gecko-dev/layout/generic/nsAbsoluteContainingBlock.cpp

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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 "nsAbsoluteContainingBlock.h"
#include "nsContainerFrame.h"
#include "nsGkAtoms.h"
#include "nsIPresShell.h"
#include "mozilla/CSSAlignUtils.h"
#include "mozilla/ReflowInput.h"
#include "nsPresContext.h"
#include "nsCSSFrameConstructor.h"
#include "nsGridContainerFrame.h"
#include "mozilla/Sprintf.h"
#ifdef DEBUG
#include "nsBlockFrame.h"
static void PrettyUC(nscoord aSize, char* aBuf, int aBufSize)
{
if (NS_UNCONSTRAINEDSIZE == aSize) {
strcpy(aBuf, "UC");
} else {
if((int32_t)0xdeadbeef == aSize) {
strcpy(aBuf, "deadbeef");
} else {
snprintf(aBuf, aBufSize, "%d", aSize);
}
}
}
#endif
using namespace mozilla;
typedef mozilla::CSSAlignUtils::AlignJustifyFlags AlignJustifyFlags;
void
nsAbsoluteContainingBlock::SetInitialChildList(nsIFrame* aDelegatingFrame,
ChildListID aListID,
nsFrameList& aChildList)
{
NS_PRECONDITION(mChildListID == aListID, "unexpected child list name");
#ifdef DEBUG
nsFrame::VerifyDirtyBitSet(aChildList);
#endif
mAbsoluteFrames.SetFrames(aChildList);
}
void
nsAbsoluteContainingBlock::AppendFrames(nsIFrame* aDelegatingFrame,
ChildListID aListID,
nsFrameList& aFrameList)
{
NS_ASSERTION(mChildListID == 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);
}
void
nsAbsoluteContainingBlock::InsertFrames(nsIFrame* aDelegatingFrame,
ChildListID aListID,
nsIFrame* aPrevFrame,
nsFrameList& aFrameList)
{
NS_ASSERTION(mChildListID == 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);
}
void
nsAbsoluteContainingBlock::RemoveFrame(nsIFrame* aDelegatingFrame,
ChildListID aListID,
nsIFrame* aOldFrame)
{
NS_ASSERTION(mChildListID == aListID, "unexpected child list");
nsIFrame* nif = aOldFrame->GetNextInFlow();
if (nif) {
nif->GetParent()->DeleteNextInFlowChild(nif, false);
}
mAbsoluteFrames.DestroyFrame(aOldFrame);
}
void
nsAbsoluteContainingBlock::Reflow(nsContainerFrame* aDelegatingFrame,
nsPresContext* aPresContext,
const ReflowInput& aReflowInput,
nsReflowStatus& aReflowStatus,
const nsRect& aContainingBlock,
AbsPosReflowFlags aFlags,
nsOverflowAreas* aOverflowAreas)
{
nsReflowStatus reflowStatus;
const bool reflowAll = aReflowInput.ShouldReflowAllKids();
const bool isGrid = !!(aFlags & AbsPosReflowFlags::eIsGridContainerCB);
nsIFrame* kidFrame;
nsOverflowContinuationTracker tracker(aDelegatingFrame, true);
for (kidFrame = mAbsoluteFrames.FirstChild(); kidFrame; kidFrame = kidFrame->GetNextSibling()) {
bool kidNeedsReflow = reflowAll || NS_SUBTREE_DIRTY(kidFrame) ||
FrameDependsOnContainer(kidFrame,
!!(aFlags & AbsPosReflowFlags::eCBWidthChanged),
!!(aFlags & AbsPosReflowFlags::eCBHeightChanged));
nscoord availBSize = aReflowInput.AvailableBSize();
const nsRect& cb = isGrid ? nsGridContainerFrame::GridItemCB(kidFrame)
: aContainingBlock;
WritingMode containerWM = aReflowInput.GetWritingMode();
if (!kidNeedsReflow && availBSize != NS_UNCONSTRAINEDSIZE) {
// If we need to redo pagination on the kid, we need to reflow it.
// This can happen either if the available height shrunk and the
// kid (or its overflow that creates overflow containers) is now
// too large to fit in the available height, or if the available
// height has increased and the kid has a next-in-flow that we
// might need to pull from.
