The Tor Browser: layout/generic/nsFontInflationData.cpp@6474c204b198 (annotated)

layout/generic/nsFontInflationData.cpp@6474c204b198 (annotated)

layout/generic/nsFontInflationData.cpp

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */
 /* 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/. */
 /* Per-block-formatting-context manager of font size inflation for pan and zoom UI. */
 #include "nsFontInflationData.h"
 #include "FramePropertyTable.h"
 #include "nsTextControlFrame.h"
 #include "nsListControlFrame.h"
 #include "nsComboboxControlFrame.h"
 #include "nsHTMLReflowState.h"
 #include "nsTextFrameUtils.h"
 using namespace mozilla;
 using namespace mozilla::layout;
 static void
 DestroyFontInflationData(void *aPropertyValue)
 {
   delete static_cast<nsFontInflationData*>(aPropertyValue);
 }
 NS_DECLARE_FRAME_PROPERTY(FontInflationDataProperty, DestroyFontInflationData)
 /* static */ nsFontInflationData*
 nsFontInflationData::FindFontInflationDataFor(const nsIFrame *aFrame)
 {
   // We have one set of font inflation data per block formatting context.
   const nsIFrame *bfc = FlowRootFor(aFrame);
   NS_ASSERTION(bfc->GetStateBits() & NS_FRAME_FONT_INFLATION_FLOW_ROOT,
                "should have found a flow root");
   return static_cast<nsFontInflationData*>(
              bfc->Properties().Get(FontInflationDataProperty()));
 }
 /* static */ bool
 nsFontInflationData::UpdateFontInflationDataWidthFor(const nsHTMLReflowState& aReflowState)
 {
   nsIFrame *bfc = aReflowState.frame;
   NS_ASSERTION(bfc->GetStateBits() & NS_FRAME_FONT_INFLATION_FLOW_ROOT,
                "should have been given a flow root");
   FrameProperties bfcProps(bfc->Properties());
   nsFontInflationData *data = static_cast<nsFontInflationData*>(
                                 bfcProps.Get(FontInflationDataProperty()));
   bool oldInflationEnabled;
   nscoord oldNCAWidth;
   if (data) {
     oldNCAWidth = data->mNCAWidth;
     oldInflationEnabled = data->mInflationEnabled;
   } else {
     data = new nsFontInflationData(bfc);
     bfcProps.Set(FontInflationDataProperty(), data);
     oldNCAWidth = -1;
     oldInflationEnabled = true; /* not relevant */
   }
   data->UpdateWidth(aReflowState);
   if (oldInflationEnabled != data->mInflationEnabled)
     return true;
   return oldInflationEnabled &&
          oldNCAWidth != data->mNCAWidth;
 }
 /* static */ void
 nsFontInflationData::MarkFontInflationDataTextDirty(nsIFrame *aBFCFrame)
 {
   NS_ASSERTION(aBFCFrame->GetStateBits() & NS_FRAME_FONT_INFLATION_FLOW_ROOT,
                "should have been given a flow root");
   FrameProperties bfcProps(aBFCFrame->Properties());
   nsFontInflationData *data = static_cast<nsFontInflationData*>(
                                 bfcProps.Get(FontInflationDataProperty()));
   if (data) {
     data->MarkTextDirty();
   }
 }
 nsFontInflationData::nsFontInflationData(nsIFrame *aBFCFrame)
   : mBFCFrame(aBFCFrame)
   , mNCAWidth(0)
   , mTextAmount(0)
   , mTextThreshold(0)
   , mInflationEnabled(false)
   , mTextDirty(true)
 {
 }
 /**
  * Find the closest common ancestor between aFrame1 and aFrame2, except
  * treating the parent of a frame as the first-in-flow of its parent (so
  * the result doesn't change when breaking changes).
  *
  * aKnownCommonAncestor is a known common ancestor of both.
  */
 static nsIFrame*
 NearestCommonAncestorFirstInFlow(nsIFrame *aFrame1, nsIFrame *aFrame2,
                                  nsIFrame *aKnownCommonAncestor)
 {
   aFrame1 = aFrame1->FirstInFlow();
   aFrame2 = aFrame2->FirstInFlow();
   aKnownCommonAncestor = aKnownCommonAncestor->FirstInFlow();
   nsAutoTArray<nsIFrame*, 32> ancestors1, ancestors2;
   for (nsIFrame *f = aFrame1; f != aKnownCommonAncestor;
        (f = f->GetParent()) && (f = f->FirstInFlow())) {
     ancestors1.AppendElement(f);
   }
   for (nsIFrame *f = aFrame2; f != aKnownCommonAncestor;
        (f = f->GetParent()) && (f = f->FirstInFlow())) {
     ancestors2.AppendElement(f);
   }
   nsIFrame *result = aKnownCommonAncestor;
   uint32_t i1 = ancestors1.Length(),
            i2 = ancestors2.Length();
   while (i1-- != 0 && i2-- != 0) {
     if (ancestors1[i1] != ancestors2[i2]) {
       break;
     }
     result = ancestors1[i1];
   }
   return result;
 }
 static nscoord
 ComputeDescendantWidth(const nsHTMLReflowState& aAncestorReflowState,
                        nsIFrame *aDescendantFrame)
 {
   nsIFrame *ancestorFrame = aAncestorReflowState.frame->FirstInFlow();
   if (aDescendantFrame == ancestorFrame) {
     return aAncestorReflowState.ComputedWidth();
   }
   AutoInfallibleTArray<nsIFrame*, 16> frames;
