michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "nsFrameList.h"
michael@0: #include "nsIFrame.h"
michael@0: #include "nsLayoutUtils.h"
michael@0: #include "nsPresContext.h"
michael@0: #include "nsIPresShell.h"
michael@0: 
michael@0: #include "nsGkAtoms.h"
michael@0: #include "nsILineIterator.h"
michael@0: #include "nsBidiPresUtils.h"
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace layout {
michael@0: namespace detail {
michael@0: const AlignedFrameListBytes gEmptyFrameListBytes = { 0 };
michael@0: }
michael@0: }
michael@0: }
michael@0: 
michael@0: void*
michael@0: nsFrameList::operator new(size_t sz, nsIPresShell* aPresShell) CPP_THROW_NEW
michael@0: {
michael@0:   return aPresShell->AllocateByObjectID(nsPresArena::nsFrameList_id, sz);
michael@0: }
michael@0: 
michael@0: void
michael@0: nsFrameList::Delete(nsIPresShell* aPresShell)
michael@0: {
michael@0:   NS_PRECONDITION(this != &EmptyList(), "Shouldn't Delete() this list");
michael@0:   NS_ASSERTION(IsEmpty(), "Shouldn't Delete() a non-empty list");
michael@0: 
michael@0:   aPresShell->FreeByObjectID(nsPresArena::nsFrameList_id, this);
michael@0: }
michael@0: 
michael@0: void
michael@0: nsFrameList::DestroyFrames()
michael@0: {
michael@0:   while (nsIFrame* frame = RemoveFirstChild()) {
michael@0:     frame->Destroy();
michael@0:   }
michael@0:   mLastChild = nullptr;
michael@0: }
michael@0: 
michael@0: void
michael@0: nsFrameList::DestroyFramesFrom(nsIFrame* aDestructRoot)
michael@0: {
michael@0:   NS_PRECONDITION(aDestructRoot, "Missing destruct root");
michael@0: 
michael@0:   while (nsIFrame* frame = RemoveFirstChild()) {
michael@0:     frame->DestroyFrom(aDestructRoot);
michael@0:   }
michael@0:   mLastChild = nullptr;
michael@0: }
michael@0: 
michael@0: void
michael@0: nsFrameList::SetFrames(nsIFrame* aFrameList)
michael@0: {
michael@0:   NS_PRECONDITION(!mFirstChild, "Losing frames");
michael@0: 
michael@0:   mFirstChild = aFrameList;
michael@0:   mLastChild = nsLayoutUtils::GetLastSibling(mFirstChild);
michael@0: }
michael@0: 
michael@0: void
michael@0: nsFrameList::RemoveFrame(nsIFrame* aFrame)
michael@0: {
michael@0:   NS_PRECONDITION(aFrame, "null ptr");
michael@0: #ifdef DEBUG_FRAME_LIST
michael@0:   // ContainsFrame is O(N)
michael@0:   NS_PRECONDITION(ContainsFrame(aFrame), "wrong list");
michael@0: #endif
michael@0: 
michael@0:   nsIFrame* nextFrame = aFrame->GetNextSibling();
michael@0:   if (aFrame == mFirstChild) {
michael@0:     mFirstChild = nextFrame;
michael@0:     aFrame->SetNextSibling(nullptr);
michael@0:     if (!nextFrame) {
michael@0:       mLastChild = nullptr;
michael@0:     }
michael@0:   }
michael@0:   else {
michael@0:     nsIFrame* prevSibling = aFrame->GetPrevSibling();
michael@0:     NS_ASSERTION(prevSibling && prevSibling->GetNextSibling() == aFrame,
michael@0:                  "Broken frame linkage");
michael@0:     prevSibling->SetNextSibling(nextFrame);
michael@0:     aFrame->SetNextSibling(nullptr);
michael@0:     if (!nextFrame) {
michael@0:       mLastChild = prevSibling;
michael@0:     }
michael@0:   }
michael@0: }
michael@0: 
michael@0: nsFrameList
michael@0: nsFrameList::RemoveFramesAfter(nsIFrame* aAfterFrame)
michael@0: {
michael@0:   if (!aAfterFrame) {
michael@0:     nsFrameList result;
michael@0:     result.InsertFrames(nullptr, nullptr, *this);
michael@0:     return result;
michael@0:   }
michael@0: 
michael@0:   NS_PRECONDITION(NotEmpty(), "illegal operation on empty list");
michael@0: #ifdef DEBUG_FRAME_LIST
michael@0:   NS_PRECONDITION(ContainsFrame(aAfterFrame), "wrong list");
michael@0: #endif
michael@0: 
michael@0:   nsIFrame* tail = aAfterFrame->GetNextSibling();
michael@0:   // if (!tail) return EmptyList();  -- worth optimizing this case?
