =
+RequiredLayerStateForChildren(aBuilder, aManager, aParameters, *list,
+aExpectedAnimatedGeometryRootForChildren);
+if (childState > result) {
+result = childState;
+}
+}
+}
+}
+return result;
+}
+nsRect nsDisplayWrapList::GetComponentAlphaBounds(nsDisplayListBuilder* aBuilder)
+{
+nsRect bounds;
+for (nsDisplayItem* i = mList.GetBottom(); i; i = i->GetAbove()) {
+bounds.UnionRect(bounds, i->GetComponentAlphaBounds(aBuilder));
+}
+return bounds;
+}
+static nsresult
+WrapDisplayList(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
+nsDisplayList* aList, nsDisplayWrapper* aWrapper) {
+if (!aList->GetTop())
+return NS_OK;
+nsDisplayItem* item = aWrapper->WrapList(aBuilder, aFrame, aList);
+if (!item)
+return NS_ERROR_OUT_OF_MEMORY;
+// aList was emptied
+aList->AppendToTop(item);
+return NS_OK;
+}
+static nsresult
+WrapEachDisplayItem(nsDisplayListBuilder* aBuilder,
+nsDisplayList* aList, nsDisplayWrapper* aWrapper) {
+nsDisplayList newList;
+nsDisplayItem* item;
+while ((item = aList->RemoveBottom())) {
+item = aWrapper->WrapItem(aBuilder, item);
+if (!item)
+return NS_ERROR_OUT_OF_MEMORY;
+newList.AppendToTop(item);
+}
+// aList was emptied
+aList->AppendToTop(&newList);
+return NS_OK;
+}
+nsresult nsDisplayWrapper::WrapLists(nsDisplayListBuilder* aBuilder,
+nsIFrame* aFrame, const nsDisplayListSet& aIn, const nsDisplayListSet& aOut)
+{
+nsresult rv = WrapListsInPlace(aBuilder, aFrame, aIn);
+NS_ENSURE_SUCCESS(rv, rv);
+if (&aOut == &aIn)
+return NS_OK;
+aOut.BorderBackground()->AppendToTop(aIn.BorderBackground());
+aOut.BlockBorderBackgrounds()->AppendToTop(aIn.BlockBorderBackgrounds());
+aOut.Floats()->AppendToTop(aIn.Floats());
+aOut.Content()->AppendToTop(aIn.Content());
+aOut.PositionedDescendants()->AppendToTop(aIn.PositionedDescendants());
+aOut.Outlines()->AppendToTop(aIn.Outlines());
+return NS_OK;
+}
+nsresult nsDisplayWrapper::WrapListsInPlace(nsDisplayListBuilder* aBuilder,
+nsIFrame* aFrame, const nsDisplayListSet& aLists)
+{
+nsresult rv;
+if (WrapBorderBackground()) {
+// Our border-backgrounds are in-flow
+rv = WrapDisplayList(aBuilder, aFrame, aLists.BorderBackground(), this);
+NS_ENSURE_SUCCESS(rv, rv);
+}
+// Our block border-backgrounds are in-flow
+rv = WrapDisplayList(aBuilder, aFrame, aLists.BlockBorderBackgrounds(), this);
+NS_ENSURE_SUCCESS(rv, rv);
+// The floats are not in flow
+rv = WrapEachDisplayItem(aBuilder, aLists.Floats(), this);
+NS_ENSURE_SUCCESS(rv, rv);
+// Our child content is in flow
+rv = WrapDisplayList(aBuilder, aFrame, aLists.Content(), this);
+NS_ENSURE_SUCCESS(rv, rv);
+// The positioned descendants may not be in-flow
+rv = WrapEachDisplayItem(aBuilder, aLists.PositionedDescendants(), this);
+NS_ENSURE_SUCCESS(rv, rv);
+// The outlines may not be in-flow
+return WrapEachDisplayItem(aBuilder, aLists.Outlines(), this);
+}
+nsDisplayOpacity::nsDisplayOpacity(nsDisplayListBuilder* aBuilder,
+nsIFrame* aFrame, nsDisplayList* aList)
+: nsDisplayWrapList(aBuilder, aFrame, aList) {
+MOZ_COUNT_CTOR(nsDisplayOpacity);
+}
+#ifdef NS_BUILD_REFCNT_LOGGING
+nsDisplayOpacity::~nsDisplayOpacity() {
+MOZ_COUNT_DTOR(nsDisplayOpacity);
+}
+#endif
+nsRegion nsDisplayOpacity::GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
+bool* aSnap) {
+*aSnap = false;
+// We are never opaque, if our opacity was < 1 then we wouldn't have
+// been created.
+return nsRegion();
+}
+// nsDisplayOpacity uses layers for rendering
+already_AddRefed<Layer>
+nsDisplayOpacity::BuildLayer(nsDisplayListBuilder* aBuilder,
+LayerManager* aManager,
+const ContainerLayerParameters& aContainerParameters) {
+if (mFrame->StyleDisplay()->mOpacity == 0 && mFrame->GetContent() &&
+!nsLayoutUtils::HasAnimations(mFrame->GetContent(), eCSSProperty_opacity)) {
+return nullptr;
+}
+nsRefPtr<Layer> container = aManager->GetLayerBuilder()->
+BuildContainerLayerFor(aBuilder, aManager, mFrame, this, mList,
+aContainerParameters, nullptr);
+if (!container)
+return nullptr;
+container->SetOpacity(mFrame->StyleDisplay()->mOpacity);
+nsDisplayListBuilder::AddAnimationsAndTransitionsToLayer(container, aBuilder,
+this, mFrame,
+eCSSProperty_opacity);
+return container.forget();
+}
+/**
+* This doesn't take into account layer scaling --- the layer may be
+* rendered at a higher (or lower) resolution, affecting the retained layer
+* size --- but this should be good enough.
+*/
+static bool
+IsItemTooSmallForActiveLayer(nsDisplayItem* aItem)
+{
+nsIntRect visibleDevPixels = aItem->GetVisibleRect().ToOutsidePixels(
+aItem->Frame()->PresContext()->AppUnitsPerDevPixel());
+static const int MIN_ACTIVE_LAYER_SIZE_DEV_PIXELS = 16;
+return visibleDevPixels.Size() <
+nsIntSize(MIN_ACTIVE_LAYER_SIZE_DEV_PIXELS, MIN_ACTIVE_LAYER_SIZE_DEV_PIXELS);
+}
+bool
+nsDisplayOpacity::NeedsActiveLayer()
+{
+if (ActiveLayerTracker::IsStyleAnimated(mFrame, eCSSProperty_opacity) &&
+!IsItemTooSmallForActiveLayer(this))
+return true;
+if (mFrame->GetContent()) {
+if (nsLayoutUtils::HasAnimationsForCompositor(mFrame->GetContent(),
+eCSSProperty_opacity)) {
+return true;
+}
+}
+return false;
+}
+bool
+nsDisplayOpacity::ShouldFlattenAway(nsDisplayListBuilder* aBuilder)
+{
+if (NeedsActiveLayer())
+return false;
+nsDisplayItem* child = mList.GetBottom();
+// Only try folding our opacity down if we have a single
+// child. We could potentially do this also if we had multiple
+// children as long as they don't overlap.
+if (!child || child->GetAbove()) {
+return false;
+}
+return child->ApplyOpacity(aBuilder, mFrame->StyleDisplay()->mOpacity, mClip);
+}
+nsDisplayItem::LayerState
+nsDisplayOpacity::GetLayerState(nsDisplayListBuilder* aBuilder,
+LayerManager* aManager,
+const ContainerLayerParameters& aParameters) {
+if (NeedsActiveLayer())
+return LAYER_ACTIVE;
+return RequiredLayerStateForChildren(aBuilder, aManager, aParameters, mList,
+nsLayoutUtils::GetAnimatedGeometryRootFor(this, aBuilder));
+}
+bool
+nsDisplayOpacity::ComputeVisibility(nsDisplayListBuilder* aBuilder,
+nsRegion* aVisibleRegion,
+const nsRect& aAllowVisibleRegionExpansion) {
+// Our children are translucent so we should not allow them to subtract
+// area from aVisibleRegion. We do need to find out what is visible under
+// our children in the temporary compositing buffer, because if our children
+// paint our entire bounds opaquely then we don't need an alpha channel in
+// the temporary compositing buffer.
+nsRect bounds = GetClippedBounds(aBuilder);
+nsRegion visibleUnderChildren;
+visibleUnderChildren.And(*aVisibleRegion, bounds);
+nsRect allowExpansion = bounds.Intersect(aAllowVisibleRegionExpansion);
+return
+nsDisplayWrapList::ComputeVisibility(aBuilder, &visibleUnderChildren,
+allowExpansion);
+}
+bool nsDisplayOpacity::TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) {
+if (aItem->GetType() != TYPE_OPACITY)
+return false;
+// items for the same content element should be merged into a single
+// compositing group
+// aItem->GetUnderlyingFrame() returns non-null because it's nsDisplayOpacity
+if (aItem->Frame()->GetContent() != mFrame->GetContent())
+return false;
+if (aItem->GetClip() != GetClip())
+return false;
+MergeFromTrackingMergedFrames(static_cast<nsDisplayOpacity*>(aItem));
+return true;
+}
+#ifdef MOZ_DUMP_PAINTING
+void
+nsDisplayOpacity::WriteDebugInfo(nsACString& aTo)
+{
+aTo += nsPrintfCString(" (opacity %f)", mFrame->StyleDisplay()->mOpacity);
+}
+#endif
+nsDisplayMixBlendMode::nsDisplayMixBlendMode(nsDisplayListBuilder* aBuilder,
+nsIFrame* aFrame, nsDisplayList* aList,
+uint32_t aFlags)
+: nsDisplayWrapList(aBuilder, aFrame, aList) {
+MOZ_COUNT_CTOR(nsDisplayMixBlendMode);
+}
+#ifdef NS_BUILD_REFCNT_LOGGING
+nsDisplayMixBlendMode::~nsDisplayMixBlendMode() {
+MOZ_COUNT_DTOR(nsDisplayMixBlendMode);
+}
+#endif
+nsRegion nsDisplayMixBlendMode::GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
+bool* aSnap) {
+*aSnap = false;
+// We are never considered opaque
+return nsRegion();
+}
+// nsDisplayMixBlendMode uses layers for rendering
+already_AddRefed<Layer>
+nsDisplayMixBlendMode::BuildLayer(nsDisplayListBuilder* aBuilder,
+LayerManager* aManager,
+const ContainerLayerParameters& aContainerParameters) {
+ContainerLayerParameters newContainerParameters = aContainerParameters;
+newContainerParameters.mDisableSubpixelAntialiasingInDescendants = true;
+nsRefPtr<Layer> container = aManager->GetLayerBuilder()->
+BuildContainerLayerFor(aBuilder, aManager, mFrame, this, mList,
+newContainerParameters, nullptr);
+if (!container) {
+return nullptr;
+}
+container->DeprecatedSetMixBlendMode(nsCSSRendering::GetGFXBlendMode(mFrame->StyleDisplay()->mMixBlendMode));
+return container.forget();
+}
+bool nsDisplayMixBlendMode::ComputeVisibility(nsDisplayListBuilder* aBuilder,
+nsRegion* aVisibleRegion,
+const nsRect& aAllowVisibleRegionExpansion) {
+// Our children are need their backdrop so we should not allow them to subtract
+// area from aVisibleRegion. We do need to find out what is visible under
+// our children in the temporary compositing buffer, because if our children
+// paint our entire bounds opaquely then we don't need an alpha channel in
+// the temporary compositing buffer.
