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

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

layout/generic/nsFrameList.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.

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* 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/. */
 #include "nsFrameList.h"
 #include "nsIFrame.h"
 #include "nsLayoutUtils.h"
 #include "nsPresContext.h"
 #include "nsIPresShell.h"
 #include "nsGkAtoms.h"
 #include "nsILineIterator.h"
 #include "nsBidiPresUtils.h"
 namespace mozilla {
 namespace layout {
 namespace detail {
 const AlignedFrameListBytes gEmptyFrameListBytes = { 0 };
 }
 }
 }
 void*
 nsFrameList::operator new(size_t sz, nsIPresShell* aPresShell) CPP_THROW_NEW
 {
   return aPresShell->AllocateByObjectID(nsPresArena::nsFrameList_id, sz);
 }
 void
 nsFrameList::Delete(nsIPresShell* aPresShell)
 {
   NS_PRECONDITION(this != &EmptyList(), "Shouldn't Delete() this list");
   NS_ASSERTION(IsEmpty(), "Shouldn't Delete() a non-empty list");
   aPresShell->FreeByObjectID(nsPresArena::nsFrameList_id, this);
 }
 void
 nsFrameList::DestroyFrames()
 {
   while (nsIFrame* frame = RemoveFirstChild()) {
     frame->Destroy();
   }
   mLastChild = nullptr;
 }
 void
 nsFrameList::DestroyFramesFrom(nsIFrame* aDestructRoot)
 {
   NS_PRECONDITION(aDestructRoot, "Missing destruct root");
   while (nsIFrame* frame = RemoveFirstChild()) {
     frame->DestroyFrom(aDestructRoot);
   }
   mLastChild = nullptr;
 }
 void
 nsFrameList::SetFrames(nsIFrame* aFrameList)
 {
   NS_PRECONDITION(!mFirstChild, "Losing frames");
   mFirstChild = aFrameList;
   mLastChild = nsLayoutUtils::GetLastSibling(mFirstChild);
 }
 void
 nsFrameList::RemoveFrame(nsIFrame* aFrame)
 {
   NS_PRECONDITION(aFrame, "null ptr");
 #ifdef DEBUG_FRAME_LIST
   // ContainsFrame is O(N)
   NS_PRECONDITION(ContainsFrame(aFrame), "wrong list");
 #endif
   nsIFrame* nextFrame = aFrame->GetNextSibling();
   if (aFrame == mFirstChild) {
     mFirstChild = nextFrame;
     aFrame->SetNextSibling(nullptr);
     if (!nextFrame) {
       mLastChild = nullptr;
     }
   }
   else {
     nsIFrame* prevSibling = aFrame->GetPrevSibling();
     NS_ASSERTION(prevSibling && prevSibling->GetNextSibling() == aFrame,
                  "Broken frame linkage");
     prevSibling->SetNextSibling(nextFrame);
     aFrame->SetNextSibling(nullptr);
     if (!nextFrame) {
       mLastChild = prevSibling;
     }
   }
 }
 nsFrameList
 nsFrameList::RemoveFramesAfter(nsIFrame* aAfterFrame)
 {
   if (!aAfterFrame) {
     nsFrameList result;
     result.InsertFrames(nullptr, nullptr, *this);
     return result;
   }
   NS_PRECONDITION(NotEmpty(), "illegal operation on empty list");
 #ifdef DEBUG_FRAME_LIST
   NS_PRECONDITION(ContainsFrame(aAfterFrame), "wrong list");
 #endif
   nsIFrame* tail = aAfterFrame->GetNextSibling();
   // if (!tail) return EmptyList();  -- worth optimizing this case?