michael@0:   nsIFrame* oldLastChild = mLastChild;
michael@0:   mLastChild = aAfterFrame;
michael@0:   aAfterFrame->SetNextSibling(nullptr);
michael@0:   return nsFrameList(tail, tail ? oldLastChild : nullptr);
michael@0: }
michael@0: 
michael@0: nsIFrame*
michael@0: nsFrameList::RemoveFirstChild()
michael@0: {
michael@0:   if (mFirstChild) {
michael@0:     nsIFrame* firstChild = mFirstChild;
michael@0:     RemoveFrame(firstChild);
michael@0:     return firstChild;
michael@0:   }
michael@0:   return nullptr;
michael@0: }
michael@0: 
michael@0: void
michael@0: nsFrameList::DestroyFrame(nsIFrame* aFrame)
michael@0: {
michael@0:   NS_PRECONDITION(aFrame, "null ptr");
michael@0:   RemoveFrame(aFrame);
michael@0:   aFrame->Destroy();
michael@0: }
michael@0: 
michael@0: nsFrameList::Slice
michael@0: nsFrameList::InsertFrames(nsIFrame* aParent, nsIFrame* aPrevSibling,
michael@0:                           nsFrameList& aFrameList)
michael@0: {
michael@0:   NS_PRECONDITION(aFrameList.NotEmpty(), "Unexpected empty list");
michael@0: 
michael@0:   if (aParent) {
michael@0:     aFrameList.ApplySetParent(aParent);
michael@0:   }
michael@0: 
michael@0:   NS_ASSERTION(IsEmpty() ||
michael@0:                FirstChild()->GetParent() == aFrameList.FirstChild()->GetParent(),
michael@0:                "frame to add has different parent");
michael@0:   NS_ASSERTION(!aPrevSibling ||
michael@0:                aPrevSibling->GetParent() == aFrameList.FirstChild()->GetParent(),
michael@0:                "prev sibling has different parent");
michael@0: #ifdef DEBUG_FRAME_LIST
michael@0:   // ContainsFrame is O(N)
michael@0:   NS_ASSERTION(!aPrevSibling || ContainsFrame(aPrevSibling),
michael@0:                "prev sibling is not on this list");
michael@0: #endif
michael@0: 
michael@0:   nsIFrame* firstNewFrame = aFrameList.FirstChild();
michael@0:   nsIFrame* nextSibling;
michael@0:   if (aPrevSibling) {
michael@0:     nextSibling = aPrevSibling->GetNextSibling();
michael@0:     aPrevSibling->SetNextSibling(firstNewFrame);
michael@0:   }
michael@0:   else {
michael@0:     nextSibling = mFirstChild;
michael@0:     mFirstChild = firstNewFrame;
michael@0:   }
michael@0: 
michael@0:   nsIFrame* lastNewFrame = aFrameList.LastChild();
michael@0:   lastNewFrame->SetNextSibling(nextSibling);
michael@0:   if (!nextSibling) {
michael@0:     mLastChild = lastNewFrame;
michael@0:   }
michael@0: 
michael@0:   VerifyList();
michael@0: 
michael@0:   aFrameList.Clear();
michael@0:   return Slice(*this, firstNewFrame, nextSibling);
michael@0: }
michael@0: 
michael@0: nsFrameList
michael@0: nsFrameList::ExtractHead(FrameLinkEnumerator& aLink)
michael@0: {
michael@0:   NS_PRECONDITION(&aLink.List() == this, "Unexpected list");
michael@0:   NS_PRECONDITION(!aLink.PrevFrame() ||
michael@0:                   aLink.PrevFrame()->GetNextSibling() ==
michael@0:                     aLink.NextFrame(),
michael@0:                   "Unexpected PrevFrame()");
michael@0:   NS_PRECONDITION(aLink.PrevFrame() ||
michael@0:                   aLink.NextFrame() == FirstChild(),
michael@0:                   "Unexpected NextFrame()");
michael@0:   NS_PRECONDITION(!aLink.PrevFrame() ||
michael@0:                   aLink.NextFrame() != FirstChild(),
michael@0:                   "Unexpected NextFrame()");
michael@0:   NS_PRECONDITION(aLink.mEnd == nullptr,
michael@0:                   "Unexpected mEnd for frame link enumerator");
michael@0: 
michael@0:   nsIFrame* prev = aLink.PrevFrame();
michael@0:   nsIFrame* newFirstFrame = nullptr;
michael@0:   if (prev) {
michael@0:     // Truncate the list after |prev| and hand the first part to our new list.
