gecko-dev/layout/generic/nsSplittableFrame.cpp

301 строка
8.6 KiB
C++

/* -*- 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/. */
/*
* base class for rendering objects that can be split across lines,
* columns, or pages
*/
#include "nsSplittableFrame.h"
#include "nsContainerFrame.h"
#include "nsIFrameInlines.h"
using namespace mozilla;
void
nsSplittableFrame::Init(nsIContent* aContent,
nsContainerFrame* aParent,
nsIFrame* aPrevInFlow)
{
nsFrame::Init(aContent, aParent, aPrevInFlow);
if (aPrevInFlow) {
// Hook the frame into the flow
SetPrevInFlow(aPrevInFlow);
aPrevInFlow->SetNextInFlow(this);
}
}
void
nsSplittableFrame::DestroyFrom(nsIFrame* aDestructRoot, PostDestroyData& aPostDestroyData)
{
// Disconnect from the flow list
if (mPrevContinuation || mNextContinuation) {
RemoveFromFlow(this);
}
// Let the base class destroy the frame
nsFrame::DestroyFrom(aDestructRoot, aPostDestroyData);
}
nsSplittableType
nsSplittableFrame::GetSplittableType() const
{
return NS_FRAME_SPLITTABLE;
}
nsIFrame* nsSplittableFrame::GetPrevContinuation() const
{
return mPrevContinuation;
}
void
nsSplittableFrame::SetPrevContinuation(nsIFrame* aFrame)
{
NS_ASSERTION(!aFrame || Type() == aFrame->Type(),
"setting a prev continuation with incorrect type!");
NS_ASSERTION(!IsInPrevContinuationChain(aFrame, this),
"creating a loop in continuation chain!");
mPrevContinuation = aFrame;
RemoveStateBits(NS_FRAME_IS_FLUID_CONTINUATION);
}
nsIFrame* nsSplittableFrame::GetNextContinuation() const
{
return mNextContinuation;
}
void
nsSplittableFrame::SetNextContinuation(nsIFrame* aFrame)
{
NS_ASSERTION(!aFrame || Type() == aFrame->Type(),
"setting a next continuation with incorrect type!");
NS_ASSERTION (!IsInNextContinuationChain(aFrame, this), "creating a loop in continuation chain!");
mNextContinuation = aFrame;
if (aFrame)
aFrame->RemoveStateBits(NS_FRAME_IS_FLUID_CONTINUATION);
}
nsIFrame*
nsSplittableFrame::FirstContinuation() const
{
nsSplittableFrame* firstContinuation = const_cast<nsSplittableFrame*>(this);
while (firstContinuation->mPrevContinuation) {
firstContinuation = static_cast<nsSplittableFrame*>(firstContinuation->mPrevContinuation);
}
MOZ_ASSERT(firstContinuation, "post-condition failed");
return firstContinuation;
}
nsIFrame*
nsSplittableFrame::LastContinuation() const
{
nsSplittableFrame* lastContinuation = const_cast<nsSplittableFrame*>(this);
while (lastContinuation->mNextContinuation) {
lastContinuation = static_cast<nsSplittableFrame*>(lastContinuation->mNextContinuation);
}
MOZ_ASSERT(lastContinuation, "post-condition failed");
return lastContinuation;
}
#ifdef DEBUG
bool nsSplittableFrame::IsInPrevContinuationChain(nsIFrame* aFrame1, nsIFrame* aFrame2)
{
int32_t iterations = 0;
while (aFrame1 && iterations < 10) {
// Bail out after 10 iterations so we don't bog down debug builds too much
if (aFrame1 == aFrame2)
return true;
aFrame1 = aFrame1->GetPrevContinuation();
++iterations;
}
return false;
}
bool nsSplittableFrame::IsInNextContinuationChain(nsIFrame* aFrame1, nsIFrame* aFrame2)
{
int32_t iterations = 0;
while (aFrame1 && iterations < 10) {
// Bail out after 10 iterations so we don't bog down debug builds too much
if (aFrame1 == aFrame2)
return true;
aFrame1 = aFrame1->GetNextContinuation();
++iterations;
}
return false;
}
#endif
nsIFrame* nsSplittableFrame::GetPrevInFlow() const
{
return (GetStateBits() & NS_FRAME_IS_FLUID_CONTINUATION) ? mPrevContinuation : nullptr;
}
void
nsSplittableFrame::SetPrevInFlow(nsIFrame* aFrame)
{
NS_ASSERTION(!aFrame || Type() == aFrame->Type(),
"setting a prev in flow with incorrect type!");
NS_ASSERTION(!IsInPrevContinuationChain(aFrame, this),
"creating a loop in continuation chain!");
mPrevContinuation = aFrame;
AddStateBits(NS_FRAME_IS_FLUID_CONTINUATION);
}
nsIFrame* nsSplittableFrame::GetNextInFlow() const
{
return mNextContinuation && (mNextContinuation->GetStateBits() & NS_FRAME_IS_FLUID_CONTINUATION) ?
