gecko/layout/generic/nsAbsoluteContainingBlock.cpp
Chris Lord afe21f51a7 Bug 716403 - Add nsIDOMWindowUtils.setContentDocumentFixedPositionMargins. r=roc,dholbert
Add a function to set margins on the viewport that are respected by its
absolute containing block. This has the effect of being able to add margins to
fixed position content, which will be used on mobile to stop temporarily
visible chrome from obscuring content.
2013-03-01 15:46:34 +00:00

504 lines
20 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/. */
/*
* code for managing absolutely positioned children of a rendering
* object that is a containing block for them
*/
#include "nsCOMPtr.h"
#include "nsAbsoluteContainingBlock.h"
#include "nsContainerFrame.h"
#include "nsIPresShell.h"
#include "nsHTMLParts.h"
#include "nsPresContext.h"
#include "nsFrameManager.h"
#include "nsCSSFrameConstructor.h"
#ifdef DEBUG
#include "nsBlockFrame.h"
#endif
nsresult
nsAbsoluteContainingBlock::SetInitialChildList(nsIFrame* aDelegatingFrame,
ChildListID aListID,
nsFrameList& aChildList)
{
NS_PRECONDITION(GetChildListID() == aListID, "unexpected child list name");
#ifdef DEBUG
nsFrame::VerifyDirtyBitSet(aChildList);
#endif
mAbsoluteFrames.SetFrames(aChildList);
return NS_OK;
}
nsresult
nsAbsoluteContainingBlock::AppendFrames(nsIFrame* aDelegatingFrame,
ChildListID aListID,
nsFrameList& aFrameList)
{
NS_ASSERTION(GetChildListID() == aListID, "unexpected child list");
// Append the frames to our list of absolutely positioned frames
#ifdef DEBUG
nsFrame::VerifyDirtyBitSet(aFrameList);
#endif
mAbsoluteFrames.AppendFrames(nullptr, aFrameList);
// no damage to intrinsic widths, since absolutely positioned frames can't
// change them
aDelegatingFrame->PresContext()->PresShell()->
FrameNeedsReflow(aDelegatingFrame, nsIPresShell::eResize,
NS_FRAME_HAS_DIRTY_CHILDREN);
return NS_OK;
}
nsresult
nsAbsoluteContainingBlock::InsertFrames(nsIFrame* aDelegatingFrame,
ChildListID aListID,
nsIFrame* aPrevFrame,
nsFrameList& aFrameList)
{
NS_ASSERTION(GetChildListID() == aListID, "unexpected child list");
NS_ASSERTION(!aPrevFrame || aPrevFrame->GetParent() == aDelegatingFrame,
"inserting after sibling frame with different parent");
#ifdef DEBUG
nsFrame::VerifyDirtyBitSet(aFrameList);
#endif
mAbsoluteFrames.InsertFrames(nullptr, aPrevFrame, aFrameList);
// no damage to intrinsic widths, since absolutely positioned frames can't
// change them
aDelegatingFrame->PresContext()->PresShell()->
FrameNeedsReflow(aDelegatingFrame, nsIPresShell::eResize,
NS_FRAME_HAS_DIRTY_CHILDREN);
return NS_OK;
}
void
nsAbsoluteContainingBlock::RemoveFrame(nsIFrame* aDelegatingFrame,
ChildListID aListID,
nsIFrame* aOldFrame)
{
NS_ASSERTION(GetChildListID() == aListID, "unexpected child list");
nsIFrame* nif = aOldFrame->GetNextInFlow();
if (nif) {
static_cast<nsContainerFrame*>(nif->GetParent())
->DeleteNextInFlowChild(aOldFrame->PresContext(), nif, false);
}
mAbsoluteFrames.DestroyFrame(aOldFrame);
}
nsresult
nsAbsoluteContainingBlock::Reflow(nsContainerFrame* aDelegatingFrame,
nsPresContext* aPresContext,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aReflowStatus,
nscoord aContainingBlockWidth,
nscoord aContainingBlockHeight,
bool aConstrainHeight,
bool aCBWidthChanged,
bool aCBHeightChanged,
nsOverflowAreas* aOverflowAreas)
{
nsReflowStatus reflowStatus = NS_FRAME_COMPLETE;
bool reflowAll = aReflowState.ShouldReflowAllKids();
nsIFrame* kidFrame;
nsOverflowContinuationTracker tracker(aPresContext, aDelegatingFrame, true);
for (kidFrame = mAbsoluteFrames.FirstChild(); kidFrame; kidFrame = kidFrame->GetNextSibling()) {
