| /* |
| * Copyright (C) 2013 Google Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: |
| * |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following disclaimer |
| * in the documentation and/or other materials provided with the |
| * distribution. |
| * * Neither the name of Google Inc. nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include "core/layout/LayoutBlockFlow.h" |
| |
| #include <memory> |
| #include "core/editing/Editor.h" |
| #include "core/frame/FrameView.h" |
| #include "core/frame/LocalFrame.h" |
| #include "core/frame/UseCounter.h" |
| #include "core/html/HTMLDialogElement.h" |
| #include "core/layout/HitTestLocation.h" |
| #include "core/layout/LayoutAnalyzer.h" |
| #include "core/layout/LayoutFlowThread.h" |
| #include "core/layout/LayoutInline.h" |
| #include "core/layout/LayoutMultiColumnFlowThread.h" |
| #include "core/layout/LayoutMultiColumnSpannerPlaceholder.h" |
| #include "core/layout/LayoutPagedFlowThread.h" |
| #include "core/layout/LayoutView.h" |
| #include "core/layout/TextAutosizer.h" |
| #include "core/layout/line/GlyphOverflow.h" |
| #include "core/layout/line/InlineIterator.h" |
| #include "core/layout/line/InlineTextBox.h" |
| #include "core/layout/line/LineWidth.h" |
| #include "core/layout/shapes/ShapeOutsideInfo.h" |
| #include "core/paint/BlockFlowPaintInvalidator.h" |
| #include "core/paint/PaintLayer.h" |
| #include "platform/RuntimeEnabledFeatures.h" |
| #include "wtf/PtrUtil.h" |
| |
| namespace blink { |
| |
| bool LayoutBlockFlow::s_canPropagateFloatIntoSibling = false; |
| |
| struct SameSizeAsLayoutBlockFlow : public LayoutBlock { |
| LineBoxList lineBoxes; |
| void* pointers[2]; |
| }; |
| |
| static_assert(sizeof(LayoutBlockFlow) == sizeof(SameSizeAsLayoutBlockFlow), |
| "LayoutBlockFlow should stay small"); |
| |
| struct SameSizeAsMarginInfo { |
| uint16_t bitfields; |
| LayoutUnit margins[2]; |
| }; |
| |
| static_assert(sizeof(LayoutBlockFlow::MarginValues) == sizeof(LayoutUnit[4]), |
| "MarginValues should stay small"); |
| |
| // Caches all our current margin collapsing state. |
| class MarginInfo { |
| // Collapsing flags for whether we can collapse our margins with our |
| // children's margins. |
| bool m_canCollapseWithChildren : 1; |
| bool m_canCollapseMarginBeforeWithChildren : 1; |
| bool m_canCollapseMarginAfterWithChildren : 1; |
| bool m_canCollapseMarginAfterWithLastChild : 1; |
| |
| // Whether or not we are a quirky container, i.e., do we collapse away top and |
| // bottom margins in our container. Table cells and the body are the common |
| // examples. We also have a custom style property for Safari RSS to deal with |
| // TypePad blog articles. |
| bool m_quirkContainer : 1; |
| |
| // This flag tracks whether we are still looking at child margins that can all |
| // collapse together at the beginning of a block. They may or may not collapse |
| // with the top margin of the block (|m_canCollapseTopWithChildren| tells us |
| // that), but they will always be collapsing with one another. This variable |
| // can remain set to true through multiple iterations as long as we keep |
| // encountering self-collapsing blocks. |
| bool m_atBeforeSideOfBlock : 1; |
| |
| // This flag is set when we know we're examining bottom margins and we know |
| // we're at the bottom of the block. |
| bool m_atAfterSideOfBlock : 1; |
| |
| // These variables are used to detect quirky margins that we need to collapse |
| // away (in table cells |
| // and in the body element). |
| bool m_hasMarginBeforeQuirk : 1; |
| bool m_hasMarginAfterQuirk : 1; |
| bool m_determinedMarginBeforeQuirk : 1; |
| |
| bool m_discardMargin : 1; |
| bool m_lastChildIsSelfCollapsingBlockWithClearance : 1; |
| |
| // These flags track the previous maximal positive and negative margins. |
| LayoutUnit m_positiveMargin; |
| LayoutUnit m_negativeMargin; |
| |
| public: |
| MarginInfo(LayoutBlockFlow*, |
| LayoutUnit beforeBorderPadding, |
| LayoutUnit afterBorderPadding); |
| |
| void setAtBeforeSideOfBlock(bool b) { m_atBeforeSideOfBlock = b; } |
| void setAtAfterSideOfBlock(bool b) { m_atAfterSideOfBlock = b; } |
| void clearMargin() { |
| m_positiveMargin = LayoutUnit(); |
| m_negativeMargin = LayoutUnit(); |
| } |
| void setHasMarginBeforeQuirk(bool b) { m_hasMarginBeforeQuirk = b; } |
| void setHasMarginAfterQuirk(bool b) { m_hasMarginAfterQuirk = b; } |
| void setDeterminedMarginBeforeQuirk(bool b) { |
| m_determinedMarginBeforeQuirk = b; |
| } |
| void setPositiveMargin(LayoutUnit p) { |
| ASSERT(!m_discardMargin); |
| m_positiveMargin = p; |
| } |
| void setNegativeMargin(LayoutUnit n) { |
| ASSERT(!m_discardMargin); |
| m_negativeMargin = n; |
| } |
| void setPositiveMarginIfLarger(LayoutUnit p) { |
| ASSERT(!m_discardMargin); |
| if (p > m_positiveMargin) |
| m_positiveMargin = p; |
| } |
| void setNegativeMarginIfLarger(LayoutUnit n) { |
| ASSERT(!m_discardMargin); |
| if (n > m_negativeMargin) |
| m_negativeMargin = n; |
| } |
| |
| void setMargin(LayoutUnit p, LayoutUnit n) { |
| ASSERT(!m_discardMargin); |
| m_positiveMargin = p; |
| m_negativeMargin = n; |
| } |
| void setCanCollapseMarginAfterWithChildren(bool collapse) { |
| m_canCollapseMarginAfterWithChildren = collapse; |
| } |
| void setCanCollapseMarginAfterWithLastChild(bool collapse) { |
| m_canCollapseMarginAfterWithLastChild = collapse; |
| } |
| void setDiscardMargin(bool value) { m_discardMargin = value; } |
| |
| bool atBeforeSideOfBlock() const { return m_atBeforeSideOfBlock; } |
| bool canCollapseWithMarginBefore() const { |
| return m_atBeforeSideOfBlock && m_canCollapseMarginBeforeWithChildren; |
| } |
| bool canCollapseWithMarginAfter() const { |
| return m_atAfterSideOfBlock && m_canCollapseMarginAfterWithChildren; |
| } |
| bool canCollapseMarginBeforeWithChildren() const { |
| return m_canCollapseMarginBeforeWithChildren; |
| } |
| bool canCollapseMarginAfterWithChildren() const { |
| return m_canCollapseMarginAfterWithChildren; |
| } |
| bool canCollapseMarginAfterWithLastChild() const { |
| return m_canCollapseMarginAfterWithLastChild; |
| } |
| bool quirkContainer() const { return m_quirkContainer; } |
| bool determinedMarginBeforeQuirk() const { |
| return m_determinedMarginBeforeQuirk; |
| } |
| bool hasMarginBeforeQuirk() const { return m_hasMarginBeforeQuirk; } |
| bool hasMarginAfterQuirk() const { return m_hasMarginAfterQuirk; } |
| LayoutUnit positiveMargin() const { return m_positiveMargin; } |
| LayoutUnit negativeMargin() const { return m_negativeMargin; } |
| bool discardMargin() const { return m_discardMargin; } |
| LayoutUnit margin() const { return m_positiveMargin - m_negativeMargin; } |
| void setLastChildIsSelfCollapsingBlockWithClearance(bool value) { |
| m_lastChildIsSelfCollapsingBlockWithClearance = value; |
| } |
| bool lastChildIsSelfCollapsingBlockWithClearance() const { |
| return m_lastChildIsSelfCollapsingBlockWithClearance; |
| } |
| }; |
| |
| // Some features, such as floats, margin collapsing and fragmentation, require |
| // some knowledge about things that happened when laying out previous block |
| // child siblings. Only looking at the object currently being laid out isn't |
| // always enough. |
| class BlockChildrenLayoutInfo { |
| public: |
| BlockChildrenLayoutInfo(LayoutBlockFlow* blockFlow, |
| LayoutUnit beforeEdge, |
| LayoutUnit afterEdge) |
| : m_marginInfo(blockFlow, beforeEdge, afterEdge), |
| m_previousBreakAfterValue(EBreakBetween::kAuto), |
| m_isAtFirstInFlowChild(true) {} |
| |
| // Store multicol layout state before first layout of a block child. The child |
| // may contain a column spanner. If we need to re-lay out the block child |
| // because our initial logical top estimate was wrong, we need to roll back to |
| // how things were before laying out the child. |
| void storeMultiColumnLayoutState(const LayoutFlowThread& flowThread) { |
| m_multiColumnLayoutState = flowThread.multiColumnLayoutState(); |
| } |
| void rollBackToInitialMultiColumnLayoutState(LayoutFlowThread& flowThread) { |
| flowThread.restoreMultiColumnLayoutState(m_multiColumnLayoutState); |
| } |
| |
| const MarginInfo& marginInfo() const { return m_marginInfo; } |
| MarginInfo& marginInfo() { return m_marginInfo; } |
| LayoutUnit& previousFloatLogicalBottom() { |
| return m_previousFloatLogicalBottom; |
| } |
| |
| EBreakBetween previousBreakAfterValue() const { |
| return m_previousBreakAfterValue; |
| } |
| void setPreviousBreakAfterValue(EBreakBetween value) { |
| m_previousBreakAfterValue = value; |
| } |
| |
| bool isAtFirstInFlowChild() const { return m_isAtFirstInFlowChild; } |
| void clearIsAtFirstInFlowChild() { m_isAtFirstInFlowChild = false; } |
| |
| private: |
| MultiColumnLayoutState m_multiColumnLayoutState; |
| MarginInfo m_marginInfo; |
| LayoutUnit m_previousFloatLogicalBottom; |
| EBreakBetween m_previousBreakAfterValue; |
| bool m_isAtFirstInFlowChild; |
| }; |
| |
| LayoutBlockFlow::LayoutBlockFlow(ContainerNode* node) : LayoutBlock(node) { |
| static_assert(sizeof(MarginInfo) == sizeof(SameSizeAsMarginInfo), |
| "MarginInfo should stay small"); |
| setChildrenInline(true); |
| } |
| |
| LayoutBlockFlow::~LayoutBlockFlow() {} |
| |
| LayoutBlockFlow* LayoutBlockFlow::createAnonymous(Document* document) { |
| LayoutBlockFlow* layoutBlockFlow = new LayoutBlockFlow(nullptr); |
| layoutBlockFlow->setDocumentForAnonymous(document); |
| return layoutBlockFlow; |
| } |
| |
| LayoutObject* LayoutBlockFlow::layoutSpecialExcludedChild( |
| bool relayoutChildren, |
| SubtreeLayoutScope& layoutScope) { |
| LayoutMultiColumnFlowThread* flowThread = multiColumnFlowThread(); |
| if (!flowThread) |
| return nullptr; |
| setLogicalTopForChild(*flowThread, borderBefore() + paddingBefore()); |
| flowThread->layoutColumns(layoutScope); |
| determineLogicalLeftPositionForChild(*flowThread); |
| return flowThread; |
| } |
| |
| bool LayoutBlockFlow::updateLogicalWidthAndColumnWidth() { |
| bool relayoutChildren = LayoutBlock::updateLogicalWidthAndColumnWidth(); |
| if (LayoutMultiColumnFlowThread* flowThread = multiColumnFlowThread()) { |
| if (flowThread->needsNewWidth()) |
| return true; |
| } |
| return relayoutChildren; |
| } |
| |
| void LayoutBlockFlow::setBreakAtLineToAvoidWidow(int lineToBreak) { |
| ASSERT(lineToBreak >= 0); |
| ensureRareData(); |
| ASSERT(!m_rareData->m_didBreakAtLineToAvoidWidow); |
| m_rareData->m_lineBreakToAvoidWidow = lineToBreak; |
| } |
| |
| void LayoutBlockFlow::setDidBreakAtLineToAvoidWidow() { |
| ASSERT(!shouldBreakAtLineToAvoidWidow()); |
| |
| // This function should be called only after a break was applied to avoid |
| // widows so assert |m_rareData| exists. |
| ASSERT(m_rareData); |
| |
| m_rareData->m_didBreakAtLineToAvoidWidow = true; |
| } |
| |
| void LayoutBlockFlow::clearDidBreakAtLineToAvoidWidow() { |
| if (!m_rareData) |
| return; |
| |
| m_rareData->m_didBreakAtLineToAvoidWidow = false; |
| } |
| |
| void LayoutBlockFlow::clearShouldBreakAtLineToAvoidWidow() const { |
| ASSERT(shouldBreakAtLineToAvoidWidow()); |
| if (!m_rareData) |
| return; |
| |
| m_rareData->m_lineBreakToAvoidWidow = -1; |
| } |
| |
| bool LayoutBlockFlow::isSelfCollapsingBlock() const { |
| if (needsLayout()) { |
| // Sometimes we don't lay out objects in DOM order (column spanners being |
| // one such relevant type of object right here). As long as the object in |
| // question establishes a new formatting context, that's nothing to worry |
| // about, though. |
| ASSERT(createsNewFormattingContext()); |
| return false; |
| } |
| ASSERT(!m_isSelfCollapsing == !checkIfIsSelfCollapsingBlock()); |
| return m_isSelfCollapsing; |
| } |
| |
| bool LayoutBlockFlow::checkIfIsSelfCollapsingBlock() const { |
| // We are not self-collapsing if we |
| // (a) have a non-zero height according to layout (an optimization to avoid |
| // wasting time) |
| // (b) have border/padding, |
| // (c) have a min-height |
| // (d) have specified that one of our margins can't collapse using a CSS |
| // extension |
| // (e) establish a new block formatting context. |
| |
| // The early exit must be done before we check for clean layout. |
| // We should be able to give a quick answer if the box is a relayout boundary. |
| // Being a relayout boundary implies a block formatting context, and also |
| // our internal layout shouldn't affect our container in any way. |
| if (createsNewFormattingContext()) |
| return false; |
| |
| // Placeholder elements are not laid out until the dimensions of their parent |
| // text control are known, so they don't get layout until their parent has had |
| // layout - this is unique in the layout tree and means when we call |
| // isSelfCollapsingBlock on them we find that they still need layout. |
| ASSERT(!needsLayout() || |
| (node() && node()->isElementNode() && |
| toElement(node())->shadowPseudoId() == "-webkit-input-placeholder")); |
| |
| if (logicalHeight() > LayoutUnit() || borderAndPaddingLogicalHeight() || |
| style()->logicalMinHeight().isPositive() || |
| style()->marginBeforeCollapse() == MarginCollapseSeparate || |
| style()->marginAfterCollapse() == MarginCollapseSeparate) |
| return false; |
| |
| Length logicalHeightLength = style()->logicalHeight(); |
| bool hasAutoHeight = logicalHeightLength.isAuto(); |
| if (logicalHeightLength.isPercentOrCalc() && !document().inQuirksMode()) { |
| hasAutoHeight = true; |
| for (LayoutBlock* cb = containingBlock(); !cb->isLayoutView(); |
| cb = cb->containingBlock()) { |
| if (cb->style()->logicalHeight().isFixed() || cb->isTableCell()) |
| hasAutoHeight = false; |
| } |
| } |
| |
| // If the height is 0 or auto, then whether or not we are a self-collapsing |
| // block depends on whether we have content that is all self-collapsing. |
| // TODO(alancutter): Make this work correctly for calc lengths. |
| if (hasAutoHeight || ((logicalHeightLength.isFixed() || |
| logicalHeightLength.isPercentOrCalc()) && |
| logicalHeightLength.isZero())) { |
| // If the block has inline children, see if we generated any line boxes. |
| // If we have any line boxes, then we can't be self-collapsing, since we |
| // have content. |
| if (childrenInline()) |
| return !firstLineBox(); |
| |
| // Whether or not we collapse is dependent on whether all our normal flow |
| // children are also self-collapsing. |
| for (LayoutBox* child = firstChildBox(); child; |
| child = child->nextSiblingBox()) { |
| if (child->isFloatingOrOutOfFlowPositioned() || child->isColumnSpanAll()) |
| continue; |
| if (!child->isSelfCollapsingBlock()) |
| return false; |
| } |
| return true; |
| } |
| return false; |
| } |
| |
| DISABLE_CFI_PERF |
| void LayoutBlockFlow::layoutBlock(bool relayoutChildren) { |
| ASSERT(needsLayout()); |
| ASSERT(isInlineBlockOrInlineTable() || !isInline()); |
| |
| if (!relayoutChildren && simplifiedLayout()) |
| return; |
| |
| LayoutAnalyzer::BlockScope analyzer(*this); |
| SubtreeLayoutScope layoutScope(*this); |
| |
| LayoutUnit previousHeight = logicalHeight(); |
| LayoutUnit oldLeft = logicalLeft(); |
| bool logicalWidthChanged = updateLogicalWidthAndColumnWidth(); |
| relayoutChildren |= logicalWidthChanged; |
| |
| TextAutosizer::LayoutScope textAutosizerLayoutScope(this, &layoutScope); |
| |
| bool paginationStateChanged = m_paginationStateChanged; |
| bool preferredLogicalWidthsWereDirty = preferredLogicalWidthsDirty(); |
| |
| // Multiple passes might be required for column based layout. |
| // The number of passes could be as high as the number of columns. |
| LayoutMultiColumnFlowThread* flowThread = multiColumnFlowThread(); |
| do { |
| LayoutState state(*this, logicalWidthChanged); |
| if (m_paginationStateChanged) { |
| // We now need a deep layout to clean up struts after pagination, if we |
| // just ceased to be paginated, or, if we just became paginated on the |
| // other hand, we now need the deep layout, to insert pagination struts. |
| m_paginationStateChanged = false; |
| state.setPaginationStateChanged(); |
| } |
| |
| layoutChildren(relayoutChildren, layoutScope); |
| |
| if (!preferredLogicalWidthsWereDirty && preferredLogicalWidthsDirty()) { |
| // The only thing that should dirty preferred widths at this point is the |
| // addition of overflow:auto scrollbars in a descendant. To avoid a |
| // potential infinite loop, run layout again with auto scrollbars frozen |
| // in their current state. |
| PaintLayerScrollableArea::FreezeScrollbarsScope freezeScrollbars; |
| relayoutChildren |= updateLogicalWidthAndColumnWidth(); |
| layoutChildren(relayoutChildren, layoutScope); |
| } |
| |
| if (flowThread && flowThread->columnHeightsChanged()) { |
| setChildNeedsLayout(MarkOnlyThis); |
| continue; |
| } |
| |
| if (shouldBreakAtLineToAvoidWidow()) { |
| setEverHadLayout(); |
| continue; |
| } |
| break; |
| } while (true); |
| |
| LayoutState state(*this, logicalWidthChanged); |
| if (paginationStateChanged) { |
| // We still haven't laid out positioned descendants, and we need to perform |
| // a deep layout on those too if pagination state changed. |
| state.setPaginationStateChanged(); |
| } |
| |
| // Remember the automatic logical height we got from laying out the children. |
| LayoutUnit unconstrainedHeight = logicalHeight(); |
| LayoutUnit unconstrainedClientAfterEdge = clientLogicalBottom(); |
| |
| // Adjust logical height to satisfy whatever computed style requires. |
| updateLogicalHeight(); |
| |
| if (!childrenInline()) |
| addOverhangingFloatsFromChildren(unconstrainedHeight); |
| |
| if (logicalHeight() != previousHeight || isDocumentElement()) |
| relayoutChildren = true; |
| |
| PositionedLayoutBehavior behavior = DefaultLayout; |
| if (oldLeft != logicalLeft()) |
| behavior = ForcedLayoutAfterContainingBlockMoved; |
| layoutPositionedObjects(relayoutChildren, behavior); |
| |
| // Add overflow from children. |
| computeOverflow(unconstrainedClientAfterEdge); |
| |
| m_descendantsWithFloatsMarkedForLayout = false; |
| |
| updateLayerTransformAfterLayout(); |
| |
| updateAfterLayout(); |
| |
| if (isHTMLDialogElement(node()) && isOutOfFlowPositioned()) |
| positionDialog(); |
| |
| clearNeedsLayout(); |
| updateIsSelfCollapsing(); |
| } |
| |
| DISABLE_CFI_PERF |
| void LayoutBlockFlow::resetLayout() { |
| if (!firstChild() && !isAnonymousBlock()) |
| setChildrenInline(true); |
| setContainsInlineWithOutlineAndContinuation(false); |
| |
| rebuildFloatsFromIntruding(); |
| |
| // We use four values, maxTopPos, maxTopNeg, maxBottomPos, and maxBottomNeg, |
| // to track our current maximal positive and negative margins. These values |
| // are used when we are collapsed with adjacent blocks, so for example, if you |
| // have block A and B collapsing together, then you'd take the maximal |
| // positive margin from both A and B and subtract it from the maximal negative |
| // margin from both A and B to get the true collapsed margin. This algorithm |
| // is recursive, so when we finish layout() our block knows its current |
| // maximal positive/negative values. |
| // |
| // Start out by setting our margin values to our current margins. Table cells |
| // have no margins, so we don't fill in the values for table cells. |
| if (!isTableCell()) { |
| initMaxMarginValues(); |
| setHasMarginBeforeQuirk(style()->hasMarginBeforeQuirk()); |
| setHasMarginAfterQuirk(style()->hasMarginAfterQuirk()); |
| } |
| |
| if (view()->layoutState()->isPaginated()) { |
| setPaginationStrutPropagatedFromChild(LayoutUnit()); |
| setFirstForcedBreakOffset(LayoutUnit()); |
| |
| // Start with any applicable computed break-after and break-before values |
| // for this object. During child layout, breakBefore will be joined with the |
| // breakBefore value of the first in-flow child, and breakAfter will be |
| // joined with the breakAfter value of the last in-flow child. This is done |
