/* -*- 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/. */ /* * code for managing absolutely positioned children of a rendering * object that is a containing block for them */ #include "nsAbsoluteContainingBlock.h" #include "nsAtomicContainerFrame.h" #include "nsContainerFrame.h" #include "nsGkAtoms.h" #include "mozilla/CSSAlignUtils.h" #include "mozilla/PresShell.h" #include "mozilla/ReflowInput.h" #include "nsPlaceholderFrame.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, FrameChildListID aListID, nsFrameList&& aChildList) { MOZ_ASSERT(mChildListID == aListID, "unexpected child list name"); #ifdef DEBUG nsIFrame::VerifyDirtyBitSet(aChildList); for (nsIFrame* f : aChildList) { MOZ_ASSERT(f->GetParent() == aDelegatingFrame, "Unexpected parent"); } #endif mAbsoluteFrames = std::move(aChildList); } void nsAbsoluteContainingBlock::AppendFrames(nsIFrame* aDelegatingFrame, FrameChildListID aListID, nsFrameList&& aFrameList) { NS_ASSERTION(mChildListID == aListID, "unexpected child list"); // Append the frames to our list of absolutely positioned frames #ifdef DEBUG nsIFrame::VerifyDirtyBitSet(aFrameList); #endif mAbsoluteFrames.AppendFrames(nullptr, std::move(aFrameList)); // no damage to intrinsic widths, since absolutely positioned frames can't // change them aDelegatingFrame->PresShell()->FrameNeedsReflow( aDelegatingFrame, IntrinsicDirty::None, NS_FRAME_HAS_DIRTY_CHILDREN); } void nsAbsoluteContainingBlock::InsertFrames(nsIFrame* aDelegatingFrame, FrameChildListID 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 nsIFrame::VerifyDirtyBitSet(aFrameList); #endif mAbsoluteFrames.InsertFrames(nullptr, aPrevFrame, std::move(aFrameList)); // no damage to intrinsic widths, since absolutely positioned frames can't // change them aDelegatingFrame->PresShell()->FrameNeedsReflow( aDelegatingFrame, IntrinsicDirty::None, NS_FRAME_HAS_DIRTY_CHILDREN); } void nsAbsoluteContainingBlock::RemoveFrame(FrameDestroyContext& aContext, FrameChildListID aListID, nsIFrame* aOldFrame) { NS_ASSERTION(mChildListID == aListID, "unexpected child list"); if (nsIFrame* nif = aOldFrame->GetNextInFlow()) { nif->GetParent()->DeleteNextInFlowChild(aContext, nif, false); } mAbsoluteFrames.DestroyFrame(aContext, aOldFrame); } static void MaybeMarkAncestorsAsHavingDescendantDependentOnItsStaticPos( nsIFrame* aFrame, nsIFrame* aContainingBlockFrame) { MOZ_ASSERT(aFrame->HasAnyStateBits(NS_FRAME_OUT_OF_FLOW)); if (!aFrame->StylePosition()->NeedsHypotheticalPositionIfAbsPos()) { return; } // We should have set the bit when reflowing the previous continuations // already. if (aFrame->GetPrevContinuation()) { return; } auto* placeholder = aFrame->GetPlaceholderFrame(); MOZ_ASSERT(placeholder); // Only fixed-pos frames can escape their containing block. if (!placeholder->HasAnyStateBits(PLACEHOLDER_FOR_FIXEDPOS)) { return; } for (nsIFrame* ancestor = placeholder->GetParent(); ancestor; ancestor = ancestor->GetParent()) { // Walk towards the ancestor's first continuation. That's the only one that // really matters, since it's the only one restyling will look at. We also // flag the following continuations just so it's caught on the first // early-return ones just to avoid walking them over and over. do { if (ancestor->DescendantMayDependOnItsStaticPosition()) { return; } // Moving the containing block or anything above it would move our static // position as well, so no need to flag it or any of its ancestors. if (aFrame == aContainingBlockFrame) { return; } ancestor->SetDescendantMayDependOnItsStaticPosition(true); nsIFrame* prev = ancestor->GetPrevContinuation(); if (!prev) { break; } ancestor = prev; } while (true); } } void nsAbsoluteContainingBlock::Reflow(nsContainerFrame* aDelegatingFrame, nsPresContext* aPresContext, const ReflowInput& aReflowInput, nsReflowStatus& aReflowStatus, const nsRect& aContainingBlock, AbsPosReflowFlags aFlags, OverflowAreas* aOverflowAreas) { // PageContentFrame replicates fixed pos children so we really don't want // them contributing to overflow areas because that means we'll create new // pages ad infinitum if one of them overflows the page. if (aDelegatingFrame->IsPageContentFrame()) { MOZ_ASSERT(mChildListID == FrameChildListID::Fixed); aOverflowAreas = nullptr; } nsReflowStatus reflowStatus; const bool reflowAll = aReflowInput.ShouldReflowAllKids(); const bool isGrid = !!