gecko/layout/generic/nsSplittableFrame.cpp

310 lines
9.9 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 "nsIContent.h"
#include "nsPresContext.h"
#include "nsStyleContext.h"
#include "nsContainerFrame.h"
NS_IMPL_FRAMEARENA_HELPERS(nsSplittableFrame)
void
nsSplittableFrame::Init(nsIContent* aContent,
nsIFrame* 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)
{
// Disconnect from the flow list
if (mPrevContinuation || mNextContinuation) {
RemoveFromFlow(this);
}
// Let the base class destroy the frame
nsFrame::DestroyFrom(aDestructRoot);
}
nsSplittableType
nsSplittableFrame::GetSplittableType() const
{
return NS_FRAME_SPLITTABLE;
}
nsIFrame* nsSplittableFrame::GetPrevContinuation() const
{
return mPrevContinuation;
}
NS_METHOD nsSplittableFrame::SetPrevContinuation(nsIFrame* aFrame)
{
NS_ASSERTION (!aFrame || GetType() == aFrame->GetType(), "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);
return NS_OK;
}
nsIFrame* nsSplittableFrame::GetNextContinuation() const
{
return mNextContinuation;
}
NS_METHOD nsSplittableFrame::SetNextContinuation(nsIFrame* aFrame)
{
NS_ASSERTION (!aFrame || GetType() == aFrame->GetType(), "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);
return NS_OK;
}
nsIFrame* nsSplittableFrame::GetFirstContinuation() const
{
nsSplittableFrame* firstContinuation = const_cast<nsSplittableFrame*>(this);
while (firstContinuation->mPrevContinuation) {
firstContinuation = static_cast<nsSplittableFrame*>(firstContinuation->mPrevContinuation);
}
NS_POSTCONDITION(firstContinuation, "illegal state in continuation chain.");
return firstContinuation;
}
nsIFrame* nsSplittableFrame::GetLastContinuation() const
{
nsSplittableFrame* lastContinuation = const_cast<nsSplittableFrame*>(this);
while (lastContinuation->mNextContinuation) {
lastContinuation = static_cast<nsSplittableFrame*>(lastContinuation->mNextContinuation);
}
NS_POSTCONDITION(lastContinuation, "illegal state in continuation chain.");
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;
}
NS_METHOD nsSplittableFrame::SetPrevInFlow(nsIFrame* aFrame)
{
NS_ASSERTION (!aFrame || GetType() == aFrame->GetType(), "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);
return NS_OK;
}
nsIFrame* nsSplittableFrame::GetNextInFlow() const
{
return mNextContinuation && (mNextContinuation->GetStateBits() & NS_FRAME_IS_FLUID_CONTINUATION) ?
mNextContinuation : nullptr;
}
NS_METHOD nsSplittableFrame::SetNextInFlow(nsIFrame* aFrame)
{
NS_ASSERTION (!aFrame || GetType() == aFrame->GetType(), "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);
return NS_OK;
}
nsIFrame* nsSplittableFrame::GetFirstInFlow() const
{
nsSplittableFrame* firstInFlow = const_cast<nsSplittableFrame*>(this);
while (nsIFrame *prev = firstInFlow->GetPrevInFlow()) {
firstInFlow = static_cast<nsSplittableFrame*>(prev);
}
NS_POSTCONDITION(firstInFlow, "illegal state in flow chain.");
return firstInFlow;
}
nsIFrame* nsSplittableFrame::GetLastInFlow() const
{
nsSplittableFrame* lastInFlow = const_cast<nsSplittableFrame*>(this);
while (nsIFrame* next = lastInFlow->GetNextInFlow()) {
lastInFlow = static_cast<nsSplittableFrame*>(next);
}
NS_POSTCONDITION(lastInFlow, "illegal state in flow chain.");
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::GetConsumedHeight() const
{
nscoord height = 0;
// Reduce the height by the computed height of prev-in-flows.
for (nsIFrame* prev = GetPrevInFlow(); prev; prev = prev->GetPrevInFlow()) {
height += prev->GetRect().height;
}
return height;
}
nscoord
nsSplittableFrame::GetEffectiveComputedHeight(const nsHTMLReflowState& aReflowState,
nscoord aConsumedHeight) const
{
nscoord height = aReflowState.ComputedHeight();
if (height == NS_INTRINSICSIZE) {
return NS_INTRINSICSIZE;
}
if (aConsumedHeight == NS_INTRINSICSIZE) {
aConsumedHeight = GetConsumedHeight();
}
height -= aConsumedHeight;
if (aConsumedHeight != 0 && aConsumedHeight != NS_INTRINSICSIZE) {
// We just subtracted our top-border padding, since it was included in the
// first frame's height. Add it back to get the content height.
height += aReflowState.mComputedBorderPadding.top;
}
// We may have stretched the frame beyond its computed height. Oh well.
height = std::max(0, height);
return height;
}
void
nsSplittableFrame::ComputeFinalHeight(const nsHTMLReflowState& aReflowState,
nsReflowStatus* aStatus,
nscoord aContentHeight,
const nsMargin& aBorderPadding,
nsHTMLReflowMetrics& aMetrics,
nscoord aConsumed)
{
// Figure out how much of the computed height should be
// applied to this frame.
nscoord computedHeightLeftOver = GetEffectiveComputedHeight(aReflowState,
aConsumed);
NS_ASSERTION(!( IS_TRUE_OVERFLOW_CONTAINER(this)
&& computedHeightLeftOver ),
"overflow container must not have computedHeightLeftOver");
aMetrics.height =
NSCoordSaturatingAdd(NSCoordSaturatingAdd(aBorderPadding.top,
computedHeightLeftOver),
aBorderPadding.bottom);
if (NS_FRAME_IS_NOT_COMPLETE(*aStatus)
&& aMetrics.height < aReflowState.availableHeight) {
// We ran out of height on this page but we're incomplete
// Set status to complete except for overflow
NS_FRAME_SET_OVERFLOW_INCOMPLETE(*aStatus);
}
if (NS_FRAME_IS_COMPLETE(*aStatus)) {
if (computedHeightLeftOver > 0 &&
NS_UNCONSTRAINEDSIZE != aReflowState.availableHeight &&
aMetrics.height > aReflowState.availableHeight) {
// We don't fit and we consumed some of the computed height,
// so we should consume all the available height and then
// break. If our bottom border/padding straddles the break
// point, then this will increase our height and push the
// border/padding to the next page/column.
aMetrics.height = std::max(aReflowState.availableHeight,
aContentHeight);
NS_FRAME_SET_INCOMPLETE(*aStatus);
if (!GetNextInFlow())
*aStatus |= NS_FRAME_REFLOW_NEXTINFLOW;
}
}
}
#ifdef DEBUG
void
nsSplittableFrame::DumpBaseRegressionData(nsPresContext* aPresContext, FILE* out, int32_t aIndent)
{
nsFrame::DumpBaseRegressionData(aPresContext, out, aIndent);
if (nullptr != mNextContinuation) {
IndentBy(out, aIndent);
fprintf(out, "<next-continuation va=\"%p\"/>\n", (void*)mNextContinuation);
}
if (nullptr != mPrevContinuation) {
IndentBy(out, aIndent);
fprintf(out, "<prev-continuation va=\"%p\"/>\n", (void*)mPrevContinuation);
}
}
#endif