| // in order to honor the requirement that a class A break point [1] may only |
| // exists *between* in-flow siblings (i.e. not before the first child and |
| // not after the last child). |
| // |
| // [1] https://drafts.csswg.org/css-break/#possible-breaks |
| setBreakBefore(LayoutBlock::breakBefore()); |
| setBreakAfter(LayoutBlock::breakAfter()); |
| } |
| } |
| |
| DISABLE_CFI_PERF |
| void LayoutBlockFlow::layoutChildren(bool relayoutChildren, |
| SubtreeLayoutScope& layoutScope) { |
| resetLayout(); |
| |
| LayoutUnit beforeEdge = borderBefore() + paddingBefore(); |
| LayoutUnit afterEdge = |
| borderAfter() + paddingAfter() + scrollbarLogicalHeight(); |
| setLogicalHeight(beforeEdge); |
| |
| if (childrenInline()) |
| layoutInlineChildren(relayoutChildren, afterEdge); |
| else |
| layoutBlockChildren(relayoutChildren, layoutScope, beforeEdge, afterEdge); |
| |
| // Expand our intrinsic height to encompass floats. |
| if (lowestFloatLogicalBottom() > (logicalHeight() - afterEdge) && |
| createsNewFormattingContext()) |
| setLogicalHeight(lowestFloatLogicalBottom() + afterEdge); |
| } |
| |
| void LayoutBlockFlow::addOverhangingFloatsFromChildren( |
| LayoutUnit unconstrainedHeight) { |
| LayoutBlockFlow* lowestBlock = nullptr; |
| bool addedOverhangingFloats = false; |
| // One of our children's floats may have become an overhanging float for us. |
| for (LayoutObject* child = lastChild(); child; |
| child = child->previousSibling()) { |
| // TODO(robhogan): We should exclude blocks that create formatting |
| // contexts, not just out of flow or floating blocks. |
| if (child->isLayoutBlockFlow() && |
| !child->isFloatingOrOutOfFlowPositioned()) { |
| LayoutBlockFlow* block = toLayoutBlockFlow(child); |
| if (!block->containsFloats()) |
| continue; |
| lowestBlock = block; |
| if (unconstrainedHeight <= logicalHeight()) |
| break; |
| LayoutUnit logicalBottom = |
| block->logicalTop() + block->lowestFloatLogicalBottom(); |
| if (logicalBottom <= logicalHeight()) |
| break; |
| addOverhangingFloats(block, false); |
| addedOverhangingFloats = true; |
| } |
| } |
| // If we have no overhanging floats we still pass a record of the lowest |
| // non-overhanging float up the tree so we can enclose it if we are a |
| // formatting context and allow siblings to avoid it if they have negative |
| // margin and find themselves in its vicinity. |
| if (!addedOverhangingFloats) |
| addLowestFloatFromChildren(lowestBlock); |
| } |
| |
| void LayoutBlockFlow::addLowestFloatFromChildren(LayoutBlockFlow* block) { |
| // TODO(robhogan): Make createsNewFormattingContext an ASSERT. |
| if (!block || !block->containsFloats() || |
| block->createsNewFormattingContext()) |
| return; |
| |
| FloatingObject* floatingObject = |
| block->m_floatingObjects->lowestFloatingObject(); |
| if (!floatingObject || containsFloat(floatingObject->layoutObject())) |
| return; |
| |
| LayoutSize offset(-block->logicalLeft(), -block->logicalTop()); |
| if (!isHorizontalWritingMode()) |
| offset = offset.transposedSize(); |
| |
| if (!m_floatingObjects) |
| createFloatingObjects(); |
| FloatingObject* newFloatingObject = m_floatingObjects->add( |
| floatingObject->copyToNewContainer(offset, false, true)); |
| newFloatingObject->setIsLowestNonOverhangingFloatInChild(true); |
| } |
| |
| DISABLE_CFI_PERF |
| void LayoutBlockFlow::determineLogicalLeftPositionForChild(LayoutBox& child) { |
| LayoutUnit startPosition = borderStart() + paddingStart(); |
| LayoutUnit initialStartPosition = startPosition; |
| if (shouldPlaceBlockDirectionScrollbarOnLogicalLeft()) |
| startPosition -= verticalScrollbarWidth(); |
| LayoutUnit totalAvailableLogicalWidth = |
| borderAndPaddingLogicalWidth() + availableLogicalWidth(); |
| |
| LayoutUnit childMarginStart = marginStartForChild(child); |
| LayoutUnit newPosition = startPosition + childMarginStart; |
| |
| if (child.avoidsFloats() && containsFloats()) { |
| LayoutUnit positionToAvoidFloats = |
| startOffsetForLine(logicalTopForChild(child), DoNotIndentText, |
| logicalHeightForChild(child)); |
| |
| // If the child has an offset from the content edge to avoid floats then use |
| // that, otherwise let any negative margin pull it back over the content |
| // edge or any positive margin push it out. |
| // If the child is being centred then the margin calculated to do that has |
| // factored in any offset required to avoid floats, so use it if necessary. |
| if (style()->textAlign() == ETextAlign::kWebkitCenter || |
| child.style()->marginStartUsing(style()).isAuto()) |
| newPosition = |
| std::max(newPosition, positionToAvoidFloats + childMarginStart); |
| else if (positionToAvoidFloats > initialStartPosition) |
| newPosition = std::max(newPosition, positionToAvoidFloats); |
| } |
| |
| setLogicalLeftForChild(child, style()->isLeftToRightDirection() |
| ? newPosition |
| : totalAvailableLogicalWidth - newPosition - |
| logicalWidthForChild(child)); |
| } |
| |
| void LayoutBlockFlow::setLogicalLeftForChild(LayoutBox& child, |
| LayoutUnit logicalLeft) { |
| if (isHorizontalWritingMode()) { |
| child.setX(logicalLeft); |
| } else { |
| child.setY(logicalLeft); |
| } |
| } |
| |
| void LayoutBlockFlow::setLogicalTopForChild(LayoutBox& child, |
| LayoutUnit logicalTop) { |
| if (isHorizontalWritingMode()) { |
| child.setY(logicalTop); |
| } else { |
| child.setX(logicalTop); |
| } |
| } |
| |
| void LayoutBlockFlow::markDescendantsWithFloatsForLayoutIfNeeded( |
| LayoutBlockFlow& child, |
| LayoutUnit newLogicalTop, |
| LayoutUnit previousFloatLogicalBottom) { |
| // TODO(mstensho): rework the code to return early when there is no need for |
| // marking, instead of this |markDescendantsWithFloats| flag. |
| bool markDescendantsWithFloats = false; |
| if (newLogicalTop != child.logicalTop() && !child.avoidsFloats() && |
| child.containsFloats()) { |
| markDescendantsWithFloats = true; |
| } else if (UNLIKELY(newLogicalTop.mightBeSaturated())) { |
| // The logical top might be saturated for very large elements. Comparing |
| // with the old logical top might then yield a false negative, as adding and |
| // removing margins, borders etc. from a saturated number might yield |
| // incorrect results. If this is the case, always mark for layout. |
| markDescendantsWithFloats = true; |
| } else if (!child.avoidsFloats() || child.shrinkToAvoidFloats()) { |
| // If an element might be affected by the presence of floats, then always |
| // mark it for layout. |
| if (std::max(previousFloatLogicalBottom, lowestFloatLogicalBottom()) > |
| newLogicalTop) |
| markDescendantsWithFloats = true; |
| } |
| |
| if (markDescendantsWithFloats) |
| child.markAllDescendantsWithFloatsForLayout(); |
| } |
| |
| bool LayoutBlockFlow::positionAndLayoutOnceIfNeeded( |
| LayoutBox& child, |
| LayoutUnit newLogicalTop, |
| BlockChildrenLayoutInfo& layoutInfo) { |
| if (LayoutFlowThread* flowThread = flowThreadContainingBlock()) |
| layoutInfo.rollBackToInitialMultiColumnLayoutState(*flowThread); |
| |
| if (child.isLayoutBlockFlow()) { |
| LayoutUnit& previousFloatLogicalBottom = |
| layoutInfo.previousFloatLogicalBottom(); |
| LayoutBlockFlow& childBlockFlow = toLayoutBlockFlow(child); |
| if (childBlockFlow.containsFloats() || containsFloats()) |
| markDescendantsWithFloatsForLayoutIfNeeded(childBlockFlow, newLogicalTop, |
| previousFloatLogicalBottom); |
| |
| // TODO(mstensho): A writing mode root is one thing, but we should be able |
| // to skip anything that establishes a new block formatting context here. |
| // Their floats don't affect us. |
| if (!childBlockFlow.isWritingModeRoot()) |
| previousFloatLogicalBottom = |
| std::max(previousFloatLogicalBottom, |
| childBlockFlow.logicalTop() + |
| childBlockFlow.lowestFloatLogicalBottom()); |
| } |
| |
| LayoutUnit oldLogicalTop = logicalTopForChild(child); |
| setLogicalTopForChild(child, newLogicalTop); |
| |
| SubtreeLayoutScope layoutScope(child); |
| if (!child.needsLayout()) { |
| if (newLogicalTop != oldLogicalTop && child.shrinkToAvoidFloats()) { |
| // The child's width is affected by adjacent floats. When the child shifts |
| // to clear an item, its width can change (because it has more available |
| // width). |
| layoutScope.setChildNeedsLayout(&child); |
| } else { |
| markChildForPaginationRelayoutIfNeeded(child, layoutScope); |
| } |
| } |
| |
| bool neededLayout = child.needsLayout(); |
| if (neededLayout) |
| child.layout(); |
| if (view()->layoutState()->isPaginated()) |
| updateFragmentationInfoForChild(child); |
| return neededLayout; |
| } |
| |
| void LayoutBlockFlow::insertForcedBreakBeforeChildIfNeeded( |
| LayoutBox& child, |
| BlockChildrenLayoutInfo& layoutInfo) { |
| if (layoutInfo.isAtFirstInFlowChild()) { |
| // There's no class A break point before the first child (only *between* |
| // siblings), so steal its break value and join it with what we already have |
| // here. |
| setBreakBefore( |
| joinFragmentainerBreakValues(breakBefore(), child.breakBefore())); |
| return; |
| } |
| |
| // Figure out if a forced break should be inserted in front of the child. If |
| // we insert a forced break, the margins on this child may not collapse with |
| // those preceding the break. |
| EBreakBetween classABreakPointValue = |
| child.classABreakPointValue(layoutInfo.previousBreakAfterValue()); |
| if (isForcedFragmentainerBreakValue(classABreakPointValue)) { |
| layoutInfo.marginInfo().clearMargin(); |
| LayoutUnit oldLogicalTop = logicalHeight(); |
| LayoutUnit newLogicalTop = |
| applyForcedBreak(oldLogicalTop, classABreakPointValue); |
| setLogicalHeight(newLogicalTop); |
| LayoutUnit paginationStrut = newLogicalTop - oldLogicalTop; |
| child.setPaginationStrut(paginationStrut); |
| } |
| } |
| |
| void LayoutBlockFlow::layoutBlockChild(LayoutBox& child, |
| BlockChildrenLayoutInfo& layoutInfo) { |
| MarginInfo& marginInfo = layoutInfo.marginInfo(); |
| LayoutBlockFlow* childLayoutBlockFlow = |
| child.isLayoutBlockFlow() ? toLayoutBlockFlow(&child) : nullptr; |
| LayoutUnit oldPosMarginBefore = maxPositiveMarginBefore(); |
| LayoutUnit oldNegMarginBefore = maxNegativeMarginBefore(); |
| |
| // The child is a normal flow object. Compute the margins we will use for |
| // collapsing now. |
| child.computeAndSetBlockDirectionMargins(this); |
| |
| // Try to guess our correct logical top position. In most cases this guess |
| // will be correct. Only if we're wrong (when we compute the real logical top |
| // position) will we have to potentially relayout. |
| LayoutUnit estimateWithoutPagination; |
| LayoutUnit logicalTopEstimate = |
| estimateLogicalTopPosition(child, layoutInfo, estimateWithoutPagination); |
| |
| LayoutRect oldRect = child.frameRect(); |
| |
| if (LayoutFlowThread* flowThread = flowThreadContainingBlock()) |
| layoutInfo.storeMultiColumnLayoutState(*flowThread); |
| |
| // Use the estimated block position and lay out the child if needed. After |
| // child layout, when we have enough information to perform proper margin |
| // collapsing, float clearing and pagination, we may have to reposition and |
| // lay out again if the estimate was wrong. |
| bool childNeededLayout = |
| positionAndLayoutOnceIfNeeded(child, logicalTopEstimate, layoutInfo); |
| |
| // Cache if we are at the top of the block right now. |
| bool atBeforeSideOfBlock = marginInfo.atBeforeSideOfBlock(); |
| bool childIsSelfCollapsing = child.isSelfCollapsingBlock(); |
| bool childDiscardMarginBefore = mustDiscardMarginBeforeForChild(child); |
| bool childDiscardMarginAfter = mustDiscardMarginAfterForChild(child); |
| bool paginated = view()->layoutState()->isPaginated(); |
| |
| // If there should be a forced break before the child, we need to insert it |
| // before attempting to collapse margins or apply clearance. |
| if (paginated) { |
| // We will now insert the strut needed by any forced break. After this |
| // operation, we will have calculated the offset where we can apply margin |
| // collapsing and clearance. After having applied those things, we'll be at |
| // the position where we can honor requirements of unbreakable content, |
| // which may extend the strut further. |
| child.resetPaginationStrut(); |
| insertForcedBreakBeforeChildIfNeeded(child, layoutInfo); |
| } |
| |
| // Now determine the correct ypos based off examination of collapsing margin |
| // values. |
| LayoutUnit logicalTopBeforeClear = |
| collapseMargins(child, layoutInfo, childIsSelfCollapsing, |
| childDiscardMarginBefore, childDiscardMarginAfter); |
| |
| // Now check for clear. |
| bool childDiscardMargin = childDiscardMarginBefore || childDiscardMarginAfter; |
| LayoutUnit newLogicalTop = clearFloatsIfNeeded( |
| child, marginInfo, oldPosMarginBefore, oldNegMarginBefore, |
| logicalTopBeforeClear, childIsSelfCollapsing, childDiscardMargin); |
| |
| // If there's a forced break in front of this child, its final position has |
| // already been determined. Otherwise, see if there are other reasons for |
| // breaking before it (break-inside:avoid, or not enough space for the first |
| // piece of child content to fit in the current fragmentainer), and adjust the |
| // position accordingly. |
| if (paginated) { |
| if (estimateWithoutPagination != newLogicalTop) { |
| // We got a new position due to clearance or margin collapsing. Before we |
| // attempt to paginate (which may result in the position changing again), |
| // let's try again at the new position (since a new position may result in |
| // a new logical height). |
| positionAndLayoutOnceIfNeeded(child, newLogicalTop, layoutInfo); |
| } |
| |
| // We have now applied forced breaks, margin collapsing and clearance, and |
| // we're at the position where we can honor requirements of unbreakable |
| // content. |
| newLogicalTop = adjustBlockChildForPagination( |
| newLogicalTop, child, layoutInfo, |
| atBeforeSideOfBlock && logicalTopBeforeClear == newLogicalTop); |
| } |
| |
| // Clearance, margin collapsing or pagination may have given us a new logical |
| // top, in which case we may have to reposition and possibly relayout as well. |
| // If we determined during child layout that we need to insert a break to |
| // honor widows, we also need to relayout. |
| if (newLogicalTop != logicalTopEstimate || child.needsLayout() || |
| (paginated && childLayoutBlockFlow && |
| childLayoutBlockFlow->shouldBreakAtLineToAvoidWidow())) { |
| positionAndLayoutOnceIfNeeded(child, newLogicalTop, layoutInfo); |
| } |
| |
| // If we previously encountered a self-collapsing sibling of this child that |
| // had clearance then we set this bit to ensure we would not collapse the |
| // child's margins, and those of any subsequent self-collapsing siblings, with |
| // our parent. If this child is not self-collapsing then it can collapse its |
| // margins with the parent so reset the bit. |
| if (!marginInfo.canCollapseMarginAfterWithLastChild() && |
| !childIsSelfCollapsing) |
| marginInfo.setCanCollapseMarginAfterWithLastChild(true); |
| |
| // We are no longer at the top of the block if we encounter a non-empty child. |
| // This has to be done after checking for clear, so that margins can be reset |
| // if a clear occurred. |
| if (marginInfo.atBeforeSideOfBlock() && !childIsSelfCollapsing) |
| marginInfo.setAtBeforeSideOfBlock(false); |
| |
| // Now place the child in the correct left position |
| determineLogicalLeftPositionForChild(child); |
| |
| LayoutSize childOffset = child.location() - oldRect.location(); |
| |
| // Update our height now that the child has been placed in the correct |
| // position. |
| setLogicalHeight(logicalHeight() + logicalHeightForChild(child)); |
| if (mustSeparateMarginAfterForChild(child)) { |
| setLogicalHeight(logicalHeight() + marginAfterForChild(child)); |
| marginInfo.clearMargin(); |
| } |
| // If the child has overhanging floats that intrude into following siblings |
| // (or possibly out of this block), then the parent gets notified of the |
| // floats now. |
| if (childLayoutBlockFlow) |
| addOverhangingFloats(childLayoutBlockFlow, !childNeededLayout); |
| |
| // If the child moved, we have to invalidate its paint as well as any |
| // floating/positioned descendants. An exception is if we need a layout. |
| // In this case, we know we're going to invalidate our paint (and the child) |
| // anyway. |
| if (!selfNeedsLayout() && (childOffset.width() || childOffset.height()) && |
| child.isLayoutBlockFlow()) |
| BlockFlowPaintInvalidator(toLayoutBlockFlow(child)) |
| .invalidatePaintForOverhangingFloats(); |
| |
| if (paginated) { |
| // Keep track of the break-after value of the child, so that it can be |
| // joined with the break-before value of the next in-flow object at the next |
| // class A break point. |
| layoutInfo.setPreviousBreakAfterValue(child.breakAfter()); |
| |
| paginatedContentWasLaidOut(child.logicalBottom()); |
| |
| if (childLayoutBlockFlow) { |
| // If a forced break was inserted inside the child, translate and |
| // propagate the offset to this object. |
| if (LayoutUnit offset = childLayoutBlockFlow->firstForcedBreakOffset()) |
| setFirstForcedBreakOffset(offset + newLogicalTop); |
| } |
| } |
| |
| if (child.isLayoutMultiColumnSpannerPlaceholder()) { |
| // The actual column-span:all element is positioned by this placeholder |
| // child. |
| positionSpannerDescendant(toLayoutMultiColumnSpannerPlaceholder(child)); |
| } |
| } |
| |
| LayoutUnit LayoutBlockFlow::adjustBlockChildForPagination( |
| LayoutUnit logicalTop, |
| LayoutBox& child, |
| BlockChildrenLayoutInfo& layoutInfo, |
| bool atBeforeSideOfBlock) { |
| LayoutBlockFlow* childBlockFlow = |
| child.isLayoutBlockFlow() ? toLayoutBlockFlow(&child) : 0; |
| |
| // See if we need a soft (unforced) break in front of this child, and set the |
| // pagination strut in that case. An unforced break may come from two sources: |
| // 1. The first piece of content inside the child doesn't fit in the current |
| // page or column |
| // 2. The child itself has breaking restrictions (break-inside:avoid, replaced |
| // content, etc.) and doesn't fully fit in the current page or column. |
| // |
| // No matter which source, if we need to insert a strut, it should always take |
| // us to the exact top of a page or column further ahead, or be zero. |
| |
| // The first piece of content inside the child may have set a strut during |
| // layout. Currently, only block flows support strut propagation, but this may |
| // (and should) change in the future. See crbug.com/539873 |
| LayoutUnit strutFromContent = |
| childBlockFlow ? childBlockFlow->paginationStrutPropagatedFromChild() |
| : LayoutUnit(); |
| LayoutUnit logicalTopWithContentStrut = logicalTop + strutFromContent; |
| |
| LayoutUnit logicalTopAfterUnsplittable = |
| adjustForUnsplittableChild(child, logicalTop); |
| |
| // Pick the largest offset. Tall unsplittable content may take us to a page or |
| // column further ahead than the next one. |
| LayoutUnit logicalTopAfterPagination = |
| std::max(logicalTopWithContentStrut, logicalTopAfterUnsplittable); |
| LayoutUnit newLogicalTop = logicalTop; |
| |
| // Forced breaks may already have caused a strut, and this needs to be added |
| // together with any strut detected here in this method. |
| LayoutUnit previousStrut = child.paginationStrut(); |
| |
| if (LayoutUnit paginationStrut = |
| logicalTopAfterPagination - logicalTop + previousStrut) { |
| ASSERT(paginationStrut > 0); |
| // If we're not at the first in-flow child, there's a class A break point |
| // before the child. If we *are* at the first in-flow child, but the child |
| // isn't flush with the content edge of its container, due to e.g. |
| // clearance, there's a class C break point before the child. Otherwise we |
| // should propagate the strut to our parent block, and attempt to break |