WritingMode kidWM = kidFrame->GetWritingMode();
if (containerWM.GetBlockDir() != kidWM.GetBlockDir()) {
// Not sure what the right test would be here.
kidNeedsReflow = true;
} else {
nscoord kidBEnd = kidFrame->GetLogicalRect(cb.Size()).BEnd(kidWM);
nscoord kidOverflowBEnd =
LogicalRect(containerWM,
// Use ...RelativeToSelf to ignore transforms
kidFrame->GetScrollableOverflowRectRelativeToSelf() +
kidFrame->GetPosition(),
aContainingBlock.Size()).BEnd(containerWM);
MOZ_ASSERT(kidOverflowBEnd >= kidBEnd);
if (kidOverflowBEnd > availBSize ||
(kidBEnd < availBSize && kidFrame->GetNextInFlow())) {
kidNeedsReflow = true;
}
}
}
if (kidNeedsReflow && !aPresContext->HasPendingInterrupt()) {
// Reflow the frame
nsReflowStatus kidStatus;
ReflowAbsoluteFrame(aDelegatingFrame, aPresContext, aReflowInput, cb,
aFlags, kidFrame, kidStatus, aOverflowAreas);
nsIFrame* nextFrame = kidFrame->GetNextInFlow();
if (!kidStatus.IsFullyComplete() &&
aDelegatingFrame->IsFrameOfType(nsIFrame::eCanContainOverflowContainers)) {
// Need a continuation
if (!nextFrame) {
nextFrame =
aPresContext->PresShell()->FrameConstructor()->
CreateContinuingFrame(aPresContext, kidFrame, aDelegatingFrame);
}
// 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);
reflowStatus.MergeCompletionStatusFrom(kidStatus);
}
else {
// Delete any continuations
if (nextFrame) {
nsOverflowContinuationTracker::AutoFinish fini(&tracker, kidFrame);
nextFrame->GetParent()->DeleteNextInFlowChild(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 (reflowStatus.IsIncomplete())
reflowStatus.SetOverflowIncomplete();
aReflowStatus.MergeCompletionStatusFrom(reflowStatus);
}
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 ReflowInput::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();
WritingMode wm = f->GetWritingMode();
if (wm.IsVertical() ? aCBHeightChanged : aCBWidthChanged) {
// See if f's inline-size might have changed.
// If margin-inline-start/end, padding-inline-start/end,
// inline-size, min/max-inline-size are all lengths, 'none', or enumerated,
// then our frame isize does not depend on the parent isize.
// Note that borders never depend on the parent isize.
// XXX All of the enumerated values except -moz-available are ok too.
if (pos->ISizeDependsOnContainer(wm) ||
pos->MinISizeDependsOnContainer(wm) ||
pos->MaxISizeDependsOnContainer(wm) ||
!IsFixedPaddingSize(padding->mPadding.GetIStart(wm)) ||
!IsFixedPaddingSize(padding->mPadding.GetIEnd(wm))) {
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.GetIStart(wm)) ||
!IsFixedMarginSize(margin->mMargin.GetIEnd(wm))) {
return true;
}
}
if (wm.IsVertical() ? aCBWidthChanged : aCBHeightChanged) {
// See if f's block-size might have changed.
// If margin-block-start/end, padding-block-start/end,
// min-block-size, and max-block-size are all lengths or 'none',
// and bsize is a length or bsize and bend are auto and bstart is not auto,
// then our frame bsize does not depend on the parent bsize.
// Note that borders never depend on the parent bsize.
if ((pos->BSizeDependsOnContainer(wm) &&
!(pos->BSize(wm).GetUnit() == eStyleUnit_Auto &&
pos->mOffset.GetBEndUnit(wm) == eStyleUnit_Auto &&
pos->mOffset.GetBStartUnit(wm) != eStyleUnit_Auto)) ||
pos->MinBSizeDependsOnContainer(wm) ||
pos->MaxBSizeDependsOnContainer(wm) ||
!IsFixedPaddingSize(padding->mPadding.GetBStart(wm)) ||
!IsFixedPaddingSize(padding->mPadding.GetBEnd(wm))) {
return true;
}
// See if f's position might have changed.
