diff options
Diffstat (limited to 'layout/generic/nsFrameList.cpp')
| -rw-r--r-- | layout/generic/nsFrameList.cpp | 496 |
1 files changed, 496 insertions, 0 deletions
diff --git a/layout/generic/nsFrameList.cpp b/layout/generic/nsFrameList.cpp new file mode 100644 index 0000000000..942b5aa48b --- /dev/null +++ b/layout/generic/nsFrameList.cpp @@ -0,0 +1,496 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* 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 "mozilla/ArenaObjectID.h" +#include "mozilla/PresShell.h" +#include "nsBidiPresUtils.h" +#include "nsContainerFrame.h" +#include "nsGkAtoms.h" +#include "nsILineIterator.h" +#include "nsLayoutUtils.h" +#include "nsPresContext.h" + +using namespace mozilla; + +namespace mozilla { +namespace layout { +namespace detail { +const AlignedFrameListBytes gEmptyFrameListBytes = {0}; +} // namespace detail +} // namespace layout +} // namespace mozilla + +void* nsFrameList::operator new(size_t sz, mozilla::PresShell* aPresShell) { + return aPresShell->AllocateByObjectID(eArenaObjectID_nsFrameList, sz); +} + +void nsFrameList::Delete(mozilla::PresShell* aPresShell) { + MOZ_ASSERT(this != &EmptyList(), "Shouldn't Delete() this list"); + NS_ASSERTION(IsEmpty(), "Shouldn't Delete() a non-empty list"); + + aPresShell->FreeByObjectID(eArenaObjectID_nsFrameList, this); +} + +void nsFrameList::DestroyFrames() { + while (nsIFrame* frame = RemoveFirstChild()) { + frame->Destroy(); + } + mLastChild = nullptr; +} + +void nsFrameList::DestroyFramesFrom( + nsIFrame* aDestructRoot, layout::PostFrameDestroyData& aPostDestroyData) { + MOZ_ASSERT(aDestructRoot, "Missing destruct root"); + + while (nsIFrame* frame = RemoveFirstChild()) { + frame->DestroyFrom(aDestructRoot, aPostDestroyData); + } + mLastChild = nullptr; +} + +void nsFrameList::SetFrames(nsIFrame* aFrameList) { + MOZ_ASSERT(!mFirstChild, "Losing frames"); + + mFirstChild = aFrameList; + mLastChild = nsLayoutUtils::GetLastSibling(mFirstChild); +} + +void nsFrameList::RemoveFrame(nsIFrame* aFrame) { + MOZ_ASSERT(aFrame, "null ptr"); +#ifdef DEBUG_FRAME_LIST + // ContainsFrame is O(N) + MOZ_ASSERT(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; + } + + MOZ_ASSERT(NotEmpty(), "illegal operation on empty list"); +#ifdef DEBUG_FRAME_LIST + MOZ_ASSERT(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) { + MOZ_ASSERT(aFrame, "null ptr"); + RemoveFrame(aFrame); + aFrame->Destroy(); +} + +nsFrameList::Slice nsFrameList::InsertFrames(nsContainerFrame* aParent, + nsIFrame* aPrevSibling, + nsFrameList& aFrameList) { + MOZ_ASSERT(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) { + MOZ_ASSERT(&aLink.List() == this, "Unexpected list"); + MOZ_ASSERT(!aLink.PrevFrame() || + aLink.PrevFrame()->GetNextSibling() == aLink.NextFrame(), + "Unexpected PrevFrame()"); + MOZ_ASSERT(aLink.PrevFrame() || aLink.NextFrame() == FirstChild(), + "Unexpected NextFrame()"); + MOZ_ASSERT(!aLink.PrevFrame() || aLink.NextFrame() != FirstChild(), + "Unexpected NextFrame()"); + MOZ_ASSERT(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) { + MOZ_ASSERT(&aLink.List() == this, "Unexpected list"); + MOZ_ASSERT(!aLink.PrevFrame() || + aLink.PrevFrame()->GetNextSibling() == aLink.NextFrame(), + "Unexpected PrevFrame()"); + MOZ_ASSERT(aLink.PrevFrame() || aLink.NextFrame() == FirstChild(), + "Unexpected NextFrame()"); + MOZ_ASSERT(!aLink.PrevFrame() || aLink.NextFrame() != FirstChild(), + "Unexpected