| // there instead. See https://drafts.csswg.org/css-break/#possible-breaks |
| bool canBreak = !layoutInfo.isAtFirstInFlowChild() || !atBeforeSideOfBlock; |
| if (!canBreak && child.getPaginationBreakability() == ForbidBreaks && |
| !allowsPaginationStrut()) { |
| // The child is monolithic content, e.g. an image. It is truly |
| // unsplittable. Breaking inside it would be bad. Since this block doesn't |
| // allow pagination struts to be propagated to it, we're left to handle it |
| // on our own right here. Break before the child, even if we're currently |
| // at the block start (i.e. there's no class A or C break point here). |
| canBreak = true; |
| } |
| if (canBreak) { |
| child.setPaginationStrut(paginationStrut); |
| // |previousStrut| was already baked into the logical top, so don't add |
| // it again. |
| newLogicalTop += paginationStrut - previousStrut; |
| } else { |
| // No valid break point here. Propagate the strut from the child to this |
| // block, but only if the block allows it. If the block doesn't allow it, |
| // we'll just ignore the strut and carry on, without breaking. This |
| // happens e.g. when a tall break-inside:avoid object with a top margin is |
| // the first in-flow child in the fragmentation context. |
| if (allowsPaginationStrut()) { |
| paginationStrut += logicalTop; |
| setPaginationStrutPropagatedFromChild(paginationStrut); |
| if (childBlockFlow) |
| childBlockFlow->setPaginationStrutPropagatedFromChild(LayoutUnit()); |
| } |
| child.resetPaginationStrut(); |
| } |
| } |
| |
| // Similar to how we apply clearance. Go ahead and boost height() to be the |
| // place where we're going to position the child. |
| setLogicalHeight(logicalHeight() + (newLogicalTop - logicalTop)); |
| |
| // Return the final adjusted logical top. |
| return newLogicalTop; |
| } |
| |
| LayoutUnit LayoutBlockFlow::adjustFloatLogicalTopForPagination( |
| LayoutBox& child, |
| LayoutUnit logicalTopMarginEdge) { |
| // The first piece of content inside the child may have set a strut during |
| // layout. |
| LayoutUnit strut; |
| if (child.isLayoutBlockFlow()) |
| strut = toLayoutBlockFlow(child).paginationStrutPropagatedFromChild(); |
| |
| LayoutUnit marginBefore = marginBeforeForChild(child); |
| if (marginBefore > LayoutUnit()) { |
| // Avoid breaking inside the top margin of a float. |
| if (strut) { |
| // If we already had decided to break, just add the margin. The strut so |
| // far only accounts for pushing the top border edge to the next |
| // fragmentainer. We need to push the margin over as well, because |
| // there's no break opportunity between margin and border. |
| strut += marginBefore; |
| } else { |
| // Even if we didn't break before the border box to the next |
| // fragmentainer, we need to check if we can fit the margin before it. |
| if (pageLogicalHeightForOffset(logicalTopMarginEdge)) { |
| LayoutUnit remainingSpace = pageRemainingLogicalHeightForOffset( |
| logicalTopMarginEdge, AssociateWithLatterPage); |
| if (remainingSpace <= marginBefore) { |
| strut += calculatePaginationStrutToFitContent( |
| logicalTopMarginEdge, remainingSpace, marginBefore); |
| } |
| } |
| } |
| } |
| if (!strut) { |
| // If we are unsplittable and don't fit, move to the next page or column |
| // if that helps the situation. |
| LayoutUnit newLogicalTopMarginEdge = |
| adjustForUnsplittableChild(child, logicalTopMarginEdge); |
| strut = newLogicalTopMarginEdge - logicalTopMarginEdge; |
| } |
| |
| child.setPaginationStrut(strut); |
| return logicalTopMarginEdge + strut; |
| } |
| |
| static bool shouldSetStrutOnBlock(const LayoutBlockFlow& block, |
| const RootInlineBox& lineBox, |
| LayoutUnit lineLogicalOffset, |
| int lineIndex, |
| LayoutUnit pageLogicalHeight) { |
| if (lineBox == block.firstRootBox()) { |
| // This is the first line in the block. We can take the whole block with us |
| // to the next page or column, rather than keeping a content-less portion of |
| // it in the previous one. Only do this if the line is flush with the |
| // content edge of the block, though. If it isn't, it means that the line |
| // was pushed downwards by preceding floats that didn't fit beside the line, |
| // and we don't want to move all that, since it has already been established |
| // that it fits nicely where it is. In this case we have a class "C" break |
| // point [1] in front of this line. |
| // |
| // [1] https://drafts.csswg.org/css-break/#possible-breaks |
| if (lineLogicalOffset > block.borderAndPaddingBefore()) |
| return false; |
| |
| LayoutUnit lineHeight = |
| lineBox.lineBottomWithLeading() - lineBox.lineTopWithLeading(); |
| LayoutUnit totalLogicalHeight = |
| lineHeight + lineLogicalOffset.clampNegativeToZero(); |
| // It's rather pointless to break before the block if the current line isn't |
| // going to fit in the same column or page, so check that as well. |
| if (totalLogicalHeight > pageLogicalHeight) |
| return false; |
| } else { |
| if (lineIndex > block.style()->orphans()) |
| return false; |
| |
| // Not enough orphans here. Push the entire block to the next column / page |
| // as an attempt to better satisfy the orphans requirement. |
| // |
| // Note that we should ideally check if the first line in the block is flush |
| // with the content edge of the block here, because if it isn't, we should |
| // break at the class "C" break point in front of the first line, rather |
| // than before the entire block. |
| } |
| return block.allowsPaginationStrut(); |
| } |
| |
| void LayoutBlockFlow::adjustLinePositionForPagination(RootInlineBox& lineBox, |
| LayoutUnit& delta) { |
| // TODO(mstensho): Pay attention to line overflow. It should be painted in the |
| // same column as the rest of the line, possibly overflowing the column. We |
| // currently only allow overflow above the first column. We clip at all other |
| // column boundaries, and that's how it has to be for now. The paint we have |
| // to do when a column has overflow has to be special. |
| // We need to exclude content that paints in a previous column (and content |
| // that paints in the following column). |
| // |
| // FIXME: Another problem with simply moving lines is that the available line |
| // width may change (because of floats). Technically if the location we move |
| // the line to has a different line width than our old position, then we need |
| // to dirty the line and all following lines. |
| LayoutUnit logicalOffset = lineBox.lineTopWithLeading(); |
| LayoutUnit lineHeight = lineBox.lineBottomWithLeading() - logicalOffset; |
| logicalOffset += delta; |
| lineBox.setPaginationStrut(LayoutUnit()); |
| lineBox.setIsFirstAfterPageBreak(false); |
| if (!view()->layoutState()->isPaginated()) |
| return; |
| LayoutUnit pageLogicalHeight = pageLogicalHeightForOffset(logicalOffset); |
| if (!pageLogicalHeight) |
| return; |
| LayoutUnit remainingLogicalHeight = pageRemainingLogicalHeightForOffset( |
| logicalOffset, AssociateWithLatterPage); |
| int lineIndex = lineCount(&lineBox); |
| if (remainingLogicalHeight < lineHeight || |
| (shouldBreakAtLineToAvoidWidow() && |
| lineBreakToAvoidWidow() == lineIndex)) { |
| LayoutUnit paginationStrut = calculatePaginationStrutToFitContent( |
| logicalOffset, remainingLogicalHeight, lineHeight); |
| LayoutUnit newLogicalOffset = logicalOffset + paginationStrut; |
| // Moving to a different page or column may mean that its height is |
| // different. |
| pageLogicalHeight = pageLogicalHeightForOffset(newLogicalOffset); |
| if (lineHeight > pageLogicalHeight) { |
| // Too tall to fit in one page / column. Give up. Don't push to the next |
| // page / column. |
| // TODO(mstensho): Get rid of this. This is just utter weirdness, but the |
| // other browsers also do something slightly similar, although in much |
| // more specific cases than we do here, and printing Google Docs depends |
| // on it. |
| paginatedContentWasLaidOut(logicalOffset + lineHeight); |
| return; |
| } |
| |
| // We need to insert a break now, either because there's no room for the |
| // line in the current column / page, or because we have determined that we |
| // need a break to satisfy widow requirements. |
| if (shouldBreakAtLineToAvoidWidow() && |
| lineBreakToAvoidWidow() == lineIndex) { |
| clearShouldBreakAtLineToAvoidWidow(); |
| setDidBreakAtLineToAvoidWidow(); |
| } |
| if (shouldSetStrutOnBlock(*this, lineBox, logicalOffset, lineIndex, |
| pageLogicalHeight)) { |
| // Note that when setting the strut on a block, it may be propagated to |
| // parent blocks later on, if a block's logical top is flush with that of |
| // its parent. We don't want content-less portions (struts) at the |
| // beginning of a block before a break, if it can be avoided. After all, |
| // that's the reason for setting struts on blocks and not lines in the |
| // first place. |
| setPaginationStrutPropagatedFromChild(paginationStrut + logicalOffset); |
| } else { |
| delta += paginationStrut; |
| lineBox.setPaginationStrut(paginationStrut); |
| lineBox.setIsFirstAfterPageBreak(true); |
| } |
| paginatedContentWasLaidOut(newLogicalOffset + lineHeight); |
| return; |
| } |
| |
| LayoutUnit strutToPropagate; |
| if (remainingLogicalHeight == pageLogicalHeight) { |
| // We're at the very top of a page or column. |
| if (lineBox != firstRootBox()) |
| lineBox.setIsFirstAfterPageBreak(true); |
| // If this is the first line in the block, and the block has a top border or |
| // padding, we may want to set a strut on the block, so that everything ends |
| // up in the next column or page. Setting a strut on the block is also |
| // important when it comes to satisfying orphan requirements. |
| if (shouldSetStrutOnBlock(*this, lineBox, logicalOffset, lineIndex, |
| pageLogicalHeight)) |
| strutToPropagate = logicalOffset; |
| } else if (lineBox == firstRootBox() && allowsPaginationStrut()) { |
| // This is the first line in the block. The block may still start in the |
| // previous column or page, and if that's the case, attempt to pull it over |
| // to where this line is, so that we don't split the top border or padding. |
| LayoutUnit strut = |
| remainingLogicalHeight + logicalOffset - pageLogicalHeight; |
| if (strut > LayoutUnit()) { |
| // The block starts in a previous column or page. Set a strut on the block |
| // if there's room for the top border, padding and the line in one column |
| // or page. |
| if (logicalOffset + lineHeight <= pageLogicalHeight) |
| strutToPropagate = strut; |
| } |
| } |
| |
| // If we found that some preceding content (lines, border and padding) belongs |
| // together with this line, we should pull the entire block with us to the |
| // fragmentainer we're currently in. We need to avoid this when the block |
| // precedes the first fragmentainer, though. We shouldn't fragment content |
| // there, but rather let it appear in the overflow area before the first |
| // fragmentainer. |
| if (strutToPropagate && offsetFromLogicalTopOfFirstPage() > LayoutUnit()) |
| setPaginationStrutPropagatedFromChild(strutToPropagate); |
| |
| paginatedContentWasLaidOut(logicalOffset + lineHeight); |
| } |
| |
| LayoutUnit LayoutBlockFlow::adjustForUnsplittableChild( |
| LayoutBox& child, |
| LayoutUnit logicalOffset) const { |
| if (child.getPaginationBreakability() == AllowAnyBreaks) |
| return logicalOffset; |
| LayoutUnit childLogicalHeight = logicalHeightForChild(child); |
| // Floats' margins do not collapse with page or column boundaries. |
| if (child.isFloating()) |
| childLogicalHeight += |
| marginBeforeForChild(child) + marginAfterForChild(child); |
| LayoutUnit pageLogicalHeight = pageLogicalHeightForOffset(logicalOffset); |
| if (!pageLogicalHeight) |
| return logicalOffset; |
| LayoutUnit remainingLogicalHeight = pageRemainingLogicalHeightForOffset( |
| logicalOffset, AssociateWithLatterPage); |
| if (remainingLogicalHeight >= childLogicalHeight) |
| return logicalOffset; // It fits fine where it is. No need to break. |
| LayoutUnit paginationStrut = calculatePaginationStrutToFitContent( |
| logicalOffset, remainingLogicalHeight, childLogicalHeight); |
| if (paginationStrut == remainingLogicalHeight && |
| remainingLogicalHeight == pageLogicalHeight) { |
| // Don't break if we were at the top of a page, and we failed to fit the |
| // content completely. No point in leaving a page completely blank. |
| return logicalOffset; |
| } |
| |
| if (child.isLayoutBlockFlow()) { |
| // If there's a forced break inside this object, figure out if we can fit |
| // everything before that forced break in the current fragmentainer. If it |
| // fits, we don't need to insert a break before the child. |
| const LayoutBlockFlow& blockChild = toLayoutBlockFlow(child); |
| if (LayoutUnit firstBreakOffset = blockChild.firstForcedBreakOffset()) { |
| if (remainingLogicalHeight >= firstBreakOffset) |
| return logicalOffset; |
| } |
| } |
| |
| return logicalOffset + paginationStrut; |
| } |
| |
| DISABLE_CFI_PERF |
| void LayoutBlockFlow::rebuildFloatsFromIntruding() { |
| if (m_floatingObjects) |
| m_floatingObjects->setHorizontalWritingMode(isHorizontalWritingMode()); |
| |
| HashSet<LayoutBox*> oldIntrudingFloatSet; |
| if (!childrenInline() && m_floatingObjects) { |
| const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set(); |
| FloatingObjectSetIterator end = floatingObjectSet.end(); |
| for (FloatingObjectSetIterator it = floatingObjectSet.begin(); it != end; |
| ++it) { |
| const FloatingObject& floatingObject = *it->get(); |
| if (!floatingObject.isDescendant()) |
| oldIntrudingFloatSet.insert(floatingObject.layoutObject()); |
| } |
| } |
| |
| // Inline blocks are covered by the isAtomicInlineLevel() check in the |
| // avoidFloats method. |
| if (avoidsFloats() || isDocumentElement() || isLayoutView() || |
| isFloatingOrOutOfFlowPositioned() || isTableCell()) { |
| if (m_floatingObjects) { |
| m_floatingObjects->clear(); |
| } |
| if (!oldIntrudingFloatSet.isEmpty()) |
| markAllDescendantsWithFloatsForLayout(); |
| return; |
| } |
| |
| LayoutBoxToFloatInfoMap floatMap; |
| |
| if (m_floatingObjects) { |
| if (childrenInline()) |
| m_floatingObjects->moveAllToFloatInfoMap(floatMap); |
| else |
| m_floatingObjects->clear(); |
| } |
| |
| // We should not process floats if the parent node is not a LayoutBlockFlow. |
| // Otherwise, we will add floats in an invalid context. This will cause a |
| // crash arising from a bad cast on the parent. |
| // See <rdar://problem/8049753>, where float property is applied on a text |
| // node in a SVG. |
| if (!parent() || !parent()->isLayoutBlockFlow()) |
| return; |
| |
| // Attempt to locate a previous sibling with overhanging floats. We skip any |
| // elements that may have shifted to avoid floats, and any objects whose |
| // floats cannot interact with objects outside it (i.e. objects that create a |
| // new block formatting context). |
| LayoutBlockFlow* parentBlockFlow = toLayoutBlockFlow(parent()); |
| bool siblingFloatMayIntrude = false; |
| LayoutObject* prev = previousSibling(); |
| while (prev && (!prev->isBox() || !prev->isLayoutBlock() || |
| toLayoutBlock(prev)->avoidsFloats() || |
| toLayoutBlock(prev)->createsNewFormattingContext())) { |
| if (prev->isFloating()) |
| siblingFloatMayIntrude = true; |
| prev = prev->previousSibling(); |
| } |
| |
| // First add in floats from the parent. Self-collapsing blocks let their |
| // parent track any floats that intrude into them (as opposed to floats they |
| // contain themselves) so check for those here too. If margin collapsing has |
| // moved us up past the top a previous sibling then we need to check for |
| // floats from the parent too. |
| bool parentFloatsMayIntrude = |
| !siblingFloatMayIntrude && |
| (!prev || toLayoutBlockFlow(prev)->isSelfCollapsingBlock() || |
| toLayoutBlock(prev)->logicalTop() > logicalTop()) && |
| parentBlockFlow->lowestFloatLogicalBottom() > logicalTop(); |
| if (siblingFloatMayIntrude || parentFloatsMayIntrude) |
| addIntrudingFloats(parentBlockFlow, |
| parentBlockFlow->logicalLeftOffsetForContent(), |
| logicalTop()); |
| |
| // Add overhanging floats from the previous LayoutBlockFlow, but only if it |
| // has a float that intrudes into our space. |
| if (prev) { |
| LayoutBlockFlow* previousBlockFlow = toLayoutBlockFlow(prev); |
| if (logicalTop() < previousBlockFlow->logicalTop() + |
| previousBlockFlow->lowestFloatLogicalBottom()) |
| addIntrudingFloats(previousBlockFlow, LayoutUnit(), |
| logicalTop() - previousBlockFlow->logicalTop()); |
| } |
| |
| if (childrenInline()) { |
| LayoutUnit changeLogicalTop = LayoutUnit::max(); |
| LayoutUnit changeLogicalBottom = LayoutUnit::min(); |
| if (m_floatingObjects) { |
| const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set(); |
| FloatingObjectSetIterator end = floatingObjectSet.end(); |
| for (FloatingObjectSetIterator it = floatingObjectSet.begin(); it != end; |
| ++it) { |
| const FloatingObject& floatingObject = *it->get(); |
| FloatingObject* oldFloatingObject = |
| floatMap.at(floatingObject.layoutObject()); |
| LayoutUnit logicalBottom = logicalBottomForFloat(floatingObject); |
| if (oldFloatingObject) { |
| LayoutUnit oldLogicalBottom = |
| logicalBottomForFloat(*oldFloatingObject); |
| if (logicalWidthForFloat(floatingObject) != |
| logicalWidthForFloat(*oldFloatingObject) || |
| logicalLeftForFloat(floatingObject) != |
| logicalLeftForFloat(*oldFloatingObject)) { |
| changeLogicalTop = LayoutUnit(); |
| changeLogicalBottom = std::max( |
| changeLogicalBottom, std::max(logicalBottom, oldLogicalBottom)); |
| } else { |
| if (logicalBottom != oldLogicalBottom) { |
| changeLogicalTop = std::min( |
| changeLogicalTop, std::min(logicalBottom, oldLogicalBottom)); |
| changeLogicalBottom = |
| std::max(changeLogicalBottom, |
| std::max(logicalBottom, oldLogicalBottom)); |
| } |
| LayoutUnit logicalTop = logicalTopForFloat(floatingObject); |
| LayoutUnit oldLogicalTop = logicalTopForFloat(*oldFloatingObject); |
| if (logicalTop != oldLogicalTop) { |
| changeLogicalTop = std::min(changeLogicalTop, |
| std::min(logicalTop, oldLogicalTop)); |
| changeLogicalBottom = std::max( |
| changeLogicalBottom, std::max(logicalTop, oldLogicalTop)); |
| } |
| } |
| |
| if (oldFloatingObject->originatingLine() && !selfNeedsLayout()) { |
| ASSERT(oldFloatingObject->originatingLine() |
| ->getLineLayoutItem() |
| .isEqual(this)); |
| oldFloatingObject->originatingLine()->markDirty(); |
| } |
| |
| floatMap.erase(floatingObject.layoutObject()); |
| } else { |
| changeLogicalTop = LayoutUnit(); |
| changeLogicalBottom = std::max(changeLogicalBottom, logicalBottom); |
| } |
| } |
| } |
| |
| LayoutBoxToFloatInfoMap::iterator end = floatMap.end(); |
| for (LayoutBoxToFloatInfoMap::iterator it = floatMap.begin(); it != end; |
| ++it) { |
| std::unique_ptr<FloatingObject>& floatingObject = it->value; |
| if (!floatingObject->isDescendant()) { |
| changeLogicalTop = LayoutUnit(); |
| changeLogicalBottom = std::max(changeLogicalBottom, |
| logicalBottomForFloat(*floatingObject)); |
| } |
| } |
| |
| markLinesDirtyInBlockRange(changeLogicalTop, changeLogicalBottom); |
| } else if (!oldIntrudingFloatSet.isEmpty()) { |
| // If there are previously intruding floats that no longer intrude, then |
| // children with floats should also get layout because they might need their |
| // floating object lists cleared. |
| if (m_floatingObjects->set().size() < oldIntrudingFloatSet.size()) { |
| markAllDescendantsWithFloatsForLayout(); |
| } else { |
| const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set(); |
| FloatingObjectSetIterator end = floatingObjectSet.end(); |
| for (FloatingObjectSetIterator it = floatingObjectSet.begin(); |
| it != end && !oldIntrudingFloatSet.isEmpty(); ++it) |
| oldIntrudingFloatSet.erase((*it)->layoutObject()); |