+nsRect bounds = GetClippedBounds(aBuilder);
+nsRegion visibleUnderChildren;
+visibleUnderChildren.And(*aVisibleRegion, bounds);
+nsRect allowExpansion = bounds.Intersect(aAllowVisibleRegionExpansion);
+return
+nsDisplayWrapList::ComputeVisibility(aBuilder, &visibleUnderChildren,
+allowExpansion);
+}
+bool nsDisplayMixBlendMode::TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) {
+if (aItem->GetType() != TYPE_MIX_BLEND_MODE)
+return false;
+// items for the same content element should be merged into a single
+// compositing group
+// aItem->GetUnderlyingFrame() returns non-null because it's nsDisplayOpacity
+if (aItem->Frame()->GetContent() != mFrame->GetContent())
+return false;
+if (aItem->GetClip() != GetClip())
+return false;
+MergeFromTrackingMergedFrames(static_cast<nsDisplayMixBlendMode*>(aItem));
+return true;
+}
+nsDisplayBlendContainer::nsDisplayBlendContainer(nsDisplayListBuilder* aBuilder,
+nsIFrame* aFrame, nsDisplayList* aList,
+uint32_t aFlags)
+: nsDisplayWrapList(aBuilder, aFrame, aList) {
+MOZ_COUNT_CTOR(nsDisplayBlendContainer);
+}
+#ifdef NS_BUILD_REFCNT_LOGGING
+nsDisplayBlendContainer::~nsDisplayBlendContainer() {
+MOZ_COUNT_DTOR(nsDisplayBlendContainer);
+}
+#endif
+// nsDisplayBlendContainer uses layers for rendering
+already_AddRefed<Layer>
+nsDisplayBlendContainer::BuildLayer(nsDisplayListBuilder* aBuilder,
+LayerManager* aManager,
+const ContainerLayerParameters& aContainerParameters) {
+// turn off anti-aliasing in the parent stacking context because it changes
+// how the group is initialized.
+ContainerLayerParameters newContainerParameters = aContainerParameters;
+newContainerParameters.mDisableSubpixelAntialiasingInDescendants = true;
+nsRefPtr<Layer> container = aManager->GetLayerBuilder()->
+BuildContainerLayerFor(aBuilder, aManager, mFrame, this, mList,
+newContainerParameters, nullptr);
+if (!container) {
+return nullptr;
+}
+container->SetForceIsolatedGroup(true);
+return container.forget();
+}
+bool nsDisplayBlendContainer::TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) {
+if (aItem->GetType() != TYPE_BLEND_CONTAINER)
+return false;
+// items for the same content element should be merged into a single
+// compositing group
+// aItem->GetUnderlyingFrame() returns non-null because it's nsDisplayOpacity
+if (aItem->Frame()->GetContent() != mFrame->GetContent())
+return false;
+if (aItem->GetClip() != GetClip())
+return false;
+MergeFromTrackingMergedFrames(static_cast<nsDisplayBlendContainer*>(aItem));
+return true;
+}
+nsDisplayOwnLayer::nsDisplayOwnLayer(nsDisplayListBuilder* aBuilder,
+nsIFrame* aFrame, nsDisplayList* aList,
+uint32_t aFlags, ViewID aScrollTarget)
+: nsDisplayWrapList(aBuilder, aFrame, aList)
+, mFlags(aFlags)
+, mScrollTarget(aScrollTarget) {
+MOZ_COUNT_CTOR(nsDisplayOwnLayer);
+}
+#ifdef NS_BUILD_REFCNT_LOGGING
+nsDisplayOwnLayer::~nsDisplayOwnLayer() {
+MOZ_COUNT_DTOR(nsDisplayOwnLayer);
+}
+#endif
+// nsDisplayOpacity uses layers for rendering
+already_AddRefed<Layer>
+nsDisplayOwnLayer::BuildLayer(nsDisplayListBuilder* aBuilder,
+LayerManager* aManager,
+const ContainerLayerParameters& aContainerParameters) {
+nsRefPtr<ContainerLayer> layer = aManager->GetLayerBuilder()->
+BuildContainerLayerFor(aBuilder, aManager, mFrame, this, mList,
+aContainerParameters, nullptr);
+if (mFlags & VERTICAL_SCROLLBAR) {
+layer->SetScrollbarData(mScrollTarget, Layer::ScrollDirection::VERTICAL);
+}
+if (mFlags & HORIZONTAL_SCROLLBAR) {
+layer->SetScrollbarData(mScrollTarget, Layer::ScrollDirection::HORIZONTAL);
+}
+if (mFlags & GENERATE_SUBDOC_INVALIDATIONS) {
+mFrame->PresContext()->SetNotifySubDocInvalidationData(layer);
+}
+return layer.forget();
+}
+nsDisplaySubDocument::nsDisplaySubDocument(nsDisplayListBuilder* aBuilder,
+nsIFrame* aFrame, nsDisplayList* aList,
+uint32_t aFlags)
+: nsDisplayOwnLayer(aBuilder, aFrame, aList, aFlags)
+, mScrollParentId(aBuilder->GetCurrentScrollParentId())
+{
+MOZ_COUNT_CTOR(nsDisplaySubDocument);
+}
+#ifdef NS_BUILD_REFCNT_LOGGING
+nsDisplaySubDocument::~nsDisplaySubDocument() {
+MOZ_COUNT_DTOR(nsDisplaySubDocument);
+}
+#endif
+already_AddRefed<Layer>
+nsDisplaySubDocument::BuildLayer(nsDisplayListBuilder* aBuilder,
+LayerManager* aManager,
+const ContainerLayerParameters& aContainerParameters) {
+nsRefPtr<Layer> layer = nsDisplayOwnLayer::BuildLayer(
+aBuilder, aManager, aContainerParameters);
+if (!(mFlags & GENERATE_SCROLLABLE_LAYER)) {
+return layer.forget();
+}
+NS_ASSERTION(layer->AsContainerLayer(), "nsDisplayOwnLayer should have made a ContainerLayer");
+if (ContainerLayer* container = layer->AsContainerLayer()) {
+nsPresContext* presContext = mFrame->PresContext();
+nsIFrame* rootScrollFrame = presContext->PresShell()->GetRootScrollFrame();
+bool isRootContentDocument = presContext->IsRootContentDocument();
+bool usingDisplayport = false;
+bool usingCriticalDisplayport = false;
+nsRect displayport, criticalDisplayport;
+ViewID scrollId = FrameMetrics::NULL_SCROLL_ID;
+if (rootScrollFrame) {
+nsIContent* content = rootScrollFrame->GetContent();
+if (content) {
+usingDisplayport = nsLayoutUtils::GetDisplayPort(content, &displayport);
+usingCriticalDisplayport =
+nsLayoutUtils::GetCriticalDisplayPort(content, &criticalDisplayport);
+if (isRootContentDocument) {
+scrollId = nsLayoutUtils::FindOrCreateIDFor(content);
+} else {
+nsLayoutUtils::FindIDFor(content, &scrollId);
+}
+}
+}
+nsRect viewport = mFrame->GetRect() -
+mFrame->GetPosition() +
+mFrame->GetOffsetToCrossDoc(ReferenceFrame());
+container->SetScrollHandoffParentId(mScrollParentId);
+RecordFrameMetrics(mFrame, rootScrollFrame, ReferenceFrame(),
+container, mList.GetVisibleRect(), viewport,
+(usingDisplayport ? &displayport : nullptr),
+(usingCriticalDisplayport ? &criticalDisplayport : nullptr),
+scrollId, isRootContentDocument, aContainerParameters);
+}
+return layer.forget();
+}
+nsRect
+nsDisplaySubDocument::GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap)
+{
+bool usingDisplayPort =
+nsLayoutUtils::ViewportHasDisplayPort(mFrame->PresContext());
+if ((mFlags & GENERATE_SCROLLABLE_LAYER) && usingDisplayPort) {
+*aSnap = false;
+return mFrame->GetRect() + aBuilder->ToReferenceFrame(mFrame);
+}
+return nsDisplayOwnLayer::GetBounds(aBuilder, aSnap);
+}
+bool
+nsDisplaySubDocument::ComputeVisibility(nsDisplayListBuilder* aBuilder,
+nsRegion* aVisibleRegion,
+const nsRect& aAllowVisibleRegionExpansion)
+{
+nsRect displayport;
+bool usingDisplayPort =
+nsLayoutUtils::ViewportHasDisplayPort(mFrame->PresContext(), &displayport);
+if (!(mFlags & GENERATE_SCROLLABLE_LAYER) || !usingDisplayPort) {
+return nsDisplayWrapList::ComputeVisibility(aBuilder, aVisibleRegion,
+aAllowVisibleRegionExpansion);
+}
+nsRegion childVisibleRegion;
+// The visible region for the children may be much bigger than the hole we
+// are viewing the children from, so that the compositor process has enough
+// content to asynchronously pan while content is being refreshed.
+childVisibleRegion = displayport + mFrame->GetOffsetToCrossDoc(ReferenceFrame());
+nsRect boundedRect =
+childVisibleRegion.GetBounds().Intersect(mList.GetBounds(aBuilder));
+nsRect allowExpansion = boundedRect.Intersect(aAllowVisibleRegionExpansion);
+bool visible = mList.ComputeVisibilityForSublist(
+aBuilder, &childVisibleRegion, boundedRect, allowExpansion,
+usingDisplayPort ? mFrame : nullptr);
+// We don't allow this computation to influence aVisibleRegion, on the
+// assumption that the layer can be asynchronously scrolled so we'll
+// definitely need all the content under it.
+return visible;
+}
+bool
+nsDisplaySubDocument::ShouldBuildLayerEvenIfInvisible(nsDisplayListBuilder* aBuilder)
+{
+bool usingDisplayPort =
+nsLayoutUtils::ViewportHasDisplayPort(mFrame->PresContext());
+if ((mFlags & GENERATE_SCROLLABLE_LAYER) && usingDisplayPort) {
+return true;
+}
+return nsDisplayOwnLayer::ShouldBuildLayerEvenIfInvisible(aBuilder);
+}
+nsRegion
+nsDisplaySubDocument::GetOpaqueRegion(nsDisplayListBuilder* aBuilder, bool* aSnap)
+{
+bool usingDisplayPort =
+nsLayoutUtils::ViewportHasDisplayPort(mFrame->PresContext());
+if ((mFlags & GENERATE_SCROLLABLE_LAYER) && usingDisplayPort) {
+*aSnap = false;
+return nsRegion();
+}
+return nsDisplayOwnLayer::GetOpaqueRegion(aBuilder, aSnap);
+}
+nsDisplayResolution::nsDisplayResolution(nsDisplayListBuilder* aBuilder,
+nsIFrame* aFrame, nsDisplayList* aList,
+uint32_t aFlags)
+: nsDisplaySubDocument(aBuilder, aFrame, aList, aFlags) {
+MOZ_COUNT_CTOR(nsDisplayResolution);
+}
+#ifdef NS_BUILD_REFCNT_LOGGING
+nsDisplayResolution::~nsDisplayResolution() {
+MOZ_COUNT_DTOR(nsDisplayResolution);
+}
+#endif
+already_AddRefed<Layer>
+nsDisplayResolution::BuildLayer(nsDisplayListBuilder* aBuilder,
+LayerManager* aManager,
+const ContainerLayerParameters& aContainerParameters) {
+nsIPresShell* presShell = mFrame->PresContext()->PresShell();
+ContainerLayerParameters containerParameters(
+presShell->GetXResolution(), presShell->GetYResolution(), nsIntPoint(),
+aContainerParameters);
+nsRefPtr<Layer> layer = nsDisplaySubDocument::BuildLayer(
+aBuilder, aManager, containerParameters);
+layer->SetPostScale(1.0f / presShell->GetXResolution(),
+1.0f / presShell->GetYResolution());
+return layer.forget();
+}
+nsDisplayStickyPosition::nsDisplayStickyPosition(nsDisplayListBuilder* aBuilder,
+nsIFrame* aFrame,
+nsDisplayList* aList)
+: nsDisplayOwnLayer(aBuilder, aFrame, aList)
+{
+MOZ_COUNT_CTOR(nsDisplayStickyPosition);
+}
+#ifdef NS_BUILD_REFCNT_LOGGING
+nsDisplayStickyPosition::~nsDisplayStickyPosition() {
+MOZ_COUNT_DTOR(nsDisplayStickyPosition);
+}
+#endif
+already_AddRefed<Layer>
+nsDisplayStickyPosition::BuildLayer(nsDisplayListBuilder* aBuilder,
+LayerManager* aManager,
+const ContainerLayerParameters& aContainerParameters) {
+nsRefPtr<Layer> layer =
+nsDisplayOwnLayer::BuildLayer(aBuilder, aManager, aContainerParameters);
+StickyScrollContainer* stickyScrollContainer = StickyScrollContainer::
+GetStickyScrollContainerForFrame(mFrame);
+if (!stickyScrollContainer) {
+return layer.forget();
+}
+nsIFrame* scrollFrame = do_QueryFrame(stickyScrollContainer->ScrollFrame());
+nsPresContext* presContext = scrollFrame->PresContext();
+// Sticky position frames whose scroll frame is the root scroll frame are
+// reflowed into the scroll-port size if one has been set.