NextFrame()"); + MOZ_ASSERT(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; + + MOZ_ASSERT(aLink.AtEnd(), "What's going on here?"); + + return nsFrameList(newFirstFrame, newLastFrame); +} + +nsIFrame* nsFrameList::FrameAt(int32_t aIndex) const { + MOZ_ASSERT(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 { + MOZ_ASSERT(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(nsContainerFrame* 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(); + + nsBidiDirection paraDir = nsBidiPresUtils::ParagraphDirection(mFirstChild); + + nsAutoLineIterator iter = parent->GetLineIterator(); + if (!iter) { + // Parent is not a block Frame + if (parent->IsLineFrame()) { + // Line frames are not bidi-splittable, so need to consider bidi + // reordering + if (paraDir == 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. + if (nsBidiPresUtils::IsFrameInParagraphDirection(mFirstChild)) { + 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; + + if (aFrame) { + auto line = iter->GetLine(thisLine).unwrap(); + + if (paraDir == NSBIDI_LTR) { + frame = nsBidiPresUtils::GetFrameToLeftOf(aFrame, line.mFirstFrameOnLine, + line.mNumFramesOnLine); + } else { // RTL + frame = nsBidiPresUtils::GetFrameToRightOf(aFrame, line.mFirstFrameOnLine, + line.mNumFramesOnLine); + } + } + + if (!frame && thisLine > 0) { + // Get the last frame of the previous line + auto line = iter->GetLine(thisLine - 1).unwrap(); + + if (paraDir == NSBIDI_LTR) { + frame = nsBidiPresUtils::GetFrameToLeftOf(nullptr, line.mFirstFrameOnLine, + line.mNumFramesOnLine); + } else { // RTL + frame = nsBidiPresUtils::GetFrameToRightOf( + nullptr, line.mFirstFrameOnLine, line.mNumFramesOnLine); + } + } + return frame; +} + +nsIFrame* nsFrameList::GetNextVisualFor(nsIFrame* aFrame) const { + if (!mFirstChild) return nullptr; + + nsIFrame* parent = mFirstChild->GetParent(); + if (!parent) return aFrame ? aFrame->GetPrevSibling() : mFirstChild; + + nsBidiDirection paraDir = nsBidiPresUtils::ParagraphDirection(mFirstChild); + + nsAutoLineIterator iter = parent->GetLineIterator(); + if (!iter) { + // Parent is not a block Frame + if (parent->IsLineFrame()) { + // Line frames are not bidi-splittable, so need to consider bidi + // reordering + if (paraDir == 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. + if (nsBidiPresUtils::IsFrameInParagraphDirection(mFirstChild)) { + 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; + + if (aFrame) { + auto line = iter->GetLine(thisLine).unwrap(); + + if (paraDir == NSBIDI_LTR) { + frame = nsBidiPresUtils::GetFrameToRightOf(aFrame, line.mFirstFrameOnLine, + line.mNumFramesOnLine); + } else { // RTL + frame = nsBidiPresUtils::GetFrameToLeftOf(aFrame, line.mFirstFrameOnLine, + line.mNumFramesOnLine); + } + } + + int32_t numLines = iter->GetNumLines(); + if (!frame && thisLine < numLines - 1) { + // Get the first frame of the next line + auto line = iter->GetLine(thisLine + 1).unwrap(); + + if (paraDir == NSBIDI_LTR) { + frame = nsBidiPresUtils::GetFrameToRightOf( + nullptr, line.mFirstFrameOnLine, line.mNumFramesOnLine); + } else { // RTL + frame = nsBidiPresUtils::GetFrameToLeftOf(nullptr, line.mFirstFrameOnLine, + line.mNumFramesOnLine); + } + } + 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 { + +AutoFrameListPtr::~AutoFrameListPtr() { + if (mFrameList) { + mFrameList->Delete(mPresContext->PresShell()); + } +} + +} // namespace mozilla |