| if (!oldIntrudingFloatSet.isEmpty()) |
| markAllDescendantsWithFloatsForLayout(); |
| } |
| } |
| } |
| |
| void LayoutBlockFlow::layoutBlockChildren(bool relayoutChildren, |
| SubtreeLayoutScope& layoutScope, |
| LayoutUnit beforeEdge, |
| LayoutUnit afterEdge) { |
| dirtyForLayoutFromPercentageHeightDescendants(layoutScope); |
| |
| BlockChildrenLayoutInfo layoutInfo(this, beforeEdge, afterEdge); |
| MarginInfo& marginInfo = layoutInfo.marginInfo(); |
| |
| // Fieldsets need to find their legend and position it inside the border of |
| // the object. |
| // The legend then gets skipped during normal layout. The same is true for |
| // ruby text. |
| // It doesn't get included in the normal layout process but is instead skipped |
| LayoutObject* childToExclude = |
| layoutSpecialExcludedChild(relayoutChildren, layoutScope); |
| |
| // TODO(foolip): Speculative CHECKs to crash if any non-LayoutBox |
| // children ever appear, the childrenInline() check at the call site |
| // should make this impossible. crbug.com/632848 |
| LayoutObject* firstChild = this->firstChild(); |
| CHECK(!firstChild || firstChild->isBox()); |
| LayoutBox* next = toLayoutBox(firstChild); |
| LayoutBox* lastNormalFlowChild = nullptr; |
| |
| while (next) { |
| LayoutBox* child = next; |
| LayoutObject* nextSibling = child->nextSibling(); |
| CHECK(!nextSibling || nextSibling->isBox()); |
| next = toLayoutBox(nextSibling); |
| |
| child->setMayNeedPaintInvalidation(); |
| |
| if (childToExclude == child) |
| continue; // Skip this child, since it will be positioned by the |
| // specialized subclass (fieldsets and ruby runs). |
| |
| updateBlockChildDirtyBitsBeforeLayout(relayoutChildren, *child); |
| |
| if (child->isOutOfFlowPositioned()) { |
| child->containingBlock()->insertPositionedObject(child); |
| adjustPositionedBlock(*child, layoutInfo); |
| continue; |
| } |
| if (child->isFloating()) { |
| insertFloatingObject(*child); |
| adjustFloatingBlock(marginInfo); |
| continue; |
| } |
| if (child->isColumnSpanAll()) { |
| // This is not the containing block of the spanner. The spanner's |
| // placeholder will lay it out in due course. For now we just need to |
| // consult our flow thread, so that the columns (if any) preceding and |
| // following the spanner are laid out correctly. But first we apply the |
| // pending margin, so that it's taken into consideration and doesn't end |
| // up on the other side of the spanner. |
| setLogicalHeight(logicalHeight() + marginInfo.margin()); |
| marginInfo.clearMargin(); |
| |
| child->spannerPlaceholder()->flowThread()->skipColumnSpanner( |
| child, offsetFromLogicalTopOfFirstPage() + logicalHeight()); |
| continue; |
| } |
| |
| // Lay out the child. |
| layoutBlockChild(*child, layoutInfo); |
| layoutInfo.clearIsAtFirstInFlowChild(); |
| lastNormalFlowChild = child; |
| } |
| |
| // Now do the handling of the bottom of the block, adding in our bottom |
| // border/padding and determining the correct collapsed bottom margin |
| // information. |
| handleAfterSideOfBlock(lastNormalFlowChild, beforeEdge, afterEdge, |
| marginInfo); |
| } |
| |
| // Our MarginInfo state used when laying out block children. |
| MarginInfo::MarginInfo(LayoutBlockFlow* blockFlow, |
| LayoutUnit beforeBorderPadding, |
| LayoutUnit afterBorderPadding) |
| : m_canCollapseMarginAfterWithLastChild(true), |
| m_atBeforeSideOfBlock(true), |
| m_atAfterSideOfBlock(false), |
| m_hasMarginBeforeQuirk(false), |
| m_hasMarginAfterQuirk(false), |
| m_determinedMarginBeforeQuirk(false), |
| m_discardMargin(false), |
| m_lastChildIsSelfCollapsingBlockWithClearance(false) { |
| const ComputedStyle& blockStyle = blockFlow->styleRef(); |
| ASSERT(blockFlow->isLayoutView() || blockFlow->parent()); |
| m_canCollapseWithChildren = !blockFlow->createsNewFormattingContext() && |
| !blockFlow->isLayoutFlowThread() && |
| !blockFlow->isLayoutView(); |
| |
| m_canCollapseMarginBeforeWithChildren = |
| m_canCollapseWithChildren && !beforeBorderPadding && |
| blockStyle.marginBeforeCollapse() != MarginCollapseSeparate; |
| |
| // If any height other than auto is specified in CSS, then we don't collapse |
| // our bottom margins with our children's margins. To do otherwise would be to |
| // risk odd visual effects when the children overflow out of the parent block |
| // and yet still collapse with it. We also don't collapse if we have any |
| // bottom border/padding. |
| m_canCollapseMarginAfterWithChildren = |
| m_canCollapseWithChildren && !afterBorderPadding && |
| (blockStyle.logicalHeight().isAuto() && |
| !blockStyle.logicalHeight().value()) && |
| blockStyle.marginAfterCollapse() != MarginCollapseSeparate; |
| |
| m_quirkContainer = blockFlow->isTableCell() || blockFlow->isBody(); |
| |
| m_discardMargin = m_canCollapseMarginBeforeWithChildren && |
| blockFlow->mustDiscardMarginBefore(); |
| |
| m_positiveMargin = (m_canCollapseMarginBeforeWithChildren && |
| !blockFlow->mustDiscardMarginBefore()) |
| ? blockFlow->maxPositiveMarginBefore() |
| : LayoutUnit(); |
| m_negativeMargin = (m_canCollapseMarginBeforeWithChildren && |
| !blockFlow->mustDiscardMarginBefore()) |
| ? blockFlow->maxNegativeMarginBefore() |
| : LayoutUnit(); |
| } |
| |
| LayoutBlockFlow::MarginValues LayoutBlockFlow::marginValuesForChild( |
| LayoutBox& child) const { |
| LayoutUnit childBeforePositive; |
| LayoutUnit childBeforeNegative; |
| LayoutUnit childAfterPositive; |
| LayoutUnit childAfterNegative; |
| |
| LayoutUnit beforeMargin; |
| LayoutUnit afterMargin; |
| |
| LayoutBlockFlow* childLayoutBlockFlow = |
| child.isLayoutBlockFlow() ? toLayoutBlockFlow(&child) : 0; |
| |
| // If the child has the same directionality as we do, then we can just return |
| // its margins in the same direction. |
| if (!child.isWritingModeRoot()) { |
| if (childLayoutBlockFlow) { |
| childBeforePositive = childLayoutBlockFlow->maxPositiveMarginBefore(); |
| childBeforeNegative = childLayoutBlockFlow->maxNegativeMarginBefore(); |
| childAfterPositive = childLayoutBlockFlow->maxPositiveMarginAfter(); |
| childAfterNegative = childLayoutBlockFlow->maxNegativeMarginAfter(); |
| } else { |
| beforeMargin = child.marginBefore(); |
| afterMargin = child.marginAfter(); |
| } |
| } else if (child.isHorizontalWritingMode() == isHorizontalWritingMode()) { |
| // The child has a different directionality. If the child is parallel, then |
| // it's just flipped relative to us. We can use the margins for the opposite |
| // edges. |
| if (childLayoutBlockFlow) { |
| childBeforePositive = childLayoutBlockFlow->maxPositiveMarginAfter(); |
| childBeforeNegative = childLayoutBlockFlow->maxNegativeMarginAfter(); |
| childAfterPositive = childLayoutBlockFlow->maxPositiveMarginBefore(); |
| childAfterNegative = childLayoutBlockFlow->maxNegativeMarginBefore(); |
| } else { |
| beforeMargin = child.marginAfter(); |
| afterMargin = child.marginBefore(); |
| } |
| } else { |
| // The child is perpendicular to us, which means its margins don't collapse |
| // but are on the "logical left/right" sides of the child box. We can just |
| // return the raw margin in this case. |
| beforeMargin = marginBeforeForChild(child); |
| afterMargin = marginAfterForChild(child); |
| } |
| |
| // Resolve uncollapsing margins into their positive/negative buckets. |
| if (beforeMargin) { |
| if (beforeMargin > 0) |
| childBeforePositive = beforeMargin; |
| else |
| childBeforeNegative = -beforeMargin; |
| } |
| if (afterMargin) { |
| if (afterMargin > 0) |
| childAfterPositive = afterMargin; |
| else |
| childAfterNegative = -afterMargin; |
| } |
| |
| return LayoutBlockFlow::MarginValues(childBeforePositive, childBeforeNegative, |
| childAfterPositive, childAfterNegative); |
| } |
| |
| LayoutUnit LayoutBlockFlow::adjustedMarginBeforeForPagination( |
| const LayoutBox& child, |
| LayoutUnit logicalTopMarginEdge, |
| LayoutUnit logicalTopBorderEdge, |
| const BlockChildrenLayoutInfo& layoutInfo) const { |
| LayoutUnit effectiveMargin = logicalTopBorderEdge - logicalTopMarginEdge; |
| DCHECK(isPageLogicalHeightKnown()); |
| if (effectiveMargin <= LayoutUnit()) |
| return effectiveMargin; |
| // If margins would pull us past the top of the next fragmentainer, then we |
| // need to pull back and let the margins collapse into the fragmentainer |
| // boundary. If we're at a fragmentainer boundary, and there's no forced break |
| // involved, collapse the margin with the boundary we're at. Otherwise, |
| // preserve the margin at the top of the fragmentainer, but collapse it with |
| // the next fragmentainer boundary, since no margin should ever live in more |
| // than one fragmentainer. |
| PageBoundaryRule rule = AssociateWithLatterPage; |
| if (!child.needsForcedBreakBefore(layoutInfo.previousBreakAfterValue()) && |
| offsetFromLogicalTopOfFirstPage() + logicalTopMarginEdge > LayoutUnit()) |
| rule = AssociateWithFormerPage; |
| LayoutUnit remainingSpace = |
| pageRemainingLogicalHeightForOffset(logicalTopMarginEdge, rule); |
| return std::min(effectiveMargin, remainingSpace); |
| } |
| |
| LayoutUnit LayoutBlockFlow::collapseMargins(LayoutBox& child, |
| BlockChildrenLayoutInfo& layoutInfo, |
| bool childIsSelfCollapsing, |
| bool childDiscardMarginBefore, |
| bool childDiscardMarginAfter) { |
| MarginInfo& marginInfo = layoutInfo.marginInfo(); |
| |
| // The child discards the before margin when the the after margin has discard |
| // in the case of a self collapsing block. |
| childDiscardMarginBefore = childDiscardMarginBefore || |
| (childDiscardMarginAfter && childIsSelfCollapsing); |
| |
| // Get the four margin values for the child and cache them. |
| const LayoutBlockFlow::MarginValues childMargins = |
| marginValuesForChild(child); |
| |
| // Get our max pos and neg top margins. |
| LayoutUnit posTop = childMargins.positiveMarginBefore(); |
| LayoutUnit negTop = childMargins.negativeMarginBefore(); |
| |
| // For self-collapsing blocks, collapse our bottom margins into our |
| // top to get new posTop and negTop values. |
| if (childIsSelfCollapsing) { |
| posTop = std::max(posTop, childMargins.positiveMarginAfter()); |
| negTop = std::max(negTop, childMargins.negativeMarginAfter()); |
| } |
| |
| // See if the top margin is quirky. We only care if this child has |
| // margins that will collapse with us. |
| bool topQuirk = hasMarginBeforeQuirk(&child); |
| |
| if (marginInfo.canCollapseWithMarginBefore()) { |
| if (!childDiscardMarginBefore && !marginInfo.discardMargin()) { |
| // This child is collapsing with the top of the |
| // block. If it has larger margin values, then we need to update |
| // our own maximal values. |
| if (!document().inQuirksMode() || !marginInfo.quirkContainer() || |
| !topQuirk) |
| setMaxMarginBeforeValues(std::max(posTop, maxPositiveMarginBefore()), |
| std::max(negTop, maxNegativeMarginBefore())); |
| |
| // The minute any of the margins involved isn't a quirk, don't |
| // collapse it away, even if the margin is smaller (www.webreference.com |
| // has an example of this, a <dt> with 0.8em author-specified inside |
| // a <dl> inside a <td>. |
| if (!marginInfo.determinedMarginBeforeQuirk() && !topQuirk && |
| (posTop - negTop)) { |
| setHasMarginBeforeQuirk(false); |
| marginInfo.setDeterminedMarginBeforeQuirk(true); |
| } |
| |
| if (!marginInfo.determinedMarginBeforeQuirk() && topQuirk && |
| !marginBefore()) { |
| // We have no top margin and our top child has a quirky margin. |
| // We will pick up this quirky margin and pass it through. |
| // This deals with the <td><div><p> case. |
| // Don't do this for a block that split two inlines though. You do |
| // still apply margins in this case. |
| setHasMarginBeforeQuirk(true); |
| } |
| } else { |
| // The before margin of the container will also discard all the margins it |
| // is collapsing with. |
| setMustDiscardMarginBefore(); |
| } |
| } |
| |
| // Once we find a child with discardMarginBefore all the margins collapsing |
| // with us must also discard. |
| if (childDiscardMarginBefore) { |
| marginInfo.setDiscardMargin(true); |
| marginInfo.clearMargin(); |
| } |
| |
| if (marginInfo.quirkContainer() && marginInfo.atBeforeSideOfBlock() && |
| (posTop - negTop)) |
| marginInfo.setHasMarginBeforeQuirk(topQuirk); |
| |
| LayoutUnit beforeCollapseLogicalTop = logicalHeight(); |
| LayoutUnit logicalTop = beforeCollapseLogicalTop; |
| |
| LayoutObject* prev = child.previousSibling(); |
| LayoutBlockFlow* previousBlockFlow = |
| prev && prev->isLayoutBlockFlow() ? toLayoutBlockFlow(prev) : nullptr; |
| bool previousBlockFlowCanSelfCollapse = |
| previousBlockFlow && |
| !previousBlockFlow->isFloatingOrOutOfFlowPositioned(); |
| // If the child's previous sibling is a self-collapsing block that cleared a |
| // float then its top border edge has been set at the bottom border edge of |
| // the float. Since we want to collapse the child's top margin with the self- |
| // collapsing block's top and bottom margins we need to adjust our parent's |
| // height to match the margin top of the self-collapsing block. If the |
| // resulting collapsed margin leaves the child still intruding into the float |
| // then we will want to clear it. |
| if (!marginInfo.canCollapseWithMarginBefore() && |
| previousBlockFlowCanSelfCollapse && |
| marginInfo.lastChildIsSelfCollapsingBlockWithClearance()) |
| setLogicalHeight( |
| logicalHeight() - |
| marginValuesForChild(*previousBlockFlow).positiveMarginBefore()); |
| |
| if (childIsSelfCollapsing) { |
| // For a self collapsing block both the before and after margins get |
| // discarded. The block doesn't contribute anything to the height of the |
| // block. Also, the child's top position equals the logical height of the |
| // container. |
| if (!childDiscardMarginBefore && !marginInfo.discardMargin()) { |
| // This child has no height. We need to compute our |
| // position before we collapse the child's margins together, |
| // so that we can get an accurate position for the zero-height block. |
| LayoutUnit collapsedBeforePos = std::max( |
| marginInfo.positiveMargin(), childMargins.positiveMarginBefore()); |
| LayoutUnit collapsedBeforeNeg = std::max( |
| marginInfo.negativeMargin(), childMargins.negativeMarginBefore()); |
| marginInfo.setMargin(collapsedBeforePos, collapsedBeforeNeg); |
| |
| // Now collapse the child's margins together, which means examining our |
| // bottom margin values as well. |
| marginInfo.setPositiveMarginIfLarger(childMargins.positiveMarginAfter()); |
| marginInfo.setNegativeMarginIfLarger(childMargins.negativeMarginAfter()); |
| |
| if (!marginInfo.canCollapseWithMarginBefore()) { |
| // We need to make sure that the position of the self-collapsing block |
| // is correct, since it could have overflowing content |
| // that needs to be positioned correctly (e.g., a block that |
| // had a specified height of 0 but that actually had subcontent). |
| logicalTop = logicalHeight() + collapsedBeforePos - collapsedBeforeNeg; |
| } |
| } |
| } else { |
| if (mustSeparateMarginBeforeForChild(child)) { |
| ASSERT(!marginInfo.discardMargin() || |
| (marginInfo.discardMargin() && !marginInfo.margin())); |
| // If we are at the before side of the block and we collapse, ignore the |
| // computed margin and just add the child margin to the container height. |
| // This will correctly position the child inside the container. |
| LayoutUnit separateMargin = !marginInfo.canCollapseWithMarginBefore() |
| ? marginInfo.margin() |
| : LayoutUnit(); |
| setLogicalHeight(logicalHeight() + separateMargin + |
| marginBeforeForChild(child)); |
| logicalTop = logicalHeight(); |
| } else if (!marginInfo.discardMargin() && |
| (!marginInfo.atBeforeSideOfBlock() || |
| (!marginInfo.canCollapseMarginBeforeWithChildren() && |
| (!document().inQuirksMode() || !marginInfo.quirkContainer() || |
| !marginInfo.hasMarginBeforeQuirk())))) { |
| // We're collapsing with a previous sibling's margins and not |
| // with the top of the block. |
| setLogicalHeight(logicalHeight() + |
| std::max(marginInfo.positiveMargin(), posTop) - |
| std::max(marginInfo.negativeMargin(), negTop)); |
| logicalTop = logicalHeight(); |
| } |
| |
| marginInfo.setDiscardMargin(childDiscardMarginAfter); |
| |
| if (!marginInfo.discardMargin()) { |
| marginInfo.setPositiveMargin(childMargins.positiveMarginAfter()); |
| marginInfo.setNegativeMargin(childMargins.negativeMarginAfter()); |
| } else { |
| marginInfo.clearMargin(); |
| } |
| |
| if (marginInfo.margin()) |
| marginInfo.setHasMarginAfterQuirk(hasMarginAfterQuirk(&child)); |
| } |
| |
| if (view()->layoutState()->isPaginated() && isPageLogicalHeightKnown()) { |
| LayoutUnit oldLogicalTop = logicalTop; |
| LayoutUnit margin = adjustedMarginBeforeForPagination( |
| child, beforeCollapseLogicalTop, logicalTop, layoutInfo); |
| logicalTop = beforeCollapseLogicalTop + margin; |
| setLogicalHeight(logicalHeight() + (logicalTop - oldLogicalTop)); |
| } |
| |
| // If |child| has moved up into previous siblings it needs to avoid or clear |
| // any floats they contain. |
| if (logicalTop < beforeCollapseLogicalTop) { |
| LayoutUnit oldLogicalHeight = logicalHeight(); |
| setLogicalHeight(logicalTop); |
| while (previousBlockFlow) { |
| auto lowestFloat = previousBlockFlow->logicalTop() + |
| previousBlockFlow->lowestFloatLogicalBottom(); |
| if (lowestFloat > logicalTop) |
| addOverhangingFloats(previousBlockFlow, false); |
| else |
| break; |
| LayoutObject* prev = previousBlockFlow->previousSibling(); |
| if (prev && prev->isLayoutBlockFlow()) |
| previousBlockFlow = toLayoutBlockFlow(prev); |
| else |
| previousBlockFlow = nullptr; |
| } |
| setLogicalHeight(oldLogicalHeight); |
| } |
| |
| if (previousBlockFlowCanSelfCollapse) { |
| // If |child|'s previous sibling is or contains a self-collapsing block that |
| // cleared a float and margin collapsing resulted in |child| moving up |
| // into the margin area of the self-collapsing block then the float it |
| // clears is now intruding into |child|. Layout again so that we can look |
| // for floats in the parent that overhang |child|'s new logical top. |
| bool logicalTopIntrudesIntoFloat = logicalTop < beforeCollapseLogicalTop; |
| if (logicalTopIntrudesIntoFloat && containsFloats() && |
| !child.avoidsFloats() && lowestFloatLogicalBottom() > logicalTop) |
| child.setNeedsLayoutAndFullPaintInvalidation( |
| LayoutInvalidationReason::AncestorMarginCollapsing); |
| } |
| |
| return logicalTop; |
| } |
| |
| void LayoutBlockFlow::adjustPositionedBlock( |
| LayoutBox& child, |
| const BlockChildrenLayoutInfo& layoutInfo) { |
| LayoutUnit logicalTop = logicalHeight(); |
| |
| // Forced breaks are only specified on in-flow objects, but auto-positioned |
| // out-of-flow objects may be affected by a break-after value of the previous |
| // in-flow object. |
| if (view()->layoutState()->isPaginated()) |
| logicalTop = |
| applyForcedBreak(logicalTop, layoutInfo.previousBreakAfterValue()); |
| |
| updateStaticInlinePositionForChild(child, logicalTop); |
| |
| const MarginInfo& marginInfo = layoutInfo.marginInfo(); |
| if (!marginInfo.canCollapseWithMarginBefore()) { |
| // Positioned blocks don't collapse margins, so add the margin provided by |
| // the container now. The child's own margin is added later when calculating |
| // its logical top. |
| LayoutUnit collapsedBeforePos = marginInfo.positiveMargin(); |
| LayoutUnit collapsedBeforeNeg = marginInfo.negativeMargin(); |
| logicalTop += collapsedBeforePos - collapsedBeforeNeg; |
| } |
| |
| PaintLayer* childLayer = child.layer(); |
| if (childLayer->staticBlockPosition() != logicalTop) |
| childLayer->setStaticBlockPosition(logicalTop); |
| } |
| |
| LayoutUnit LayoutBlockFlow::clearFloatsIfNeeded(LayoutBox& child, |
| MarginInfo& marginInfo, |
| LayoutUnit oldTopPosMargin, |