if (!IsFixedMarginSize(margin->mMargin.GetBStart(wm)) ||
!IsFixedMarginSize(margin->mMargin.GetBEnd(wm))) {
return true;
}
}
// Since we store coordinates relative to top and left, the position
// of a frame depends on that of its container if it is fixed relative
// to the right or bottom, or if it is positioned using percentages
// relative to the left or top. Because of the dependency on the
// sides (left and top) that we use to store coordinates, these tests
// are easier to do using physical coordinates rather than logical.
if (aCBWidthChanged) {
if (!IsFixedOffset(pos->mOffset.GetLeft())) {
return true;
}
// Note that even if 'left' is a length, our position can still
// depend on the containing block width, because if our direction or
// writing-mode moves from right to left (in either block or inline
// progression) and 'right' is not 'auto', 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 ((wm.GetInlineDir() == WritingMode::eInlineRTL ||
wm.GetBlockDir() == WritingMode::eBlockRL) &&
pos->mOffset.GetRightUnit() != eStyleUnit_Auto) {
return true;
}
}
if (aCBHeightChanged) {
if (!IsFixedOffset(pos->mOffset.GetTop())) {
return true;
}
// See comment above for width changes.
if (wm.GetInlineDir() == WritingMode::eInlineBTT &&
pos->mOffset.GetBottomUnit() != eStyleUnit_Auto) {
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) {
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);
}
}
}
// Given an out-of-flow frame, this method returns the parent frame of its
// placeholder frame or null if it doesn't have a placeholder for some reason.
static nsContainerFrame*
GetPlaceholderContainer(nsIFrame* aPositionedFrame)
{
nsIFrame* placeholder = aPositionedFrame->GetPlaceholderFrame();
return placeholder ? placeholder->GetParent() : nullptr;
}
/**
* This function returns the offset of an abs/fixed-pos child's static
* position, with respect to the "start" corner of its alignment container,
* according to CSS Box Alignment. This function only operates in a single
* axis at a time -- callers can choose which axis via the |aAbsPosCBAxis|
* parameter.
*
* @param aKidReflowInput The ReflowInput for the to-be-aligned abspos child.
* @param aKidSizeInAbsPosCBWM The child frame's size (after it's been given
* the opportunity to reflow), in terms of
* aAbsPosCBWM.
* @param aAbsPosCBSize The abspos CB size, in terms of aAbsPosCBWM.
* @param aPlaceholderContainer The parent of the child frame's corresponding
* placeholder frame, cast to a nsContainerFrame.
* (This will help us choose which alignment enum
* we should use for the child.)
* @param aAbsPosCBWM The child frame's containing block's WritingMode.
* @param aAbsPosCBAxis The axis (of the containing block) that we should
* be doing this computation for.
*/
static nscoord
OffsetToAlignedStaticPos(const ReflowInput& aKidReflowInput,
const LogicalSize& aKidSizeInAbsPosCBWM,
const LogicalSize& aAbsPosCBSize,
nsContainerFrame* aPlaceholderContainer,
WritingMode aAbsPosCBWM,
LogicalAxis aAbsPosCBAxis)
{
if (!aPlaceholderContainer) {
// (The placeholder container should be the thing that kicks this whole
// process off, by setting PLACEHOLDER_STATICPOS_NEEDS_CSSALIGN. So it
// should exist... but bail gracefully if it doesn't.)
NS_ERROR("Missing placeholder-container when computing a "
"CSS Box Alignment static position");
return 0;
}
// (Most of this function is simply preparing args that we'll pass to
// AlignJustifySelf at the end.)
// NOTE: Our alignment container is aPlaceholderContainer's content-box
// (or an area within it, if aPlaceholderContainer is a grid). So, we'll
// perform most of our arithmetic/alignment in aPlaceholderContainer's
// WritingMode. For brevity, we use the abbreviation "pc" for "placeholder
// container" in variables below.
WritingMode pcWM = aPlaceholderContainer->GetWritingMode();
// Find what axis aAbsPosCBAxis corresponds to, in placeholder's parent's
// writing-mode.