michael@0:     prev->SetNextSibling(nullptr);
michael@0:     newFirstFrame = mFirstChild;
michael@0:     mFirstChild = aLink.NextFrame();
michael@0:     if (!mFirstChild) { // we handed over the whole list
michael@0:       mLastChild = nullptr;
michael@0:     }
michael@0: 
michael@0:     // Now make sure aLink doesn't point to a frame we no longer have.
michael@0:     aLink.mPrev = nullptr;
michael@0:   }
michael@0:   // else aLink is pointing to before our first frame.  Nothing to do.
michael@0: 
michael@0:   return nsFrameList(newFirstFrame, prev);
michael@0: }
michael@0: 
michael@0: nsFrameList
michael@0: nsFrameList::ExtractTail(FrameLinkEnumerator& aLink)
michael@0: {
michael@0:   NS_PRECONDITION(&aLink.List() == this, "Unexpected list");
michael@0:   NS_PRECONDITION(!aLink.PrevFrame() ||
michael@0:                   aLink.PrevFrame()->GetNextSibling() ==
michael@0:                     aLink.NextFrame(),
michael@0:                   "Unexpected PrevFrame()");
michael@0:   NS_PRECONDITION(aLink.PrevFrame() ||
michael@0:                   aLink.NextFrame() == FirstChild(),
michael@0:                   "Unexpected NextFrame()");
michael@0:   NS_PRECONDITION(!aLink.PrevFrame() ||
michael@0:                   aLink.NextFrame() != FirstChild(),
michael@0:                   "Unexpected NextFrame()");
michael@0:   NS_PRECONDITION(aLink.mEnd == nullptr,
michael@0:                   "Unexpected mEnd for frame link enumerator");
michael@0: 
michael@0:   nsIFrame* prev = aLink.PrevFrame();
michael@0:   nsIFrame* newFirstFrame;
michael@0:   nsIFrame* newLastFrame;
michael@0:   if (prev) {
michael@0:     // Truncate the list after |prev| and hand the second part to our new list
michael@0:     prev->SetNextSibling(nullptr);
michael@0:     newFirstFrame = aLink.NextFrame();
michael@0:     newLastFrame = newFirstFrame ? mLastChild : nullptr;
michael@0:     mLastChild = prev;
michael@0:   } else {
michael@0:     // Hand the whole list over to our new list
michael@0:     newFirstFrame = mFirstChild;
michael@0:     newLastFrame = mLastChild;
michael@0:     Clear();
michael@0:   }
michael@0: 
michael@0:   // Now make sure aLink doesn't point to a frame we no longer have.