+nsSize scrollFrameSize = scrollFrame->GetSize();
+if (scrollFrame == presContext->PresShell()->GetRootScrollFrame() &&
+presContext->PresShell()->IsScrollPositionClampingScrollPortSizeSet()) {
+scrollFrameSize = presContext->PresShell()->
+GetScrollPositionClampingScrollPortSize();
+}
+nsLayoutUtils::SetFixedPositionLayerData(layer, scrollFrame,
+nsRect(scrollFrame->GetOffsetToCrossDoc(ReferenceFrame()), scrollFrameSize),
+mFrame, presContext, aContainerParameters);
+ViewID scrollId = nsLayoutUtils::FindOrCreateIDFor(
+stickyScrollContainer->ScrollFrame()->GetScrolledFrame()->GetContent());
+float factor = presContext->AppUnitsPerDevPixel();
+nsRect outer;
+nsRect inner;
+stickyScrollContainer->GetScrollRanges(mFrame, &outer, &inner);
+LayerRect stickyOuter(NSAppUnitsToFloatPixels(outer.x, factor) *
+aContainerParameters.mXScale,
+NSAppUnitsToFloatPixels(outer.y, factor) *
+aContainerParameters.mYScale,
+NSAppUnitsToFloatPixels(outer.width, factor) *
+aContainerParameters.mXScale,
+NSAppUnitsToFloatPixels(outer.height, factor) *
+aContainerParameters.mYScale);
+LayerRect stickyInner(NSAppUnitsToFloatPixels(inner.x, factor) *
+aContainerParameters.mXScale,
+NSAppUnitsToFloatPixels(inner.y, factor) *
+aContainerParameters.mYScale,
+NSAppUnitsToFloatPixels(inner.width, factor) *
+aContainerParameters.mXScale,
+NSAppUnitsToFloatPixels(inner.height, factor) *
+aContainerParameters.mYScale);
+layer->SetStickyPositionData(scrollId, stickyOuter, stickyInner);
+return layer.forget();
+}
+bool nsDisplayStickyPosition::TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) {
+if (aItem->GetType() != TYPE_STICKY_POSITION)
+return false;
+// Items with the same fixed position frame can be merged.
+nsDisplayStickyPosition* other = static_cast<nsDisplayStickyPosition*>(aItem);
+if (other->mFrame != mFrame)
+return false;
+if (aItem->GetClip() != GetClip())
+return false;
+MergeFromTrackingMergedFrames(other);
+return true;
+}
+nsDisplayScrollLayer::nsDisplayScrollLayer(nsDisplayListBuilder* aBuilder,
+nsDisplayList* aList,
+nsIFrame* aForFrame,
+nsIFrame* aScrolledFrame,
+nsIFrame* aScrollFrame)
+: nsDisplayWrapList(aBuilder, aForFrame, aList)
+, mScrollFrame(aScrollFrame)
+, mScrolledFrame(aScrolledFrame)
+, mScrollParentId(aBuilder->GetCurrentScrollParentId())
+{
+#ifdef NS_BUILD_REFCNT_LOGGING
+MOZ_COUNT_CTOR(nsDisplayScrollLayer);
+#endif
+NS_ASSERTION(mScrolledFrame && mScrolledFrame->GetContent(),
+"Need a child frame with content");
+}
+nsDisplayScrollLayer::nsDisplayScrollLayer(nsDisplayListBuilder* aBuilder,
+nsDisplayItem* aItem,
+nsIFrame* aForFrame,
+nsIFrame* aScrolledFrame,
+nsIFrame* aScrollFrame)
+: nsDisplayWrapList(aBuilder, aForFrame, aItem)
+, mScrollFrame(aScrollFrame)
+, mScrolledFrame(aScrolledFrame)
+, mScrollParentId(aBuilder->GetCurrentScrollParentId())
+{
+#ifdef NS_BUILD_REFCNT_LOGGING
+MOZ_COUNT_CTOR(nsDisplayScrollLayer);
+#endif
+NS_ASSERTION(mScrolledFrame && mScrolledFrame->GetContent(),
+"Need a child frame with content");
+}
+nsDisplayScrollLayer::nsDisplayScrollLayer(nsDisplayListBuilder* aBuilder,
+nsIFrame* aForFrame,
+nsIFrame* aScrolledFrame,
+nsIFrame* aScrollFrame)
+: nsDisplayWrapList(aBuilder, aForFrame)
+, mScrollFrame(aScrollFrame)
+, mScrolledFrame(aScrolledFrame)
+, mScrollParentId(aBuilder->GetCurrentScrollParentId())
+{
+#ifdef NS_BUILD_REFCNT_LOGGING
+MOZ_COUNT_CTOR(nsDisplayScrollLayer);
+#endif
+NS_ASSERTION(mScrolledFrame && mScrolledFrame->GetContent(),
+"Need a child frame with content");
+}
+#ifdef NS_BUILD_REFCNT_LOGGING
+nsDisplayScrollLayer::~nsDisplayScrollLayer()
+{
+MOZ_COUNT_DTOR(nsDisplayScrollLayer);
+}
+#endif
+nsRect
+nsDisplayScrollLayer::GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap)
+{
+nsIScrollableFrame* sf = do_QueryFrame(mScrollFrame);
+if (sf) {
+*aSnap = false;
+return sf->GetScrollPortRect() + aBuilder->ToReferenceFrame(mScrollFrame);
+}
+return nsDisplayWrapList::GetBounds(aBuilder, aSnap);
+}
+already_AddRefed<Layer>
+nsDisplayScrollLayer::BuildLayer(nsDisplayListBuilder* aBuilder,
+LayerManager* aManager,
+const ContainerLayerParameters& aContainerParameters) {
+nsRefPtr<ContainerLayer> layer = aManager->GetLayerBuilder()->
+BuildContainerLayerFor(aBuilder, aManager, mFrame, this, mList,
+aContainerParameters, nullptr);
+// Get the already set unique ID for scrolling this content remotely.
+// Or, if not set, generate a new ID.
+nsIContent* content = mScrolledFrame->GetContent();
+ViewID scrollId = nsLayoutUtils::FindOrCreateIDFor(content);
+nsRect viewport = mScrollFrame->GetRect() -
+mScrollFrame->GetPosition() +
+mScrollFrame->GetOffsetToCrossDoc(ReferenceFrame());
+bool usingDisplayport = false;
+bool usingCriticalDisplayport = false;
+nsRect displayport, criticalDisplayport;
+if (content) {
+usingDisplayport = nsLayoutUtils::GetDisplayPort(content, &displayport);
+usingCriticalDisplayport =
+nsLayoutUtils::GetCriticalDisplayPort(content, &criticalDisplayport);
+}
+layer->SetScrollHandoffParentId(mScrollParentId);
+RecordFrameMetrics(mScrolledFrame, mScrollFrame, ReferenceFrame(), layer,
+mList.GetVisibleRect(), viewport,
+(usingDisplayport ? &displayport : nullptr),
+(usingCriticalDisplayport ? &criticalDisplayport : nullptr),
+scrollId, false, aContainerParameters);
+return layer.forget();
+}
+bool
+nsDisplayScrollLayer::ShouldBuildLayerEvenIfInvisible(nsDisplayListBuilder* aBuilder)
+{
+if (nsLayoutUtils::GetDisplayPort(mScrolledFrame->GetContent(), nullptr)) {
+return true;
+}
+return nsDisplayWrapList::ShouldBuildLayerEvenIfInvisible(aBuilder);
+}
+bool
+nsDisplayScrollLayer::ComputeVisibility(nsDisplayListBuilder* aBuilder,
+nsRegion* aVisibleRegion,
+const nsRect& aAllowVisibleRegionExpansion)
+{
+nsRect displayport;
+bool usingDisplayPort =
+nsLayoutUtils::GetDisplayPort(mScrolledFrame->GetContent(), &displayport);
+nsRegion childVisibleRegion;
+if (usingDisplayPort) {
+// The visible region for the children may be much bigger than the hole we
+// are viewing the children from, so that the compositor process has enough
+// content to asynchronously pan while content is being refreshed.
+childVisibleRegion = displayport + mScrollFrame->GetOffsetToCrossDoc(ReferenceFrame());
+} else {
+bool snap;
+childVisibleRegion = GetBounds(aBuilder, &snap);
+}
+nsRect boundedRect =
+childVisibleRegion.GetBounds().Intersect(mList.GetBounds(aBuilder));
+nsRect allowExpansion = boundedRect.Intersect(aAllowVisibleRegionExpansion);
+bool visible = mList.ComputeVisibilityForSublist(
+aBuilder, &childVisibleRegion, boundedRect, allowExpansion,
+usingDisplayPort ? mScrollFrame : nullptr);
+// We don't allow this computation to influence aVisibleRegion, on the
+// assumption that the layer can be asynchronously scrolled so we'll
+// definitely need all the content under it.
+return visible;
+}
+LayerState
+nsDisplayScrollLayer::GetLayerState(nsDisplayListBuilder* aBuilder,
+LayerManager* aManager,
+const ContainerLayerParameters& aParameters)
+{
+// Force this as a layer so we can scroll asynchronously.
+// This causes incorrect rendering for rounded clips!
+return LAYER_ACTIVE_FORCE;
+}
+// Check if we are going to clip an abs pos item that we don't contain.
+// Root scroll frames clip all their descendants, so we don't need to worry
+// about them.
+bool
+WouldCauseIncorrectClippingOnAbsPosItem(nsDisplayListBuilder* aBuilder,
+nsDisplayScrollLayer* aItem)
+{
+nsIFrame* scrollFrame = aItem->GetScrollFrame();
+nsIPresShell* presShell = scrollFrame->PresContext()->PresShell();
+if (scrollFrame == presShell->GetRootScrollFrame()) {
+return false;
+}
+nsIFrame* scrolledFrame = aItem->GetScrolledFrame();
+nsIFrame* frame = aItem->Frame();
+if (frame == scrolledFrame || !frame->IsAbsolutelyPositioned() ||
+nsLayoutUtils::IsAncestorFrameCrossDoc(scrollFrame, frame, presShell->GetRootFrame())) {
+return false;
+}
+if (!aItem->GetClip().IsRectAffectedByClip(aItem->GetChildren()->GetBounds(aBuilder))) {
+return false;
+}
+return true;
+}
+bool
+nsDisplayScrollLayer::TryMerge(nsDisplayListBuilder* aBuilder,
+nsDisplayItem* aItem)
+{
+if (aItem->GetType() != TYPE_SCROLL_LAYER) {
+return false;
+}
+nsDisplayScrollLayer* other = static_cast<nsDisplayScrollLayer*>(aItem);
+if (other->mScrolledFrame != this->mScrolledFrame) {
+return false;
+}
+if (aItem->GetClip() != GetClip()) {
+return false;
+}
+if (WouldCauseIncorrectClippingOnAbsPosItem(aBuilder, this) ||
+WouldCauseIncorrectClippingOnAbsPosItem(aBuilder, other)) {
+return false;
+}
+NS_ASSERTION(other->mReferenceFrame == mReferenceFrame,
+"Must have the same reference frame!");
+FrameProperties props = mScrolledFrame->Properties();
+props.Set(nsIFrame::ScrollLayerCount(),
+reinterpret_cast<void*>(GetScrollLayerCount() - 1));
+// Swap frames with the other item before doing MergeFrom.