   nsIFrame* oldLastChild = mLastChild;
   mLastChild = aAfterFrame;
   aAfterFrame->SetNextSibling(nullptr);
   return nsFrameList(tail, tail ? oldLastChild : nullptr);
 }
 nsIFrame*
 nsFrameList::RemoveFirstChild()
 {
   if (mFirstChild) {
     nsIFrame* firstChild = mFirstChild;
     RemoveFrame(firstChild);
     return firstChild;
   }
   return nullptr;
 }
 void
 nsFrameList::DestroyFrame(nsIFrame* aFrame)
 {
   NS_PRECONDITION(aFrame, "null ptr");
   RemoveFrame(aFrame);
   aFrame->Destroy();
 }
 nsFrameList::Slice
 nsFrameList::InsertFrames(nsIFrame* aParent, nsIFrame* aPrevSibling,
                           nsFrameList& aFrameList)
 {
   NS_PRECONDITION(aFrameList.NotEmpty(), "Unexpected empty list");
   if (aParent) {
     aFrameList.ApplySetParent(aParent);
   }
   NS_ASSERTION(IsEmpty() ||
                FirstChild()->GetParent() == aFrameList.FirstChild()->GetParent(),
                "frame to add has different parent");
   NS_ASSERTION(!aPrevSibling ||
                aPrevSibling->GetParent() == aFrameList.FirstChild()->GetParent(),
                "prev sibling has different parent");
 #ifdef DEBUG_FRAME_LIST
   // ContainsFrame is O(N)
   NS_ASSERTION(!aPrevSibling || ContainsFrame(aPrevSibling),
                "prev sibling is not on this list");
 #endif
   nsIFrame* firstNewFrame = aFrameList.FirstChild();
   nsIFrame* nextSibling;
   if (aPrevSibling) {
     nextSibling = aPrevSibling->GetNextSibling();
     aPrevSibling->SetNextSibling(firstNewFrame);
   }
   else {
     nextSibling = mFirstChild;
     mFirstChild = firstNewFrame;
   }
   nsIFrame* lastNewFrame = aFrameList.LastChild();
   lastNewFrame->SetNextSibling(nextSibling);
   if (!nextSibling) {
     mLastChild = lastNewFrame;
   }
   VerifyList();
   aFrameList.Clear();
   return Slice(*this, firstNewFrame, nextSibling);
 }
 nsFrameList
 nsFrameList::ExtractHead(FrameLinkEnumerator& aLink)
 {
   NS_PRECONDITION(&aLink.List() == this, "Unexpected list");
   NS_PRECONDITION(!aLink.PrevFrame() ||
                   aLink.PrevFrame()->GetNextSibling() ==
                     aLink.NextFrame(),
                   "Unexpected PrevFrame()");
   NS_PRECONDITION(aLink.PrevFrame() ||
                   aLink.NextFrame() == FirstChild(),
                   "Unexpected NextFrame()");
   NS_PRECONDITION(!aLink.PrevFrame() ||
                   aLink.NextFrame() != FirstChild(),
                   "Unexpected NextFrame()");
   NS_PRECONDITION(aLink.mEnd == nullptr,
                   "Unexpected mEnd for frame link enumerator");
   nsIFrame* prev = aLink.PrevFrame();
   nsIFrame* newFirstFrame = nullptr;
   if (prev) {
     // Truncate the list after |prev| and hand the first part to our new list.
     prev->SetNextSibling(nullptr);
     newFirstFrame = mFirstChild;
     mFirstChild = aLink.NextFrame();
     if (!mFirstChild) { // we handed over the whole list
       mLastChild = nullptr;
     }
     // Now make sure aLink doesn't point to a frame we no longer have.
     aLink.mPrev = nullptr;
   }
   // else aLink is pointing to before our first frame.  Nothing to do.