mNextContinuation : nullptr;
}
void
nsSplittableFrame::SetNextInFlow(nsIFrame* aFrame)
{
NS_ASSERTION(!aFrame || Type() == aFrame->Type(),
"setting a next in flow with incorrect type!");
NS_ASSERTION(!IsInNextContinuationChain(aFrame, this),
"creating a loop in continuation chain!");
mNextContinuation = aFrame;
if (aFrame)
aFrame->AddStateBits(NS_FRAME_IS_FLUID_CONTINUATION);
}
nsIFrame*
nsSplittableFrame::FirstInFlow() const
{
nsSplittableFrame* firstInFlow = const_cast<nsSplittableFrame*>(this);
while (nsIFrame* prev = firstInFlow->GetPrevInFlow()) {
firstInFlow = static_cast<nsSplittableFrame*>(prev);
}
MOZ_ASSERT(firstInFlow, "post-condition failed");
return firstInFlow;
}
nsIFrame*
nsSplittableFrame::LastInFlow() const
{
nsSplittableFrame* lastInFlow = const_cast<nsSplittableFrame*>(this);
while (nsIFrame* next = lastInFlow->GetNextInFlow()) {
lastInFlow = static_cast<nsSplittableFrame*>(next);
}
MOZ_ASSERT(lastInFlow, "post-condition failed");
return lastInFlow;
}
// Remove this frame from the flow. Connects prev in flow and next in flow
void
nsSplittableFrame::RemoveFromFlow(nsIFrame* aFrame)
{
nsIFrame* prevContinuation = aFrame->GetPrevContinuation();
nsIFrame* nextContinuation = aFrame->GetNextContinuation();
// The new continuation is fluid only if the continuation on both sides
// of the removed frame was fluid
if (aFrame->GetPrevInFlow() && aFrame->GetNextInFlow()) {
if (prevContinuation) {
prevContinuation->SetNextInFlow(nextContinuation);
}
if (nextContinuation) {
nextContinuation->SetPrevInFlow(prevContinuation);
}
} else {
if (prevContinuation) {
prevContinuation->SetNextContinuation(nextContinuation);
}
if (nextContinuation) {
nextContinuation->SetPrevContinuation(prevContinuation);
}
}
aFrame->SetPrevInFlow(nullptr);
aFrame->SetNextInFlow(nullptr);
}
nscoord
nsSplittableFrame::ConsumedBSize(WritingMode aWM) const
{
nscoord bSize = 0;
for (nsIFrame* prev = GetPrevInFlow(); prev; prev = prev->GetPrevInFlow()) {
bSize += prev->ContentBSize(aWM);
}
return bSize;
}
nscoord
nsSplittableFrame::GetEffectiveComputedBSize(const ReflowInput& aReflowInput,
nscoord aConsumedBSize) const
{
nscoord bSize = aReflowInput.ComputedBSize();
if (bSize == NS_INTRINSICSIZE) {
return NS_INTRINSICSIZE;
}
if (aConsumedBSize == NS_INTRINSICSIZE) {
aConsumedBSize = ConsumedBSize(aReflowInput.GetWritingMode());
}
bSize -= aConsumedBSize;
// We may have stretched the frame beyond its computed height. Oh well.
return std::max(0, bSize);
}
nsIFrame::LogicalSides
nsSplittableFrame::GetLogicalSkipSides(const ReflowInput* aReflowInput) const
{
if (IS_TRUE_OVERFLOW_CONTAINER(this)) {
return LogicalSides(eLogicalSideBitsBBoth);
}
if (MOZ_UNLIKELY(StyleBorder()->mBoxDecorationBreak ==
StyleBoxDecorationBreak::Clone)) {
return LogicalSides();
}
LogicalSides skip;
if (GetPrevInFlow()) {
skip |= eLogicalSideBitsBStart;
}
if (aReflowInput) {
// We're in the midst of reflow right now, so it's possible that we haven't
// created a nif yet. If our content height is going to exceed our available
// height, though, then we're going to need a next-in-flow, it just hasn't
// been created yet.
if (NS_UNCONSTRAINEDSIZE != aReflowInput->AvailableBSize()) {
nscoord effectiveCH = this->GetEffectiveComputedBSize(*aReflowInput);
if (effectiveCH != NS_INTRINSICSIZE &&
effectiveCH > aReflowInput->AvailableBSize()) {
// Our content height is going to exceed our available height, so we're
// going to need a next-in-flow.
skip |= eLogicalSideBitsBEnd;
}
}
} else {
nsIFrame* nif = GetNextInFlow();
if (nif && !IS_TRUE_OVERFLOW_CONTAINER(nif)) {
skip |= eLogicalSideBitsBEnd;
}
}
return skip;
}
LogicalSides
nsSplittableFrame::PreReflowBlockLevelLogicalSkipSides() const
{
if (MOZ_UNLIKELY(IS_TRUE_OVERFLOW_CONTAINER(this))) {
return LogicalSides(mozilla::eLogicalSideBitsBBoth);
}
if (MOZ_LIKELY(StyleBorder()->mBoxDecorationBreak !=
StyleBoxDecorationBreak::Clone) &&
GetPrevInFlow()) {
return LogicalSides(mozilla::eLogicalSideBitsBStart);
}
return LogicalSides();
}