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/* -*- 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
/* representation of one line within a block frame, a CSS line box */
#include "nsLineBox.h"
#include "mozilla/ArenaObjectID.h"
#include "mozilla/Assertions.h"
#include "mozilla/Likely.h"
#include "mozilla/PresShell.h"
#include "mozilla/Sprintf.h"
#include "mozilla/WritingModes.h"
#include "mozilla/ToString.h"
#include "nsBidiPresUtils.h"
#include "nsIFrame.h"
#include "nsIFrameInlines.h"
#include "nsPresArena.h"
#include "nsPrintfCString.h"
#include "nsWindowSizes.h"
#ifdef DEBUG
static int32_t ctorCount;
int32_t nsLineBox::GetCtorCount() { return ctorCount; }
#endif
#ifndef _MSC_VER
// static nsLineBox constant; initialized in the header file.
const uint32_t nsLineBox::kMinChildCountForHashtable;
#endif
using namespace mozilla;
nsLineBox::nsLineBox(nsIFrame* aFrame, int32_t aCount, bool aIsBlock)
: mFirstChild(aFrame),
mContainerSize(-1, -1),
mBounds(WritingMode()), // mBounds will be initialized with the correct
// writing mode when it is set
mFrames(),
mAscent(),
mAllFlags(0),
mData(nullptr) {
// Assert that the union elements chosen for initialisation are at
// least as large as all other elements in their respective unions, so
// as to ensure that no parts are missed.
static_assert(sizeof(mFrames) >= sizeof(mChildCount), "nsLineBox init #1");
static_assert(sizeof(mAllFlags) >= sizeof(mFlags), "nsLineBox init #2");
static_assert(sizeof(mData) >= sizeof(mBlockData), "nsLineBox init #3");
static_assert(sizeof(mData) >= sizeof(mInlineData), "nsLineBox init #4");
MOZ_COUNT_CTOR(nsLineBox);
#ifdef DEBUG
++ctorCount;
NS_ASSERTION(!aIsBlock || aCount == 1, "Blocks must have exactly one child");
nsIFrame* f = aFrame;
for (int32_t n = aCount; n > 0; f = f->GetNextSibling(), --n) {
NS_ASSERTION(aIsBlock == f->IsBlockOutside(), "wrong kind of child frame");
}
#endif
mChildCount = aCount;
MarkDirty();
mFlags.mBlock = aIsBlock;
}
nsLineBox::~nsLineBox() {
MOZ_COUNT_DTOR(nsLineBox);
if (MOZ_UNLIKELY(mFlags.mHasHashedFrames)) {
delete mFrames;
}
Cleanup();
}
nsLineBox* NS_NewLineBox(PresShell* aPresShell, nsIFrame* aFrame,
bool aIsBlock) {
return new (aPresShell) nsLineBox(aFrame, 1, aIsBlock);
}
nsLineBox* NS_NewLineBox(PresShell* aPresShell, nsLineBox* aFromLine,
nsIFrame* aFrame, int32_t aCount) {
nsLineBox* newLine = new (aPresShell) nsLineBox(aFrame, aCount, false);
newLine->NoteFramesMovedFrom(aFromLine);
newLine->mContainerSize = aFromLine->mContainerSize;
return newLine;
}
void nsLineBox::AddSizeOfExcludingThis(nsWindowSizes& aSizes) const {
if (mFlags.mHasHashedFrames) {
aSizes.mLayoutFramePropertiesSize +=
mFrames->ShallowSizeOfIncludingThis(aSizes.mState.mMallocSizeOf);
}
}
void nsLineBox::StealHashTableFrom(nsLineBox* aFromLine,
uint32_t aFromLineNewCount) {
MOZ_ASSERT(!mFlags.mHasHashedFrames);
MOZ_ASSERT(GetChildCount() >= int32_t(aFromLineNewCount));
mFrames = aFromLine->mFrames;
mFlags.mHasHashedFrames = 1;
aFromLine->mFlags.mHasHashedFrames = 0;
aFromLine->mChildCount = aFromLineNewCount;
// remove aFromLine's frames that aren't on this line
nsIFrame* f = aFromLine->mFirstChild;
for (uint32_t i = 0; i < aFromLineNewCount; f = f->GetNextSibling(), ++i) {
mFrames->Remove(f);
}
}
void nsLineBox::NoteFramesMovedFrom(nsLineBox* aFromLine) {
uint32_t fromCount = aFromLine->GetChildCount();
uint32_t toCount = GetChildCount();
MOZ_ASSERT(toCount <= fromCount, "moved more frames than aFromLine has");
uint32_t fromNewCount = fromCount - toCount;
if (MOZ_LIKELY(!aFromLine->mFlags.mHasHashedFrames)) {
aFromLine->mChildCount = fromNewCount;
MOZ_ASSERT(toCount < kMinChildCountForHashtable);
} else if (fromNewCount < kMinChildCountForHashtable) {
// aFromLine has a hash table but will not have it after moving the frames
// so this line can steal the hash table if it needs it.