   return nsFrameList(newFirstFrame, prev);
 }
 nsFrameList
 nsFrameList::ExtractTail(FrameLinkEnumerator& aLink)
 {
   NS_PRECONDITION(&aLink.List() == this, "Unexpected list");
   NS_PRECONDITION(!aLink.PrevFrame() ||
                   aLink.PrevFrame()->GetNextSibling() ==
                     aLink.NextFrame(),
                   "Unexpected PrevFrame()");
   NS_PRECONDITION(aLink.PrevFrame() ||
                   aLink.NextFrame() == FirstChild(),
                   "Unexpected NextFrame()");
   NS_PRECONDITION(!aLink.PrevFrame() ||
                   aLink.NextFrame() != FirstChild(),
                   "Unexpected NextFrame()");
   NS_PRECONDITION(aLink.mEnd == nullptr,
                   "Unexpected mEnd for frame link enumerator");
   nsIFrame* prev = aLink.PrevFrame();
   nsIFrame* newFirstFrame;
   nsIFrame* newLastFrame;
   if (prev) {
     // Truncate the list after |prev| and hand the second part to our new list
     prev->SetNextSibling(nullptr);
     newFirstFrame = aLink.NextFrame();
     newLastFrame = newFirstFrame ? mLastChild : nullptr;
     mLastChild = prev;
   } else {
     // Hand the whole list over to our new list
     newFirstFrame = mFirstChild;
     newLastFrame = mLastChild;
     Clear();
   }
   // Now make sure aLink doesn't point to a frame we no longer have.
   aLink.mFrame = nullptr;
   NS_POSTCONDITION(aLink.AtEnd(), "What's going on here?");
   return nsFrameList(newFirstFrame, newLastFrame);
 }
 nsIFrame*
 nsFrameList::FrameAt(int32_t aIndex) const
 {
   NS_PRECONDITION(aIndex >= 0, "invalid arg");
   if (aIndex < 0) return nullptr;
   nsIFrame* frame = mFirstChild;
   while ((aIndex-- > 0) && frame) {
     frame = frame->GetNextSibling();
   }
   return frame;
 }
 int32_t
 nsFrameList::IndexOf(nsIFrame* aFrame) const
 {
   int32_t count = 0;
   for (nsIFrame* f = mFirstChild; f; f = f->GetNextSibling()) {
     if (f == aFrame)
       return count;
     ++count;
   }
   return -1;
 }
 bool
 nsFrameList::ContainsFrame(const nsIFrame* aFrame) const
 {
   NS_PRECONDITION(aFrame, "null ptr");
   nsIFrame* frame = mFirstChild;
   while (frame) {
     if (frame == aFrame) {
       return true;
     }
     frame = frame->GetNextSibling();
   }
   return false;
 }
 int32_t
 nsFrameList::GetLength() const
 {
   int32_t count = 0;
   nsIFrame* frame = mFirstChild;
   while (frame) {
     count++;
     frame = frame->GetNextSibling();
   }
   return count;
 }
 void
 nsFrameList::ApplySetParent(nsIFrame* aParent) const
 {
   NS_ASSERTION(aParent, "null ptr");
   for (nsIFrame* f = FirstChild(); f; f = f->GetNextSibling()) {
     f->SetParent(aParent);
   }
 }
 /* static */ void
 nsFrameList::UnhookFrameFromSiblings(nsIFrame* aFrame)
 {
   MOZ_ASSERT(aFrame->GetPrevSibling() && aFrame->GetNextSibling());
   nsIFrame* const nextSibling = aFrame->GetNextSibling();
   nsIFrame* const prevSibling = aFrame->GetPrevSibling();
   aFrame->SetNextSibling(nullptr);
   prevSibling->SetNextSibling(nextSibling);
   MOZ_ASSERT(!aFrame->GetPrevSibling() && !aFrame->GetNextSibling());
 }
 #ifdef DEBUG_FRAME_DUMP
 void
 nsFrameList::List(FILE* out) const
 {
   fprintf_stderr(out, "<\n");
   for (nsIFrame* frame = mFirstChild; frame;
        frame = frame->GetNextSibling()) {
     frame->List(out, "  ");
   }
   fprintf_stderr(out, ">\n");
 }
 #endif
 nsIFrame*
 nsFrameList::GetPrevVisualFor(nsIFrame* aFrame) const
 {
   if (!mFirstChild)
     return nullptr;
   nsIFrame* parent = mFirstChild->GetParent();
   if (!parent)
     return aFrame ? aFrame->GetPrevSibling() : LastChild();
   nsBidiLevel baseLevel = nsBidiPresUtils::GetFrameBaseLevel(mFirstChild);
   nsAutoLineIterator iter = parent->GetLineIterator();
   if (!iter) {
     // Parent is not a block Frame
     if (parent->GetType() == nsGkAtoms::lineFrame) {
       // Line frames are not bidi-splittable, so need to consider bidi reordering
       if (baseLevel == NSBIDI_LTR) {
         return nsBidiPresUtils::GetFrameToLeftOf(aFrame, mFirstChild, -1);
       } else { // RTL
         return nsBidiPresUtils::GetFrameToRightOf(aFrame, mFirstChild, -1);
       }
     } else {
       // Just get the next or prev sibling, depending on block and frame direction.