   for (nsIFrame *f = aDescendantFrame; f != ancestorFrame;
        f = f->GetParent()->FirstInFlow()) {
     frames.AppendElement(f);
   }
   // This ignores the width contributions made by scrollbars, though in
   // reality we don't have any scrollbars on the sorts of devices on
   // which we use font inflation, so it's not a problem.  But it may
   // occasionally cause problems when writing tests on desktop.
   uint32_t len = frames.Length();
   nsHTMLReflowState *reflowStates = static_cast<nsHTMLReflowState*>
                                 (moz_xmalloc(sizeof(nsHTMLReflowState) * len));
   nsPresContext *presContext = aDescendantFrame->PresContext();
   for (uint32_t i = 0; i < len; ++i) {
     const nsHTMLReflowState &parentReflowState =
       (i == 0) ? aAncestorReflowState : reflowStates[i - 1];
     nsSize availSize(parentReflowState.ComputedWidth(), NS_UNCONSTRAINEDSIZE);
     nsIFrame *frame = frames[len - i - 1];
     NS_ABORT_IF_FALSE(frame->GetParent()->FirstInFlow() ==
                         parentReflowState.frame->FirstInFlow(),
                       "bad logic in this function");
     new (reflowStates + i) nsHTMLReflowState(presContext, parentReflowState,
                                              frame, availSize);
   }
   NS_ABORT_IF_FALSE(reflowStates[len - 1].frame == aDescendantFrame,
                     "bad logic in this function");
   nscoord result = reflowStates[len - 1].ComputedWidth();
   for (uint32_t i = len; i-- != 0; ) {
     reflowStates[i].~nsHTMLReflowState();
   }
   moz_free(reflowStates);
   return result;
 }
 void
 nsFontInflationData::UpdateWidth(const nsHTMLReflowState &aReflowState)
 {
   nsIFrame *bfc = aReflowState.frame;
   NS_ASSERTION(bfc->GetStateBits() & NS_FRAME_FONT_INFLATION_FLOW_ROOT,
                "must be block formatting context");
   nsIFrame *firstInflatableDescendant =
              FindEdgeInflatableFrameIn(bfc, eFromStart);
   if (!firstInflatableDescendant) {
     mTextAmount = 0;
     mTextThreshold = 0; // doesn't matter
     mTextDirty = false;
     mInflationEnabled = false;
     return;
   }
   nsIFrame *lastInflatableDescendant =
              FindEdgeInflatableFrameIn(bfc, eFromEnd);
   NS_ABORT_IF_FALSE(!firstInflatableDescendant == !lastInflatableDescendant,
                     "null-ness should match; NearestCommonAncestorFirstInFlow"
                     " will crash when passed null");
   // Particularly when we're computing for the root BFC, the width of
   // nca might differ significantly for the width of bfc.
   nsIFrame *nca = NearestCommonAncestorFirstInFlow(firstInflatableDescendant,
                                                    lastInflatableDescendant,
                                                    bfc);
   while (!nca->IsContainerForFontSizeInflation()) {
     nca = nca->GetParent()->FirstInFlow();
   }
   nscoord newNCAWidth = ComputeDescendantWidth(aReflowState, nca);
   // See comment above "font.size.inflation.lineThreshold" in
   // modules/libpref/src/init/all.js .
   nsIPresShell* presShell = bfc->PresContext()->PresShell();
   uint32_t lineThreshold = presShell->FontSizeInflationLineThreshold();
   nscoord newTextThreshold = (newNCAWidth * lineThreshold) / 100;
   if (mTextThreshold <= mTextAmount && mTextAmount < newTextThreshold) {
     // Because we truncate our scan when we hit sufficient text, we now
     // need to rescan.
     mTextDirty = true;
   }
   mNCAWidth = newNCAWidth;
   mTextThreshold = newTextThreshold;
   mInflationEnabled = mTextAmount >= mTextThreshold;
 }
 /* static */ nsIFrame*
 nsFontInflationData::FindEdgeInflatableFrameIn(nsIFrame* aFrame,
                                                SearchDirection aDirection)
 {
   // NOTE: This function has a similar structure to ScanTextIn!
   // FIXME: Should probably only scan the text that's actually going to
   // be inflated!
   nsIFormControlFrame* fcf = do_QueryFrame(aFrame);
   if (fcf) {
     return aFrame;
   }
   // FIXME: aDirection!
   nsAutoTArray<FrameChildList, 4> lists;
   aFrame->GetChildLists(&lists);
   for (uint32_t i = 0, len = lists.Length(); i < len; ++i) {
     const nsFrameList& list =
       lists[(aDirection == eFromStart) ? i : len - i - 1].mList;
     for (nsIFrame *kid = (aDirection == eFromStart) ? list.FirstChild()
                                                     : list.LastChild();
          kid;
          kid = (aDirection == eFromStart) ? kid->GetNextSibling()
                                           : kid->GetPrevSibling()) {
       if (kid->GetStateBits() & NS_FRAME_FONT_INFLATION_FLOW_ROOT) {