if (toCount >= kMinChildCountForHashtable) {
StealHashTableFrom(aFromLine, fromNewCount);
} else {
delete aFromLine->mFrames;
aFromLine->mFlags.mHasHashedFrames = 0;
aFromLine->mChildCount = fromNewCount;
}
} else {
// aFromLine still needs a hash table.
if (toCount < kMinChildCountForHashtable) {
// remove the moved frames from it
nsIFrame* f = mFirstChild;
for (uint32_t i = 0; i < toCount; f = f->GetNextSibling(), ++i) {
aFromLine->mFrames->Remove(f);
}
} else if (toCount <= fromNewCount) {
// This line needs a hash table, allocate a hash table for it since that
// means fewer hash ops.
nsIFrame* f = mFirstChild;
for (uint32_t i = 0; i < toCount; f = f->GetNextSibling(), ++i) {
aFromLine->mFrames->Remove(f); // toCount RemoveEntry
}
SwitchToHashtable(); // toCount PutEntry
} else {
// This line needs a hash table, but it's fewer hash ops to steal
// aFromLine's hash table and allocate a new hash table for that line.
StealHashTableFrom(aFromLine, fromNewCount); // fromNewCount RemoveEntry
aFromLine->SwitchToHashtable(); // fromNewCount PutEntry
}
}
}
void* nsLineBox::operator new(size_t sz, PresShell* aPresShell) {
return aPresShell->AllocateByObjectID(eArenaObjectID_nsLineBox, sz);
}
void nsLineBox::Destroy(PresShell* aPresShell) {
this->nsLineBox::~nsLineBox();
aPresShell->FreeByObjectID(eArenaObjectID_nsLineBox, this);
}
void nsLineBox::Cleanup() {
if (mData) {
if (IsBlock()) {
delete mBlockData;
} else {
delete mInlineData;
}
mData = nullptr;
}
}
#ifdef DEBUG_FRAME_DUMP
static void ListFloats(FILE* out, const char* aPrefix,
const nsTArray<nsIFrame*>& aFloats) {
for (nsIFrame* f : aFloats) {
nsCString str(aPrefix);
str += nsPrintfCString("floatframe@%p ", static_cast<void*>(f));
nsAutoString frameName;
f->GetFrameName(frameName);
str += NS_ConvertUTF16toUTF8(frameName).get();
fprintf_stderr(out, "%s\n", str.get());
}
}
/* static */ const char* nsLineBox::UsedClearToString(UsedClear aClearType) {
switch (aClearType) {
case UsedClear::None:
return "none";
case UsedClear::Left:
return "left";
case UsedClear::Right:
return "right";
case UsedClear::Both:
return "both";
}
return "unknown";
}
void nsLineBox::List(FILE* out, int32_t aIndent,
nsIFrame::ListFlags aFlags) const {
nsCString str;
while (aIndent-- > 0) {
str += " ";
}
List(out, str.get(), aFlags);
}
void nsLineBox::List(FILE* out, const char* aPrefix,
nsIFrame::ListFlags aFlags) const {
nsCString str(aPrefix);
str += nsPrintfCString(
"line@%p count=%d state=%s,%s,%s,%s,%s,%s,clear-before:%s,clear-after:%s",
this, GetChildCount(), IsBlock() ? "block" : "inline",
IsDirty() ? "dirty" : "clean",
IsPreviousMarginDirty() ? "prevmargindirty" : "prevmarginclean",
IsImpactedByFloat() ? "impacted" : "not-impacted",
IsLineWrapped() ? "wrapped" : "not-wrapped",
HasForcedLineBreakAfter() ? "forced-break-after" : "no-break",
UsedClearToString(FloatClearTypeBefore()),
UsedClearToString(FloatClearTypeAfter()));
if (IsBlock() && !GetCarriedOutBEndMargin().IsZero()) {
const nscoord bm = GetCarriedOutBEndMargin().Get();
str += nsPrintfCString("bm=%s ",