(aFlags & AbsPosReflowFlags::IsGridContainerCB); nsIFrame* kidFrame; nsOverflowContinuationTracker tracker(aDelegatingFrame, true); for (kidFrame = mAbsoluteFrames.FirstChild(); kidFrame; kidFrame = kidFrame->GetNextSibling()) { bool kidNeedsReflow = reflowAll || kidFrame->IsSubtreeDirty() || FrameDependsOnContainer( kidFrame, !!(aFlags & AbsPosReflowFlags::CBWidthChanged), !!(aFlags & AbsPosReflowFlags::CBHeightChanged)); if (kidFrame->IsSubtreeDirty()) { MaybeMarkAncestorsAsHavingDescendantDependentOnItsStaticPos( kidFrame, aDelegatingFrame); } 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->ScrollableOverflowRectRelativeToSelf() + kidFrame->GetPosition(), aContainingBlock.Size()) .BEnd(containerWM); NS_ASSERTION(kidOverflowBEnd >= kidBEnd, "overflow area should be at least as large as frame rect"); 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); MOZ_ASSERT(!kidStatus.IsInlineBreakBefore(), "ShouldAvoidBreakInside should prevent this from happening"); nsIFrame* nextFrame = kidFrame->GetNextInFlow(); if (!kidStatus.IsFullyComplete() && aDelegatingFrame->CanContainOverflowContainers()) { // Need a continuation if (!nextFrame) { nextFrame = aPresContext->PresShell() ->FrameConstructor() ->CreateContinuingFrame(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 if (nextFrame) { // Delete any continuations nsOverflowContinuationTracker::AutoFinish fini(&tracker, kidFrame); FrameDestroyContext context(aPresContext->PresShell()); nextFrame->GetParent()->DeleteNextInFlowChild(context, 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->HasAnyStateBits(NS_FRAME_IS_DIRTY)) { kidFrame->MarkSubtreeDirty(); } 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(); reflowStatus.SetNextInFlowNeedsReflow(); } aReflowStatus.MergeCompletionStatusFrom(reflowStatus); } static inline bool IsFixedPaddingSize(const LengthPercentage& aCoord) { return aCoord.ConvertsToLength(); } static inline bool IsFixedMarginSize(const LengthPercentageOrAuto& aCoord) { return aCoord.ConvertsToLength(); } static inline bool IsFixedOffset(const LengthPercentageOrAuto& 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. if (pos->NeedsHypotheticalPositionIfAbsPos()) { 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. // // FIXME(emilio): Should the BSize(wm).IsAuto() check also for the extremum // lengths? if ((pos->BSizeDependsOnContainer(wm) && !(pos->BSize(wm).IsAuto() && pos->mOffset.GetBEnd(wm).IsAuto() && !pos->mOffset.GetBStart(wm).IsAuto())) || 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.Get(eSideLeft))) { 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.Get(eSideRight).IsAuto()) { return true; } } if (aCBHeightChanged) { if (!IsFixedOffset(pos->mOffset.Get(eSideTop))) { return true; } // See comment above for width changes. if (wm.GetInlineDir() == WritingMode::eInlineBTT && !pos->mOffset.Get(eSideBottom).IsAuto()) { return true; } } return false; } void nsAbsoluteContainingBlock::DestroyFrames(DestroyContext& aContext) { mAbsoluteFrames.DestroyFrames(aContext); } void nsAbsoluteContainingBlock::MarkSizeDependentFramesDirty() { DoMarkFramesDirty(false); } void nsAbsoluteContainingBlock::MarkAllFramesDirty() { DoMarkFramesDirty(true); } void nsAbsoluteContainingBlock::DoMarkFramesDirty(bool