       nsBidiLevel frameEmbeddingLevel = nsBidiPresUtils::GetFrameEmbeddingLevel(mFirstChild);
       if ((frameEmbeddingLevel & 1) == (baseLevel & 1)) {
         return aFrame ? aFrame->GetPrevSibling() : LastChild();
       } else {
         return aFrame ? aFrame->GetNextSibling() : mFirstChild;
       }
     }
   }
   // Parent is a block frame, so use the LineIterator to find the previous visual
   // sibling on this line, or the last one on the previous line.
   int32_t thisLine;
   if (aFrame) {
     thisLine = iter->FindLineContaining(aFrame);
     if (thisLine < 0)
       return nullptr;
   } else {
     thisLine = iter->GetNumLines();
   }
   nsIFrame* frame = nullptr;
   nsIFrame* firstFrameOnLine;
   int32_t numFramesOnLine;
   nsRect lineBounds;
   uint32_t lineFlags;
   if (aFrame) {
     iter->GetLine(thisLine, &firstFrameOnLine, &numFramesOnLine, lineBounds, &lineFlags);
     if (baseLevel == NSBIDI_LTR) {
       frame = nsBidiPresUtils::GetFrameToLeftOf(aFrame, firstFrameOnLine, numFramesOnLine);
     } else { // RTL
       frame = nsBidiPresUtils::GetFrameToRightOf(aFrame, firstFrameOnLine, numFramesOnLine);
     }
   }
   if (!frame && thisLine > 0) {
     // Get the last frame of the previous line
     iter->GetLine(thisLine - 1, &firstFrameOnLine, &numFramesOnLine, lineBounds, &lineFlags);
     if (baseLevel == NSBIDI_LTR) {
       frame = nsBidiPresUtils::GetFrameToLeftOf(nullptr, firstFrameOnLine, numFramesOnLine);
     } else { // RTL
       frame = nsBidiPresUtils::GetFrameToRightOf(nullptr, firstFrameOnLine, numFramesOnLine);
     }
   }
   return frame;
 }
 nsIFrame*
 nsFrameList::GetNextVisualFor(nsIFrame* aFrame) const
 {
   if (!mFirstChild)
     return nullptr;
   nsIFrame* parent = mFirstChild->GetParent();
   if (!parent)
     return aFrame ? aFrame->GetPrevSibling() : mFirstChild;
   nsBidiLevel baseLevel = nsBidiPresUtils::GetFrameBaseLevel(mFirstChild);
   nsAutoLineIterator iter = parent->GetLineIterator();
   if (!iter) {
     // Parent is not a block Frame
     if (parent->GetType() == nsGkAtoms::lineFrame) {
       // Line frames are not bidi-splittable, so need to consider bidi reordering
       if (baseLevel == NSBIDI_LTR) {
         return nsBidiPresUtils::GetFrameToRightOf(aFrame, mFirstChild, -1);
       } else { // RTL
         return nsBidiPresUtils::GetFrameToLeftOf(aFrame, mFirstChild, -1);
       }
     } else {
       // Just get the next or prev sibling, depending on block and frame direction.