nsIFrame::ConvertToString(bm, aFlags).c_str());
}
nsRect bounds = GetPhysicalBounds();
str +=
nsPrintfCString("%s ", nsIFrame::ConvertToString(bounds, aFlags).c_str());
if (mWritingMode.IsVertical() || mWritingMode.IsBidiRTL()) {
str += nsPrintfCString(
"wm=%s cs=(%s) logical-rect=%s ", ToString(mWritingMode).c_str(),
nsIFrame::ConvertToString(mContainerSize, aFlags).c_str(),
nsIFrame::ConvertToString(mBounds, mWritingMode, aFlags).c_str());
}
if (mData) {
const nsRect vo = mData->mOverflowAreas.InkOverflow();
const nsRect so = mData->mOverflowAreas.ScrollableOverflow();
if (!vo.IsEqualEdges(bounds) || !so.IsEqualEdges(bounds)) {
str += nsPrintfCString("ink-overflow=%s scr-overflow=%s ",
nsIFrame::ConvertToString(vo, aFlags).c_str(),
nsIFrame::ConvertToString(so, aFlags).c_str());
}
if (mData->mInFlowChildBounds) {
str += nsPrintfCString(
"in-flow-scr-overflow=%s ",
nsIFrame::ConvertToString(*mData->mInFlowChildBounds, aFlags)
.c_str());
}
}
fprintf_stderr(out, "%s<\n", str.get());
nsIFrame* frame = mFirstChild;
int32_t n = GetChildCount();
nsCString pfx(aPrefix);
pfx += " ";
while (--n >= 0) {
frame->List(out, pfx.get(), aFlags);
frame = frame->GetNextSibling();
}
if (HasFloats()) {
fprintf_stderr(out, "%s> floats <\n", aPrefix);
ListFloats(out, pfx.get(), mInlineData->mFloats);
}
fprintf_stderr(out, "%s>\n", aPrefix);
}
nsIFrame* nsLineBox::LastChild() const {
nsIFrame* frame = mFirstChild;
int32_t n = GetChildCount() - 1;
while (--n >= 0) {
frame = frame->GetNextSibling();
}
return frame;
}
#endif
int32_t nsLineBox::IndexOf(const nsIFrame* aFrame) const {
int32_t i, n = GetChildCount();
const nsIFrame* frame = mFirstChild;
for (i = 0; i < n; i++) {
if (frame == aFrame) {
return i;
}
frame = frame->GetNextSibling();
}
return -1;
}
int32_t nsLineBox::RLIndexOf(const nsIFrame* aFrame,
const nsIFrame* aLastFrameInLine) const {
const nsIFrame* leftFrame = mFirstChild;
const nsIFrame* rightFrame = aLastFrameInLine;
int32_t leftIndex = 0, rightIndex = GetChildCount() - 1;
while (true) {
if (aFrame == rightFrame) {
return rightIndex;
}
if (leftIndex == rightIndex) {
MOZ_ASSERT(leftFrame == rightFrame,
"caller provided incorrect last frame");
break;
}
if (aFrame == leftFrame) {
return leftIndex;
}
if (++leftIndex == rightIndex) {
MOZ_ASSERT(leftFrame->GetNextSibling() == rightFrame,
"caller provided incorrect last frame");
break;
}
leftFrame = leftFrame->GetNextSibling();
rightFrame = rightFrame->GetPrevSibling();
--rightIndex;
}
return -1;
}
bool nsLineBox::IsEmpty() const {
if (IsBlock()) {
return mFirstChild->IsEmpty();
}
nsIFrame* kid = mFirstChild;
for (int32_t n = GetChildCount(); n > 0; --n, kid = kid->GetNextSibling()) {
if (!kid->IsEmpty()) {
return false;
}
}
if (HasMarker()) {
return false;
}
return true;
}
bool nsLineBox::CachedIsEmpty() {
if (mFlags.mDirty) {
return IsEmpty();
}
if (mFlags.mEmptyCacheValid) {
return mFlags.mEmptyCacheState;
}
bool result;
if (IsBlock()) {
result = mFirstChild->CachedIsEmpty();
} else {
nsIFrame* kid = mFirstChild;
result = true;