bool kidNeedsReflow = reflowAll || NS_SUBTREE_DIRTY(kidFrame) ||
FrameDependsOnContainer(kidFrame, aCBWidthChanged, aCBHeightChanged);
if (kidNeedsReflow && !aPresContext->HasPendingInterrupt()) {
// Reflow the frame
nsReflowStatus kidStatus = NS_FRAME_COMPLETE;
ReflowAbsoluteFrame(aDelegatingFrame, aPresContext, aReflowState,
aContainingBlockWidth, aContainingBlockHeight,
aConstrainHeight, kidFrame, kidStatus,
aOverflowAreas);
nsIFrame* nextFrame = kidFrame->GetNextInFlow();
if (!NS_FRAME_IS_FULLY_COMPLETE(kidStatus)) {
// Need a continuation
if (!nextFrame) {
nsresult rv = aPresContext->PresShell()->FrameConstructor()->
CreateContinuingFrame(aPresContext, kidFrame, aDelegatingFrame, &nextFrame);
NS_ENSURE_SUCCESS(rv, rv);
}
// Add it as an overflow container.
//XXXfr This is a hack to fix some of our printing dataloss.
// See bug 154892. Not sure how to do it "right" yet; probably want
// to keep continuations within an nsAbsoluteContainingBlock eventually.
tracker.Insert(nextFrame, kidStatus);
NS_MergeReflowStatusInto(&reflowStatus, kidStatus);
}
else {
// Delete any continuations
if (nextFrame) {
tracker.Finish(kidFrame);
static_cast<nsContainerFrame*>(nextFrame->GetParent())
->DeleteNextInFlowChild(aPresContext, nextFrame, true);
}
}
}
else {
tracker.Skip(kidFrame, reflowStatus);
if (aOverflowAreas) {
aDelegatingFrame->ConsiderChildOverflow(*aOverflowAreas, kidFrame);
}
}
// Make a CheckForInterrupt call, here, not just HasPendingInterrupt. That
// will make sure that we end up reflowing aDelegatingFrame in cases when
// one of our kids interrupted. Otherwise we'd set the dirty or
// dirty-children bit on the kid in the condition below, and then when
// reflow completes and we go to mark dirty bits on all ancestors of that
// kid we'll immediately bail out, because the kid already has a dirty bit.
// In particular, we won't set any dirty bits on aDelegatingFrame, so when
// the following reflow happens we won't reflow the kid in question. This
// might be slightly suboptimal in cases where |kidFrame| itself did not
// interrupt, since we'll trigger a reflow of it too when it's not strictly
// needed. But the logic to not do that is enough more complicated, and
// the case enough of an edge case, that this is probably better.
if (kidNeedsReflow && aPresContext->CheckForInterrupt(aDelegatingFrame)) {
if (aDelegatingFrame->GetStateBits() & NS_FRAME_IS_DIRTY) {
kidFrame->AddStateBits(NS_FRAME_IS_DIRTY);
} else {
kidFrame->AddStateBits(NS_FRAME_HAS_DIRTY_CHILDREN);
}
}
}
// Abspos frames can't cause their parent to be incomplete,
// only overflow incomplete.
if (NS_FRAME_IS_NOT_COMPLETE(reflowStatus))
NS_FRAME_SET_OVERFLOW_INCOMPLETE(reflowStatus);
NS_MergeReflowStatusInto(&aReflowStatus, reflowStatus);
return NS_OK;
}
static inline bool IsFixedPaddingSize(const nsStyleCoord& aCoord)
{ return aCoord.ConvertsToLength(); }
static inline bool IsFixedMarginSize(const nsStyleCoord& aCoord)
{ return aCoord.ConvertsToLength(); }
static inline bool IsFixedOffset(const nsStyleCoord& aCoord)
{ return aCoord.ConvertsToLength(); }
bool
nsAbsoluteContainingBlock::FrameDependsOnContainer(nsIFrame* f,
bool aCBWidthChanged,
bool aCBHeightChanged)
{
const nsStylePosition* pos = f->StylePosition();
// See if f's position might have changed because it depends on a
// placeholder's position
// This can happen in the following cases:
// 1) Vertical positioning. "top" must be auto and "bottom" must be auto
// (otherwise the vertical position is completely determined by
// whichever of them is not auto and the height).