+// XXX - This ensures that the frame associated with a scroll layer after
+// merging is the first, rather than the last. This tends to change less,
+// ensuring we're more likely to retain the associated gfx layer.
+// See Bug 729534 and Bug 731641.
+nsIFrame* tmp = mFrame;
+mFrame = other->mFrame;
+other->mFrame = tmp;
+MergeFromTrackingMergedFrames(other);
+return true;
+}
+void
+PropagateClip(nsDisplayListBuilder* aBuilder, const DisplayItemClip& aClip,
+nsDisplayList* aList)
+{
+for (nsDisplayItem* i = aList->GetBottom(); i != nullptr; i = i->GetAbove()) {
+DisplayItemClip clip(i->GetClip());
+clip.IntersectWith(aClip);
+i->SetClip(aBuilder, clip);
+nsDisplayList* list = i->GetSameCoordinateSystemChildren();
+if (list) {
+PropagateClip(aBuilder, aClip, list);
+}
+}
+}
+bool
+nsDisplayScrollLayer::ShouldFlattenAway(nsDisplayListBuilder* aBuilder)
+{
+bool badAbsPosClip = WouldCauseIncorrectClippingOnAbsPosItem(aBuilder, this);
+if (GetScrollLayerCount() > 1 || badAbsPosClip) {
+// Propagate our clip to our children. The clip for the scroll frame is
+// on this item, but not our child items so that they can draw non-visible
+// parts of the display port. But if we are flattening we failed and can't
+// draw the extra content, so it needs to be clipped.
+// But don't induce our clip on abs pos frames that we shouldn't be clipping.
+if (!badAbsPosClip) {
+PropagateClip(aBuilder, GetClip(), &mList);
+}
+return true;
+}
+if (mFrame != mScrolledFrame) {
+mMergedFrames.AppendElement(mFrame);
+mFrame = mScrolledFrame;
+}
+return false;
+}
+intptr_t
+nsDisplayScrollLayer::GetScrollLayerCount()
+{
+FrameProperties props = mScrolledFrame->Properties();
+#ifdef DEBUG
+bool hasCount = false;
+intptr_t result = reinterpret_cast<intptr_t>(
+props.Get(nsIFrame::ScrollLayerCount(), &hasCount));
+// If this aborts, then the property was either not added before scroll
+// layers were created or the property was deleted to early. If the latter,
+// make sure that nsDisplayScrollInfoLayer is on the bottom of the list so
+// that it is processed last.
+NS_ABORT_IF_FALSE(hasCount, "nsDisplayScrollLayer should always be defined");
+return result;
+#else
+return reinterpret_cast<intptr_t>(props.Get(nsIFrame::ScrollLayerCount()));
+#endif
+}
+#ifdef MOZ_DUMP_PAINTING
+void
+nsDisplayScrollLayer::WriteDebugInfo(nsACString& aTo)
+{
+aTo += nsPrintfCString(" (scrollframe %p scrolledframe %p)",
+mScrollFrame, mScrolledFrame);
+}
+#endif
+nsDisplayScrollInfoLayer::nsDisplayScrollInfoLayer(
+nsDisplayListBuilder* aBuilder,
+nsIFrame* aScrolledFrame,
+nsIFrame* aScrollFrame)
+: nsDisplayScrollLayer(aBuilder, aScrollFrame, aScrolledFrame, aScrollFrame)
+{
+#ifdef NS_BUILD_REFCNT_LOGGING
+MOZ_COUNT_CTOR(nsDisplayScrollInfoLayer);
+#endif
+}
+nsDisplayScrollInfoLayer::~nsDisplayScrollInfoLayer()
+{
+FrameProperties props = mScrolledFrame->Properties();
+props.Remove(nsIFrame::ScrollLayerCount());
+MOZ_COUNT_DTOR(nsDisplayScrollInfoLayer);
+}
+nsRect
+nsDisplayScrollInfoLayer::GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap)
+{
+return nsDisplayWrapList::GetBounds(aBuilder, aSnap);
+}
+LayerState
+nsDisplayScrollInfoLayer::GetLayerState(nsDisplayListBuilder* aBuilder,
+LayerManager* aManager,
+const ContainerLayerParameters& aParameters)
+{
+return LAYER_ACTIVE_EMPTY;
+}
+bool
+nsDisplayScrollInfoLayer::TryMerge(nsDisplayListBuilder* aBuilder,
+nsDisplayItem* aItem)
+{
+return false;
+}
+bool
+nsDisplayScrollInfoLayer::ShouldFlattenAway(nsDisplayListBuilder* aBuilder)
+{
+// Layer metadata for a particular scroll frame needs to be unique. Only
+// one nsDisplayScrollLayer (with rendered content) or one
+// nsDisplayScrollInfoLayer (with only the metadata) should survive the
+// visibility computation.
+return GetScrollLayerCount() == 1;
+}
+nsDisplayZoom::nsDisplayZoom(nsDisplayListBuilder* aBuilder,
+nsIFrame* aFrame, nsDisplayList* aList,
+int32_t aAPD, int32_t aParentAPD,
+uint32_t aFlags)
+: nsDisplaySubDocument(aBuilder, aFrame, aList, aFlags)
+, mAPD(aAPD), mParentAPD(aParentAPD) {
+MOZ_COUNT_CTOR(nsDisplayZoom);
+}
+#ifdef NS_BUILD_REFCNT_LOGGING
+nsDisplayZoom::~nsDisplayZoom() {
+MOZ_COUNT_DTOR(nsDisplayZoom);
+}
+#endif
+nsRect nsDisplayZoom::GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap)
+{
+nsRect bounds = nsDisplaySubDocument::GetBounds(aBuilder, aSnap);
+*aSnap = false;
+return bounds.ConvertAppUnitsRoundOut(mAPD, mParentAPD);
+}
+void nsDisplayZoom::HitTest(nsDisplayListBuilder *aBuilder,
+const nsRect& aRect,
+HitTestState *aState,
+nsTArray<nsIFrame*> *aOutFrames)
+{
+nsRect rect;
+// A 1x1 rect indicates we are just hit testing a point, so pass down a 1x1
+// rect as well instead of possibly rounding the width or height to zero.
+if (aRect.width == 1 && aRect.height == 1) {
+rect.MoveTo(aRect.TopLeft().ConvertAppUnits(mParentAPD, mAPD));
+rect.width = rect.height = 1;
+} else {
+rect = aRect.ConvertAppUnitsRoundOut(mParentAPD, mAPD);
+}
+mList.HitTest(aBuilder, rect, aState, aOutFrames);
+}
+void nsDisplayZoom::Paint(nsDisplayListBuilder* aBuilder,
+nsRenderingContext* aCtx)
+{
+mList.PaintForFrame(aBuilder, aCtx, mFrame, nsDisplayList::PAINT_DEFAULT);
+}
+bool nsDisplayZoom::ComputeVisibility(nsDisplayListBuilder *aBuilder,
+nsRegion *aVisibleRegion,
+const nsRect& aAllowVisibleRegionExpansion)
+{
+// Convert the passed in visible region to our appunits.
+nsRegion visibleRegion;
+// mVisibleRect has been clipped to GetClippedBounds
+visibleRegion.And(*aVisibleRegion, mVisibleRect);
+visibleRegion = visibleRegion.ConvertAppUnitsRoundOut(mParentAPD, mAPD);
+nsRegion originalVisibleRegion = visibleRegion;
+nsRect transformedVisibleRect =
+mVisibleRect.ConvertAppUnitsRoundOut(mParentAPD, mAPD);
+nsRect allowExpansion =
+aAllowVisibleRegionExpansion.ConvertAppUnitsRoundIn(mParentAPD, mAPD);
+bool retval;
+// If we are to generate a scrollable layer we call
+// nsDisplaySubDocument::ComputeVisibility to make the necessary adjustments
+// for ComputeVisibility, it does all it's calculations in the child APD.
+bool usingDisplayPort =
+nsLayoutUtils::ViewportHasDisplayPort(mFrame->PresContext());
+if (!(mFlags & GENERATE_SCROLLABLE_LAYER) || !usingDisplayPort) {
+retval =
+mList.ComputeVisibilityForSublist(aBuilder, &visibleRegion,
+transformedVisibleRect,
+allowExpansion);
+} else {
+retval =
+nsDisplaySubDocument::ComputeVisibility(aBuilder, &visibleRegion,
+allowExpansion);
+}
+nsRegion removed;
+// removed = originalVisibleRegion - visibleRegion
+removed.Sub(originalVisibleRegion, visibleRegion);
+// Convert removed region to parent appunits.
+removed = removed.ConvertAppUnitsRoundIn(mAPD, mParentAPD);
+// aVisibleRegion = aVisibleRegion - removed (modulo any simplifications
+// SubtractFromVisibleRegion does)
+aBuilder->SubtractFromVisibleRegion(aVisibleRegion, removed);
+return retval;
+}
+///////////////////////////////////////////////////
+// nsDisplayTransform Implementation
+//
+// Write #define UNIFIED_CONTINUATIONS here to have the transform property try
+// to transform content with continuations as one unified block instead of
+// several smaller ones.  This is currently disabled because it doesn't work
+// correctly, since when the frames are initially being reflowed, their
+// continuations all compute their bounding rects independently of each other
+// and consequently get the wrong value.  Write #define DEBUG_HIT here to have
+// the nsDisplayTransform class dump out a bunch of information about hit
+// detection.
+#undef  UNIFIED_CONTINUATIONS
+#undef  DEBUG_HIT
+/* Returns the bounds of a frame as defined for transforms.  If
+* UNIFIED_CONTINUATIONS is not defined, this is simply the frame's bounding
+* rectangle, translated to the origin. Otherwise, returns the smallest
+* rectangle containing a frame and all of its continuations.  For example, if
+* there is a <span> element with several continuations split over several
+* lines, this function will return the rectangle containing all of those
+* continuations.  This rectangle is relative to the origin of the frame's local
+* coordinate space.
+*/
+#ifndef UNIFIED_CONTINUATIONS
+nsRect
+nsDisplayTransform::GetFrameBoundsForTransform(const nsIFrame* aFrame)
+{
+NS_PRECONDITION(aFrame, "Can't get the bounds of a nonexistent frame!");
+if (aFrame->GetStateBits() & NS_FRAME_SVG_LAYOUT) {
+// TODO: SVG needs to define what percentage translations resolve against.
+return nsRect();
+}
+return nsRect(nsPoint(0, 0), aFrame->GetSize());
+}
+#else
+nsRect
+nsDisplayTransform::GetFrameBoundsForTransform(const nsIFrame* aFrame)
+{
+NS_PRECONDITION(aFrame, "Can't get the bounds of a nonexistent frame!");
+nsRect result;
+if (aFrame->GetStateBits() & NS_FRAME_SVG_LAYOUT) {
+// TODO: SVG needs to define what percentage translations resolve against.