       nsBidiLevel frameEmbeddingLevel = nsBidiPresUtils::GetFrameEmbeddingLevel(mFirstChild);
       if ((frameEmbeddingLevel & 1) == (baseLevel & 1)) {
         return aFrame ? aFrame->GetNextSibling() : mFirstChild;
       } else {
         return aFrame ? aFrame->GetPrevSibling() : LastChild();
       }
     }
   }
   // Parent is a block frame, so use the LineIterator to find the next visual
   // sibling on this line, or the first one on the next line.
   int32_t thisLine;
   if (aFrame) {
     thisLine = iter->FindLineContaining(aFrame);
     if (thisLine < 0)
       return nullptr;
   } else {
     thisLine = -1;
   }
   nsIFrame* frame = nullptr;
   nsIFrame* firstFrameOnLine;
   int32_t numFramesOnLine;
   nsRect lineBounds;
   uint32_t lineFlags;
   if (aFrame) {
     iter->GetLine(thisLine, &firstFrameOnLine, &numFramesOnLine, lineBounds, &lineFlags);
     if (baseLevel == NSBIDI_LTR) {
       frame = nsBidiPresUtils::GetFrameToRightOf(aFrame, firstFrameOnLine, numFramesOnLine);
     } else { // RTL
       frame = nsBidiPresUtils::GetFrameToLeftOf(aFrame, firstFrameOnLine, numFramesOnLine);
     }
   }
   int32_t numLines = iter->GetNumLines();
   if (!frame && thisLine < numLines - 1) {
     // Get the first frame of the next line
     iter->GetLine(thisLine + 1, &firstFrameOnLine, &numFramesOnLine, lineBounds, &lineFlags);
     if (baseLevel == NSBIDI_LTR) {
       frame = nsBidiPresUtils::GetFrameToRightOf(nullptr, firstFrameOnLine, numFramesOnLine);
     } else { // RTL
       frame = nsBidiPresUtils::GetFrameToLeftOf(nullptr, firstFrameOnLine, numFramesOnLine);
     }
   }
   return frame;
 }
 #ifdef DEBUG_FRAME_LIST
 void
 nsFrameList::VerifyList() const
 {
   NS_ASSERTION((mFirstChild == nullptr) == (mLastChild == nullptr),
                "bad list state");
   if (IsEmpty()) {
     return;
   }
   // Simple algorithm to find a loop in a linked list -- advance pointers
   // through it at speeds of 1 and 2, and if they ever get to be equal bail
   NS_ASSERTION(!mFirstChild->GetPrevSibling(), "bad prev sibling pointer");
   nsIFrame *first = mFirstChild, *second = mFirstChild;
   for (;;) {
     first = first->GetNextSibling();
     second = second->GetNextSibling();
     if (!second) {
       break;
     }
     NS_ASSERTION(second->GetPrevSibling()->GetNextSibling() == second,
                  "bad prev sibling pointer");
     second = second->GetNextSibling();
     if (first == second) {
       // Loop detected!  Since second advances faster, they can't both be null;
       // we would have broken out of the loop long ago.
       NS_ERROR("loop in frame list.  This will probably hang soon.");
       return;
     }
     if (!second) {
       break;
     }
     NS_ASSERTION(second->GetPrevSibling()->GetNextSibling() == second,
                  "bad prev sibling pointer");
   }
   NS_ASSERTION(mLastChild == nsLayoutUtils::GetLastSibling(mFirstChild),
                "bogus mLastChild");
   // XXX we should also assert that all GetParent() are either null or
   // the same non-null value, but nsCSSFrameConstructor::nsFrameItems
   // prevents that, e.g. table captions.
 }
 #endif
 namespace mozilla {
 namespace layout {
 AutoFrameListPtr::~AutoFrameListPtr()
 {
   if (mFrameList) {
     mFrameList->Delete(mPresContext->PresShell());
   }
 }
 }
 }

The Tor Browser / annotate

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

layout/generic/nsFrameList.cpp