aMarkAllDirty) { for (nsIFrame* kidFrame : mAbsoluteFrames) { if (aMarkAllDirty) { kidFrame->MarkSubtreeDirty(); } 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); const bool placeholderContainerIsContainingBlock = aPlaceholderContainer == aKidReflowInput.mCBReflowInput->mFrame; LayoutFrameType parentType = aPlaceholderContainer->Type(); LogicalSize alignAreaSize(pcWM); if (parentType == LayoutFrameType::FlexContainer) { // We store the frame rect in FinishAndStoreOverflow, which runs _after_ // reflowing the absolute frames, so handle the special case of the frame // being the actual containing block here, by getting the size from // aAbsPosCBSize. // // The alignment container is the flex container's content box. if (placeholderContainerIsContainingBlock) { alignAreaSize = aAbsPosCBSize.ConvertTo(pcWM, aAbsPosCBWM); // aAbsPosCBSize is the padding-box, so substract the padding to get the // content box. alignAreaSize -= aPlaceholderContainer->GetLogicalUsedPadding(pcWM).Size(pcWM); } else { 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 (placeholderContainerIsContainingBlock) { // 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 content box (which // we can get by subtracting away its border & padding from frame's size): alignAreaSize = aPlaceholderContainer->GetLogicalSize(pcWM); LogicalMargin pcBorderPadding = aPlaceholderContainer->GetLogicalUsedBorderAndPadding(pcWM); alignAreaSize -= pcBorderPadding.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::IgnoreAutoMargins; StyleAlignFlags alignConst = aPlaceholderContainer->CSSAlignmentForAbsPosChild(aKidReflowInput, pcAxis); // If the safe bit in alignConst is set, set the safe flag in |flags|. // Note: If no is specified, we behave as 'unsafe'. // This doesn't quite match the css-align spec, which has an [at-risk] // "smart default" behavior with some extra nuance about scroll containers. if (alignConst & StyleAlignFlags::SAFE) { flags |= AlignJustifyFlags::OverflowSafe; } alignConst &= ~StyleAlignFlags::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::SameSide; } // (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(outerWM, *aOffsets); } } void nsAbsoluteContainingBlock::ResolveAutoMarginsAfterLayout( ReflowInput& aKidReflowInput, const LogicalSize* aLogicalCBSize, const LogicalSize& aKidSize, LogicalMargin& aMargin, LogicalMargin& aOffsets) { MOZ_ASSERT(aKidReflowInput.mFrame->HasIntrinsicKeywordForBSize()); WritingMode wm = aKidReflowInput.GetWritingMode(); WritingMode outerWM = aKidReflowInput.mParentReflowInput->GetWritingMode(); const LogicalSize kidSizeInWM = aKidSize.ConvertTo(wm, outerWM); LogicalMargin marginInWM = aMargin.ConvertTo(wm, outerWM); LogicalMargin offsetsInWM = aOffsets.ConvertTo(wm, outerWM); // No need to substract border sizes because aKidSize has it included // already. Also, if any offset is auto, the auto margin resolves to zero. // https://drafts.csswg.org/css-position-3/#abspos-margins const bool autoOffset = offsetsInWM.BEnd(wm) == NS_AUTOOFFSET || offsetsInWM.BStart(wm) == NS_AUTOOFFSET; nscoord availMarginSpace = autoOffset ? 0 : aLogicalCBSize->BSize(wm) - kidSizeInWM.BSize(wm) - offsetsInWM.BStartEnd(wm) - marginInWM.BStartEnd(wm); const auto& styleMargin = aKidReflowInput.mStyleMargin; if (wm.IsOrthogonalTo(outerWM)) { ReflowInput::ComputeAbsPosInlineAutoMargin( availMarginSpace, outerWM, styleMargin->mMargin.GetIStart(outerWM).IsAuto(), styleMargin->mMargin.GetIEnd(outerWM).IsAuto(), aMargin, aOffsets); } else { ReflowInput::ComputeAbsPosBlockAutoMargin( availMarginSpace, outerWM, styleMargin->mMargin.GetBStart(outerWM).IsAuto(), styleMargin->mMargin.GetBEnd(outerWM).IsAuto(), aMargin, aOffsets); } aKidReflowInput.SetComputedLogicalMargin(outerWM, aMargin); aKidReflowInput.SetComputedLogicalOffsets(outerWM, aOffsets); nsMargin* propValue = aKidReflowInput.mFrame->GetProperty(nsIFrame::UsedMarginProperty()); // InitOffsets should've created a UsedMarginProperty for us, if any margin is // auto. MOZ_ASSERT_IF(styleMargin->HasInlineAxisAuto(outerWM) || styleMargin->HasBlockAxisAuto(outerWM), propValue); if (propValue) { *propValue = aMargin.GetPhysicalMargin(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 == FrameChildListID::Fixed, 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, OverflowAreas* aOverflowAreas) { MOZ_ASSERT(aStatus.IsEmpty(), "Caller should pass a fresh reflow status!"); #ifdef DEBUG if (nsBlockFrame::gNoisyReflow) { nsIFrame::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); } ReflowInput::InitFlags initFlags; if (aFlags & AbsPosReflowFlags::IsGridContainerCB) { // 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) { initFlags += ReflowInput::InitFlag::StaticPosIsCBOrigin; } } bool constrainBSize = (aReflowInput.AvailableBSize() != NS_UNCONSTRAINEDSIZE) && // Don't split if told not to (e.g. for fixed frames) (aFlags & AbsPosReflowFlags::ConstrainHeight) && // XXX we don't handle splitting frames for inline absolute containing // blocks yet !aDelegatingFrame->IsInlineFrame() && // Bug 1588623: Support splitting absolute positioned multicol containers. !aKidFrame->IsColumnSetWrapperFrame() && // 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. (aKidFrame->GetLogicalRect(aContainingBlock.Size()).BStart(wm) <= aReflowInput.AvailableBSize()); // Get the border values const WritingMode outerWM = aReflowInput.GetWritingMode(); const LogicalMargin border = aDelegatingFrame->GetLogicalUsedBorder(outerWM); const nscoord availBSize = constrainBSize ? aReflowInput.AvailableBSize() - border.ConvertTo(wm, outerWM).BStart(wm) : NS_UNCONSTRAINEDSIZE; ReflowInput kidReflowInput(aPresContext, aReflowInput, aKidFrame, LogicalSize(wm, availISize, availBSize), Some(logicalCBSize), initFlags); if (nscoord kidAvailBSize = kidReflowInput.AvailableBSize(); kidAvailBSize != NS_UNCONSTRAINEDSIZE) { // Shrink available block-size if it's constrained. kidAvailBSize -= kidReflowInput.ComputedLogicalMargin(wm).BStart(wm); const nscoord kidOffsetBStart = kidReflowInput.ComputedLogicalOffsets(wm).BStart(wm); if (NS_AUTOOFFSET != kidOffsetBStart) { kidAvailBSize -= kidOffsetBStart; } kidReflowInput.SetAvailableBSize(kidAvailBSize); } // Do the reflow ReflowOutput kidDesiredSize(kidReflowInput); aKidFrame->Reflow(aPresContext, kidDesiredSize, kidReflowInput, aStatus); // Position the child relative to our padding edge. Don't do this for popups, // which handle their own positioning. if (!aKidFrame->IsMenuPopupFrame()) { const LogicalSize kidSize = kidDesiredSize.Size(outerWM); LogicalMargin offsets = kidReflowInput.ComputedLogicalOffsets(outerWM); LogicalMargin margin = kidReflowInput.ComputedLogicalMargin(outerWM); // 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; } // 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); if (kidReflowInput.mFrame->HasIntrinsicKeywordForBSize()) { ResolveAutoMarginsAfterLayout(kidReflowInput, &logicalCBSize, kidSize, margin, offsets); } LogicalRect rect(outerWM, border.StartOffset(outerWM) + offsets.StartOffset(outerWM) + margin.StartOffset(outerWM), kidSize); 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. r.x += aContainingBlock.x; 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.InkOverflow()); } else { nsContainerFrame::PositionChildViews(aKidFrame); } } aKidFrame->DidReflow(aPresContext, &kidReflowInput); const nsRect r = aKidFrame->GetRect(); #ifdef DEBUG if (nsBlockFrame::gNoisyReflow) { nsIFrame::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(aKidFrame), r.x, r.y, r.width, r.height); } #endif if (aOverflowAreas) { aOverflowAreas->UnionWith(kidDesiredSize.mOverflowAreas + r.TopLeft()); } }