+return result;
+}
+/* Iterate through the continuation list, unioning together all the
+* bounding rects.
+*/
+for (const nsIFrame *currFrame = aFrame->FirstContinuation();
+currFrame != nullptr;
+currFrame = currFrame->GetNextContinuation())
+{
+/* Get the frame rect in local coordinates, then translate back to the
+* original coordinates.
+*/
+result.UnionRect(result, nsRect(currFrame->GetOffsetTo(aFrame),
+currFrame->GetSize()));
+}
+return result;
+}
+#endif
+nsDisplayTransform::nsDisplayTransform(nsDisplayListBuilder* aBuilder, nsIFrame *aFrame,
+nsDisplayList *aList, ComputeTransformFunction aTransformGetter,
+uint32_t aIndex)
+: nsDisplayItem(aBuilder, aFrame)
+, mStoredList(aBuilder, aFrame, aList)
+, mTransformGetter(aTransformGetter)
+, mIndex(aIndex)
+{
+MOZ_COUNT_CTOR(nsDisplayTransform);
+NS_ABORT_IF_FALSE(aFrame, "Must have a frame!");
+NS_ABORT_IF_FALSE(!aFrame->IsTransformed(), "Can't specify a transform getter for a transformed frame!");
+mStoredList.SetClip(aBuilder, DisplayItemClip::NoClip());
+}
+nsDisplayTransform::nsDisplayTransform(nsDisplayListBuilder* aBuilder, nsIFrame *aFrame,
+nsDisplayList *aList, uint32_t aIndex)
+: nsDisplayItem(aBuilder, aFrame)
+, mStoredList(aBuilder, aFrame, aList)
+, mTransformGetter(nullptr)
+, mIndex(aIndex)
+{
+MOZ_COUNT_CTOR(nsDisplayTransform);
+NS_ABORT_IF_FALSE(aFrame, "Must have a frame!");
+mReferenceFrame =
+aBuilder->FindReferenceFrameFor(GetTransformRootFrame(aFrame));
+mToReferenceFrame = aFrame->GetOffsetToCrossDoc(mReferenceFrame);
+mStoredList.SetClip(aBuilder, DisplayItemClip::NoClip());
+}
+nsDisplayTransform::nsDisplayTransform(nsDisplayListBuilder* aBuilder, nsIFrame *aFrame,
+nsDisplayItem *aItem, uint32_t aIndex)
+: nsDisplayItem(aBuilder, aFrame)
+, mStoredList(aBuilder, aFrame, aItem)
+, mTransformGetter(nullptr)
+, mIndex(aIndex)
+{
+MOZ_COUNT_CTOR(nsDisplayTransform);
+NS_ABORT_IF_FALSE(aFrame, "Must have a frame!");
+mReferenceFrame =
+aBuilder->FindReferenceFrameFor(GetTransformRootFrame(aFrame));
+mToReferenceFrame = aFrame->GetOffsetToCrossDoc(mReferenceFrame);
+mStoredList.SetClip(aBuilder, DisplayItemClip::NoClip());
+}
+/* Returns the delta specified by the -moz-transform-origin property.
+* This is a positive delta, meaning that it indicates the direction to move
+* to get from (0, 0) of the frame to the transform origin.  This function is
+* called off the main thread.
+*/
+/* static */ gfxPoint3D
+nsDisplayTransform::GetDeltaToTransformOrigin(const nsIFrame* aFrame,
+float aAppUnitsPerPixel,
+const nsRect* aBoundsOverride)
+{
+NS_PRECONDITION(aFrame, "Can't get delta for a null frame!");
+NS_PRECONDITION(aFrame->IsTransformed() || aFrame->StyleDisplay()->BackfaceIsHidden(),
+"Shouldn't get a delta for an untransformed frame!");
+if (!aFrame->IsTransformed()) {
+return gfxPoint3D();
+}
+/* For both of the coordinates, if the value of -moz-transform is a
+* percentage, it's relative to the size of the frame.  Otherwise, if it's
+* a distance, it's already computed for us!
+*/
+const nsStyleDisplay* display = aFrame->StyleDisplay();
+nsRect boundingRect = (aBoundsOverride ? *aBoundsOverride :
+nsDisplayTransform::GetFrameBoundsForTransform(aFrame));
+/* Allows us to access named variables by index. */
+float coords[3];
+const nscoord* dimensions[2] =
+{&boundingRect.width, &boundingRect.height};
+for (uint8_t index = 0; index < 2; ++index) {
+/* If the -moz-transform-origin specifies a percentage, take the percentage
+* of the size of the box.
+*/
+const nsStyleCoord &coord = display->mTransformOrigin[index];
+if (coord.GetUnit() == eStyleUnit_Calc) {
+const nsStyleCoord::Calc *calc = coord.GetCalcValue();
+coords[index] =
+NSAppUnitsToFloatPixels(*dimensions[index], aAppUnitsPerPixel) *
+calc->mPercent +
+NSAppUnitsToFloatPixels(calc->mLength, aAppUnitsPerPixel);
+} else if (coord.GetUnit() == eStyleUnit_Percent) {
+coords[index] =
+NSAppUnitsToFloatPixels(*dimensions[index], aAppUnitsPerPixel) *
+coord.GetPercentValue();
+} else {
+NS_ABORT_IF_FALSE(coord.GetUnit() == eStyleUnit_Coord, "unexpected unit");
+coords[index] =
+NSAppUnitsToFloatPixels(coord.GetCoordValue(), aAppUnitsPerPixel);
+}
+if ((aFrame->GetStateBits() & NS_FRAME_SVG_LAYOUT) &&
+coord.GetUnit() != eStyleUnit_Percent) {
+// <length> values represent offsets from the origin of the SVG element's
+// user space, not the top left of its bounds, so we must adjust for that:
+nscoord offset =
+(index == 0) ? aFrame->GetPosition().x : aFrame->GetPosition().y;
+coords[index] -= NSAppUnitsToFloatPixels(offset, aAppUnitsPerPixel);
+}
+}
+coords[2] = NSAppUnitsToFloatPixels(display->mTransformOrigin[2].GetCoordValue(),
+aAppUnitsPerPixel);
+/* Adjust based on the origin of the rectangle. */
+coords[0] += NSAppUnitsToFloatPixels(boundingRect.x, aAppUnitsPerPixel);
+coords[1] += NSAppUnitsToFloatPixels(boundingRect.y, aAppUnitsPerPixel);
+return gfxPoint3D(coords[0], coords[1], coords[2]);
+}
+/* Returns the delta specified by the -moz-perspective-origin property.
+* This is a positive delta, meaning that it indicates the direction to move
+* to get from (0, 0) of the frame to the perspective origin. This function is
+* called off the main thread.
+*/
+/* static */ gfxPoint3D
+nsDisplayTransform::GetDeltaToPerspectiveOrigin(const nsIFrame* aFrame,
+float aAppUnitsPerPixel)
+{
+NS_PRECONDITION(aFrame, "Can't get delta for a null frame!");
+NS_PRECONDITION(aFrame->IsTransformed() || aFrame->StyleDisplay()->BackfaceIsHidden(),
+"Shouldn't get a delta for an untransformed frame!");
+if (!aFrame->IsTransformed()) {
+return gfxPoint3D();
+}
+/* For both of the coordinates, if the value of -moz-perspective-origin is a
+* percentage, it's relative to the size of the frame.  Otherwise, if it's
+* a distance, it's already computed for us!
+*/
+//TODO: Should this be using our bounds or the parent's bounds?
+// How do we handle aBoundsOverride in the latter case?
+nsIFrame* parent = aFrame->GetParentStyleContextFrame();
+if (!parent) {
+return gfxPoint3D();
+}
+const nsStyleDisplay* display = parent->StyleDisplay();
+nsRect boundingRect = nsDisplayTransform::GetFrameBoundsForTransform(parent);
+/* Allows us to access named variables by index. */
+gfxPoint3D result;
+result.z = 0.0f;
+gfxFloat* coords[2] = {&result.x, &result.y};
+const nscoord* dimensions[2] =
+{&boundingRect.width, &boundingRect.height};
+for (uint8_t index = 0; index < 2; ++index) {
+/* If the -moz-transform-origin specifies a percentage, take the percentage
+* of the size of the box.
+*/
+const nsStyleCoord &coord = display->mPerspectiveOrigin[index];
+if (coord.GetUnit() == eStyleUnit_Calc) {
+const nsStyleCoord::Calc *calc = coord.GetCalcValue();
+*coords[index] =
+NSAppUnitsToFloatPixels(*dimensions[index], aAppUnitsPerPixel) *
+calc->mPercent +
+NSAppUnitsToFloatPixels(calc->mLength, aAppUnitsPerPixel);
+} else if (coord.GetUnit() == eStyleUnit_Percent) {
+*coords[index] =
+NSAppUnitsToFloatPixels(*dimensions[index], aAppUnitsPerPixel) *
+coord.GetPercentValue();
+} else {
+NS_ABORT_IF_FALSE(coord.GetUnit() == eStyleUnit_Coord, "unexpected unit");
+*coords[index] =
+NSAppUnitsToFloatPixels(coord.GetCoordValue(), aAppUnitsPerPixel);
+}
+}
+nsPoint parentOffset = aFrame->GetOffsetTo(parent);
+gfxPoint3D gfxOffset(
+NSAppUnitsToFloatPixels(parentOffset.x, aAppUnitsPerPixel),
+NSAppUnitsToFloatPixels(parentOffset.y, aAppUnitsPerPixel),
+0.0f);
+return result - gfxOffset;
+}
+nsDisplayTransform::FrameTransformProperties::FrameTransformProperties(const nsIFrame* aFrame,
+float aAppUnitsPerPixel,
+const nsRect* aBoundsOverride)
+: mFrame(aFrame)
+, mTransformList(aFrame->StyleDisplay()->mSpecifiedTransform)
+, mToTransformOrigin(GetDeltaToTransformOrigin(aFrame, aAppUnitsPerPixel, aBoundsOverride))
+, mToPerspectiveOrigin(GetDeltaToPerspectiveOrigin(aFrame, aAppUnitsPerPixel))
+, mChildPerspective(0)
+{
+const nsStyleDisplay* parentDisp = nullptr;
+nsStyleContext* parentStyleContext = aFrame->StyleContext()->GetParent();
+if (parentStyleContext) {
+parentDisp = parentStyleContext->StyleDisplay();
+}
+if (parentDisp && parentDisp->mChildPerspective.GetUnit() == eStyleUnit_Coord) {
+mChildPerspective = parentDisp->mChildPerspective.GetCoordValue();
+}
+}
+/* Wraps up the -moz-transform matrix in a change-of-basis matrix pair that
+* translates from local coordinate space to transform coordinate space, then
+* hands it back.
+*/
+gfx3DMatrix
+nsDisplayTransform::GetResultingTransformMatrix(const FrameTransformProperties& aProperties,
+const nsPoint& aOrigin,
+float aAppUnitsPerPixel,
+const nsRect* aBoundsOverride,
+nsIFrame** aOutAncestor)
+{
+return GetResultingTransformMatrixInternal(aProperties, aOrigin, aAppUnitsPerPixel,
+aBoundsOverride, aOutAncestor);
+}
+gfx3DMatrix
+nsDisplayTransform::GetResultingTransformMatrix(const nsIFrame* aFrame,
+const nsPoint& aOrigin,
+float aAppUnitsPerPixel,
+const nsRect* aBoundsOverride,
+nsIFrame** aOutAncestor)
+{
+FrameTransformProperties props(aFrame,
+aAppUnitsPerPixel,
+aBoundsOverride);
+return GetResultingTransformMatrixInternal(props, aOrigin, aAppUnitsPerPixel,
+aBoundsOverride, aOutAncestor);
+}
+gfx3DMatrix
+nsDisplayTransform::GetResultingTransformMatrixInternal(const FrameTransformProperties& aProperties,
+const nsPoint& aOrigin,
+float aAppUnitsPerPixel,
+const nsRect* aBoundsOverride,
+nsIFrame** aOutAncestor)
+{
+const nsIFrame *frame = aProperties.mFrame;
+if (aOutAncestor) {
+*aOutAncestor = nsLayoutUtils::GetCrossDocParentFrame(frame);
+}
+/* Account for the -moz-transform-origin property by translating the
+* coordinate space to the new origin.