| LayoutUnit oldTopNegMargin, |
| LayoutUnit yPos, |
| bool childIsSelfCollapsing, |
| bool childDiscardMargin) { |
| LayoutUnit heightIncrease = getClearDelta(&child, yPos); |
| marginInfo.setLastChildIsSelfCollapsingBlockWithClearance(false); |
| |
| if (!heightIncrease) |
| return yPos; |
| |
| if (childIsSelfCollapsing) { |
| marginInfo.setLastChildIsSelfCollapsingBlockWithClearance(true); |
| marginInfo.setDiscardMargin(childDiscardMargin); |
| |
| // For self-collapsing blocks that clear, they can still collapse their |
| // margins with following siblings. Reset the current margins to represent |
| // the self-collapsing block's margins only. |
| // If DISCARD is specified for -webkit-margin-collapse, reset the margin |
| // values. |
| LayoutBlockFlow::MarginValues childMargins = marginValuesForChild(child); |
| if (!childDiscardMargin) { |
| marginInfo.setPositiveMargin( |
| std::max(childMargins.positiveMarginBefore(), |
| childMargins.positiveMarginAfter())); |
| marginInfo.setNegativeMargin( |
| std::max(childMargins.negativeMarginBefore(), |
| childMargins.negativeMarginAfter())); |
| } else { |
| marginInfo.clearMargin(); |
| } |
| |
| // CSS2.1 states: |
| // "If the top and bottom margins of an element with clearance are |
| // adjoining, its margins collapse with the adjoining margins of following |
| // siblings but that resulting margin does not collapse with the bottom |
| // margin of the parent block." |
| // So the parent's bottom margin cannot collapse through this block or any |
| // subsequent self-collapsing blocks. Set a bit to ensure this happens; it |
| // will get reset if we encounter an in-flow sibling that is not |
| // self-collapsing. |
| marginInfo.setCanCollapseMarginAfterWithLastChild(false); |
| |
| // For now set the border-top of |child| flush with the bottom border-edge |
| // of the float so it can layout any floating or positioned children of its |
| // own at the correct vertical position. If subsequent siblings attempt to |
| // collapse with |child|'s margins in |collapseMargins| we will adjust the |
| // height of the parent to |child|'s margin top (which if it is positive |
| // sits up 'inside' the float it's clearing) so that all three margins can |
| // collapse at the correct vertical position. |
| // Per CSS2.1 we need to ensure that any negative margin-top clears |child| |
| // beyond the bottom border-edge of the float so that the top border edge of |
| // the child (i.e. its clearance) is at a position that satisfies the |
| // equation: "the amount of clearance is set so that: |
| // clearance + margin-top = [height of float], |
| // i.e., clearance = [height of float] - margin-top". |
| setLogicalHeight(child.logicalTop() + childMargins.negativeMarginBefore()); |
| } else { |
| // Increase our height by the amount we had to clear. |
| setLogicalHeight(logicalHeight() + heightIncrease); |
| } |
| |
| if (marginInfo.canCollapseWithMarginBefore()) { |
| // We can no longer collapse with the top of the block since a clear |
| // occurred. The empty blocks collapse into the cleared block. |
| setMaxMarginBeforeValues(oldTopPosMargin, oldTopNegMargin); |
| marginInfo.setAtBeforeSideOfBlock(false); |
| |
| // In case the child discarded the before margin of the block we need to |
| // reset the mustDiscardMarginBefore flag to the initial value. |
| setMustDiscardMarginBefore(style()->marginBeforeCollapse() == |
| MarginCollapseDiscard); |
| } |
| |
| return yPos + heightIncrease; |
| } |
| |
| void LayoutBlockFlow::setCollapsedBottomMargin(const MarginInfo& marginInfo) { |
| if (marginInfo.canCollapseWithMarginAfter() && |
| !marginInfo.canCollapseWithMarginBefore()) { |
| // Update the after side margin of the container to discard if the after |
| // margin of the last child also discards and we collapse with it. |
| // Don't update the max margin values because we won't need them anyway. |
| if (marginInfo.discardMargin()) { |
| setMustDiscardMarginAfter(); |
| return; |
| } |
| |
| // Update our max pos/neg bottom margins, since we collapsed our bottom |
| // margins with our children. |
| setMaxMarginAfterValues( |
| std::max(maxPositiveMarginAfter(), marginInfo.positiveMargin()), |
| std::max(maxNegativeMarginAfter(), marginInfo.negativeMargin())); |
| |
| if (!marginInfo.hasMarginAfterQuirk()) |
| setHasMarginAfterQuirk(false); |
| |
| if (marginInfo.hasMarginAfterQuirk() && !marginAfter()) { |
| // We have no bottom margin and our last child has a quirky margin. |
| // We will pick up this quirky margin and pass it through. |
| // This deals with the <td><div><p> case. |
| setHasMarginAfterQuirk(true); |
| } |
| } |
| } |
| |
| DISABLE_CFI_PERF |
| void LayoutBlockFlow::marginBeforeEstimateForChild( |
| LayoutBox& child, |
| LayoutUnit& positiveMarginBefore, |
| LayoutUnit& negativeMarginBefore, |
| bool& discardMarginBefore) const { |
| // Give up if in quirks mode and we're a body/table cell and the top margin of |
| // the child box is quirky. |
| // Give up if the child specified -webkit-margin-collapse: separate that |
| // prevents collapsing. |
| // FIXME: Use writing mode independent accessor for marginBeforeCollapse. |
| if ((document().inQuirksMode() && hasMarginBeforeQuirk(&child) && |
| (isTableCell() || isBody())) || |
| child.style()->marginBeforeCollapse() == MarginCollapseSeparate) |
| return; |
| |
| // The margins are discarded by a child that specified |
| // -webkit-margin-collapse: discard. |
| // FIXME: Use writing mode independent accessor for marginBeforeCollapse. |
| if (child.style()->marginBeforeCollapse() == MarginCollapseDiscard) { |
| positiveMarginBefore = LayoutUnit(); |
| negativeMarginBefore = LayoutUnit(); |
| discardMarginBefore = true; |
| return; |
| } |
| |
| LayoutUnit beforeChildMargin = marginBeforeForChild(child); |
| positiveMarginBefore = std::max(positiveMarginBefore, beforeChildMargin); |
| negativeMarginBefore = std::max(negativeMarginBefore, -beforeChildMargin); |
| |
| if (!child.isLayoutBlockFlow()) |
| return; |
| |
| LayoutBlockFlow* childBlockFlow = toLayoutBlockFlow(&child); |
| if (childBlockFlow->childrenInline() || childBlockFlow->isWritingModeRoot()) |
| return; |
| |
| MarginInfo childMarginInfo( |
| childBlockFlow, |
| childBlockFlow->borderBefore() + childBlockFlow->paddingBefore(), |
| childBlockFlow->borderAfter() + childBlockFlow->paddingAfter()); |
| if (!childMarginInfo.canCollapseMarginBeforeWithChildren()) |
| return; |
| |
| LayoutBox* grandchildBox = childBlockFlow->firstChildBox(); |
| for (; grandchildBox; grandchildBox = grandchildBox->nextSiblingBox()) { |
| if (!grandchildBox->isFloatingOrOutOfFlowPositioned() && |
| !grandchildBox->isColumnSpanAll()) |
| break; |
| } |
| |
| if (!grandchildBox) |
| return; |
| |
| // Make sure to update the block margins now for the grandchild box so that |
| // we're looking at current values. |
| if (grandchildBox->needsLayout()) { |
| grandchildBox->computeAndSetBlockDirectionMargins(this); |
| if (grandchildBox->isLayoutBlock()) { |
| LayoutBlock* grandchildBlock = toLayoutBlock(grandchildBox); |
| grandchildBlock->setHasMarginBeforeQuirk( |
| grandchildBox->style()->hasMarginBeforeQuirk()); |
| grandchildBlock->setHasMarginAfterQuirk( |
| grandchildBox->style()->hasMarginAfterQuirk()); |
| } |
| } |
| |
| // If we have a 'clear' value but also have a margin we may not actually |
| // require clearance to move past any floats. If that's the case we want to be |
| // sure we estimate the correct position including margins after any floats |
| // rather than use 'clearance' later which could give us the wrong position. |
| if (grandchildBox->style()->clear() != EClear::kNone && |
| childBlockFlow->marginBeforeForChild(*grandchildBox) == 0) |
| return; |
| |
| // Collapse the margin of the grandchild box with our own to produce an |
| // estimate. |
| childBlockFlow->marginBeforeEstimateForChild( |
| *grandchildBox, positiveMarginBefore, negativeMarginBefore, |
| discardMarginBefore); |
| } |
| |
| LayoutUnit LayoutBlockFlow::estimateLogicalTopPosition( |
| LayoutBox& child, |
| const BlockChildrenLayoutInfo& layoutInfo, |
| LayoutUnit& estimateWithoutPagination) { |
| const MarginInfo& marginInfo = layoutInfo.marginInfo(); |
| // FIXME: We need to eliminate the estimation of vertical position, because |
| // when it's wrong we sometimes trigger a pathological |
| // relayout if there are intruding floats. |
| LayoutUnit logicalTopEstimate = logicalHeight(); |
| LayoutUnit positiveMarginBefore; |
| LayoutUnit negativeMarginBefore; |
| bool discardMarginBefore = false; |
| if (!marginInfo.canCollapseWithMarginBefore()) { |
| if (child.selfNeedsLayout()) { |
| // Try to do a basic estimation of how the collapse is going to go. |
| marginBeforeEstimateForChild(child, positiveMarginBefore, |
| negativeMarginBefore, discardMarginBefore); |
| } else { |
| // Use the cached collapsed margin values from a previous layout. Most of |
| // the time they will be right. |
| LayoutBlockFlow::MarginValues marginValues = marginValuesForChild(child); |
| positiveMarginBefore = |
| std::max(positiveMarginBefore, marginValues.positiveMarginBefore()); |
| negativeMarginBefore = |
| std::max(negativeMarginBefore, marginValues.negativeMarginBefore()); |
| discardMarginBefore = mustDiscardMarginBeforeForChild(child); |
| } |
| |
| // Collapse the result with our current margins. |
| if (!discardMarginBefore) |
| logicalTopEstimate += |
| std::max(marginInfo.positiveMargin(), positiveMarginBefore) - |
| std::max(marginInfo.negativeMargin(), negativeMarginBefore); |
| } |
| |
| LayoutState* layoutState = view()->layoutState(); |
| if (layoutState->isPaginated() && isPageLogicalHeightKnown()) { |
| LayoutUnit margin = adjustedMarginBeforeForPagination( |
| child, logicalHeight(), logicalTopEstimate, layoutInfo); |
| logicalTopEstimate = logicalHeight() + margin; |
| } |
| |
| logicalTopEstimate += getClearDelta(&child, logicalTopEstimate); |
| |
| estimateWithoutPagination = logicalTopEstimate; |
| |
| if (layoutState->isPaginated()) { |
| if (!layoutInfo.isAtFirstInFlowChild()) { |
| // Estimate the need for a forced break in front of this child. The final |
| // break policy at this class A break point isn't known until we have laid |
| // out the children of |child|. There may be forced break-before values |
| // set on first-children inside that get propagated up to the child. |
| // Just make an estimate with what we know so far. |
| EBreakBetween breakValue = |
| child.classABreakPointValue(layoutInfo.previousBreakAfterValue()); |
| if (isForcedFragmentainerBreakValue(breakValue)) { |
| logicalTopEstimate = applyForcedBreak(logicalHeight(), breakValue); |
| // Disregard previous margins, since they will collapse with the |
| // fragmentainer boundary, due to the forced break. Only apply margins |
| // that have been specified on the child or its descendants. |
| if (!discardMarginBefore) |
| logicalTopEstimate += positiveMarginBefore - negativeMarginBefore; |
| |
| // Clearance may already have taken us past the beginning of the next |
| // fragmentainer. |
| return std::max(estimateWithoutPagination, logicalTopEstimate); |
| } |
| |
| logicalTopEstimate = |
| adjustForUnsplittableChild(child, logicalTopEstimate); |
| } |
| } |
| |
| return logicalTopEstimate; |
| } |
| |
| void LayoutBlockFlow::adjustFloatingBlock(const MarginInfo& marginInfo) { |
| // The float should be positioned taking into account the bottom margin |
| // of the previous flow. We add that margin into the height, get the |
| // float positioned properly, and then subtract the margin out of the |
| // height again. In the case of self-collapsing blocks, we always just |
| // use the top margins, since the self-collapsing block collapsed its |
| // own bottom margin into its top margin. |
| // |
| // Note also that the previous flow may collapse its margin into the top of |
| // our block. If this is the case, then we do not add the margin in to our |
| // height when computing the position of the float. This condition can be |
| // tested for by simply calling canCollapseWithMarginBefore. See |
| // http://www.hixie.ch/tests/adhoc/css/box/block/margin-collapse/046.html for |
| // an example of this scenario. |
| LayoutUnit logicalTop = logicalHeight(); |
| if (!marginInfo.canCollapseWithMarginBefore()) |
| logicalTop += marginInfo.margin(); |
| placeNewFloats(logicalTop); |
| } |
| |
| void LayoutBlockFlow::handleAfterSideOfBlock(LayoutBox* lastChild, |
| LayoutUnit beforeSide, |
| LayoutUnit afterSide, |
| MarginInfo& marginInfo) { |
| marginInfo.setAtAfterSideOfBlock(true); |
| |
| // If our last child was a self-collapsing block with clearance then our |
| // logical height is flush with the bottom edge of the float that the child |
| // clears. The correct vertical position for the margin-collapsing we want to |
| // perform now is at the child's margin-top - so adjust our height to that |
| // position. |
| if (marginInfo.lastChildIsSelfCollapsingBlockWithClearance()) { |
| ASSERT(lastChild); |
| setLogicalHeight(logicalHeight() - |
| marginValuesForChild(*lastChild).positiveMarginBefore()); |
| } |
| |
| if (marginInfo.canCollapseMarginAfterWithChildren() && |
| !marginInfo.canCollapseMarginAfterWithLastChild()) |
| marginInfo.setCanCollapseMarginAfterWithChildren(false); |
| |
| // If we can't collapse with children then go ahead and add in the bottom |
| // margin. |
| if (!marginInfo.discardMargin() && |
| (!marginInfo.canCollapseWithMarginAfter() && |
| !marginInfo.canCollapseWithMarginBefore() && |
| (!document().inQuirksMode() || !marginInfo.quirkContainer() || |
| !marginInfo.hasMarginAfterQuirk()))) |
| setLogicalHeight(logicalHeight() + marginInfo.margin()); |
| |
| // Now add in our bottom border/padding. |
| setLogicalHeight(logicalHeight() + afterSide); |
| |
| // Negative margins can cause our height to shrink below our minimal height |
| // (border/padding). If this happens, ensure that the computed height is |
| // increased to the minimal height. |
| setLogicalHeight(std::max(logicalHeight(), beforeSide + afterSide)); |
| |
| // Update our bottom collapsed margin info. |
| setCollapsedBottomMargin(marginInfo); |
| |
| // There's no class A break point right after the last child, only *between* |
| // siblings. So propagate the break-after value, and keep looking for a class |
| // A break point (at the next in-flow block-level object), where we'll join |
| // this break-after value with the break-before value there. |
| if (view()->layoutState()->isPaginated() && lastChild) |
| setBreakAfter( |
| joinFragmentainerBreakValues(breakAfter(), lastChild->breakAfter())); |
| } |
| |
| void LayoutBlockFlow::setMustDiscardMarginBefore(bool value) { |
| if (style()->marginBeforeCollapse() == MarginCollapseDiscard) { |
| ASSERT(value); |
| return; |
| } |
| |
| if (!m_rareData && !value) |
| return; |
| |
| if (!m_rareData) |
| m_rareData = WTF::makeUnique<LayoutBlockFlowRareData>(this); |
| |
| m_rareData->m_discardMarginBefore = value; |
| } |
| |
| void LayoutBlockFlow::setMustDiscardMarginAfter(bool value) { |
| if (style()->marginAfterCollapse() == MarginCollapseDiscard) { |
| ASSERT(value); |
| return; |
| } |
| |
| if (!m_rareData && !value) |
| return; |
| |
| if (!m_rareData) |
| m_rareData = WTF::makeUnique<LayoutBlockFlowRareData>(this); |
| |
| m_rareData->m_discardMarginAfter = value; |
| } |
| |
| bool LayoutBlockFlow::mustDiscardMarginBefore() const { |
| return style()->marginBeforeCollapse() == MarginCollapseDiscard || |
| (m_rareData && m_rareData->m_discardMarginBefore); |
| } |
| |
| bool LayoutBlockFlow::mustDiscardMarginAfter() const { |
| return style()->marginAfterCollapse() == MarginCollapseDiscard || |
| (m_rareData && m_rareData->m_discardMarginAfter); |
| } |
| |
| bool LayoutBlockFlow::mustDiscardMarginBeforeForChild( |
| const LayoutBox& child) const { |
| ASSERT(!child.selfNeedsLayout()); |
| if (!child.isWritingModeRoot()) |
| return child.isLayoutBlockFlow() |
| ? toLayoutBlockFlow(&child)->mustDiscardMarginBefore() |
| : (child.style()->marginBeforeCollapse() == |
| MarginCollapseDiscard); |
| if (child.isHorizontalWritingMode() == isHorizontalWritingMode()) |
| return child.isLayoutBlockFlow() |
| ? toLayoutBlockFlow(&child)->mustDiscardMarginAfter() |
| : (child.style()->marginAfterCollapse() == |
| MarginCollapseDiscard); |
| |
| // FIXME: We return false here because the implementation is not geometrically |
| // complete. We have values only for before/after, not start/end. |
| // In case the boxes are perpendicular we assume the property is not |
| // specified. |
| return false; |
| } |
| |
| bool LayoutBlockFlow::mustDiscardMarginAfterForChild( |
| const LayoutBox& child) const { |
| ASSERT(!child.selfNeedsLayout()); |
| if (!child.isWritingModeRoot()) |
| return child.isLayoutBlockFlow() |
| ? toLayoutBlockFlow(&child)->mustDiscardMarginAfter() |
| : (child.style()->marginAfterCollapse() == |
| MarginCollapseDiscard); |
| if (child.isHorizontalWritingMode() == isHorizontalWritingMode()) |
| return child.isLayoutBlockFlow() |
| ? toLayoutBlockFlow(&child)->mustDiscardMarginBefore() |
| : (child.style()->marginBeforeCollapse() == |
| MarginCollapseDiscard); |
| |
| // FIXME: See |mustDiscardMarginBeforeForChild| above. |
| return false; |
| } |
| |
| void LayoutBlockFlow::setMaxMarginBeforeValues(LayoutUnit pos, LayoutUnit neg) { |
| if (!m_rareData) { |
| if (pos == LayoutBlockFlowRareData::positiveMarginBeforeDefault(this) && |
| neg == LayoutBlockFlowRareData::negativeMarginBeforeDefault(this)) |
| return; |
| m_rareData = WTF::makeUnique<LayoutBlockFlowRareData>(this); |
| } |
| m_rareData->m_margins.setPositiveMarginBefore(pos); |
| m_rareData->m_margins.setNegativeMarginBefore(neg); |
| } |
| |
| void LayoutBlockFlow::setMaxMarginAfterValues(LayoutUnit pos, LayoutUnit neg) { |
| if (!m_rareData) { |
| if (pos == LayoutBlockFlowRareData::positiveMarginAfterDefault(this) && |
| neg == LayoutBlockFlowRareData::negativeMarginAfterDefault(this)) |
| return; |
| m_rareData = WTF::makeUnique<LayoutBlockFlowRareData>(this); |
| } |
| m_rareData->m_margins.setPositiveMarginAfter(pos); |
| m_rareData->m_margins.setNegativeMarginAfter(neg); |
| } |
| |
| bool LayoutBlockFlow::mustSeparateMarginBeforeForChild( |
| const LayoutBox& child) const { |
| ASSERT(!child.selfNeedsLayout()); |
| const ComputedStyle& childStyle = child.styleRef(); |
| if (!child.isWritingModeRoot()) |
| return childStyle.marginBeforeCollapse() == MarginCollapseSeparate; |
| if (child.isHorizontalWritingMode() == isHorizontalWritingMode()) |
| return childStyle.marginAfterCollapse() == MarginCollapseSeparate; |
| |
| // FIXME: See |mustDiscardMarginBeforeForChild| above. |
| return false; |
| } |
| |
| bool LayoutBlockFlow::mustSeparateMarginAfterForChild( |
| const LayoutBox& child) const { |
| ASSERT(!child.selfNeedsLayout()); |
| const ComputedStyle& childStyle = child.styleRef(); |
| if (!child.isWritingModeRoot()) |
| return childStyle.marginAfterCollapse() == MarginCollapseSeparate; |
| if (child.isHorizontalWritingMode() == isHorizontalWritingMode()) |
| return childStyle.marginBeforeCollapse() == MarginCollapseSeparate; |
| |
| // FIXME: See |mustDiscardMarginBeforeForChild| above. |
| return false; |
| } |
| |
| LayoutUnit LayoutBlockFlow::applyForcedBreak(LayoutUnit logicalOffset, |
| EBreakBetween breakValue) { |
| if (!isForcedFragmentainerBreakValue(breakValue)) |
| return logicalOffset; |
| // TODO(mstensho): honor breakValue. There are different types of forced |
| // breaks. We currently just assume that we want to break to the top of the |
| // next fragmentainer of the fragmentation context we're in. However, we may |
| // want to find the next left or right page - even if we're inside a multicol |