michael@0:   aLink.mFrame = nullptr;
michael@0: 
michael@0:   NS_POSTCONDITION(aLink.AtEnd(), "What's going on here?");
michael@0: 
michael@0:   return nsFrameList(newFirstFrame, newLastFrame);
michael@0: }
michael@0: 
michael@0: nsIFrame*
michael@0: nsFrameList::FrameAt(int32_t aIndex) const
michael@0: {
michael@0:   NS_PRECONDITION(aIndex >= 0, "invalid arg");
michael@0:   if (aIndex < 0) return nullptr;
michael@0:   nsIFrame* frame = mFirstChild;
michael@0:   while ((aIndex-- > 0) && frame) {
michael@0:     frame = frame->GetNextSibling();
michael@0:   }
michael@0:   return frame;
michael@0: }
michael@0: 
michael@0: int32_t
michael@0: nsFrameList::IndexOf(nsIFrame* aFrame) const
michael@0: {
michael@0:   int32_t count = 0;
michael@0:   for (nsIFrame* f = mFirstChild; f; f = f->GetNextSibling()) {
michael@0:     if (f == aFrame)
michael@0:       return count;
michael@0:     ++count;
michael@0:   }
michael@0:   return -1;
michael@0: }
michael@0: 
michael@0: bool
michael@0: nsFrameList::ContainsFrame(const nsIFrame* aFrame) const
michael@0: {
michael@0:   NS_PRECONDITION(aFrame, "null ptr");
michael@0: 
michael@0:   nsIFrame* frame = mFirstChild;
michael@0:   while (frame) {
michael@0:     if (frame == aFrame) {
michael@0:       return true;
michael@0:     }
michael@0:     frame = frame->GetNextSibling();
michael@0:   }
michael@0:   return false;
michael@0: }
michael@0: 
michael@0: int32_t
michael@0: nsFrameList::GetLength() const
michael@0: {
michael@0:   int32_t count = 0;
michael@0:   nsIFrame* frame = mFirstChild;
michael@0:   while (frame) {
michael@0:     count++;
michael@0:     frame = frame->GetNextSibling();
michael@0:   }
michael@0:   return count;
michael@0: }
michael@0: 
michael@0: void
michael@0: nsFrameList::ApplySetParent(nsIFrame* aParent) const
michael@0: {
michael@0:   NS_ASSERTION(aParent, "null ptr");
michael@0: 
michael@0:   for (nsIFrame* f = FirstChild(); f; f = f->GetNextSibling()) {
michael@0:     f->SetParent(aParent);
michael@0:   }
michael@0: }
michael@0: 
michael@0: /* static */ void
michael@0: nsFrameList::UnhookFrameFromSiblings(nsIFrame* aFrame)
michael@0: {
michael@0:   MOZ_ASSERT(aFrame->GetPrevSibling() && aFrame->GetNextSibling());
michael@0:   nsIFrame* const nextSibling = aFrame->GetNextSibling();
michael@0:   nsIFrame* const prevSibling = aFrame->GetPrevSibling();
michael@0:   aFrame->SetNextSibling(nullptr);
michael@0:   prevSibling->SetNextSibling(nextSibling);
michael@0:   MOZ_ASSERT(!aFrame->GetPrevSibling() && !aFrame->GetNextSibling());
michael@0: }
michael@0: 
michael@0: #ifdef DEBUG_FRAME_DUMP
michael@0: void
michael@0: nsFrameList::List(FILE* out) const
michael@0: {
michael@0:   fprintf_stderr(out, "<\n");
michael@0:   for (nsIFrame* frame = mFirstChild; frame;
michael@0:        frame = frame->GetNextSibling()) {
michael@0:     frame->List(out, "  ");
michael@0:   }
michael@0:   fprintf_stderr(out, ">\n");
michael@0: }
michael@0: #endif
michael@0: 
michael@0: nsIFrame*
michael@0: nsFrameList::GetPrevVisualFor(nsIFrame* aFrame) const
michael@0: {
michael@0:   if (!mFirstChild)
michael@0:     return nullptr;
michael@0:   
michael@0:   nsIFrame* parent = mFirstChild->GetParent();
michael@0:   if (!parent)
michael@0:     return aFrame ? aFrame->GetPrevSibling() : LastChild();
michael@0: 
michael@0:   nsBidiLevel baseLevel = nsBidiPresUtils::GetFrameBaseLevel(mFirstChild);  
michael@0: 
michael@0:   nsAutoLineIterator iter = parent->GetLineIterator();
michael@0:   if (!iter) { 
michael@0:     // Parent is not a block Frame
michael@0:     if (parent->GetType() == nsGkAtoms::lineFrame) {
michael@0:       // Line frames are not bidi-splittable, so need to consider bidi reordering
michael@0:       if (baseLevel == NSBIDI_LTR) {
michael@0:         return nsBidiPresUtils::GetFrameToLeftOf(aFrame, mFirstChild, -1);
michael@0:       } else { // RTL
michael@0:         return nsBidiPresUtils::GetFrameToRightOf(aFrame, mFirstChild, -1);
michael@0:       }
michael@0:     } else {
michael@0:       // Just get the next or prev sibling, depending on block and frame direction.
michael@0:       nsBidiLevel frameEmbeddingLevel = nsBidiPresUtils::GetFrameEmbeddingLevel(mFirstChild);
michael@0:       if ((frameEmbeddingLevel & 1) == (baseLevel & 1)) {
michael@0:         return aFrame ? aFrame->GetPrevSibling() : LastChild();
michael@0:       } else {
michael@0:         return aFrame ? aFrame->GetNextSibling() : mFirstChild;
michael@0:       }    
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   // Parent is a block frame, so use the LineIterator to find the previous visual 
michael@0:   // sibling on this line, or the last one on the previous line.