+*/
+gfxPoint3D newOrigin =
+gfxPoint3D(NSAppUnitsToFloatPixels(aOrigin.x, aAppUnitsPerPixel),
+NSAppUnitsToFloatPixels(aOrigin.y, aAppUnitsPerPixel),
+0.0f);
+/* Get the underlying transform matrix.  This requires us to get the
+* bounds of the frame.
+*/
+nsRect bounds = (aBoundsOverride ? *aBoundsOverride :
+nsDisplayTransform::GetFrameBoundsForTransform(frame));
+/* Get the matrix, then change its basis to factor in the origin. */
+bool dummy;
+gfx3DMatrix result;
+// Call IsSVGTransformed() regardless of the value of
+// disp->mSpecifiedTransform, since we still need any transformFromSVGParent.
+mozilla::gfx::Matrix svgTransform, transformFromSVGParent;
+bool hasSVGTransforms =
+frame && frame->IsSVGTransformed(&svgTransform, &transformFromSVGParent);
+/* Transformed frames always have a transform, or are preserving 3d (and might still have perspective!) */
+if (aProperties.mTransformList) {
+result = nsStyleTransformMatrix::ReadTransforms(aProperties.mTransformList->mHead,
+frame ? frame->StyleContext() : nullptr,
+frame ? frame->PresContext() : nullptr,
+dummy, bounds, aAppUnitsPerPixel);
+} else if (hasSVGTransforms) {
+// Correct the translation components for zoom:
+float pixelsPerCSSPx = frame->PresContext()->AppUnitsPerCSSPixel() /
+aAppUnitsPerPixel;
+svgTransform._31 *= pixelsPerCSSPx;
+svgTransform._32 *= pixelsPerCSSPx;
+result = gfx3DMatrix::From2D(ThebesMatrix(svgTransform));
+}
+if (hasSVGTransforms && !transformFromSVGParent.IsIdentity()) {
+// Correct the translation components for zoom:
+float pixelsPerCSSPx = frame->PresContext()->AppUnitsPerCSSPixel() /
+aAppUnitsPerPixel;
+transformFromSVGParent._31 *= pixelsPerCSSPx;
+transformFromSVGParent._32 *= pixelsPerCSSPx;
+result = result * gfx3DMatrix::From2D(ThebesMatrix(transformFromSVGParent));
+}
+if (aProperties.mChildPerspective > 0.0) {
+gfx3DMatrix perspective;
+perspective._34 =
+-1.0 / NSAppUnitsToFloatPixels(aProperties.mChildPerspective, aAppUnitsPerPixel);
+/* At the point when perspective is applied, we have been translated to the transform origin.
+* The translation to the perspective origin is the difference between these values.
+*/
+result = result * nsLayoutUtils::ChangeMatrixBasis(aProperties.mToPerspectiveOrigin - aProperties.mToTransformOrigin, perspective);
+}
+gfxPoint3D rounded(hasSVGTransforms ? newOrigin.x : NS_round(newOrigin.x),
+hasSVGTransforms ? newOrigin.y : NS_round(newOrigin.y),
+0);
+if (frame && frame->Preserves3D()) {
+// Include the transform set on our parent
+NS_ASSERTION(frame->GetParent() &&
+frame->GetParent()->IsTransformed() &&
+frame->GetParent()->Preserves3DChildren(),
+"Preserve3D mismatch!");
+FrameTransformProperties props(frame->GetParent(),
+aAppUnitsPerPixel,
+nullptr);
+gfx3DMatrix parent =
+GetResultingTransformMatrixInternal(props,
+aOrigin - frame->GetPosition(),
+aAppUnitsPerPixel, nullptr, aOutAncestor);
+return nsLayoutUtils::ChangeMatrixBasis(rounded + aProperties.mToTransformOrigin, result) * parent;
+}
+return nsLayoutUtils::ChangeMatrixBasis
+(rounded + aProperties.mToTransformOrigin, result);
+}
+bool
+nsDisplayOpacity::CanUseAsyncAnimations(nsDisplayListBuilder* aBuilder)
+{
+if (ActiveLayerTracker::IsStyleAnimated(mFrame, eCSSProperty_opacity)) {
+return true;
+}
+if (nsLayoutUtils::IsAnimationLoggingEnabled()) {
+nsCString message;
+message.AppendLiteral("Performance warning: Async animation disabled because frame was not marked active for opacity animation");
+CommonElementAnimationData::LogAsyncAnimationFailure(message,
+Frame()->GetContent());
+}
+return false;
+}
+bool
+nsDisplayTransform::CanUseAsyncAnimations(nsDisplayListBuilder* aBuilder)
+{
+return ShouldPrerenderTransformedContent(aBuilder,
+Frame(),
+nsLayoutUtils::IsAnimationLoggingEnabled());
+}
+/* static */ bool
+nsDisplayTransform::ShouldPrerenderTransformedContent(nsDisplayListBuilder* aBuilder,
+nsIFrame* aFrame,
+bool aLogAnimations)
+{
+// Elements whose transform has been modified recently, or which
+// have a compositor-animated transform, can be prerendered. An element
+// might have only just had its transform animated in which case
+// the ActiveLayerManager may not have been notified yet.
+if (!ActiveLayerTracker::IsStyleAnimated(aFrame, eCSSProperty_transform) &&
+(!aFrame->GetContent() ||
+!nsLayoutUtils::HasAnimationsForCompositor(aFrame->GetContent(),
+eCSSProperty_transform))) {
+if (aLogAnimations) {
+nsCString message;
+message.AppendLiteral("Performance warning: Async animation disabled because frame was not marked active for transform animation");
+CommonElementAnimationData::LogAsyncAnimationFailure(message,
+aFrame->GetContent());
+}
+return false;
+}
+nsSize refSize = aBuilder->RootReferenceFrame()->GetSize();
+// Only prerender if the transformed frame's size (in the reference
+// frames coordinate space) is <= the reference frame size (~viewport),
+// allowing a 1/8th fuzz factor for shadows, borders, etc.
+refSize += nsSize(refSize.width / 8, refSize.height / 8);
+nsRect frameRect = aFrame->GetVisualOverflowRectRelativeToSelf();
+frameRect =
+nsLayoutUtils::TransformFrameRectToAncestor(aFrame, frameRect,
+aBuilder->RootReferenceFrame());
+if (frameRect.Size() <= refSize) {
+return true;
+}
+if (aLogAnimations) {
+nsCString message;
+message.AppendLiteral("Performance warning: Async animation disabled because frame size (");
+message.AppendInt(nsPresContext::AppUnitsToIntCSSPixels(frameRect.width));
+message.AppendLiteral(", ");
+message.AppendInt(nsPresContext::AppUnitsToIntCSSPixels(frameRect.height));
+message.AppendLiteral(") is bigger than the viewport (");
+message.AppendInt(nsPresContext::AppUnitsToIntCSSPixels(refSize.width));
+message.AppendLiteral(", ");
+message.AppendInt(nsPresContext::AppUnitsToIntCSSPixels(refSize.height));
+message.AppendLiteral(")");
+CommonElementAnimationData::LogAsyncAnimationFailure(message,
+aFrame->GetContent());
+}
+return false;
+}
+/* If the matrix is singular, or a hidden backface is shown, the frame won't be visible or hit. */
+static bool IsFrameVisible(nsIFrame* aFrame, const gfx3DMatrix& aMatrix)
+{
+if (aMatrix.IsSingular()) {
+return false;
+}
+if (aFrame->StyleDisplay()->mBackfaceVisibility == NS_STYLE_BACKFACE_VISIBILITY_HIDDEN &&
+aMatrix.IsBackfaceVisible()) {
+return false;
+}
+return true;
+}
+const gfx3DMatrix&
+nsDisplayTransform::GetTransform()
+{
+if (mTransform.IsIdentity()) {
+float scale = mFrame->PresContext()->AppUnitsPerDevPixel();
+gfxPoint3D newOrigin =
+gfxPoint3D(NSAppUnitsToFloatPixels(mToReferenceFrame.x, scale),
+NSAppUnitsToFloatPixels(mToReferenceFrame.y, scale),
+0.0f);
+if (mTransformGetter) {
+mTransform = mTransformGetter(mFrame, scale);
+mTransform = nsLayoutUtils::ChangeMatrixBasis(newOrigin, mTransform);
+} else {
+mTransform =
+GetResultingTransformMatrix(mFrame, ToReferenceFrame(), scale);
+/**
+* Shift the coorindates to be relative to our reference frame instead of relative to this frame.
+*  When we have preserve-3d, our reference frame is already guaranteed to be an ancestor of the
+* preserve-3d chain, so we only need to do this once.
+*/
+bool hasSVGTransforms = mFrame->IsSVGTransformed();
+gfxPoint3D rounded(hasSVGTransforms ? newOrigin.x : NS_round(newOrigin.x),
+hasSVGTransforms ? newOrigin.y : NS_round(newOrigin.y),
+0);
+mTransform.Translate(rounded);
+}
+}
+return mTransform;
+}
+bool
+nsDisplayTransform::ShouldBuildLayerEvenIfInvisible(nsDisplayListBuilder* aBuilder)
+{
+return ShouldPrerenderTransformedContent(aBuilder, mFrame, false);
+}
+already_AddRefed<Layer> nsDisplayTransform::BuildLayer(nsDisplayListBuilder *aBuilder,
+LayerManager *aManager,
+const ContainerLayerParameters& aContainerParameters)
+{
+const gfx3DMatrix& newTransformMatrix = GetTransform();
+if (mFrame->StyleDisplay()->mBackfaceVisibility == NS_STYLE_BACKFACE_VISIBILITY_HIDDEN &&
+newTransformMatrix.IsBackfaceVisible()) {
+return nullptr;
+}
+uint32_t flags = ShouldPrerenderTransformedContent(aBuilder, mFrame, false) ?
+FrameLayerBuilder::CONTAINER_NOT_CLIPPED_BY_ANCESTORS : 0;
+nsRefPtr<ContainerLayer> container = aManager->GetLayerBuilder()->
+BuildContainerLayerFor(aBuilder, aManager, mFrame, this, *mStoredList.GetChildren(),
+aContainerParameters, &newTransformMatrix, flags);
+if (!container) {
+return nullptr;
+}
+// Add the preserve-3d flag for this layer, BuildContainerLayerFor clears all flags,
+// so we never need to explicitely unset this flag.
+if (mFrame->Preserves3D() || mFrame->Preserves3DChildren()) {
+container->SetContentFlags(container->GetContentFlags() | Layer::CONTENT_PRESERVE_3D);
+} else {
+container->SetContentFlags(container->GetContentFlags() & ~Layer::CONTENT_PRESERVE_3D);
+}
+nsDisplayListBuilder::AddAnimationsAndTransitionsToLayer(container, aBuilder,
+this, mFrame,
+eCSSProperty_transform);
+if (ShouldPrerenderTransformedContent(aBuilder, mFrame, false)) {
+container->SetUserData(nsIFrame::LayerIsPrerenderedDataKey(),
+/*the value is irrelevant*/nullptr);
+container->SetContentFlags(container->GetContentFlags() | Layer::CONTENT_MAY_CHANGE_TRANSFORM);
+} else {
+container->RemoveUserData(nsIFrame::LayerIsPrerenderedDataKey());
+container->SetContentFlags(container->GetContentFlags() & ~Layer::CONTENT_MAY_CHANGE_TRANSFORM);
+}
+return container.forget();
+}
+nsDisplayItem::LayerState
+nsDisplayTransform::GetLayerState(nsDisplayListBuilder* aBuilder,
+LayerManager* aManager,
+const ContainerLayerParameters& aParameters) {
+// If the transform is 3d, or the layer takes part in preserve-3d sorting
+// then we *always* want this to be an active layer.