// 2) Horizontal positioning. "left" must be auto and "right" must be auto
// (otherwise the horizontal position is completely determined by
// whichever of them is not auto and the width).
// See nsHTMLReflowState::InitAbsoluteConstraints -- these are the
// only cases when we call CalculateHypotheticalBox().
if ((pos->mOffset.GetTopUnit() == eStyleUnit_Auto &&
pos->mOffset.GetBottomUnit() == eStyleUnit_Auto) ||
(pos->mOffset.GetLeftUnit() == eStyleUnit_Auto &&
pos->mOffset.GetRightUnit() == eStyleUnit_Auto)) {
return true;
}
if (!aCBWidthChanged && !aCBHeightChanged) {
// skip getting style data
return false;
}
const nsStylePadding* padding = f->StylePadding();
const nsStyleMargin* margin = f->StyleMargin();
if (aCBWidthChanged) {
// See if f's width might have changed.
// If border-left, border-right, padding-left, padding-right,
// width, min-width, and max-width are all lengths, 'none', or enumerated,
// then our frame width does not depend on the parent width.
// Note that borders never depend on the parent width
// XXX All of the enumerated values except -moz-available are ok too.
if (pos->WidthDependsOnContainer() ||
pos->MinWidthDependsOnContainer() ||
pos->MaxWidthDependsOnContainer() ||
!IsFixedPaddingSize(padding->mPadding.GetLeft()) ||
!IsFixedPaddingSize(padding->mPadding.GetRight())) {
return true;
}
// See if f's position might have changed. If we're RTL then the
// rules are slightly different. We'll assume percentage or auto
// margins will always induce a dependency on the size
if (!IsFixedMarginSize(margin->mMargin.GetLeft()) ||
!IsFixedMarginSize(margin->mMargin.GetRight())) {
return true;
}
if (f->StyleVisibility()->mDirection == NS_STYLE_DIRECTION_RTL) {
// Note that even if 'left' is a length, our position can
// still depend on the containing block width, because if
// 'right' is also a length we will discard 'left' and be
// positioned relative to the containing block right edge.
// 'left' length and 'right' auto is the only combination
// we can be sure of.
if (!IsFixedOffset(pos->mOffset.GetLeft()) ||
pos->mOffset.GetRightUnit() != eStyleUnit_Auto) {
return true;
}
} else {
if (!IsFixedOffset(pos->mOffset.GetLeft())) {
return true;
}
}
}
if (aCBHeightChanged) {
// See if f's height might have changed.
// If border-top, border-bottom, padding-top, padding-bottom,
// min-height, and max-height are all lengths or 'none',
// and height is a length or height and bottom are auto and top is not auto,
// then our frame height does not depend on the parent height.
// Note that borders never depend on the parent height
if ((pos->HeightDependsOnContainer() &&
!(pos->mHeight.GetUnit() == eStyleUnit_Auto &&
pos->mOffset.GetBottomUnit() == eStyleUnit_Auto &&
pos->mOffset.GetTopUnit() != eStyleUnit_Auto)) ||
pos->MinHeightDependsOnContainer() ||
pos->MaxHeightDependsOnContainer() ||
!IsFixedPaddingSize(padding->mPadding.GetTop()) ||
!IsFixedPaddingSize(padding->mPadding.GetBottom())) {
return true;
}
// See if f's position might have changed.