LogicalAxis pcAxis = (pcWM.IsOrthogonalTo(aAbsPosCBWM)
? GetOrthogonalAxis(aAbsPosCBAxis)
: aAbsPosCBAxis);
LayoutFrameType parentType = aPlaceholderContainer->Type();
LogicalSize alignAreaSize(pcWM);
if (parentType == LayoutFrameType::FlexContainer) {
// The alignment container is the flex container's content box:
alignAreaSize = aPlaceholderContainer->GetLogicalSize(pcWM);
LogicalMargin pcBorderPadding =
aPlaceholderContainer->GetLogicalUsedBorderAndPadding(pcWM);
alignAreaSize -= pcBorderPadding.Size(pcWM);
} else if (parentType == LayoutFrameType::GridContainer) {
// This abspos elem's parent is a grid container. Per CSS Grid 10.1 & 10.2:
// - If the grid container *also* generates the abspos containing block (a
// grid area) for this abspos child, we use that abspos containing block as
// the alignment container, too. (And its size is aAbsPosCBSize.)
// - Otherwise, we use the grid's padding box as the alignment container.
// https://drafts.csswg.org/css-grid/#static-position
if (aPlaceholderContainer == aKidReflowInput.mCBReflowInput->mFrame) {
// The alignment container is the grid area that we're using as the
// absolute containing block.
alignAreaSize = aAbsPosCBSize.ConvertTo(pcWM, aAbsPosCBWM);
} else {
// The alignment container is a the grid container's padding box (which
// we can get by subtracting away its border from frame's size):
alignAreaSize = aPlaceholderContainer->GetLogicalSize(pcWM);
LogicalMargin pcBorder =
aPlaceholderContainer->GetLogicalUsedBorder(pcWM);
alignAreaSize -= pcBorder.Size(pcWM);
}
} else {
NS_ERROR("Unsupported container for abpsos CSS Box Alignment");
return 0; // (leave the child at the start of its alignment container)
}
nscoord alignAreaSizeInAxis = (pcAxis == eLogicalAxisInline)
? alignAreaSize.ISize(pcWM)
: alignAreaSize.BSize(pcWM);
AlignJustifyFlags flags = AlignJustifyFlags::eIgnoreAutoMargins;
uint16_t alignConst =
aPlaceholderContainer->CSSAlignmentForAbsPosChild(aKidReflowInput, pcAxis);
// XXXdholbert: Handle <overflow-position> in bug 1311892 (by conditionally
// setting AlignJustifyFlags::eOverflowSafe in |flags|.) For now, we behave
// as if "unsafe" was the specified value (which is basically equivalent to
// the default behavior, when no value is specified -- though the default
// behavior also has some [at-risk] extra nuance about scroll containers...)
// For now we ignore & strip off <overflow-position> bits, until bug 1311892.
alignConst &= ~NS_STYLE_ALIGN_FLAG_BITS;
// Find out if placeholder-container & the OOF child have the same start-sides
// in the placeholder-container's pcAxis.
WritingMode kidWM = aKidReflowInput.GetWritingMode();
if (pcWM.ParallelAxisStartsOnSameSide(pcAxis, kidWM)) {
flags |= AlignJustifyFlags::eSameSide;
}
// (baselineAdjust is unused. CSSAlignmentForAbsPosChild() should've
// converted 'baseline'/'last baseline' enums to their fallback values.)
const nscoord baselineAdjust = nscoord(0);
// AlignJustifySelf operates in the kid's writing mode, so we need to
// represent the child's size and the desired axis in that writing mode:
LogicalSize kidSizeInOwnWM = aKidSizeInAbsPosCBWM.ConvertTo(kidWM,
aAbsPosCBWM);
LogicalAxis kidAxis = (kidWM.IsOrthogonalTo(aAbsPosCBWM)
? GetOrthogonalAxis(aAbsPosCBAxis)
: aAbsPosCBAxis);
nscoord offset =
CSSAlignUtils::AlignJustifySelf(alignConst, kidAxis, flags,
baselineAdjust, alignAreaSizeInAxis,
aKidReflowInput, kidSizeInOwnWM);
// "offset" is in terms of the CSS Box Alignment container (i.e. it's in
// terms of pcWM). But our return value needs to in terms of the containing
// block's writing mode, which might have the opposite directionality in the
// given axis. In that case, we just need to negate "offset" when returning,
// to make it have the right effect as an offset for coordinates in the
// containing block's writing mode.