+if (!GetTransform().Is2D() || mFrame->Preserves3D()) {
+return LAYER_ACTIVE_FORCE;
+}
+// Here we check if the *post-transform* bounds of this item are big enough
+// to justify an active layer.
+if (ActiveLayerTracker::IsStyleAnimated(mFrame, eCSSProperty_transform) &&
+!IsItemTooSmallForActiveLayer(this))
+return LAYER_ACTIVE;
+if (mFrame->GetContent()) {
+if (nsLayoutUtils::HasAnimationsForCompositor(mFrame->GetContent(),
+eCSSProperty_transform)) {
+return LAYER_ACTIVE;
+}
+}
+const nsStyleDisplay* disp = mFrame->StyleDisplay();
+if ((disp->mWillChangeBitField & NS_STYLE_WILL_CHANGE_TRANSFORM)) {
+return LAYER_ACTIVE;
+}
+// Expect the child display items to have this frame as their animated
+// geometry root (since it will be their reference frame). If they have a
+// different animated geometry root, we'll make this an active layer so the
+// animation can be accelerated.
+return RequiredLayerStateForChildren(aBuilder, aManager, aParameters,
+*mStoredList.GetChildren(), Frame());
+}
+bool nsDisplayTransform::ComputeVisibility(nsDisplayListBuilder *aBuilder,
+nsRegion *aVisibleRegion,
+const nsRect& aAllowVisibleRegionExpansion)
+{
+/* As we do this, we need to be sure to
+* untransform the visible rect, since we want everything that's painting to
+* think that it's painting in its original rectangular coordinate space.
+* If we can't untransform, take the entire overflow rect */
+nsRect untransformedVisibleRect;
+if (ShouldPrerenderTransformedContent(aBuilder, mFrame) ||
+!UntransformVisibleRect(aBuilder, &untransformedVisibleRect))
+{
+untransformedVisibleRect = mFrame->GetVisualOverflowRectRelativeToSelf();
+}
+nsRegion untransformedVisible = untransformedVisibleRect;
+// Call RecomputeVisiblity instead of ComputeVisibility since
+// nsDisplayItem::ComputeVisibility should only be called from
+// nsDisplayList::ComputeVisibility (which sets mVisibleRect on the item)
+mStoredList.RecomputeVisibility(aBuilder, &untransformedVisible);
+return true;
+}
+#ifdef DEBUG_HIT
+#include <time.h>
+#endif
+/* HitTest does some fun stuff with matrix transforms to obtain the answer. */
+void nsDisplayTransform::HitTest(nsDisplayListBuilder *aBuilder,
+const nsRect& aRect,
+HitTestState *aState,
+nsTArray<nsIFrame*> *aOutFrames)
+{
+/* Here's how this works:
+* 1. Get the matrix.  If it's singular, abort (clearly we didn't hit
+*    anything).
+* 2. Invert the matrix.
+* 3. Use it to transform the rect into the correct space.
+* 4. Pass that rect down through to the list's version of HitTest.
+*/
+// GetTransform always operates in dev pixels.
+float factor = mFrame->PresContext()->AppUnitsPerDevPixel();
+gfx3DMatrix matrix = GetTransform();
+if (!IsFrameVisible(mFrame, matrix)) {
+return;
+}
+/* We want to go from transformed-space to regular space.
+* Thus we have to invert the matrix, which normally does
+* the reverse operation (e.g. regular->transformed)
+*/
+bool snap;
+nsRect childBounds = mStoredList.GetBounds(aBuilder, &snap);
+gfxRect childGfxBounds(NSAppUnitsToFloatPixels(childBounds.x, factor),
+NSAppUnitsToFloatPixels(childBounds.y, factor),
+NSAppUnitsToFloatPixels(childBounds.width, factor),
+NSAppUnitsToFloatPixels(childBounds.height, factor));
+/* Now, apply the transform and pass it down the channel. */
+nsRect resultingRect;
+if (aRect.width == 1 && aRect.height == 1) {
+// Magic width/height indicating we're hit testing a point, not a rect
+gfxPoint point;
+if (!matrix.UntransformPoint(gfxPoint(NSAppUnitsToFloatPixels(aRect.x, factor),
+NSAppUnitsToFloatPixels(aRect.y, factor)),
+childGfxBounds,
+&point)) {
+return;
+}
+resultingRect = nsRect(NSFloatPixelsToAppUnits(float(point.x), factor),
+NSFloatPixelsToAppUnits(float(point.y), factor),
+1, 1);
+} else {
+gfxRect originalRect(NSAppUnitsToFloatPixels(aRect.x, factor),
+NSAppUnitsToFloatPixels(aRect.y, factor),
+NSAppUnitsToFloatPixels(aRect.width, factor),
+NSAppUnitsToFloatPixels(aRect.height, factor));
+gfxRect rect = matrix.UntransformBounds(originalRect, childGfxBounds);
+resultingRect = nsRect(NSFloatPixelsToAppUnits(float(rect.X()), factor),
+NSFloatPixelsToAppUnits(float(rect.Y()), factor),
+NSFloatPixelsToAppUnits(float(rect.Width()), factor),
+NSFloatPixelsToAppUnits(float(rect.Height()), factor));
+}
+if (resultingRect.IsEmpty()) {
+return;
+}
+#ifdef DEBUG_HIT
+printf("Frame: %p\n", dynamic_cast<void *>(mFrame));
+printf("  Untransformed point: (%f, %f)\n", resultingRect.X(), resultingRect.Y());
+uint32_t originalFrameCount = aOutFrames.Length();
+#endif
+mStoredList.HitTest(aBuilder, resultingRect, aState, aOutFrames);
+#ifdef DEBUG_HIT
+if (originalFrameCount != aOutFrames.Length())
+printf("  Hit! Time: %f, first frame: %p\n", static_cast<double>(clock()),
+dynamic_cast<void *>(aOutFrames.ElementAt(0)));
+printf("=== end of hit test ===\n");
+#endif
+}
+float
+nsDisplayTransform::GetHitDepthAtPoint(nsDisplayListBuilder* aBuilder, const nsPoint& aPoint)
+{
+// GetTransform always operates in dev pixels.
+float factor = mFrame->PresContext()->AppUnitsPerDevPixel();
+gfx3DMatrix matrix = GetTransform();
+NS_ASSERTION(IsFrameVisible(mFrame, matrix), "We can't have hit a frame that isn't visible!");
+bool snap;
+nsRect childBounds = mStoredList.GetBounds(aBuilder, &snap);
+gfxRect childGfxBounds(NSAppUnitsToFloatPixels(childBounds.x, factor),
+NSAppUnitsToFloatPixels(childBounds.y, factor),
+NSAppUnitsToFloatPixels(childBounds.width, factor),
+NSAppUnitsToFloatPixels(childBounds.height, factor));
+gfxPoint point;
+DebugOnly<bool> result = matrix.UntransformPoint(gfxPoint(NSAppUnitsToFloatPixels(aPoint.x, factor),
+NSAppUnitsToFloatPixels(aPoint.y, factor)),
+childGfxBounds,
+&point);
+NS_ASSERTION(result, "Why are we trying to get the depth for a point we didn't hit?");
+gfxPoint3D transformed = matrix.Transform3D(gfxPoint3D(point.x, point.y, 0));
+return transformed.z;
+}
+/* The bounding rectangle for the object is the overflow rectangle translated
+* by the reference point.
+*/
+nsRect nsDisplayTransform::GetBounds(nsDisplayListBuilder *aBuilder, bool* aSnap)
+{
+nsRect untransformedBounds =
+ShouldPrerenderTransformedContent(aBuilder, mFrame) ?
+mFrame->GetVisualOverflowRectRelativeToSelf() :
+mStoredList.GetBounds(aBuilder, aSnap);
+*aSnap = false;
+// GetTransform always operates in dev pixels.
+float factor = mFrame->PresContext()->AppUnitsPerDevPixel();
+return nsLayoutUtils::MatrixTransformRect(untransformedBounds,
+GetTransform(),
+factor);
+}
+/* The transform is opaque iff the transform consists solely of scales and
+* translations and if the underlying content is opaque.  Thus if the transform
+* is of the form
+*
+* |a c e|
+* |b d f|
+* |0 0 1|
+*
+* We need b and c to be zero.
+*
+* We also need to check whether the underlying opaque content completely fills
+* our visible rect. We use UntransformRect which expands to the axis-aligned
+* bounding rect, but that's OK since if
+* mStoredList.GetVisibleRect().Contains(untransformedVisible), then it
+* certainly contains the actual (non-axis-aligned) untransformed rect.
+*/
+nsRegion nsDisplayTransform::GetOpaqueRegion(nsDisplayListBuilder *aBuilder,
+bool* aSnap)
+{
+*aSnap = false;
+nsRect untransformedVisible;
+// If we're going to prerender all our content, pretend like we
+// don't have opqaue content so that everything under us is rendered
+// as well.  That will increase graphics memory usage if our frame
+// covers the entire window, but it allows our transform to be
+// updated extremely cheaply, without invalidating any other
+// content.
+if (ShouldPrerenderTransformedContent(aBuilder, mFrame) ||
+!UntransformVisibleRect(aBuilder, &untransformedVisible)) {
+return nsRegion();
+}
+const gfx3DMatrix& matrix = GetTransform();
+nsRegion result;
+gfxMatrix matrix2d;
+bool tmpSnap;
+if (matrix.Is2D(&matrix2d) &&
+matrix2d.PreservesAxisAlignedRectangles() &&
+mStoredList.GetOpaqueRegion(aBuilder, &tmpSnap).Contains(untransformedVisible)) {
+result = mVisibleRect;
+}
+return result;
+}
+/* The transform is uniform if it fills the entire bounding rect and the
+* wrapped list is uniform.  See GetOpaqueRegion for discussion of why this
+* works.
+*/
+bool nsDisplayTransform::IsUniform(nsDisplayListBuilder *aBuilder, nscolor* aColor)
+{
+nsRect untransformedVisible;
+if (!UntransformVisibleRect(aBuilder, &untransformedVisible)) {
+return false;
+}
+const gfx3DMatrix& matrix = GetTransform();
+gfxMatrix matrix2d;
+return matrix.Is2D(&matrix2d) &&
+matrix2d.PreservesAxisAlignedRectangles() &&
+mStoredList.GetVisibleRect().Contains(untransformedVisible) &&
+mStoredList.IsUniform(aBuilder, aColor);
+}
+/* If UNIFIED_CONTINUATIONS is defined, we can merge two display lists that
+* share the same underlying content.  Otherwise, doing so results in graphical
+* glitches.
+*/
+#ifndef UNIFIED_CONTINUATIONS
+bool
+nsDisplayTransform::TryMerge(nsDisplayListBuilder *aBuilder,
+nsDisplayItem *aItem)
+{
+return false;
+}
+#else
+bool
+nsDisplayTransform::TryMerge(nsDisplayListBuilder *aBuilder,
+nsDisplayItem *aItem)
+{
+NS_PRECONDITION(aItem, "Why did you try merging with a null item?");
+NS_PRECONDITION(aBuilder, "Why did you try merging with a null builder?");
+/* Make sure that we're dealing with two transforms. */
+if (aItem->GetType() != TYPE_TRANSFORM)
+return false;
+/* Check to see that both frames are part of the same content. */
+if (aItem->Frame()->GetContent() != mFrame->GetContent())
+return false;
+if (aItem->GetClip() != GetClip())
+return false;
+/* Now, move everything over to this frame and signal that
+* we merged things!