michael@0: 
michael@0:   int32_t thisLine;
michael@0:   if (aFrame) {
michael@0:     thisLine = iter->FindLineContaining(aFrame);
michael@0:     if (thisLine < 0)
michael@0:       return nullptr;
michael@0:   } else {
michael@0:     thisLine = iter->GetNumLines();
michael@0:   }
michael@0: 
michael@0:   nsIFrame* frame = nullptr;
michael@0:   nsIFrame* firstFrameOnLine;
michael@0:   int32_t numFramesOnLine;
michael@0:   nsRect lineBounds;
michael@0:   uint32_t lineFlags;
michael@0: 
michael@0:   if (aFrame) {
michael@0:     iter->GetLine(thisLine, &firstFrameOnLine, &numFramesOnLine, lineBounds, &lineFlags);
michael@0: 
michael@0:     if (baseLevel == NSBIDI_LTR) {
michael@0:       frame = nsBidiPresUtils::GetFrameToLeftOf(aFrame, firstFrameOnLine, numFramesOnLine);
michael@0:     } else { // RTL
michael@0:       frame = nsBidiPresUtils::GetFrameToRightOf(aFrame, firstFrameOnLine, numFramesOnLine);
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   if (!frame && thisLine > 0) {
michael@0:     // Get the last frame of the previous line
michael@0:     iter->GetLine(thisLine - 1, &firstFrameOnLine, &numFramesOnLine, lineBounds, &lineFlags);
michael@0: 
michael@0:     if (baseLevel == NSBIDI_LTR) {
michael@0:       frame = nsBidiPresUtils::GetFrameToLeftOf(nullptr, firstFrameOnLine, numFramesOnLine);
michael@0:     } else { // RTL
michael@0:       frame = nsBidiPresUtils::GetFrameToRightOf(nullptr, firstFrameOnLine, numFramesOnLine);
michael@0:     }
michael@0:   }
michael@0:   return frame;
michael@0: }
michael@0: 
michael@0: nsIFrame*
michael@0: nsFrameList::GetNextVisualFor(nsIFrame* aFrame) const
michael@0: {
michael@0:   if (!mFirstChild)
michael@0:     return nullptr;
michael@0:   
michael@0:   nsIFrame* parent = mFirstChild->GetParent();
michael@0:   if (!parent)
michael@0:     return aFrame ? aFrame->GetPrevSibling() : mFirstChild;
michael@0: 
michael@0:   nsBidiLevel baseLevel = nsBidiPresUtils::GetFrameBaseLevel(mFirstChild);
michael@0:   
michael@0:   nsAutoLineIterator iter = parent->GetLineIterator();
michael@0:   if (!iter) { 
michael@0:     // Parent is not a block Frame
michael@0:     if (parent->GetType() == nsGkAtoms::lineFrame) {
michael@0:       // Line frames are not bidi-splittable, so need to consider bidi reordering
michael@0:       if (baseLevel == NSBIDI_LTR) {
michael@0:         return nsBidiPresUtils::GetFrameToRightOf(aFrame, mFirstChild, -1);
michael@0:       } else { // RTL
michael@0:         return nsBidiPresUtils::GetFrameToLeftOf(aFrame, mFirstChild, -1);
michael@0:       }
michael@0:     } else {
michael@0:       // Just get the next or prev sibling, depending on block and frame direction.
michael@0:       nsBidiLevel frameEmbeddingLevel = nsBidiPresUtils::GetFrameEmbeddingLevel(mFirstChild);
michael@0:       if ((frameEmbeddingLevel & 1) == (baseLevel & 1)) {
michael@0:         return aFrame ? aFrame->GetNextSibling() : mFirstChild;
michael@0:       } else {
michael@0:         return aFrame ? aFrame->GetPrevSibling() : LastChild();
michael@0:       }
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   // Parent is a block frame, so use the LineIterator to find the next visual 
michael@0:   // sibling on this line, or the first one on the next line.