if (!pcWM.ParallelAxisStartsOnSameSide(pcAxis, aAbsPosCBWM)) {
return -offset;
}
return offset;
}
void
nsAbsoluteContainingBlock::ResolveSizeDependentOffsets(
nsPresContext* aPresContext,
ReflowInput& aKidReflowInput,
const LogicalSize& aKidSize,
const LogicalMargin& aMargin,
LogicalMargin* aOffsets,
LogicalSize* aLogicalCBSize)
{
WritingMode wm = aKidReflowInput.GetWritingMode();
WritingMode outerWM = aKidReflowInput.mParentReflowInput->GetWritingMode();
// Now that we know the child's size, we resolve any sentinel values in its
// IStart/BStart offset coordinates that depend on that size.
// * NS_AUTOOFFSET indicates that the child's position in the given axis
// is determined by its end-wards offset property, combined with its size and
// available space. e.g.: "top: auto; height: auto; bottom: 50px"
// * m{I,B}OffsetsResolvedAfterSize indicate that the child is using its
// static position in that axis, *and* its static position is determined by
// the axis-appropriate css-align property (which may require the child's
// size, e.g. to center it within the parent).
if ((NS_AUTOOFFSET == aOffsets->IStart(outerWM)) ||
(NS_AUTOOFFSET == aOffsets->BStart(outerWM)) ||
aKidReflowInput.mFlags.mIOffsetsNeedCSSAlign ||
aKidReflowInput.mFlags.mBOffsetsNeedCSSAlign) {
if (-1 == aLogicalCBSize->ISize(wm)) {
// Get the containing block width/height
const ReflowInput* parentRI = aKidReflowInput.mParentReflowInput;
*aLogicalCBSize =
aKidReflowInput.ComputeContainingBlockRectangle(aPresContext,
parentRI);
}
const LogicalSize logicalCBSizeOuterWM = aLogicalCBSize->ConvertTo(outerWM,
wm);
// placeholderContainer is used in each of the m{I,B}OffsetsNeedCSSAlign
// clauses. We declare it at this scope so we can avoid having to look
// it up twice (and only look it up if it's needed).
nsContainerFrame* placeholderContainer = nullptr;
if (NS_AUTOOFFSET == aOffsets->IStart(outerWM)) {
NS_ASSERTION(NS_AUTOOFFSET != aOffsets->IEnd(outerWM),
"Can't solve for both start and end");
aOffsets->IStart(outerWM) =
logicalCBSizeOuterWM.ISize(outerWM) -
aOffsets->IEnd(outerWM) - aMargin.IStartEnd(outerWM) -
aKidSize.ISize(outerWM);
} else if (aKidReflowInput.mFlags.mIOffsetsNeedCSSAlign) {
placeholderContainer = GetPlaceholderContainer(aKidReflowInput.mFrame);
nscoord offset = OffsetToAlignedStaticPos(aKidReflowInput, aKidSize,
logicalCBSizeOuterWM,
placeholderContainer,
outerWM, eLogicalAxisInline);
// Shift IStart from its current position (at start corner of the
// alignment container) by the returned offset. And set IEnd to the
// distance between the kid's end edge to containing block's end edge.
aOffsets->IStart(outerWM) += offset;
aOffsets->IEnd(outerWM) =
logicalCBSizeOuterWM.ISize(outerWM) -
(aOffsets->IStart(outerWM) + aKidSize.ISize(outerWM));
}
if (NS_AUTOOFFSET == aOffsets->BStart(outerWM)) {
aOffsets->BStart(outerWM) =
logicalCBSizeOuterWM.BSize(outerWM) -
aOffsets->BEnd(outerWM) - aMargin.BStartEnd(outerWM) -
aKidSize.BSize(outerWM);
} else if (aKidReflowInput.mFlags.mBOffsetsNeedCSSAlign) {
if (!placeholderContainer) {
placeholderContainer = GetPlaceholderContainer(aKidReflowInput.mFrame);
}
nscoord offset = OffsetToAlignedStaticPos(aKidReflowInput, aKidSize,
logicalCBSizeOuterWM,
placeholderContainer,
outerWM, eLogicalAxisBlock);
// Shift BStart from its current position (at start corner of the
// alignment container) by the returned offset. And set BEnd to the
// distance between the kid's end edge to containing block's end edge.