+*/
+mStoredList.MergeFrom(&static_cast<nsDisplayTransform*>(aItem)->mStoredList);
+return true;
+}
+#endif
+/* TransformRect takes in as parameters a rectangle (in app space) and returns
+* the smallest rectangle (in app space) containing the transformed image of
+* that rectangle.  That is, it takes the four corners of the rectangle,
+* transforms them according to the matrix associated with the specified frame,
+* then returns the smallest rectangle containing the four transformed points.
+*
+* @param aUntransformedBounds The rectangle (in app units) to transform.
+* @param aFrame The frame whose transformation should be applied.
+* @param aOrigin The delta from the frame origin to the coordinate space origin
+* @param aBoundsOverride (optional) Force the frame bounds to be the
+*        specified bounds.
+* @return The smallest rectangle containing the image of the transformed
+*         rectangle.
+*/
+nsRect nsDisplayTransform::TransformRect(const nsRect &aUntransformedBounds,
+const nsIFrame* aFrame,
+const nsPoint &aOrigin,
+const nsRect* aBoundsOverride)
+{
+NS_PRECONDITION(aFrame, "Can't take the transform based on a null frame!");
+float factor = aFrame->PresContext()->AppUnitsPerDevPixel();
+return nsLayoutUtils::MatrixTransformRect
+(aUntransformedBounds,
+GetResultingTransformMatrix(aFrame, aOrigin, factor, aBoundsOverride),
+factor);
+}
+nsRect nsDisplayTransform::TransformRectOut(const nsRect &aUntransformedBounds,
+const nsIFrame* aFrame,
+const nsPoint &aOrigin,
+const nsRect* aBoundsOverride)
+{
+NS_PRECONDITION(aFrame, "Can't take the transform based on a null frame!");
+float factor = aFrame->PresContext()->AppUnitsPerDevPixel();
+return nsLayoutUtils::MatrixTransformRectOut
+(aUntransformedBounds,
+GetResultingTransformMatrix(aFrame, aOrigin, factor, aBoundsOverride),
+factor);
+}
+bool nsDisplayTransform::UntransformRect(const nsRect &aTransformedBounds,
+const nsRect &aChildBounds,
+const nsIFrame* aFrame,
+const nsPoint &aOrigin,
+nsRect *aOutRect)
+{
+NS_PRECONDITION(aFrame, "Can't take the transform based on a null frame!");
+float factor = aFrame->PresContext()->AppUnitsPerDevPixel();
+gfx3DMatrix transform = GetResultingTransformMatrix(aFrame, aOrigin, factor, nullptr);
+if (transform.IsSingular()) {
+return false;
+}
+gfxRect result(NSAppUnitsToFloatPixels(aTransformedBounds.x, factor),
+NSAppUnitsToFloatPixels(aTransformedBounds.y, factor),
+NSAppUnitsToFloatPixels(aTransformedBounds.width, factor),
+NSAppUnitsToFloatPixels(aTransformedBounds.height, factor));
+gfxRect childGfxBounds(NSAppUnitsToFloatPixels(aChildBounds.x, factor),
+NSAppUnitsToFloatPixels(aChildBounds.y, factor),
+NSAppUnitsToFloatPixels(aChildBounds.width, factor),
+NSAppUnitsToFloatPixels(aChildBounds.height, factor));
+result = transform.UntransformBounds(result, childGfxBounds);
+*aOutRect = nsLayoutUtils::RoundGfxRectToAppRect(result, factor);
+return true;
+}
+bool nsDisplayTransform::UntransformVisibleRect(nsDisplayListBuilder* aBuilder,
+nsRect *aOutRect)
+{
+const gfx3DMatrix& matrix = GetTransform();
+if (matrix.IsSingular())
+return false;
+// GetTransform always operates in dev pixels.
+float factor = mFrame->PresContext()->AppUnitsPerDevPixel();
+gfxRect result(NSAppUnitsToFloatPixels(mVisibleRect.x, factor),
+NSAppUnitsToFloatPixels(mVisibleRect.y, factor),
+NSAppUnitsToFloatPixels(mVisibleRect.width, factor),
+NSAppUnitsToFloatPixels(mVisibleRect.height, factor));
+bool snap;
+nsRect childBounds = mStoredList.GetBounds(aBuilder, &snap);
+gfxRect childGfxBounds(NSAppUnitsToFloatPixels(childBounds.x, factor),
+NSAppUnitsToFloatPixels(childBounds.y, factor),
+NSAppUnitsToFloatPixels(childBounds.width, factor),
+NSAppUnitsToFloatPixels(childBounds.height, factor));
+/* We want to untransform the matrix, so invert the transformation first! */
+result = matrix.UntransformBounds(result, childGfxBounds);
+*aOutRect = nsLayoutUtils::RoundGfxRectToAppRect(result, factor);
+return true;
+}
+nsDisplaySVGEffects::nsDisplaySVGEffects(nsDisplayListBuilder* aBuilder,
+nsIFrame* aFrame, nsDisplayList* aList)
+: nsDisplayWrapList(aBuilder, aFrame, aList),
+mEffectsBounds(aFrame->GetVisualOverflowRectRelativeToSelf())
+{
+MOZ_COUNT_CTOR(nsDisplaySVGEffects);
+}
+#ifdef NS_BUILD_REFCNT_LOGGING
+nsDisplaySVGEffects::~nsDisplaySVGEffects()
+{
+MOZ_COUNT_DTOR(nsDisplaySVGEffects);
+}
+#endif
+nsRegion nsDisplaySVGEffects::GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
+bool* aSnap)
+{
+*aSnap = false;
+return nsRegion();
+}
+void
+nsDisplaySVGEffects::HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
+HitTestState* aState, nsTArray<nsIFrame*> *aOutFrames)
+{
+nsPoint rectCenter(aRect.x + aRect.width / 2, aRect.y + aRect.height / 2);
+if (nsSVGIntegrationUtils::HitTestFrameForEffects(mFrame,
+rectCenter - ToReferenceFrame())) {
+mList.HitTest(aBuilder, aRect, aState, aOutFrames);
+}
+}
+void
+nsDisplaySVGEffects::PaintAsLayer(nsDisplayListBuilder* aBuilder,
+nsRenderingContext* aCtx,
+LayerManager* aManager)
+{
+nsSVGIntegrationUtils::PaintFramesWithEffects(aCtx, mFrame,
+mVisibleRect,
+aBuilder, aManager);
+}
+LayerState
+nsDisplaySVGEffects::GetLayerState(nsDisplayListBuilder* aBuilder,
+LayerManager* aManager,
+const ContainerLayerParameters& aParameters)
+{
+return LAYER_SVG_EFFECTS;
+}
+already_AddRefed<Layer>
+nsDisplaySVGEffects::BuildLayer(nsDisplayListBuilder* aBuilder,
+LayerManager* aManager,
+const ContainerLayerParameters& aContainerParameters)
+{
+const nsIContent* content = mFrame->GetContent();
+bool hasSVGLayout = (mFrame->GetStateBits() & NS_FRAME_SVG_LAYOUT);
+if (hasSVGLayout) {
+nsISVGChildFrame *svgChildFrame = do_QueryFrame(mFrame);
+if (!svgChildFrame || !mFrame->GetContent()->IsSVG()) {
+NS_ASSERTION(false, "why?");
+return nullptr;
+}
+if (!static_cast<const nsSVGElement*>(content)->HasValidDimensions()) {
+return nullptr; // The SVG spec says not to draw filters for this
+}
+}
+float opacity = mFrame->StyleDisplay()->mOpacity;
+if (opacity == 0.0f)
+return nullptr;
+nsIFrame* firstFrame =
+nsLayoutUtils::FirstContinuationOrIBSplitSibling(mFrame);
+nsSVGEffects::EffectProperties effectProperties =
+nsSVGEffects::GetEffectProperties(firstFrame);
+bool isOK = effectProperties.HasNoFilterOrHasValidFilter();
+effectProperties.GetClipPathFrame(&isOK);
+effectProperties.GetMaskFrame(&isOK);
+if (!isOK) {
+return nullptr;
+}
+ContainerLayerParameters newContainerParameters = aContainerParameters;
+if (effectProperties.HasValidFilter()) {
+newContainerParameters.mDisableSubpixelAntialiasingInDescendants = true;
+}
+nsRefPtr<ContainerLayer> container = aManager->GetLayerBuilder()->
+BuildContainerLayerFor(aBuilder, aManager, mFrame, this, mList,
+newContainerParameters, nullptr);
+return container.forget();
+}
+bool nsDisplaySVGEffects::ComputeVisibility(nsDisplayListBuilder* aBuilder,
+nsRegion* aVisibleRegion,
+const nsRect& aAllowVisibleRegionExpansion) {
+nsPoint offset = ToReferenceFrame();
+nsRect dirtyRect =
+nsSVGIntegrationUtils::GetRequiredSourceForInvalidArea(mFrame,
+mVisibleRect - offset) +
+offset;
+// Our children may be made translucent or arbitrarily deformed so we should
+// not allow them to subtract area from aVisibleRegion.
+nsRegion childrenVisible(dirtyRect);
+nsRect r = dirtyRect.Intersect(mList.GetBounds(aBuilder));
+mList.ComputeVisibilityForSublist(aBuilder, &childrenVisible, r, nsRect());
+return true;
+}
+bool nsDisplaySVGEffects::TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem)
+{
+if (aItem->GetType() != TYPE_SVG_EFFECTS)
+return false;
+// items for the same content element should be merged into a single
+// compositing group
+// aItem->GetUnderlyingFrame() returns non-null because it's nsDisplaySVGEffects
+if (aItem->Frame()->GetContent() != mFrame->GetContent())
+return false;
+if (aItem->GetClip() != GetClip())
+return false;
+nsDisplaySVGEffects* other = static_cast<nsDisplaySVGEffects*>(aItem);
+MergeFromTrackingMergedFrames(other);
+mEffectsBounds.UnionRect(mEffectsBounds,
+other->mEffectsBounds + other->mFrame->GetOffsetTo(mFrame));
+return true;
+}
+#ifdef MOZ_DUMP_PAINTING
+void
+nsDisplaySVGEffects::PrintEffects(nsACString& aTo)
+{
+nsIFrame* firstFrame =
+nsLayoutUtils::FirstContinuationOrIBSplitSibling(mFrame);
+nsSVGEffects::EffectProperties effectProperties =
+nsSVGEffects::GetEffectProperties(firstFrame);
+bool isOK = true;
+nsSVGClipPathFrame *clipPathFrame = effectProperties.GetClipPathFrame(&isOK);
+bool first = true;
+aTo += " effects=(";
+if (mFrame->StyleDisplay()->mOpacity != 1.0f) {
+first = false;
+aTo += nsPrintfCString("opacity(%f)", mFrame->StyleDisplay()->mOpacity);
+}
+if (clipPathFrame) {
+if (!first) {
+aTo += ", ";
+}
+aTo += nsPrintfCString("clip(%s)", clipPathFrame->IsTrivial() ? "trivial" : "non-trivial");
+first = false;
+}
+if (effectProperties.HasValidFilter()) {
+if (!first) {
+aTo += ", ";
+}
+aTo += "filter";
+first = false;
+}
+if (effectProperties.GetMaskFrame(&isOK)) {
+if (!first) {
+aTo += ", ";
+}
+aTo += "mask";
+}
+aTo += ")";
+}
+#endif

The Tor Browser / file comparison

comparison: layout/base/nsDisplayList.cpp

layout/base/nsDisplayList.cpp