| // container when printing. |
| LayoutUnit pageLogicalHeight = pageLogicalHeightForOffset(logicalOffset); |
| if (!pageLogicalHeight) |
| return logicalOffset; // Page height is still unknown, so we cannot insert |
| // forced breaks. |
| LayoutUnit remainingLogicalHeight = pageRemainingLogicalHeightForOffset( |
| logicalOffset, AssociateWithLatterPage); |
| if (remainingLogicalHeight == pageLogicalHeight) |
| return logicalOffset; // Don't break if we're already at the block start of |
| // a fragmentainer. |
| |
| // If this is the first forced break inside this object, store the |
| // location. We need this information later if there's a break-inside:avoid |
| // object further up. We need to know if there are any forced breaks inside |
| // such objects, in order to determine whether we need to push it to the next |
| // fragmentainer or not. |
| if (!firstForcedBreakOffset()) |
| setFirstForcedBreakOffset(logicalOffset); |
| |
| return logicalOffset + remainingLogicalHeight; |
| } |
| |
| void LayoutBlockFlow::setBreakBefore(EBreakBetween breakValue) { |
| if (breakValue != EBreakBetween::kAuto && |
| !isBreakBetweenControllable(breakValue)) |
| breakValue = EBreakBetween::kAuto; |
| if (breakValue == EBreakBetween::kAuto && !m_rareData) |
| return; |
| ensureRareData().m_breakBefore = static_cast<unsigned>(breakValue); |
| } |
| |
| void LayoutBlockFlow::setBreakAfter(EBreakBetween breakValue) { |
| if (breakValue != EBreakBetween::kAuto && |
| !isBreakBetweenControllable(breakValue)) |
| breakValue = EBreakBetween::kAuto; |
| if (breakValue == EBreakBetween::kAuto && !m_rareData) |
| return; |
| ensureRareData().m_breakAfter = static_cast<unsigned>(breakValue); |
| } |
| |
| EBreakBetween LayoutBlockFlow::breakBefore() const { |
| return m_rareData ? static_cast<EBreakBetween>(m_rareData->m_breakBefore) |
| : EBreakBetween::kAuto; |
| } |
| |
| EBreakBetween LayoutBlockFlow::breakAfter() const { |
| return m_rareData ? static_cast<EBreakBetween>(m_rareData->m_breakAfter) |
| : EBreakBetween::kAuto; |
| } |
| |
| void LayoutBlockFlow::addOverflowFromFloats() { |
| if (!m_floatingObjects) |
| return; |
| |
| const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set(); |
| FloatingObjectSetIterator end = floatingObjectSet.end(); |
| for (FloatingObjectSetIterator it = floatingObjectSet.begin(); it != end; |
| ++it) { |
| const FloatingObject& floatingObject = *it->get(); |
| if (floatingObject.isDescendant()) |
| addOverflowFromChild( |
| floatingObject.layoutObject(), |
| LayoutSize(xPositionForFloatIncludingMargin(floatingObject), |
| yPositionForFloatIncludingMargin(floatingObject))); |
| } |
| } |
| |
| void LayoutBlockFlow::computeOverflow(LayoutUnit oldClientAfterEdge, |
| bool recomputeFloats) { |
| LayoutBlock::computeOverflow(oldClientAfterEdge, recomputeFloats); |
| if (recomputeFloats || createsNewFormattingContext() || |
| hasSelfPaintingLayer()) |
| addOverflowFromFloats(); |
| } |
| |
| void LayoutBlockFlow::computeSelfHitTestRects( |
| Vector<LayoutRect>& rects, |
| const LayoutPoint& layerOffset) const { |
| LayoutBlock::computeSelfHitTestRects(rects, layerOffset); |
| |
| if (!hasHorizontalLayoutOverflow() && !hasVerticalLayoutOverflow()) |
| return; |
| |
| for (RootInlineBox* curr = firstRootBox(); curr; curr = curr->nextRootBox()) { |
| LayoutUnit top = std::max<LayoutUnit>(curr->lineTop(), curr->y()); |
| LayoutUnit bottom = |
| std::min<LayoutUnit>(curr->lineBottom(), curr->y() + curr->height()); |
| LayoutRect rect(layerOffset.x() + curr->x(), layerOffset.y() + top, |
| curr->width(), bottom - top); |
| // It's common for this rect to be entirely contained in our box, so exclude |
| // that simple case. |
| if (!rect.isEmpty() && (rects.isEmpty() || !rects[0].contains(rect))) |
| rects.push_back(rect); |
| } |
| } |
| |
| void LayoutBlockFlow::absoluteRects( |
| Vector<IntRect>& rects, |
| const LayoutPoint& accumulatedOffset) const { |
| if (!isAnonymousBlockContinuation()) { |
| LayoutBlock::absoluteRects(rects, accumulatedOffset); |
| return; |
| } |
| // For blocks inside inlines, we go ahead and include margins so that we run |
| // right up to the inline boxes above and below us (thus getting merged with |
| // them to form a single irregular shape). |
| // FIXME: This is wrong for vertical writing-modes. |
| // https://bugs.webkit.org/show_bug.cgi?id=46781 |
| LayoutRect rect(accumulatedOffset, size()); |
| rect.expand(collapsedMarginBoxLogicalOutsets()); |
| rects.push_back(pixelSnappedIntRect(rect)); |
| continuation()->absoluteRects( |
| rects, |
| accumulatedOffset - |
| toLayoutSize( |
| location() + |
| inlineElementContinuation()->containingBlock()->location())); |
| } |
| |
| void LayoutBlockFlow::absoluteQuads(Vector<FloatQuad>& quads, |
| MapCoordinatesFlags mode) const { |
| if (!isAnonymousBlockContinuation()) { |
| LayoutBlock::absoluteQuads(quads, mode); |
| return; |
| } |
| LayoutBoxModelObject::absoluteQuads(quads, mode); |
| } |
| |
| void LayoutBlockFlow::absoluteQuadsForSelf(Vector<FloatQuad>& quads, |
| MapCoordinatesFlags mode) const { |
| // For blocks inside inlines, we go ahead and include margins so that we run |
| // right up to the inline boxes above and below us (thus getting merged with |
| // them to form a single irregular shape). |
| // FIXME: This is wrong for vertical writing-modes. |
| // https://bugs.webkit.org/show_bug.cgi?id=46781 |
| LayoutRect localRect(LayoutPoint(), size()); |
| localRect.expand(collapsedMarginBoxLogicalOutsets()); |
| quads.push_back(localToAbsoluteQuad(FloatRect(localRect), mode)); |
| } |
| |
| LayoutObject* LayoutBlockFlow::hoverAncestor() const { |
| return isAnonymousBlockContinuation() ? continuation() |
| : LayoutBlock::hoverAncestor(); |
| } |
| |
| RootInlineBox* LayoutBlockFlow::createAndAppendRootInlineBox() { |
| RootInlineBox* rootBox = createRootInlineBox(); |
| m_lineBoxes.appendLineBox(rootBox); |
| |
| return rootBox; |
| } |
| |
| void LayoutBlockFlow::deleteLineBoxTree() { |
| if (containsFloats()) |
| m_floatingObjects->clearLineBoxTreePointers(); |
| |
| m_lineBoxes.deleteLineBoxTree(); |
| } |
| |
| int LayoutBlockFlow::lineCount(const RootInlineBox* stopRootInlineBox) const { |
| #ifndef NDEBUG |
| ASSERT(!stopRootInlineBox || |
| stopRootInlineBox->block().debugPointer() == this); |
| #endif |
| if (!childrenInline()) |
| return 0; |
| |
| int count = 0; |
| for (const RootInlineBox* box = firstRootBox(); box; |
| box = box->nextRootBox()) { |
| count++; |
| if (box == stopRootInlineBox) |
| break; |
| } |
| return count; |
| } |
| |
| int LayoutBlockFlow::firstLineBoxBaseline() const { |
| if (isWritingModeRoot() && !isRubyRun()) |
| return -1; |
| if (!childrenInline()) |
| return LayoutBlock::firstLineBoxBaseline(); |
| if (firstLineBox()) { |
| const SimpleFontData* fontData = style(true)->font().primaryFont(); |
| DCHECK(fontData); |
| if (!fontData) |
| return -1; |
| return (firstLineBox()->logicalTop() + |
| fontData->getFontMetrics().ascent(firstRootBox()->baselineType())) |
| .toInt(); |
| } |
| return -1; |
| } |
| |
| int LayoutBlockFlow::inlineBlockBaseline( |
| LineDirectionMode lineDirection) const { |
| // CSS2.1 states that the baseline of an 'inline-block' is: |
| // the baseline of the last line box in the normal flow, unless it has |
| // either no in-flow line boxes or if its 'overflow' property has a computed |
| // value other than 'visible', in which case the baseline is the bottom |
| // margin edge. |
| // We likewise avoid using the last line box in the case of size containment, |
| // where the block's contents shouldn't be considered when laying out its |
| // ancestors or siblings. |
| |
| if ((!style()->isOverflowVisible() && |
| !shouldIgnoreOverflowPropertyForInlineBlockBaseline()) || |
| style()->containsSize()) { |
| // We are not calling baselinePosition here because the caller should add |
| // the margin-top/margin-right, not us. |
| return (lineDirection == HorizontalLine ? size().height() + marginBottom() |
| : size().width() + marginLeft()) |
| .toInt(); |
| } |
| if (isWritingModeRoot() && !isRubyRun()) |
| return -1; |
| if (!childrenInline()) |
| return LayoutBlock::inlineBlockBaseline(lineDirection); |
| if (lastLineBox()) { |
| const SimpleFontData* fontData = |
| style(lastLineBox() == firstLineBox())->font().primaryFont(); |
| DCHECK(fontData); |
| if (!fontData) |
| return -1; |
| // InlineFlowBox::placeBoxesInBlockDirection will flip lines in |
| // case of verticalLR mode, so we can assume verticalRL for now. |
| if (style()->isFlippedLinesWritingMode()) { |
| return (logicalHeight() - lastLineBox()->logicalBottom() + |
| fontData->getFontMetrics().ascent(lastRootBox()->baselineType())) |
| .toInt(); |
| } |
| return (lastLineBox()->logicalTop() + |
| fontData->getFontMetrics().ascent(lastRootBox()->baselineType())) |
| .toInt(); |
| } |
| if (!hasLineIfEmpty()) |
| return -1; |
| |
| const SimpleFontData* fontData = firstLineStyle()->font().primaryFont(); |
| DCHECK(fontData); |
| if (!fontData) |
| return -1; |
| |
| const FontMetrics& fontMetrics = fontData->getFontMetrics(); |
| return (fontMetrics.ascent() + |
| (lineHeight(true, lineDirection, PositionOfInteriorLineBoxes) - |
| fontMetrics.height()) / |
| 2 + |
| (lineDirection == HorizontalLine ? borderTop() + paddingTop() |
| : borderRight() + paddingRight())) |
| .toInt(); |
| } |
| |
| void LayoutBlockFlow::removeFloatingObjectsFromDescendants() { |
| if (!containsFloats()) |
| return; |
| removeFloatingObjects(); |
| setChildNeedsLayout(MarkOnlyThis); |
| |
| // If our children are inline, then the only boxes which could contain floats |
| // are atomic inlines (e.g. inline-block, float etc.) and these create |
| // formatting contexts, so can't pick up intruding floats from |
| // ancestors/siblings - making them safe to skip. |
| if (childrenInline()) |
| return; |
| for (LayoutObject* child = firstChild(); child; |
| child = child->nextSibling()) { |
| // We don't skip blocks that create formatting contexts as they may have |
| // only recently changed style and their float lists may still contain |
| // floats from siblings and ancestors. |
| if (child->isLayoutBlockFlow()) |
| toLayoutBlockFlow(child)->removeFloatingObjectsFromDescendants(); |
| } |
| } |
| |
| void LayoutBlockFlow::markAllDescendantsWithFloatsForLayout( |
| LayoutBox* floatToRemove, |
| bool inLayout) { |
| if (!everHadLayout() && !containsFloats()) |
| return; |
| |
| if (m_descendantsWithFloatsMarkedForLayout && !floatToRemove) |
| return; |
| m_descendantsWithFloatsMarkedForLayout |= !floatToRemove; |
| |
| MarkingBehavior markParents = inLayout ? MarkOnlyThis : MarkContainerChain; |
| setChildNeedsLayout(markParents); |
| |
| if (floatToRemove) |
| removeFloatingObject(floatToRemove); |
| |
| // Iterate over our children and mark them as needed. If our children are |
| // inline, then the only boxes which could contain floats are atomic inlines |
| // (e.g. inline-block, float etc.) and these create formatting contexts, so |
| // can't pick up intruding floats from ancestors/siblings - making them safe |
| // to skip. |
| if (!childrenInline()) { |
| for (LayoutObject* child = firstChild(); child; |
| child = child->nextSibling()) { |
| if ((!floatToRemove && child->isFloatingOrOutOfFlowPositioned()) || |
| !child->isLayoutBlock()) |
| continue; |
| if (!child->isLayoutBlockFlow()) { |
| LayoutBlock* childBlock = toLayoutBlock(child); |
| if (childBlock->shrinkToAvoidFloats() && childBlock->everHadLayout()) |
| childBlock->setChildNeedsLayout(markParents); |
| continue; |
| } |
| LayoutBlockFlow* childBlockFlow = toLayoutBlockFlow(child); |
| if ((floatToRemove ? childBlockFlow->containsFloat(floatToRemove) |
| : childBlockFlow->containsFloats()) || |
| childBlockFlow->shrinkToAvoidFloats()) |
| childBlockFlow->markAllDescendantsWithFloatsForLayout(floatToRemove, |
| inLayout); |
| } |
| } |
| } |
| |
| void LayoutBlockFlow::markSiblingsWithFloatsForLayout( |
| LayoutBox* floatToRemove) { |
| if (!m_floatingObjects) |
| return; |
| |
| const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set(); |
| FloatingObjectSetIterator end = floatingObjectSet.end(); |
| |
| for (LayoutObject* next = nextSibling(); next; next = next->nextSibling()) { |
| if (!next->isLayoutBlockFlow() || |
| (!floatToRemove && (next->isFloatingOrOutOfFlowPositioned() || |
| toLayoutBlockFlow(next)->avoidsFloats()))) |
| continue; |
| |
| LayoutBlockFlow* nextBlock = toLayoutBlockFlow(next); |
| for (FloatingObjectSetIterator it = floatingObjectSet.begin(); it != end; |
| ++it) { |
| LayoutBox* floatingBox = (*it)->layoutObject(); |
| if (floatToRemove && floatingBox != floatToRemove) |
| continue; |
| if (nextBlock->containsFloat(floatingBox)) |
| nextBlock->markAllDescendantsWithFloatsForLayout(floatingBox); |
| } |
| } |
| } |
| |
| LayoutUnit LayoutBlockFlow::getClearDelta(LayoutBox* child, |
| LayoutUnit logicalTop) { |
| // There is no need to compute clearance if we have no floats. |
| if (!containsFloats()) |
| return LayoutUnit(); |
| |
| // At least one float is present. We need to perform the clearance |
| // computation. |
| EClear clear = child->style()->clear(); |
| LayoutUnit logicalBottom = lowestFloatLogicalBottom(clear); |
| |
| // We also clear floats if we are too big to sit on the same line as a float |
| // (and wish to avoid floats by default). |
| LayoutUnit result = clear != EClear::kNone |
| ? (logicalBottom - logicalTop).clampNegativeToZero() |
| : LayoutUnit(); |
| if (!result && child->avoidsFloats()) { |
| LayoutUnit newLogicalTop = logicalTop; |
| LayoutRect borderBox = child->borderBoxRect(); |
| LayoutUnit childLogicalWidthAtOldLogicalTopOffset = |
| isHorizontalWritingMode() ? borderBox.width() : borderBox.height(); |
| while (true) { |
| LayoutUnit availableLogicalWidthAtNewLogicalTopOffset = |
| availableLogicalWidthForLine(newLogicalTop, DoNotIndentText, |
| logicalHeightForChild(*child)); |
| if (availableLogicalWidthAtNewLogicalTopOffset == |
| availableLogicalWidthForContent()) |
| return newLogicalTop - logicalTop; |
| |
| LogicalExtentComputedValues computedValues; |
| child->logicalExtentAfterUpdatingLogicalWidth(newLogicalTop, |
| computedValues); |
| LayoutUnit childLogicalWidthAtNewLogicalTopOffset = |
| computedValues.m_extent; |
| |
| if (childLogicalWidthAtNewLogicalTopOffset <= |
| availableLogicalWidthAtNewLogicalTopOffset) { |
| // Even though we may not be moving, if the logical width did shrink |
| // because of the presence of new floats, then we need to force a |
| // relayout as though we shifted. This happens because of the dynamic |
| // addition of overhanging floats from previous siblings when negative |
| // margins exist on a child (see the addOverhangingFloats call at the |
| // end of collapseMargins). |
| if (childLogicalWidthAtOldLogicalTopOffset != |
| childLogicalWidthAtNewLogicalTopOffset) |
| child->setChildNeedsLayout(MarkOnlyThis); |
| return newLogicalTop - logicalTop; |
| } |
| |
| newLogicalTop = nextFloatLogicalBottomBelowForBlock(newLogicalTop); |
| ASSERT(newLogicalTop >= logicalTop); |
| if (newLogicalTop < logicalTop) |
| break; |
| } |
| NOTREACHED(); |
| } |
| return result; |
| } |
| |
| void LayoutBlockFlow::createFloatingObjects() { |
| m_floatingObjects = |
| WTF::wrapUnique(new FloatingObjects(this, isHorizontalWritingMode())); |
| } |
| |
| void LayoutBlockFlow::willBeDestroyed() { |
| // Mark as being destroyed to avoid trouble with merges in removeChild(). |
| m_beingDestroyed = true; |
| |
| // Make sure to destroy anonymous children first while they are still |
| // connected to the rest of the tree, so that they will properly dirty line |
| // boxes that they are removed from. Effects that do :before/:after only on |
| // hover could crash otherwise. |
| children()->destroyLeftoverChildren(); |
| |
| // Destroy our continuation before anything other than anonymous children. |
| // The reason we don't destroy it before anonymous children is that they may |
| // have continuations of their own that are anonymous children of our |
| // continuation. |
| LayoutBoxModelObject* continuation = this->continuation(); |
| if (continuation) { |
| continuation->destroy(); |
| setContinuation(nullptr); |
| } |
| |
| if (!documentBeingDestroyed()) { |
| // TODO(mstensho): figure out if we need this. We have no test coverage for |
| // it. It looks like all line boxes have been removed at this point. |
| if (firstLineBox()) { |
| // We can't wait for LayoutBox::destroy to clear the selection, |
| // because by then we will have nuked the line boxes. |
| // FIXME: The FrameSelection should be responsible for this when it |
| // is notified of DOM mutations. |
| if (isSelectionBorder()) |
| view()->clearSelection(); |
| |
| // If we are an anonymous block, then our line boxes might have children |
| // that will outlast this block. In the non-anonymous block case those |
| // children will be destroyed by the time we return from this function. |
| if (isAnonymousBlock()) { |
| for (InlineFlowBox* box = firstLineBox(); box; |
| box = box->nextLineBox()) { |
| while (InlineBox* childBox = box->firstChild()) |
| childBox->remove(); |
| } |
| } |
| } |
| } |
| |
| m_lineBoxes.deleteLineBoxes(); |
| |
| LayoutBlock::willBeDestroyed(); |
| } |
| |
| void LayoutBlockFlow::styleWillChange(StyleDifference diff, |
| const ComputedStyle& newStyle) { |
| const ComputedStyle* oldStyle = style(); |
| s_canPropagateFloatIntoSibling = |
| oldStyle ? !isFloatingOrOutOfFlowPositioned() && !avoidsFloats() : false; |
| if (oldStyle && parent() && diff.needsFullLayout() && |
| oldStyle->position() != newStyle.position() && containsFloats() && |
| !isFloating() && !isOutOfFlowPositioned() && |
| newStyle.hasOutOfFlowPosition()) |
| markAllDescendantsWithFloatsForLayout(); |
| |
| LayoutBlock::styleWillChange(diff, newStyle); |
| } |
| |
| DISABLE_CFI_PERF |
| void LayoutBlockFlow::styleDidChange(StyleDifference diff, |
| const ComputedStyle* oldStyle) { |
| bool hadSelfPaintingLayer = hasSelfPaintingLayer(); |
| LayoutBlock::styleDidChange(diff, oldStyle); |
| |
| // After our style changed, if we lose our ability to propagate floats into |
| // next sibling blocks, then we need to find the top most parent containing |
| // that overhanging float and then mark its descendants with floats for layout |
| // and clear all floats from its next sibling blocks that exist in our |
| // floating objects list. See crbug.com/56299 and crbug.com/62875. |
| bool canPropagateFloatIntoSibling = |
| !isFloatingOrOutOfFlowPositioned() && !avoidsFloats(); |
| bool siblingFloatPropagationChanged = |
| diff.needsFullLayout() && s_canPropagateFloatIntoSibling && |
| !canPropagateFloatIntoSibling && hasOverhangingFloats(); |
| |
| // When this object's self-painting layer status changed, we should update |
| // FloatingObjects::shouldPaint() flags for descendant overhanging floats in |
| // ancestors. |
| bool needsUpdateAncestorFloatObjectShouldPaintFlags = false; |
| if (hasSelfPaintingLayer() != hadSelfPaintingLayer && |
| hasOverhangingFloats()) { |
| setNeedsLayout(LayoutInvalidationReason::StyleChange); |
| if (hadSelfPaintingLayer) |
| markAllDescendantsWithFloatsForLayout(); |
| else |
| needsUpdateAncestorFloatObjectShouldPaintFlags = true; |
| } |
| |
| if (siblingFloatPropagationChanged || |
| needsUpdateAncestorFloatObjectShouldPaintFlags) { |
| LayoutBlockFlow* parentBlockFlow = this; |
| const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set(); |
| FloatingObjectSetIterator end = floatingObjectSet.end(); |
| |
| for (LayoutObject* curr = parent(); curr && !curr->isLayoutView(); |
| curr = curr->parent()) { |
| if (curr->isLayoutBlockFlow()) { |
| LayoutBlockFlow* currBlock = toLayoutBlockFlow(curr); |