if (!IsFixedMarginSize(margin->mMargin.GetTop()) ||
!IsFixedMarginSize(margin->mMargin.GetBottom())) {
return true;
}
if (!IsFixedOffset(pos->mOffset.GetTop())) {
return true;
}
}
return false;
}
void
nsAbsoluteContainingBlock::DestroyFrames(nsIFrame* aDelegatingFrame,
nsIFrame* aDestructRoot)
{
mAbsoluteFrames.DestroyFramesFrom(aDestructRoot);
}
void
nsAbsoluteContainingBlock::MarkSizeDependentFramesDirty()
{
DoMarkFramesDirty(false);
}
void
nsAbsoluteContainingBlock::MarkAllFramesDirty()
{
DoMarkFramesDirty(true);
}
void
nsAbsoluteContainingBlock::DoMarkFramesDirty(bool aMarkAllDirty)
{
for (nsIFrame* kidFrame = mAbsoluteFrames.FirstChild();
kidFrame;
kidFrame = kidFrame->GetNextSibling()) {
if (aMarkAllDirty) {
kidFrame->AddStateBits(NS_FRAME_IS_DIRTY);
} else if (FrameDependsOnContainer(kidFrame, true, true)) {
// Add the weakest flags that will make sure we reflow this frame later
kidFrame->AddStateBits(NS_FRAME_HAS_DIRTY_CHILDREN);
}
}
}
// XXX Optimize the case where it's a resize reflow and the absolutely
// positioned child has the exact same size and position and skip the
// reflow...
// When bug 154892 is checked in, make sure that when
// GetChildListID() == kFixedList, the height is unconstrained.
// since we don't allow replicated frames to split.
nsresult
nsAbsoluteContainingBlock::ReflowAbsoluteFrame(nsIFrame* aDelegatingFrame,
nsPresContext* aPresContext,
const nsHTMLReflowState& aReflowState,
nscoord aContainingBlockWidth,
nscoord aContainingBlockHeight,
bool aConstrainHeight,
nsIFrame* aKidFrame,
nsReflowStatus& aStatus,
nsOverflowAreas* aOverflowAreas)
{
#ifdef DEBUG
if (nsBlockFrame::gNoisyReflow) {
nsFrame::IndentBy(stdout,nsBlockFrame::gNoiseIndent);
printf("abs pos ");
if (aKidFrame) {
nsAutoString name;
aKidFrame->GetFrameName(name);
printf("%s ", NS_LossyConvertUTF16toASCII(name).get());
}
char width[16];
char height[16];
PrettyUC(aReflowState.availableWidth, width);
PrettyUC(aReflowState.availableHeight, height);
printf(" a=%s,%s ", width, height);
PrettyUC(aReflowState.ComputedWidth(), width);
PrettyUC(aReflowState.ComputedHeight(), height);
printf("c=%s,%s \n", width, height);
}
AutoNoisyIndenter indent(nsBlockFrame::gNoisy);
#endif // DEBUG
nsresult rv;
// Get the border values
nsMargin border = aReflowState.mStyleBorder->GetComputedBorder();
// Respect fixed position margins.
if (aDelegatingFrame->GetAbsoluteListID() == nsIFrame::kFixedList) {
const nsMargin& fixedMargins = aPresContext->PresShell()->
GetContentDocumentFixedPositionMargins();
border += fixedMargins;
aContainingBlockWidth -= fixedMargins.left + fixedMargins.right;
aContainingBlockHeight -= fixedMargins.top + fixedMargins.bottom;
}
nscoord availWidth = aContainingBlockWidth;
if (availWidth == -1) {
NS_ASSERTION(aReflowState.ComputedWidth() != NS_UNCONSTRAINEDSIZE,
"Must have a useful width _somewhere_");
availWidth =
aReflowState.ComputedWidth() + aReflowState.mComputedPadding.LeftRight();
}
nsHTMLReflowMetrics kidDesiredSize;
nsHTMLReflowState kidReflowState(aPresContext, aReflowState, aKidFrame,
nsSize(availWidth, NS_UNCONSTRAINEDSIZE),
aContainingBlockWidth,
aContainingBlockHeight);
// Send the WillReflow() notification and position the frame
aKidFrame->WillReflow(aPresContext);
bool constrainHeight = (aReflowState.availableHeight != NS_UNCONSTRAINEDSIZE)
&& aConstrainHeight
// Don't split if told not to (e.g. for fixed frames)
&& (aDelegatingFrame->GetType() != nsGkAtoms::inlineFrame)
//XXX we don't handle splitting frames for inline absolute containing blocks yet
&& (aKidFrame->GetRect().y <= aReflowState.availableHeight);
// Don't split things below the fold. (Ideally we shouldn't *have*
// anything totally below the fold, but we can't position frames
// across next-in-flow breaks yet.