michael@0:   
michael@0:   int32_t thisLine;
michael@0:   if (aFrame) {
michael@0:     thisLine = iter->FindLineContaining(aFrame);
michael@0:     if (thisLine < 0)
michael@0:       return nullptr;
michael@0:   } else {
michael@0:     thisLine = -1;
michael@0:   }
michael@0: 
michael@0:   nsIFrame* frame = nullptr;
michael@0:   nsIFrame* firstFrameOnLine;
michael@0:   int32_t numFramesOnLine;
michael@0:   nsRect lineBounds;
michael@0:   uint32_t lineFlags;
michael@0: 
michael@0:   if (aFrame) {
michael@0:     iter->GetLine(thisLine, &firstFrameOnLine, &numFramesOnLine, lineBounds, &lineFlags);
michael@0:     
michael@0:     if (baseLevel == NSBIDI_LTR) {
michael@0:       frame = nsBidiPresUtils::GetFrameToRightOf(aFrame, firstFrameOnLine, numFramesOnLine);
michael@0:     } else { // RTL
michael@0:       frame = nsBidiPresUtils::GetFrameToLeftOf(aFrame, firstFrameOnLine, numFramesOnLine);
michael@0:     }
michael@0:   }
michael@0:   
michael@0:   int32_t numLines = iter->GetNumLines();
michael@0:   if (!frame && thisLine < numLines - 1) {
michael@0:     // Get the first frame of the next line
michael@0:     iter->GetLine(thisLine + 1, &firstFrameOnLine, &numFramesOnLine, lineBounds, &lineFlags);
michael@0:     
michael@0:     if (baseLevel == NSBIDI_LTR) {
michael@0:       frame = nsBidiPresUtils::GetFrameToRightOf(nullptr, firstFrameOnLine, numFramesOnLine);
michael@0:     } else { // RTL
michael@0:       frame = nsBidiPresUtils::GetFrameToLeftOf(nullptr, firstFrameOnLine, numFramesOnLine);
michael@0:     }
michael@0:   }
michael@0:   return frame;
michael@0: }
michael@0: 
michael@0: #ifdef DEBUG_FRAME_LIST
michael@0: void
michael@0: nsFrameList::VerifyList() const
michael@0: {
michael@0:   NS_ASSERTION((mFirstChild == nullptr) == (mLastChild == nullptr),
michael@0:                "bad list state");
michael@0: 
michael@0:   if (IsEmpty()) {
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   // Simple algorithm to find a loop in a linked list -- advance pointers
michael@0:   // through it at speeds of 1 and 2, and if they ever get to be equal bail
michael@0:   NS_ASSERTION(!mFirstChild->GetPrevSibling(), "bad prev sibling pointer");
michael@0:   nsIFrame *first = mFirstChild, *second = mFirstChild;
michael@0:   for (;;) {
michael@0:     first = first->GetNextSibling();
michael@0:     second = second->GetNextSibling();
michael@0:     if (!second) {
michael@0:       break;
michael@0:     }
michael@0:     NS_ASSERTION(second->GetPrevSibling()->GetNextSibling() == second,
michael@0:                  "bad prev sibling pointer");
michael@0:     second = second->GetNextSibling();
michael@0:     if (first == second) {
michael@0:       // Loop detected!  Since second advances faster, they can't both be null;
michael@0:       // we would have broken out of the loop long ago.
michael@0:       NS_ERROR("loop in frame list.  This will probably hang soon.");
michael@0:       return;
michael@0:     }                           
michael@0:     if (!second) {
michael@0:       break;
michael@0:     }
michael@0:     NS_ASSERTION(second->GetPrevSibling()->GetNextSibling() == second,
michael@0:                  "bad prev sibling pointer");
michael@0:   }
michael@0: 
michael@0:   NS_ASSERTION(mLastChild == nsLayoutUtils::GetLastSibling(mFirstChild),
michael@0:                "bogus mLastChild");
michael@0:   // XXX we should also assert that all GetParent() are either null or
michael@0:   // the same non-null value, but nsCSSFrameConstructor::nsFrameItems
michael@0:   // prevents that, e.g. table captions.
michael@0: }
michael@0: #endif
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace layout {
michael@0: 
michael@0: AutoFrameListPtr::~AutoFrameListPtr()
michael@0: {
michael@0:   if (mFrameList) {
michael@0:     mFrameList->Delete(mPresContext->PresShell());
michael@0:   }
michael@0: }
michael@0: 
michael@0: }
michael@0: }