| |
| if (currBlock->hasOverhangingFloats()) { |
| for (FloatingObjectSetIterator it = floatingObjectSet.begin(); |
| it != end; ++it) { |
| LayoutBox* layoutBox = (*it)->layoutObject(); |
| if (currBlock->hasOverhangingFloat(layoutBox)) { |
| parentBlockFlow = currBlock; |
| break; |
| } |
| } |
| } |
| } |
| } |
| |
| parentBlockFlow->markAllDescendantsWithFloatsForLayout(); |
| if (siblingFloatPropagationChanged) |
| parentBlockFlow->markSiblingsWithFloatsForLayout(); |
| } |
| |
| if (diff.needsFullLayout() || !oldStyle) |
| createOrDestroyMultiColumnFlowThreadIfNeeded(oldStyle); |
| if (oldStyle) { |
| if (LayoutMultiColumnFlowThread* flowThread = multiColumnFlowThread()) { |
| if (!style()->columnRuleEquivalent(oldStyle)) { |
| // Column rules are painted by anonymous column set children of the |
| // multicol container. We need to notify them. |
| flowThread->columnRuleStyleDidChange(); |
| } |
| } |
| } |
| } |
| |
| void LayoutBlockFlow::updateBlockChildDirtyBitsBeforeLayout( |
| bool relayoutChildren, |
| LayoutBox& child) { |
| if (child.isLayoutMultiColumnSpannerPlaceholder()) |
| toLayoutMultiColumnSpannerPlaceholder(child) |
| .markForLayoutIfObjectInFlowThreadNeedsLayout(); |
| LayoutBlock::updateBlockChildDirtyBitsBeforeLayout(relayoutChildren, child); |
| } |
| |
| void LayoutBlockFlow::updateStaticInlinePositionForChild( |
| LayoutBox& child, |
| LayoutUnit logicalTop, |
| IndentTextOrNot indentText) { |
| if (child.style()->isOriginalDisplayInlineType()) |
| setStaticInlinePositionForChild( |
| child, startAlignedOffsetForLine(logicalTop, indentText)); |
| else |
| setStaticInlinePositionForChild(child, startOffsetForContent()); |
| } |
| |
| void LayoutBlockFlow::setStaticInlinePositionForChild( |
| LayoutBox& child, |
| LayoutUnit inlinePosition) { |
| child.layer()->setStaticInlinePosition(inlinePosition); |
| } |
| |
| LayoutInline* LayoutBlockFlow::inlineElementContinuation() const { |
| LayoutBoxModelObject* continuation = this->continuation(); |
| return continuation && continuation->isInline() ? toLayoutInline(continuation) |
| : nullptr; |
| } |
| |
| void LayoutBlockFlow::addChild(LayoutObject* newChild, |
| LayoutObject* beforeChild) { |
| if (LayoutMultiColumnFlowThread* flowThread = multiColumnFlowThread()) { |
| if (beforeChild == flowThread) |
| beforeChild = flowThread->firstChild(); |
| ASSERT(!beforeChild || beforeChild->isDescendantOf(flowThread)); |
| flowThread->addChild(newChild, beforeChild); |
| return; |
| } |
| |
| if (beforeChild && beforeChild->parent() != this) { |
| addChildBeforeDescendant(newChild, beforeChild); |
| return; |
| } |
| |
| bool madeBoxesNonInline = false; |
| |
| // A block has to either have all of its children inline, or all of its |
| // children as blocks. |
| // So, if our children are currently inline and a block child has to be |
| // inserted, we move all our inline children into anonymous block boxes. |
| bool childIsBlockLevel = |
| !newChild->isInline() && !newChild->isFloatingOrOutOfFlowPositioned(); |
| if (childrenInline()) { |
| if (childIsBlockLevel) { |
| // Wrap the inline content in anonymous blocks, to allow for the new block |
| // child to be inserted. |
| makeChildrenNonInline(beforeChild); |
| madeBoxesNonInline = true; |
| |
| if (beforeChild && beforeChild->parent() != this) { |
| beforeChild = beforeChild->parent(); |
| ASSERT(beforeChild->isAnonymousBlock()); |
| ASSERT(beforeChild->parent() == this); |
| } |
| } |
| } else if (!childIsBlockLevel) { |
| // This block has block children. We may want to put the new child into an |
| // anomyous block. Floats and out-of-flow children may live among either |
| // block or inline children, so for such children, only put them inside an |
| // anonymous block if one already exists. If the child is inline, on the |
| // other hand, we *have to* put it inside an anonymous block, so create a |
| // new one if there is none for us there already. |
| LayoutObject* afterChild = |
| beforeChild ? beforeChild->previousSibling() : lastChild(); |
| |
| if (afterChild && afterChild->isAnonymousBlock()) { |
| afterChild->addChild(newChild); |
| return; |
| } |
| |
| if (newChild->isInline()) { |
| // No suitable existing anonymous box - create a new one. |
| LayoutBlockFlow* newBlock = toLayoutBlockFlow(createAnonymousBlock()); |
| LayoutBox::addChild(newBlock, beforeChild); |
| // Reparent adjacent floating or out-of-flow siblings to the new box. |
| newBlock->reparentPrecedingFloatingOrOutOfFlowSiblings(); |
| newBlock->addChild(newChild); |
| newBlock->reparentSubsequentFloatingOrOutOfFlowSiblings(); |
| return; |
| } |
| } |
| |
| // Skip the LayoutBlock override, since that one deals with anonymous child |
| // insertion in a way that isn't sufficient for us, and can only cause trouble |
| // at this point. |
| LayoutBox::addChild(newChild, beforeChild); |
| |
| if (madeBoxesNonInline && parent() && isAnonymousBlock() && |
| parent()->isLayoutBlock()) { |
| toLayoutBlock(parent())->removeLeftoverAnonymousBlock(this); |
| // |this| may be dead now. |
| } |
| } |
| |
| static bool isMergeableAnonymousBlock(const LayoutBlockFlow* block) { |
| return block->isAnonymousBlock() && !block->continuation() && |
| !block->beingDestroyed() && !block->isRubyRun() && |
| !block->isRubyBase(); |
| } |
| |
| void LayoutBlockFlow::removeChild(LayoutObject* oldChild) { |
| // No need to waste time in merging or removing empty anonymous blocks. |
| // We can just bail out if our document is getting destroyed. |
| if (documentBeingDestroyed()) { |
| LayoutBox::removeChild(oldChild); |
| return; |
| } |
| |
| // If this child is a block, and if our previous and next siblings are |
| // both anonymous blocks with inline content, then we can go ahead and |
| // fold the inline content back together. |
| LayoutObject* prev = oldChild->previousSibling(); |
| LayoutObject* next = oldChild->nextSibling(); |
| bool mergedAnonymousBlocks = false; |
| if (prev && next && !oldChild->isInline() && |
| !oldChild->virtualContinuation() && prev->isLayoutBlockFlow() && |
| next->isLayoutBlockFlow()) { |
| if (toLayoutBlockFlow(prev)->mergeSiblingContiguousAnonymousBlock( |
| toLayoutBlockFlow(next))) { |
| mergedAnonymousBlocks = true; |
| next = nullptr; |
| } |
| } |
| |
| LayoutBlock::removeChild(oldChild); |
| |
| LayoutObject* child = prev ? prev : next; |
| if (child && child->isLayoutBlockFlow() && !child->previousSibling() && |
| !child->nextSibling()) { |
| // If the removal has knocked us down to containing only a single anonymous |
| // box we can go ahead and pull the content right back up into our |
| // box. |
| if (mergedAnonymousBlocks || |
| isMergeableAnonymousBlock(toLayoutBlockFlow(child))) |
| collapseAnonymousBlockChild(toLayoutBlockFlow(child)); |
| } |
| |
| if (!firstChild()) { |
| // If this was our last child be sure to clear out our line boxes. |
| if (childrenInline()) |
| deleteLineBoxTree(); |
| |
| // If we are an empty anonymous block in the continuation chain, |
| // we need to remove ourself and fix the continuation chain. |
| if (!beingDestroyed() && isAnonymousBlockContinuation() && |
| !oldChild->isListMarker()) { |
| LayoutObject* containingBlockIgnoringAnonymous = containingBlock(); |
| while (containingBlockIgnoringAnonymous && |
| containingBlockIgnoringAnonymous->isAnonymous()) |
| containingBlockIgnoringAnonymous = |
| containingBlockIgnoringAnonymous->containingBlock(); |
| for (LayoutObject* curr = this; curr; |
| curr = curr->previousInPreOrder(containingBlockIgnoringAnonymous)) { |
| if (curr->virtualContinuation() != this) |
| continue; |
| |
| // Found our previous continuation. We just need to point it to |
| // |this|'s next continuation. |
| LayoutBoxModelObject* nextContinuation = continuation(); |
| if (curr->isLayoutInline()) |
| toLayoutInline(curr)->setContinuation(nextContinuation); |
| else if (curr->isLayoutBlockFlow()) |
| toLayoutBlockFlow(curr)->setContinuation(nextContinuation); |
| else |
| NOTREACHED(); |
| |
| break; |
| } |
| setContinuation(nullptr); |
| destroy(); |
| } |
| } else if (!beingDestroyed() && |
| !oldChild->isFloatingOrOutOfFlowPositioned() && |
| !oldChild->isAnonymousBlock()) { |
| // If the child we're removing means that we can now treat all children as |
| // inline without the need for anonymous blocks, then do that. |
| makeChildrenInlineIfPossible(); |
| } |
| } |
| |
| void LayoutBlockFlow::moveAllChildrenIncludingFloatsTo(LayoutBlock* toBlock, |
| bool fullRemoveInsert) { |
| LayoutBlockFlow* toBlockFlow = toLayoutBlockFlow(toBlock); |
| moveAllChildrenTo(toBlockFlow, fullRemoveInsert); |
| |
| // When a portion of the layout tree is being detached, anonymous blocks |
| // will be combined as their children are deleted. In this process, the |
| // anonymous block later in the tree is merged into the one preceding it. |
| // It can happen that the later block (this) contains floats that the |
| // previous block (toBlockFlow) did not contain, and thus are not in the |
| // floating objects list for toBlockFlow. This can result in toBlockFlow |
| // containing floats that are not in it's floating objects list, but are in |
| // the floating objects lists of siblings and parents. This can cause problems |
| // when the float itself is deleted, since the deletion code assumes that if a |
| // float is not in it's containing block's floating objects list, it isn't in |
| // any floating objects list. In order to preserve this condition (removing it |
| // has serious performance implications), we need to copy the floating objects |
| // from the old block (this) to the new block (toBlockFlow). |
| // The float's metrics will likely all be wrong, but since toBlockFlow is |
| // already marked for layout, this will get fixed before anything gets |
| // displayed. |
| // See bug https://code.google.com/p/chromium/issues/detail?id=230907 |
| if (m_floatingObjects) { |
| if (!toBlockFlow->m_floatingObjects) |
| toBlockFlow->createFloatingObjects(); |
| |
| const FloatingObjectSet& fromFloatingObjectSet = m_floatingObjects->set(); |
| FloatingObjectSetIterator end = fromFloatingObjectSet.end(); |
| |
| for (FloatingObjectSetIterator it = fromFloatingObjectSet.begin(); |
| it != end; ++it) { |
| const FloatingObject& floatingObject = *it->get(); |
| |
| // Don't insert the object again if it's already in the list |
| if (toBlockFlow->containsFloat(floatingObject.layoutObject())) |
| continue; |
| |
| toBlockFlow->m_floatingObjects->add(floatingObject.unsafeClone()); |
| } |
| } |
| } |
| |
| void LayoutBlockFlow::childBecameFloatingOrOutOfFlow(LayoutBox* child) { |
| makeChildrenInlineIfPossible(); |
| |
| // Reparent the child to an adjacent anonymous block if one is available. |
| LayoutObject* prev = child->previousSibling(); |
| if (prev && prev->isAnonymousBlock() && prev->isLayoutBlockFlow()) { |
| LayoutBlockFlow* newContainer = toLayoutBlockFlow(prev); |
| moveChildTo(newContainer, child, nullptr, false); |
| // The anonymous block we've moved to may now be adjacent to former siblings |
| // of ours that it can contain also. |
| newContainer->reparentSubsequentFloatingOrOutOfFlowSiblings(); |
| return; |
| } |
| LayoutObject* next = child->nextSibling(); |
| if (next && next->isAnonymousBlock() && next->isLayoutBlockFlow()) { |
| LayoutBlockFlow* newContainer = toLayoutBlockFlow(next); |
| moveChildTo(newContainer, child, newContainer->firstChild(), false); |
| } |
| } |
| |
| void LayoutBlockFlow::collapseAnonymousBlockChild(LayoutBlockFlow* child) { |
| // It's possible that this block's destruction may have been triggered by the |
| // child's removal. Just bail if the anonymous child block is already being |
| // destroyed. See crbug.com/282088 |
| if (child->beingDestroyed()) |
| return; |
| if (child->continuation()) |
| return; |
| // Ruby elements use anonymous wrappers for ruby runs and ruby bases by |
| // design, so we don't remove them. |
| if (child->isRubyRun() || child->isRubyBase()) |
| return; |
| setNeedsLayoutAndPrefWidthsRecalcAndFullPaintInvalidation( |
| LayoutInvalidationReason::ChildAnonymousBlockChanged); |
| |
| child->moveAllChildrenTo(this, child->nextSibling(), child->hasLayer()); |
| // If we make an object's children inline we are going to frustrate any future |
| // attempts to remove floats from its children's float-lists before the next |
| // layout happens so clear down all the floatlists now - they will be rebuilt |
| // at layout. |
| if (child->childrenInline()) |
| removeFloatingObjectsFromDescendants(); |
| setChildrenInline(child->childrenInline()); |
| |
| children()->removeChildNode(this, child, child->hasLayer()); |
| child->destroy(); |
| } |
| |
| bool LayoutBlockFlow::mergeSiblingContiguousAnonymousBlock( |
| LayoutBlockFlow* siblingThatMayBeDeleted) { |
| // Note: |this| and |siblingThatMayBeDeleted| may not be adjacent siblings at |
| // this point. There may be an object between them which is about to be |
| // removed. |
| |
| if (!isMergeableAnonymousBlock(this) || |
| !isMergeableAnonymousBlock(siblingThatMayBeDeleted)) |
| return false; |
| |
| setNeedsLayoutAndPrefWidthsRecalcAndFullPaintInvalidation( |
| LayoutInvalidationReason::AnonymousBlockChange); |
| |
| // If the inlineness of children of the two block don't match, we'd need |
| // special code here (but there should be no need for it). |
| ASSERT(siblingThatMayBeDeleted->childrenInline() == childrenInline()); |
| // Take all the children out of the |next| block and put them in |
| // the |prev| block. |
| siblingThatMayBeDeleted->moveAllChildrenIncludingFloatsTo( |
| this, siblingThatMayBeDeleted->hasLayer() || hasLayer()); |
| // Delete the now-empty block's lines and nuke it. |
| siblingThatMayBeDeleted->deleteLineBoxTree(); |
| siblingThatMayBeDeleted->destroy(); |
| return true; |
| } |
| |
| void LayoutBlockFlow::reparentSubsequentFloatingOrOutOfFlowSiblings() { |
| if (!parent() || !parent()->isLayoutBlockFlow()) |
| return; |
| if (beingDestroyed() || documentBeingDestroyed()) |
| return; |
| LayoutBlockFlow* parentBlockFlow = toLayoutBlockFlow(parent()); |
| LayoutObject* child = nextSibling(); |
| while (child && child->isFloatingOrOutOfFlowPositioned()) { |
| LayoutObject* sibling = child->nextSibling(); |
| parentBlockFlow->moveChildTo(this, child, nullptr, false); |
| child = sibling; |
| } |
| |
| if (LayoutObject* next = nextSibling()) { |
| if (next->isLayoutBlockFlow()) |
| mergeSiblingContiguousAnonymousBlock(toLayoutBlockFlow(next)); |
| } |
| } |
| |
| void LayoutBlockFlow::reparentPrecedingFloatingOrOutOfFlowSiblings() { |
| if (!parent() || !parent()->isLayoutBlockFlow()) |
| return; |
| if (beingDestroyed() || documentBeingDestroyed()) |
| return; |
| LayoutBlockFlow* parentBlockFlow = toLayoutBlockFlow(parent()); |
| LayoutObject* child = previousSibling(); |
| while (child && child->isFloatingOrOutOfFlowPositioned()) { |
| LayoutObject* sibling = child->previousSibling(); |
| parentBlockFlow->moveChildTo(this, child, firstChild(), false); |
| child = sibling; |
| } |
| } |
| |
| void LayoutBlockFlow::makeChildrenInlineIfPossible() { |
| // Collapsing away anonymous wrappers isn't relevant for the children of |
| // anonymous blocks, unless they are ruby bases. |
| if (isAnonymousBlock() && !isRubyBase()) |
| return; |
| |
| Vector<LayoutBlockFlow*, 3> blocksToRemove; |
| for (LayoutObject* child = firstChild(); child; |
| child = child->nextSibling()) { |
| if (child->isFloating()) |
| continue; |
| if (child->isOutOfFlowPositioned()) |
| continue; |
| |
| // There are still block children in the container, so any anonymous |
| // wrappers are still needed. |
| if (!child->isAnonymousBlock() || !child->isLayoutBlockFlow()) |
| return; |
| // If one of the children is being destroyed then it is unsafe to clean up |
| // anonymous wrappers as the |
| // entire branch may be being destroyed. |
| if (toLayoutBlockFlow(child)->beingDestroyed()) |
| return; |
| // We can't remove anonymous wrappers if they contain continuations as this |
| // means there are block children present. |
| if (toLayoutBlockFlow(child)->continuation()) |
| return; |
| // We are only interested in removing anonymous wrappers if there are inline |
| // siblings underneath them. |
| if (!child->childrenInline()) |
| return; |
| // Ruby elements use anonymous wrappers for ruby runs and ruby bases by |
| // design, so we don't remove them. |
| if (child->isRubyRun() || child->isRubyBase()) |
| return; |
| |
| blocksToRemove.push_back(toLayoutBlockFlow(child)); |
| } |
| |
| // If we make an object's children inline we are going to frustrate any future |
| // attempts to remove floats from its children's float-lists before the next |
| // layout happens so clear down all the floatlists now - they will be rebuilt |
| // at layout. |
| removeFloatingObjectsFromDescendants(); |
| |
| for (size_t i = 0; i < blocksToRemove.size(); i++) |
| collapseAnonymousBlockChild(blocksToRemove[i]); |
| setChildrenInline(true); |
| } |
| |
| static void getInlineRun(LayoutObject* start, |
| LayoutObject* boundary, |
| LayoutObject*& inlineRunStart, |
| LayoutObject*& inlineRunEnd) { |
| // Beginning at |start| we find the largest contiguous run of inlines that |
| // we can. We denote the run with start and end points, |inlineRunStart| |
| // and |inlineRunEnd|. Note that these two values may be the same if |
| // we encounter only one inline. |
| // |
| // We skip any non-inlines we encounter as long as we haven't found any |
| // inlines yet. |
| // |
| // |boundary| indicates a non-inclusive boundary point. Regardless of whether |
| // |boundary| is inline or not, we will not include it in a run with inlines |
| // before it. It's as though we encountered a non-inline. |
| |
| // Start by skipping as many non-inlines as we can. |
| LayoutObject* curr = start; |
| bool sawInline; |
| do { |
| while (curr && |
| !(curr->isInline() || curr->isFloatingOrOutOfFlowPositioned())) |
| curr = curr->nextSibling(); |
| |
| inlineRunStart = inlineRunEnd = curr; |
| |
| if (!curr) |
| return; // No more inline children to be found. |
| |
| sawInline = curr->isInline(); |
| |
| curr = curr->nextSibling(); |
| while (curr && |
| (curr->isInline() || curr->isFloatingOrOutOfFlowPositioned()) && |
| (curr != boundary)) { |
| inlineRunEnd = curr; |
| if (curr->isInline()) |
| sawInline = true; |
| curr = curr->nextSibling(); |
| } |
| } while (!sawInline); |
| } |
| |
| void LayoutBlockFlow::makeChildrenNonInline(LayoutObject* insertionPoint) { |
| // makeChildrenNonInline takes a block whose children are *all* inline and it |
| // makes sure that inline children are coalesced under anonymous blocks. |
| // If |insertionPoint| is defined, then it represents the insertion point for |
| // the new block child that is causing us to have to wrap all the inlines. |
| // This means that we cannot coalesce inlines before |insertionPoint| with |
| // inlines following |insertionPoint|, because the new child is going to be |
| // inserted in between the inlines, splitting them. |
| ASSERT(!isInline() || isAtomicInlineLevel()); |
| ASSERT(!insertionPoint || insertionPoint->parent() == this); |
| |
| setChildrenInline(false); |
| |
| LayoutObject* child = firstChild(); |
| if (!child) |
| return; |
| |
| deleteLineBoxTree(); |
| |
| while (child) { |
| LayoutObject* inlineRunStart; |
| LayoutObject* inlineRunEnd; |
| getInlineRun(child, insertionPoint, inlineRunStart, inlineRunEnd); |
| |
| if (!inlineRunStart) |
| break; |
| |
| child = inlineRunEnd->nextSibling(); |
| |
| LayoutBlock* block = createAnonymousBlock(); |
| children()->insertChildNode(this, block, inlineRunStart); |
| moveChildrenTo(block, inlineRunStart, child); |
| } |
| |
| #if DCHECK_IS_ON() |