aOffsets->BStart(outerWM) += offset;
aOffsets->BEnd(outerWM) =
logicalCBSizeOuterWM.BSize(outerWM) -
(aOffsets->BStart(outerWM) + aKidSize.BSize(outerWM));
}
aKidReflowInput.SetComputedLogicalOffsets(aOffsets->ConvertTo(wm, outerWM));
}
}
// 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
// mChildListID == kFixedList, the height is unconstrained.
// since we don't allow replicated frames to split.
void
nsAbsoluteContainingBlock::ReflowAbsoluteFrame(nsIFrame* aDelegatingFrame,
nsPresContext* aPresContext,
const ReflowInput& aReflowInput,
const nsRect& aContainingBlock,
AbsPosReflowFlags aFlags,
nsIFrame* aKidFrame,
nsReflowStatus& aStatus,
nsOverflowAreas* aOverflowAreas)
{
#ifdef DEBUG
if (nsBlockFrame::gNoisyReflow) {
nsFrame::IndentBy(stdout,nsBlockFrame::gNoiseIndent);
printf("abs pos ");
nsAutoString name;
aKidFrame->GetFrameName(name);
printf("%s ", NS_LossyConvertUTF16toASCII(name).get());
char width[16];
char height[16];
PrettyUC(aReflowInput.AvailableWidth(), width, 16);
PrettyUC(aReflowInput.AvailableHeight(), height, 16);
printf(" a=%s,%s ", width, height);
PrettyUC(aReflowInput.ComputedWidth(), width, 16);
PrettyUC(aReflowInput.ComputedHeight(), height, 16);
printf("c=%s,%s \n", width, height);
}
AutoNoisyIndenter indent(nsBlockFrame::gNoisy);
#endif // DEBUG
WritingMode wm = aKidFrame->GetWritingMode();
LogicalSize logicalCBSize(wm, aContainingBlock.Size());
nscoord availISize = logicalCBSize.ISize(wm);
if (availISize == -1) {
NS_ASSERTION(aReflowInput.ComputedSize(wm).ISize(wm) !=
NS_UNCONSTRAINEDSIZE,
"Must have a useful inline-size _somewhere_");
availISize =
aReflowInput.ComputedSizeWithPadding(wm).ISize(wm);
}
uint32_t rsFlags = 0;
if (aFlags & AbsPosReflowFlags::eIsGridContainerCB) {
// When a grid container generates the abs.pos. CB for a *child* then
// the static position is determined via CSS Box Alignment within the
// abs.pos. CB (a grid area, i.e. a piece of the grid). In this scenario,
// due to the multiple coordinate spaces in play, we use a convenience flag
// to simply have the child's ReflowInput give it a static position at its
// abs.pos. CB origin, and then we'll align & offset it from there.
nsIFrame* placeholder = aKidFrame->GetPlaceholderFrame();
if (placeholder && placeholder->GetParent() == aDelegatingFrame) {
rsFlags |= ReflowInput::STATIC_POS_IS_CB_ORIGIN;
}
}
ReflowInput kidReflowInput(aPresContext, aReflowInput, aKidFrame,
LogicalSize(wm, availISize,
NS_UNCONSTRAINEDSIZE),
&logicalCBSize, rsFlags);
// Get the border values
WritingMode outerWM = aReflowInput.GetWritingMode();
const LogicalMargin border(outerWM, aDelegatingFrame->GetUsedBorder());
LogicalMargin margin =
kidReflowInput.ComputedLogicalMargin().ConvertTo(outerWM, wm);
// If we're doing CSS Box Alignment in either axis, that will apply the
// margin for us in that axis (since the thing that's aligned is the margin
// box). So, we clear out the margin here to avoid applying it twice.