for (int32_t n = GetChildCount(); n > 0; --n, kid = kid->GetNextSibling()) {
if (!kid->CachedIsEmpty()) {
result = false;
break;
}
}
if (HasMarker()) {
result = false;
}
}
mFlags.mEmptyCacheValid = true;
mFlags.mEmptyCacheState = result;
return result;
}
void nsLineBox::DeleteLineList(nsPresContext* aPresContext, nsLineList& aLines,
nsFrameList* aFrames, DestroyContext& aContext) {
PresShell* presShell = aPresContext->PresShell();
// Keep our line list and frame list up to date as we remove frames, in case
// something wants to traverse the frame tree while we're destroying.
//
// Note: We delete the line list and the frames in each line in reverse order
// to avoid unnecessary updates to the first-continuation and first-in-flow
// cache. If we delete them from front to back, updating the cache has a
// O(n^2) time complexity.
while (!aLines.empty()) {
nsLineBox* line = aLines.back();
if (MOZ_UNLIKELY(line->mFlags.mHasHashedFrames)) {
line->SwitchToCounter(); // Avoid expensive has table removals.
}
while (line->GetChildCount() > 0) {
nsIFrame* child = aFrames->RemoveLastChild();
MOZ_DIAGNOSTIC_ASSERT(child->PresContext() == aPresContext);
line->NoteFrameRemoved(child);
child->Destroy(aContext);
}
MOZ_DIAGNOSTIC_ASSERT(line == aLines.back(),
"destroying child frames messed up our lines!");
aLines.pop_back();
line->Destroy(presShell);
}
}
bool nsLineBox::RFindLineContaining(nsIFrame* aFrame,
const nsLineList::iterator& aBegin,
nsLineList::iterator& aEnd,
nsIFrame* aLastFrameBeforeEnd,
int32_t* aFrameIndexInLine) {
MOZ_ASSERT(aFrame, "null ptr");
nsIFrame* curFrame = aLastFrameBeforeEnd;
while (aBegin != aEnd) {
--aEnd;
NS_ASSERTION(aEnd->LastChild() == curFrame, "Unexpected curFrame");
if (MOZ_UNLIKELY(aEnd->mFlags.mHasHashedFrames) &&
!aEnd->Contains(aFrame)) {
if (aEnd->mFirstChild) {
curFrame = aEnd->mFirstChild->GetPrevSibling();
}
continue;
}
// i is the index of curFrame in aEnd
int32_t i = aEnd->GetChildCount() - 1;
while (i >= 0) {
if (curFrame == aFrame) {
*aFrameIndexInLine = i;
return true;
}
--i;
curFrame = curFrame->GetPrevSibling();
}
MOZ_ASSERT(!aEnd->mFlags.mHasHashedFrames, "Contains lied to us!");
}
*aFrameIndexInLine = -1;
return false;
}
CollapsingMargin nsLineBox::GetCarriedOutBEndMargin() const {
NS_ASSERTION(IsBlock(), "GetCarriedOutBEndMargin called on non-block line.");
return (IsBlock() && mBlockData) ? mBlockData->mCarriedOutBEndMargin
: CollapsingMargin();
}
bool nsLineBox::SetCarriedOutBEndMargin(CollapsingMargin aValue) {
bool changed = false;
if (IsBlock()) {
if (!aValue.IsZero()) {
if (!mBlockData) {
mBlockData = new ExtraBlockData(GetPhysicalBounds());
}
changed = aValue != mBlockData->mCarriedOutBEndMargin;
mBlockData->mCarriedOutBEndMargin = aValue;
} else if (mBlockData) {
changed = aValue != mBlockData->mCarriedOutBEndMargin;
mBlockData->mCarriedOutBEndMargin = aValue;
MaybeFreeData();
}
}
return changed;
}
void nsLineBox::MaybeFreeData() {
nsRect bounds = GetPhysicalBounds();
// If we have space allocated for additional data but no additional data to
// represent, just delete it.