if (constrainHeight) {
kidReflowState.availableHeight = aReflowState.availableHeight - border.top
- kidReflowState.mComputedMargin.top;
if (NS_AUTOOFFSET != kidReflowState.mComputedOffsets.top)
kidReflowState.availableHeight -= kidReflowState.mComputedOffsets.top;
}
// Do the reflow
rv = aKidFrame->Reflow(aPresContext, kidDesiredSize, kidReflowState, aStatus);
// If we're solving for 'left' or 'top', then compute it now that we know the
// width/height
if ((NS_AUTOOFFSET == kidReflowState.mComputedOffsets.left) ||
(NS_AUTOOFFSET == kidReflowState.mComputedOffsets.top)) {
if (-1 == aContainingBlockWidth) {
// Get the containing block width/height
kidReflowState.ComputeContainingBlockRectangle(aPresContext,
&aReflowState,
aContainingBlockWidth,
aContainingBlockHeight);
}
if (NS_AUTOOFFSET == kidReflowState.mComputedOffsets.left) {
NS_ASSERTION(NS_AUTOOFFSET != kidReflowState.mComputedOffsets.right,
"Can't solve for both left and right");
kidReflowState.mComputedOffsets.left = aContainingBlockWidth -
kidReflowState.mComputedOffsets.right -
kidReflowState.mComputedMargin.right -
kidDesiredSize.width -
kidReflowState.mComputedMargin.left;
}
if (NS_AUTOOFFSET == kidReflowState.mComputedOffsets.top) {
kidReflowState.mComputedOffsets.top = aContainingBlockHeight -
kidReflowState.mComputedOffsets.bottom -
kidReflowState.mComputedMargin.bottom -
kidDesiredSize.height -
kidReflowState.mComputedMargin.top;
}
}
// Position the child relative to our padding edge
nsRect rect(border.left + kidReflowState.mComputedOffsets.left + kidReflowState.mComputedMargin.left,
border.top + kidReflowState.mComputedOffsets.top + kidReflowState.mComputedMargin.top,
kidDesiredSize.width, kidDesiredSize.height);
aKidFrame->SetRect(rect);
nsView* view = aKidFrame->GetView();
if (view) {
// Size and position the view and set its opacity, visibility, content
// transparency, and clip
nsContainerFrame::SyncFrameViewAfterReflow(aPresContext, aKidFrame, view,
kidDesiredSize.VisualOverflow());
} else {
nsContainerFrame::PositionChildViews(aKidFrame);
}
aKidFrame->DidReflow(aPresContext, &kidReflowState, nsDidReflowStatus::FINISHED);
#ifdef DEBUG
if (nsBlockFrame::gNoisyReflow) {
nsFrame::IndentBy(stdout,nsBlockFrame::gNoiseIndent - 1);
printf("abs pos ");
if (aKidFrame) {
nsAutoString name;
aKidFrame->GetFrameName(name);
printf("%s ", NS_LossyConvertUTF16toASCII(name).get());
}
printf("%p rect=%d,%d,%d,%d\n", static_cast<void*>(aKidFrame),
rect.x, rect.y, rect.width, rect.height);
}
#endif
if (aOverflowAreas) {
aOverflowAreas->UnionWith(kidDesiredSize.mOverflowAreas + rect.TopLeft());
}
return rv;
}
#ifdef DEBUG
void nsAbsoluteContainingBlock::PrettyUC(nscoord aSize,
char* aBuf)
{
if (NS_UNCONSTRAINEDSIZE == aSize) {
strcpy(aBuf, "UC");
}
else {
if((int32_t)0xdeadbeef == aSize)
{
strcpy(aBuf, "deadbeef");
}
else {
sprintf(aBuf, "%d", aSize);
}
}
}
#endif