summaryrefslogtreecommitdiffstats
path: root/layout/generic/nsAbsoluteContainingBlock.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'layout/generic/nsAbsoluteContainingBlock.cpp')
-rw-r--r--layout/generic/nsAbsoluteContainingBlock.cpp763
1 files changed, 763 insertions, 0 deletions
diff --git a/layout/generic/nsAbsoluteContainingBlock.cpp b/layout/generic/nsAbsoluteContainingBlock.cpp
new file mode 100644
index 000000000..7c48aae92
--- /dev/null
+++ b/layout/generic/nsAbsoluteContainingBlock.cpp
@@ -0,0 +1,763 @@
+/* -*- 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 = NS_FRAME_COMPLETE;
+
+ 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));
+ if (kidNeedsReflow && !aPresContext->HasPendingInterrupt()) {
+ // Reflow the frame
+ nsReflowStatus kidStatus = NS_FRAME_COMPLETE;
+ const nsRect& cb = isGrid ? nsGridContainerFrame::GridItemCB(kidFrame)
+ : aContainingBlock;
+ ReflowAbsoluteFrame(aDelegatingFrame, aPresContext, aReflowInput, cb,
+ aFlags, kidFrame, kidStatus, aOverflowAreas);
+ nsIFrame* nextFrame = kidFrame->GetNextInFlow();
+ if (!NS_FRAME_IS_FULLY_COMPLETE(kidStatus) &&
+ 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);
+ NS_MergeReflowStatusInto(&reflowStatus, 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 (NS_FRAME_IS_NOT_COMPLETE(reflowStatus))
+ NS_FRAME_SET_OVERFLOW_INCOMPLETE(reflowStatus);
+
+ NS_MergeReflowStatusInto(&aReflowStatus, 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.IsBidiLTR()) {
+ // Note that even if 'istart' is a length, our position can
+ // still depend on the containing block isze, because if
+ // 'iend' is also a length we will discard 'istart' and be
+ // positioned relative to the containing block iend edge.
+ // 'istart' length and 'iend' auto is the only combination
+ // we can be sure of.
+ if (!IsFixedOffset(pos->mOffset.GetIStart(wm)) ||
+ pos->mOffset.GetIEndUnit(wm) != eStyleUnit_Auto) {
+ return true;
+ }
+ } else {
+ if (!IsFixedOffset(pos->mOffset.GetIStart(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;
+ }
+ if (!IsFixedOffset(pos->mOffset.GetBStart(wm))) {
+ 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, if that parent is a nsContainerFrame.
+static nsContainerFrame*
+GetPlaceholderContainer(nsPresContext* aPresContext,
+ nsIFrame* aPositionedFrame)
+{
+ MOZ_ASSERT(aPositionedFrame, "need non-null frame");
+ MOZ_ASSERT(aPositionedFrame->HasAnyStateBits(NS_FRAME_OUT_OF_FLOW),
+ "expecting abspos frame");
+ MOZ_ASSERT(aPresContext && aPresContext == aPositionedFrame->PresContext(),
+ "need non-null pres context which matches our frame");
+
+ nsIFrame* placeholder =
+ aPresContext->PresShell()->GetPlaceholderFrameFor(aPositionedFrame);
+
+ if (!placeholder) {
+ return nullptr;
+ }
+ return do_QueryFrame(placeholder->GetParent());
+}
+
+/**
+ * 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);
+
+ nsIAtom* parentType = aPlaceholderContainer->GetType();
+ LogicalSize alignAreaSize(pcWM);
+ if (parentType == nsGkAtoms::flexContainerFrame) {
+ // 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 == nsGkAtoms::gridContainerFrame) {
+ // 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(aPresContext,
+ 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(aPresContext,
+ 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 =
+ aPresContext->PresShell()->GetPlaceholderFrameFor(aKidFrame);
+ 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,
+ aReflowInput.mStyleBorder->GetComputedBorder());
+ 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->GetType() != nsGkAtoms::inlineFrame)
+ //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());
+ }
+}