if (kidReflowInput.mFlags.mIOffsetsNeedCSSAlign) {
margin.IStart(outerWM) = margin.IEnd(outerWM) = 0;
}
if (kidReflowInput.mFlags.mBOffsetsNeedCSSAlign) {
margin.BStart(outerWM) = margin.BEnd(outerWM) = 0;
}
bool constrainBSize = (aReflowInput.AvailableBSize() != NS_UNCONSTRAINEDSIZE)
&& (aFlags & AbsPosReflowFlags::eConstrainHeight)
// Don't split if told not to (e.g. for fixed frames)
&& !aDelegatingFrame->IsInlineFrame()
//XXX we don't handle splitting frames for inline absolute containing blocks yet
&& (aKidFrame->GetLogicalRect(aContainingBlock.Size()).BStart(wm) <=
aReflowInput.AvailableBSize());
// 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 (constrainBSize) {
kidReflowInput.AvailableBSize() =
aReflowInput.AvailableBSize() - border.ConvertTo(wm, outerWM).BStart(wm) -
kidReflowInput.ComputedLogicalMargin().BStart(wm);
if (NS_AUTOOFFSET != kidReflowInput.ComputedLogicalOffsets().BStart(wm)) {
kidReflowInput.AvailableBSize() -=
kidReflowInput.ComputedLogicalOffsets().BStart(wm);
}
}
// Do the reflow
ReflowOutput kidDesiredSize(kidReflowInput);
aKidFrame->Reflow(aPresContext, kidDesiredSize, kidReflowInput, aStatus);
const LogicalSize kidSize = kidDesiredSize.Size(wm).ConvertTo(outerWM, wm);
LogicalMargin offsets =
kidReflowInput.ComputedLogicalOffsets().ConvertTo(outerWM, wm);
// If we're solving for start in either inline or block direction,
// then compute it now that we know the dimensions.
ResolveSizeDependentOffsets(aPresContext, kidReflowInput, kidSize, margin,
&offsets, &logicalCBSize);
// Position the child relative to our padding edge
LogicalRect rect(outerWM,
border.IStart(outerWM) + offsets.IStart(outerWM) +
margin.IStart(outerWM),
border.BStart(outerWM) + offsets.BStart(outerWM) +
margin.BStart(outerWM),
kidSize.ISize(outerWM), kidSize.BSize(outerWM));
nsRect r =
rect.GetPhysicalRect(outerWM, logicalCBSize.GetPhysicalSize(wm) +
border.Size(outerWM).GetPhysicalSize(outerWM));
// Offset the frame rect by the given origin of the absolute containing block.
// If the frame is auto-positioned on both sides of an axis, it will be
// positioned based on its containing block and we don't need to offset
// (unless the caller demands it (the STATIC_POS_IS_CB_ORIGIN case)).
if (aContainingBlock.TopLeft() != nsPoint(0, 0)) {
const nsStyleSides& offsets = kidReflowInput.mStylePosition->mOffset;
if (!(offsets.GetLeftUnit() == eStyleUnit_Auto &&
offsets.GetRightUnit() == eStyleUnit_Auto) ||
(rsFlags & ReflowInput::STATIC_POS_IS_CB_ORIGIN)) {
r.x += aContainingBlock.x;
}
if (!(offsets.GetTopUnit() == eStyleUnit_Auto &&
offsets.GetBottomUnit() == eStyleUnit_Auto) ||
(rsFlags & ReflowInput::STATIC_POS_IS_CB_ORIGIN)) {
r.y += aContainingBlock.y;
}
}
aKidFrame->SetRect(r);
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, &kidReflowInput,
nsDidReflowStatus::FINISHED);
#ifdef DEBUG
if (nsBlockFrame::gNoisyReflow) {
nsFrame::IndentBy(stdout,nsBlockFrame::gNoiseIndent - 1);
printf("abs pos ");
nsAutoString name;
aKidFrame->GetFrameName(name);
printf("%s ", NS_LossyConvertUTF16toASCII(name).get());
printf("%p rect=%d,%d,%d,%d\n", static_cast<void*>(aKidFrame),
r.x, r.y, r.width, r.height);
}
#endif
if (aOverflowAreas) {
aOverflowAreas->UnionWith(kidDesiredSize.mOverflowAreas + r.TopLeft());
}
}