if (mData && mData->mOverflowAreas == OverflowAreas(bounds, bounds) &&
!mData->mInFlowChildBounds) {
if (IsInline()) {
if (mInlineData->mFloats.IsEmpty()) {
delete mInlineData;
mInlineData = nullptr;
}
} else if (mBlockData->mCarriedOutBEndMargin.IsZero()) {
delete mBlockData;
mBlockData = nullptr;
}
}
}
void nsLineBox::ClearFloats() {
MOZ_ASSERT(IsInline(), "block line can't have floats");
if (IsInline() && mInlineData) {
mInlineData->mFloats.Clear();
MaybeFreeData();
}
}
void nsLineBox::AppendFloats(nsTArray<nsIFrame*>&& aFloats) {
MOZ_ASSERT(IsInline(), "block line can't have floats");
if (MOZ_UNLIKELY(!IsInline())) {
return;
}
if (!aFloats.IsEmpty()) {
if (mInlineData) {
mInlineData->mFloats.AppendElements(std::move(aFloats));
} else {
mInlineData = new ExtraInlineData(GetPhysicalBounds());
mInlineData->mFloats = std::move(aFloats);
}
}
}
bool nsLineBox::RemoveFloat(nsIFrame* aFrame) {
MOZ_ASSERT(IsInline(), "block line can't have floats");
MOZ_ASSERT(aFrame);
if (IsInline() && mInlineData) {
if (mInlineData->mFloats.RemoveElement(aFrame)) {
// Note: the placeholder is part of the line's child list
// and will be removed later.
MaybeFreeData();
return true;
}
}
return false;
}
void nsLineBox::SetFloatEdges(nscoord aStart, nscoord aEnd) {
MOZ_ASSERT(IsInline(), "block line can't have float edges");
if (!mInlineData) {
mInlineData = new ExtraInlineData(GetPhysicalBounds());
}
mInlineData->mFloatEdgeIStart = aStart;
mInlineData->mFloatEdgeIEnd = aEnd;
}
void nsLineBox::ClearFloatEdges() {
MOZ_ASSERT(IsInline(), "block line can't have float edges");
if (mInlineData) {
mInlineData->mFloatEdgeIStart = nscoord_MIN;
mInlineData->mFloatEdgeIEnd = nscoord_MIN;
}
}
void nsLineBox::SetOverflowAreas(const OverflowAreas& aOverflowAreas) {
#ifdef DEBUG
for (const auto otype : mozilla::AllOverflowTypes()) {
NS_ASSERTION(aOverflowAreas.Overflow(otype).width >= 0,
"Illegal width for an overflow area!");
NS_ASSERTION(aOverflowAreas.Overflow(otype).height >= 0,
"Illegal height for an overflow area!");
}
#endif
nsRect bounds = GetPhysicalBounds();
if (!aOverflowAreas.InkOverflow().IsEqualInterior(bounds) ||
!aOverflowAreas.ScrollableOverflow().IsEqualEdges(bounds)) {
if (!mData) {
if (IsInline()) {
mInlineData = new ExtraInlineData(bounds);
} else {
mBlockData = new ExtraBlockData(bounds);
}
}
mData->mOverflowAreas = aOverflowAreas;
} else if (mData) {
// Store away new value so that MaybeFreeData compares against
// the right value.