         // Goes in a different set of inflation data.
         continue;
       }
       if (kid->GetType() == nsGkAtoms::textFrame) {
         nsIContent *content = kid->GetContent();
         if (content && kid == content->GetPrimaryFrame()) {
           uint32_t len = nsTextFrameUtils::
             ComputeApproximateLengthWithWhitespaceCompression(
               content, kid->StyleText());
           if (len != 0) {
             return kid;
           }
         }
       } else {
         nsIFrame *kidResult =
           FindEdgeInflatableFrameIn(kid, aDirection);
         if (kidResult) {
           return kidResult;
         }
       }
     }
   }
   return nullptr;
 }
 void
 nsFontInflationData::ScanText()
 {
   mTextDirty = false;
   mTextAmount = 0;
   ScanTextIn(mBFCFrame);
   mInflationEnabled = mTextAmount >= mTextThreshold;
 }
 static uint32_t
 DoCharCountOfLargestOption(nsIFrame *aContainer)
 {
   uint32_t result = 0;
   for (nsIFrame* option = aContainer->GetFirstPrincipalChild();
        option; option = option->GetNextSibling()) {
     uint32_t optionResult;
     if (option->GetContent()->IsHTML(nsGkAtoms::optgroup)) {
       optionResult = DoCharCountOfLargestOption(option);
     } else {
       // REVIEW: Check the frame structure for this!
       optionResult = 0;
       for (nsIFrame *optionChild = option->GetFirstPrincipalChild();
            optionChild; optionChild = optionChild->GetNextSibling()) {
         if (optionChild->GetType() == nsGkAtoms::textFrame) {
           optionResult += nsTextFrameUtils::
             ComputeApproximateLengthWithWhitespaceCompression(
               optionChild->GetContent(), optionChild->StyleText());
         }
       }
     }
     if (optionResult > result) {
       result = optionResult;
     }
   }
   return result;
 }
 static uint32_t
 CharCountOfLargestOption(nsIFrame *aListControlFrame)
 {
   return DoCharCountOfLargestOption(
     static_cast<nsListControlFrame*>(aListControlFrame)->GetOptionsContainer());
 }
 void
 nsFontInflationData::ScanTextIn(nsIFrame *aFrame)
 {
   // NOTE: This function has a similar structure to FindEdgeInflatableFrameIn!
   // FIXME: Should probably only scan the text that's actually going to
   // be inflated!
   nsIFrame::ChildListIterator lists(aFrame);
   for (; !lists.IsDone(); lists.Next()) {
     nsFrameList::Enumerator kids(lists.CurrentList());
     for (; !kids.AtEnd(); kids.Next()) {
       nsIFrame *kid = kids.get();
       if (kid->GetStateBits() & NS_FRAME_FONT_INFLATION_FLOW_ROOT) {
         // Goes in a different set of inflation data.
         continue;
       }
       nsIAtom *fType = kid->GetType();
       if (fType == nsGkAtoms::textFrame) {
         nsIContent *content = kid->GetContent();
         if (content && kid == content->GetPrimaryFrame()) {
           uint32_t len = nsTextFrameUtils::
             ComputeApproximateLengthWithWhitespaceCompression(
               content, kid->StyleText());
           if (len != 0) {
             nscoord fontSize = kid->StyleFont()->mFont.size;
             if (fontSize > 0) {
               mTextAmount += fontSize * len;
             }
           }
         }
       } else if (fType == nsGkAtoms::textInputFrame) {
         // We don't want changes to the amount of text in a text input
         // to change what we count towards inflation.
         nscoord fontSize = kid->StyleFont()->mFont.size;
         int32_t charCount = static_cast<nsTextControlFrame*>(kid)->GetCols();
         mTextAmount += charCount * fontSize;
       } else if (fType == nsGkAtoms::comboboxControlFrame) {
         // See textInputFrame above (with s/amount of text/selected option/).
         // Don't just recurse down to the list control inside, since we
         // need to exclude the display frame.
         nscoord fontSize = kid->StyleFont()->mFont.size;
         int32_t charCount = CharCountOfLargestOption(
           static_cast<nsComboboxControlFrame*>(kid)->GetDropDown());
         mTextAmount += charCount * fontSize;
       } else if (fType == nsGkAtoms::listControlFrame) {
         // See textInputFrame above (with s/amount of text/selected option/).
         nscoord fontSize = kid->StyleFont()->mFont.size;
         int32_t charCount = CharCountOfLargestOption(kid);
         mTextAmount += charCount * fontSize;
       } else {
         // recursive step
         ScanTextIn(kid);
       }
       if (mTextAmount >= mTextThreshold) {
         return;
       }
     }
   }
 }

The Tor Browser / annotate

layout/generic/nsFontInflationData.cpp@6474c204b198 (annotated)

layout/generic/nsFontInflationData.cpp