Source code

Revision control

Other Tools

/* -*- 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