mData->mOverflowAreas = aOverflowAreas;
MaybeFreeData();
}
}
void nsLineBox::SetInFlowChildBounds(const Maybe<nsRect>& aInFlowChildBounds) {
if (aInFlowChildBounds) {
if (!mData) {
nsRect bounds = GetPhysicalBounds();
if (IsInline()) {
mInlineData = new ExtraInlineData(bounds);
} else {
mBlockData = new ExtraBlockData(bounds);
}
}
mData->mInFlowChildBounds = aInFlowChildBounds;
} else if (mData) {
mData->mInFlowChildBounds = Nothing{};
MaybeFreeData();
}
}
Maybe<nsRect> nsLineBox::GetInFlowChildBounds() const {
if (!mData) {
return Nothing{};
}
return mData->mInFlowChildBounds;
}
//----------------------------------------------------------------------
Result<nsILineIterator::LineInfo, nsresult> nsLineIterator::GetLine(
int32_t aLineNumber) {
const nsLineBox* line = GetLineAt(aLineNumber);
if (!line) {
return Err(NS_ERROR_FAILURE);
}
LineInfo structure;
structure.mFirstFrameOnLine = line->mFirstChild;
structure.mNumFramesOnLine = line->GetChildCount();
structure.mLineBounds = line->GetPhysicalBounds();
structure.mIsWrapped = line->IsLineWrapped();
return structure;
}
int32_t nsLineIterator::FindLineContaining(nsIFrame* aFrame,
int32_t aStartLine) {
const nsLineBox* line = GetLineAt(aStartLine);
MOZ_ASSERT(line, "aStartLine out of range");
while (line) {
if (line->Contains(aFrame)) {
return mIndex;
}
line = GetNextLine();
}
return -1;
}
NS_IMETHODIMP
nsLineIterator::CheckLineOrder(int32_t aLine, bool* aIsReordered,
nsIFrame** aFirstVisual,
nsIFrame** aLastVisual) {
const nsLineBox* line = GetLineAt(aLine);
MOZ_ASSERT(line, "aLine out of range!");
if (!line || !line->mFirstChild) { // empty line
*aIsReordered = false;
*aFirstVisual = nullptr;
*aLastVisual = nullptr;
return NS_OK;
}
nsIFrame* leftmostFrame;
nsIFrame* rightmostFrame;
*aIsReordered =
nsBidiPresUtils::CheckLineOrder(line->mFirstChild, line->GetChildCount(),
&leftmostFrame, &rightmostFrame);
// map leftmost/rightmost to first/last according to paragraph direction
*aFirstVisual = mRightToLeft ? rightmostFrame : leftmostFrame;
*aLastVisual = mRightToLeft ? leftmostFrame : rightmostFrame;
return NS_OK;
}
NS_IMETHODIMP
nsLineIterator::FindFrameAt(int32_t aLineNumber, nsPoint aPos,
nsIFrame** aFrameFound,
bool* aPosIsBeforeFirstFrame,
bool* aPosIsAfterLastFrame) {
MOZ_ASSERT(aFrameFound && aPosIsBeforeFirstFrame && aPosIsAfterLastFrame,
"null OUT ptr");
if (!aFrameFound || !aPosIsBeforeFirstFrame || !aPosIsAfterLastFrame) {
return NS_ERROR_NULL_POINTER;
}
const nsLineBox* line = GetLineAt(aLineNumber);
if (!line) {
*aFrameFound = nullptr;
*aPosIsBeforeFirstFrame = true;
*aPosIsAfterLastFrame = false;
return NS_OK;
}
if (line->ISize() == 0 && line->BSize() == 0) {
return NS_ERROR_FAILURE;
}
LineFrameFinder finder(aPos, line->mContainerSize, line->mWritingMode,
mRightToLeft);
int32_t n = line->GetChildCount();
nsIFrame* frame = line->mFirstChild;
while (n--) {
finder.Scan(frame);
if (finder.IsDone()) {
break;
}
frame = frame->GetNextSibling();
}
finder.Finish(aFrameFound, aPosIsBeforeFirstFrame, aPosIsAfterLastFrame);
return NS_OK;
}