| for (LayoutObject* c = firstChild(); c; c = c->nextSibling()) |
| ASSERT(!c->isInline()); |
| #endif |
| |
| setShouldDoFullPaintInvalidation(); |
| } |
| |
| void LayoutBlockFlow::childBecameNonInline(LayoutObject*) { |
| makeChildrenNonInline(); |
| if (isAnonymousBlock() && parent() && parent()->isLayoutBlock()) |
| toLayoutBlock(parent())->removeLeftoverAnonymousBlock(this); |
| // |this| may be dead here |
| } |
| |
| void LayoutBlockFlow::clearFloats(EClear clear) { |
| placeNewFloats(logicalHeight()); |
| // set y position |
| LayoutUnit newY = lowestFloatLogicalBottom(clear); |
| if (size().height() < newY) |
| setLogicalHeight(newY); |
| } |
| |
| bool LayoutBlockFlow::containsFloat(LayoutBox* layoutBox) const { |
| return m_floatingObjects && |
| m_floatingObjects->set().contains<FloatingObjectHashTranslator>( |
| layoutBox); |
| } |
| |
| void LayoutBlockFlow::removeFloatingObjects() { |
| if (!m_floatingObjects) |
| return; |
| |
| markSiblingsWithFloatsForLayout(); |
| |
| m_floatingObjects->clear(); |
| } |
| |
| LayoutPoint LayoutBlockFlow::flipFloatForWritingModeForChild( |
| const FloatingObject& child, |
| const LayoutPoint& point) const { |
| if (!style()->isFlippedBlocksWritingMode()) |
| return point; |
| |
| // This is similar to LayoutBox::flipForWritingModeForChild. We have to |
| // subtract out our left offsets twice, since it's going to get added back in. |
| // We hide this complication here so that the calling code looks normal for |
| // the unflipped case. |
| return LayoutPoint(point.x() + size().width() - |
| child.layoutObject()->size().width() - |
| 2 * xPositionForFloatIncludingMargin(child), |
| point.y()); |
| } |
| |
| LayoutUnit LayoutBlockFlow::logicalLeftOffsetForPositioningFloat( |
| LayoutUnit logicalTop, |
| LayoutUnit fixedOffset, |
| LayoutUnit* heightRemaining) const { |
| LayoutUnit offset = fixedOffset; |
| if (m_floatingObjects && m_floatingObjects->hasLeftObjects()) |
| offset = m_floatingObjects->logicalLeftOffsetForPositioningFloat( |
| fixedOffset, logicalTop, heightRemaining); |
| return adjustLogicalLeftOffsetForLine(offset, DoNotIndentText); |
| } |
| |
| LayoutUnit LayoutBlockFlow::logicalRightOffsetForPositioningFloat( |
| LayoutUnit logicalTop, |
| LayoutUnit fixedOffset, |
| LayoutUnit* heightRemaining) const { |
| LayoutUnit offset = fixedOffset; |
| if (m_floatingObjects && m_floatingObjects->hasRightObjects()) |
| offset = m_floatingObjects->logicalRightOffsetForPositioningFloat( |
| fixedOffset, logicalTop, heightRemaining); |
| return adjustLogicalRightOffsetForLine(offset, DoNotIndentText); |
| } |
| |
| LayoutUnit LayoutBlockFlow::adjustLogicalLeftOffsetForLine( |
| LayoutUnit offsetFromFloats, |
| IndentTextOrNot applyTextIndent) const { |
| LayoutUnit left = offsetFromFloats; |
| |
| if (applyTextIndent == IndentText && style()->isLeftToRightDirection()) |
| left += textIndentOffset(); |
| |
| return left; |
| } |
| |
| LayoutUnit LayoutBlockFlow::adjustLogicalRightOffsetForLine( |
| LayoutUnit offsetFromFloats, |
| IndentTextOrNot applyTextIndent) const { |
| LayoutUnit right = offsetFromFloats; |
| |
| if (applyTextIndent == IndentText && !style()->isLeftToRightDirection()) |
| right -= textIndentOffset(); |
| |
| return right; |
| } |
| |
| LayoutPoint LayoutBlockFlow::computeLogicalLocationForFloat( |
| const FloatingObject& floatingObject, |
| LayoutUnit logicalTopOffset) const { |
| LayoutBox* childBox = floatingObject.layoutObject(); |
| LayoutUnit logicalLeftOffset = |
| logicalLeftOffsetForContent(); // Constant part of left offset. |
| LayoutUnit logicalRightOffset; // Constant part of right offset. |
| logicalRightOffset = logicalRightOffsetForContent(); |
| |
| LayoutUnit floatLogicalWidth = std::min( |
| logicalWidthForFloat(floatingObject), |
| logicalRightOffset - logicalLeftOffset); // The width we look for. |
| |
| LayoutUnit floatLogicalLeft; |
| |
| if (childBox->style()->floating() == EFloat::kLeft) { |
| LayoutUnit heightRemainingLeft = LayoutUnit(1); |
| LayoutUnit heightRemainingRight = LayoutUnit(1); |
| floatLogicalLeft = logicalLeftOffsetForPositioningFloat( |
| logicalTopOffset, logicalLeftOffset, &heightRemainingLeft); |
| while (logicalRightOffsetForPositioningFloat( |
| logicalTopOffset, logicalRightOffset, &heightRemainingRight) - |
| floatLogicalLeft < |
| floatLogicalWidth) { |
| logicalTopOffset += |
| std::min<LayoutUnit>(heightRemainingLeft, heightRemainingRight); |
| floatLogicalLeft = logicalLeftOffsetForPositioningFloat( |
| logicalTopOffset, logicalLeftOffset, &heightRemainingLeft); |
| } |
| floatLogicalLeft = std::max( |
| logicalLeftOffset - borderAndPaddingLogicalLeft(), floatLogicalLeft); |
| } else { |
| LayoutUnit heightRemainingLeft = LayoutUnit(1); |
| LayoutUnit heightRemainingRight = LayoutUnit(1); |
| floatLogicalLeft = logicalRightOffsetForPositioningFloat( |
| logicalTopOffset, logicalRightOffset, &heightRemainingRight); |
| while (floatLogicalLeft - |
| logicalLeftOffsetForPositioningFloat( |
| logicalTopOffset, logicalLeftOffset, &heightRemainingLeft) < |
| floatLogicalWidth) { |
| logicalTopOffset += std::min(heightRemainingLeft, heightRemainingRight); |
| floatLogicalLeft = logicalRightOffsetForPositioningFloat( |
| logicalTopOffset, logicalRightOffset, &heightRemainingRight); |
| } |
| // Use the original width of the float here, since the local variable |
| // |floatLogicalWidth| was capped to the available line width. See |
| // fast/block/float/clamped-right-float.html. |
| floatLogicalLeft -= logicalWidthForFloat(floatingObject); |
| } |
| |
| return LayoutPoint(floatLogicalLeft, logicalTopOffset); |
| } |
| |
| FloatingObject* LayoutBlockFlow::insertFloatingObject(LayoutBox& floatBox) { |
| ASSERT(floatBox.isFloating()); |
| |
| // Create the list of special objects if we don't aleady have one |
| if (!m_floatingObjects) { |
| createFloatingObjects(); |
| } else { |
| // Don't insert the object again if it's already in the list |
| const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set(); |
| FloatingObjectSetIterator it = |
| floatingObjectSet.find<FloatingObjectHashTranslator>(&floatBox); |
| if (it != floatingObjectSet.end()) |
| return it->get(); |
| } |
| |
| // Create the special object entry & append it to the list |
| |
| std::unique_ptr<FloatingObject> newObj = FloatingObject::create(&floatBox); |
| return m_floatingObjects->add(std::move(newObj)); |
| } |
| |
| void LayoutBlockFlow::removeFloatingObject(LayoutBox* floatBox) { |
| if (m_floatingObjects) { |
| const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set(); |
| FloatingObjectSetIterator it = |
| floatingObjectSet.find<FloatingObjectHashTranslator>(floatBox); |
| if (it != floatingObjectSet.end()) { |
| FloatingObject& floatingObject = *it->get(); |
| if (childrenInline()) { |
| LayoutUnit logicalTop = logicalTopForFloat(floatingObject); |
| LayoutUnit logicalBottom = logicalBottomForFloat(floatingObject); |
| |
| // Fix for https://bugs.webkit.org/show_bug.cgi?id=54995. |
| if (logicalBottom < 0 || logicalBottom < logicalTop || |
| logicalTop == LayoutUnit::max()) { |
| logicalBottom = LayoutUnit::max(); |
| } else { |
| // Special-case zero- and less-than-zero-height floats: those don't |
| // touch the line that they're on, but it still needs to be dirtied. |
| // This is accomplished by pretending they have a height of 1. |
| logicalBottom = std::max(logicalBottom, logicalTop + 1); |
| } |
| if (floatingObject.originatingLine()) { |
| if (!selfNeedsLayout()) { |
| ASSERT( |
| floatingObject.originatingLine()->getLineLayoutItem().isEqual( |
| this)); |
| floatingObject.originatingLine()->markDirty(); |
| } |
| #if DCHECK_IS_ON() |
| floatingObject.setOriginatingLine(nullptr); |
| #endif |
| } |
| markLinesDirtyInBlockRange(LayoutUnit(), logicalBottom); |
| } |
| m_floatingObjects->remove(&floatingObject); |
| } |
| } |
| } |
| |
| void LayoutBlockFlow::removeFloatingObjectsBelow(FloatingObject* lastFloat, |
| LayoutUnit logicalOffset) { |
| if (!containsFloats()) |
| return; |
| |
| const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set(); |
| FloatingObject* curr = floatingObjectSet.back().get(); |
| while (curr != lastFloat && |
| (!curr->isPlaced() || logicalTopForFloat(*curr) >= logicalOffset)) { |
| m_floatingObjects->remove(curr); |
| if (floatingObjectSet.isEmpty()) |
| break; |
| curr = floatingObjectSet.back().get(); |
| } |
| } |
| |
| bool LayoutBlockFlow::placeNewFloats(LayoutUnit logicalTopMarginEdge, |
| LineWidth* width) { |
| if (!m_floatingObjects) |
| return false; |
| |
| const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set(); |
| if (floatingObjectSet.isEmpty()) |
| return false; |
| |
| // If all floats have already been positioned, then we have no work to do. |
| if (floatingObjectSet.back()->isPlaced()) |
| return false; |
| |
| // Move backwards through our floating object list until we find a float that |
| // has already been positioned. Then we'll be able to move forward, |
| // positioning all of the new floats that need it. |
| FloatingObjectSetIterator it = floatingObjectSet.end(); |
| --it; // Go to last item. |
| FloatingObjectSetIterator begin = floatingObjectSet.begin(); |
| FloatingObject* lastPlacedFloatingObject = nullptr; |
| while (it != begin) { |
| --it; |
| if ((*it)->isPlaced()) { |
| lastPlacedFloatingObject = it->get(); |
| ++it; |
| break; |
| } |
| } |
| |
| // The float cannot start above the top position of the last positioned float. |
| if (lastPlacedFloatingObject) { |
| logicalTopMarginEdge = std::max( |
| logicalTopMarginEdge, logicalTopForFloat(*lastPlacedFloatingObject)); |
| } |
| |
| FloatingObjectSetIterator end = floatingObjectSet.end(); |
| // Now walk through the set of unpositioned floats and place them. |
| for (; it != end; ++it) { |
| FloatingObject& floatingObject = *it->get(); |
| // The containing block is responsible for positioning floats, so if we have |
| // unplaced floats in our list that come from somewhere else, we have a bug. |
| DCHECK_EQ(floatingObject.layoutObject()->containingBlock(), this); |
| |
| logicalTopMarginEdge = |
| positionAndLayoutFloat(floatingObject, logicalTopMarginEdge); |
| |
| m_floatingObjects->addPlacedObject(floatingObject); |
| |
| if (width) |
| width->shrinkAvailableWidthForNewFloatIfNeeded(floatingObject); |
| } |
| return true; |
| } |
| |
| LayoutUnit LayoutBlockFlow::positionAndLayoutFloat( |
| FloatingObject& floatingObject, |
| LayoutUnit logicalTopMarginEdge) { |
| // Once a float has been placed, we cannot update its position, or the float |
| // interval tree will be out of sync with reality. This may in turn lead to |
| // objects being used after they have been deleted. |
| CHECK(!floatingObject.isPlaced()); |
| |
| LayoutBox& child = *floatingObject.layoutObject(); |
| |
| // FIXME Investigate if this can be removed. crbug.com/370006 |
| child.setMayNeedPaintInvalidation(); |
| |
| logicalTopMarginEdge = std::max( |
| logicalTopMarginEdge, lowestFloatLogicalBottom(child.style()->clear())); |
| |
| bool isPaginated = view()->layoutState()->isPaginated(); |
| if (isPaginated && !childrenInline()) { |
| // Forced breaks are inserted at class A break points. Floats may be |
| // affected by a break-after value on the previous in-flow sibling. |
| if (LayoutBox* previousInFlowBox = child.previousInFlowSiblingBox()) { |
| logicalTopMarginEdge = applyForcedBreak(logicalTopMarginEdge, |
| previousInFlowBox->breakAfter()); |
| } |
| } |
| |
| if (child.needsLayout()) { |
| if (isPaginated) { |
| // Before we can lay out the float, we need to estimate a position for |
| // it. In order to do that, we first need to know its block start margin. |
| child.computeAndSetBlockDirectionMargins(this); |
| LayoutUnit marginBefore = marginBeforeForChild(child); |
| |
| // We have found the highest possible position for the float, so we'll |
| // lay out right there. Later on, we may be pushed further down by |
| // adjacent floats which we don't fit beside, or pushed by fragmentation |
| // if we need to break before the top margin edge of the float. |
| setLogicalTopForChild(child, logicalTopMarginEdge + marginBefore); |
| child.layout(); |
| |
| // May need to push the float to the next fragmentainer before attempting |
| // to place it. |
| logicalTopMarginEdge = |
| adjustFloatLogicalTopForPagination(child, logicalTopMarginEdge); |
| } else { |
| child.layout(); |
| } |
| } |
| |
| LayoutUnit marginStart = marginStartForChild(child); |
| LayoutUnit marginEnd = marginEndForChild(child); |
| setLogicalWidthForFloat( |
| floatingObject, logicalWidthForChild(child) + marginStart + marginEnd); |
| |
| // We have determined the logical width of the float. This is enough |
| // information to fit it among other floats according to float positioning |
| // rules. Note that logical *height* doesn't really matter yet (until we're |
| // going to place subsequent floats or other objects that are affected by |
| // floats), since no float may be positioned above the outer logical top edge |
| // of any other earlier float in the block formatting context. |
| LayoutUnit marginBefore = marginBeforeForChild(child); |
| LayoutUnit marginAfter = marginAfterForChild(child); |
| LayoutPoint floatLogicalLocation = |
| computeLogicalLocationForFloat(floatingObject, logicalTopMarginEdge); |
| logicalTopMarginEdge = floatLogicalLocation.y(); |
| setLogicalTopForChild(child, logicalTopMarginEdge + marginBefore); |
| |
| SubtreeLayoutScope layoutScope(child); |
| |
| // A new position may mean that we need to insert, move or remove breaks |
| // inside the float. We may also need to lay out if we just ceased to be |
| // fragmented, in order to remove pagination struts inside the child. |
| markChildForPaginationRelayoutIfNeeded(child, layoutScope); |
| child.layoutIfNeeded(); |
| |
| if (isPaginated) { |
| paginatedContentWasLaidOut(child.logicalBottom()); |
| |
| // We may have to insert a break before the float. |
| LayoutUnit newLogicalTopMarginEdge = |
| adjustFloatLogicalTopForPagination(child, logicalTopMarginEdge); |
| if (logicalTopMarginEdge != newLogicalTopMarginEdge) { |
| // We had already found a location for the float, but a soft |
| // fragmentainer break then made us push it further down. This may affect |
| // the inline position of the float (since we may no longer be beside the |
| // same floats anymore). Block position will remain unaffected, though. |
| floatLogicalLocation = computeLogicalLocationForFloat( |
| floatingObject, newLogicalTopMarginEdge); |
| DCHECK_EQ(floatLogicalLocation.y(), newLogicalTopMarginEdge); |
| logicalTopMarginEdge = newLogicalTopMarginEdge; |
| |
| setLogicalTopForChild(child, logicalTopMarginEdge + marginBefore); |
| |
| // Pushing the child to the next fragmentainer most likely means that we |
| // need to recalculate pagination struts inside it. |
| if (child.isLayoutBlock()) |
| child.setChildNeedsLayout(MarkOnlyThis); |
| child.layoutIfNeeded(); |
| paginatedContentWasLaidOut(child.logicalBottom()); |
| } |
| } |
| |
| LayoutUnit childLogicalLeftMargin = |
| style()->isLeftToRightDirection() ? marginStart : marginEnd; |
| setLogicalLeftForChild(child, |
| floatLogicalLocation.x() + childLogicalLeftMargin); |
| setLogicalLeftForFloat(floatingObject, floatLogicalLocation.x()); |
| setLogicalTopForFloat(floatingObject, logicalTopMarginEdge); |
| setLogicalHeightForFloat(floatingObject, logicalHeightForChild(child) + |
| marginBefore + marginAfter); |
| |
| if (ShapeOutsideInfo* shapeOutside = child.shapeOutsideInfo()) |
| shapeOutside->setReferenceBoxLogicalSize(logicalSizeForChild(child)); |
| |
| return logicalTopMarginEdge; |
| } |
| |
| bool LayoutBlockFlow::hasOverhangingFloat(LayoutBox* layoutBox) { |
| if (!m_floatingObjects || !parent()) |
| return false; |
| |
| const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set(); |
| FloatingObjectSetIterator it = |
| floatingObjectSet.find<FloatingObjectHashTranslator>(layoutBox); |
| if (it == floatingObjectSet.end()) |
| return false; |
| |
| return isOverhangingFloat(**it); |
| } |
| |
| void LayoutBlockFlow::addIntrudingFloats(LayoutBlockFlow* prev, |
| LayoutUnit logicalLeftOffset, |
| LayoutUnit logicalTopOffset) { |
| ASSERT(!avoidsFloats()); |
| |
| // If we create our own block formatting context then our contents don't |
| // interact with floats outside it, even those from our parent. |
| if (createsNewFormattingContext()) |
| return; |
| |
| // If the parent or previous sibling doesn't have any floats to add, don't |
| // bother. |
| if (!prev->m_floatingObjects) |
| return; |
| |
| logicalLeftOffset += marginLogicalLeft(); |
| |
| const FloatingObjectSet& prevSet = prev->m_floatingObjects->set(); |
| FloatingObjectSetIterator prevEnd = prevSet.end(); |
| for (FloatingObjectSetIterator prevIt = prevSet.begin(); prevIt != prevEnd; |
| ++prevIt) { |
| FloatingObject& floatingObject = *prevIt->get(); |
| if (logicalBottomForFloat(floatingObject) > logicalTopOffset) { |
| if (!m_floatingObjects || |
| !m_floatingObjects->set().contains(&floatingObject)) { |
| // We create the floating object list lazily. |
| if (!m_floatingObjects) |
| createFloatingObjects(); |
| |
| // Applying the child's margin makes no sense in the case where the |
| // child was passed in since this margin was added already through the |
| // modification of the |logicalLeftOffset| variable above. |
| // |logicalLeftOffset| will equal the margin in this case, so it's |
| // already been taken into account. Only apply this code if prev is the |
| // parent, since otherwise the left margin will get applied twice. |
| LayoutSize offset = |
| isHorizontalWritingMode() |
| ? LayoutSize( |
| logicalLeftOffset - (prev != parent() ? prev->marginLeft() |
| : LayoutUnit()), |
| logicalTopOffset) |
| : LayoutSize( |
| logicalTopOffset, |
| logicalLeftOffset - (prev != parent() ? prev->marginTop() |
| : LayoutUnit())); |
| |
| m_floatingObjects->add(floatingObject.copyToNewContainer(offset)); |
| } |
| } |
| } |
| } |
| |
| void LayoutBlockFlow::addOverhangingFloats(LayoutBlockFlow* child, |
| bool makeChildPaintOtherFloats) { |
| // Prevent floats from being added to the canvas by the root element, e.g., |
| // <html>. |
| if (!child->containsFloats() || child->createsNewFormattingContext()) |
| return; |
| |
| LayoutUnit childLogicalTop = child->logicalTop(); |
| LayoutUnit childLogicalLeft = child->logicalLeft(); |
| |
| // Floats that will remain the child's responsibility to paint should factor |
| // into its overflow. |
| FloatingObjectSetIterator childEnd = child->m_floatingObjects->set().end(); |
| for (FloatingObjectSetIterator childIt = |
| child->m_floatingObjects->set().begin(); |
| childIt != childEnd; ++childIt) { |
| FloatingObject& floatingObject = *childIt->get(); |
| LayoutUnit logicalBottomForFloat = |
| std::min(this->logicalBottomForFloat(floatingObject), |
| LayoutUnit::max() - childLogicalTop); |
| LayoutUnit logicalBottom = childLogicalTop + logicalBottomForFloat; |
| |
| if (logicalBottom > logicalHeight()) { |
| // If the object is not in the list, we add it now. |
| if (!containsFloat(floatingObject.layoutObject())) { |
| LayoutSize offset = |
| isHorizontalWritingMode() |
| ? LayoutSize(-childLogicalLeft, -childLogicalTop) |
| : LayoutSize(-childLogicalTop, -childLogicalLeft); |
| bool shouldPaint = false; |
| |
| // The nearest enclosing layer always paints the float (so that zindex |
| // and stacking behaves properly). We always want to propagate the |
| // desire to paint the float as far out as we can, to the outermost |
| // block that overlaps the float, stopping only if we hit a |
| // self-painting layer boundary. |
| if (floatingObject.layoutObject()->enclosingFloatPaintingLayer() == |
| enclosingFloatPaintingLayer() && |
| !floatingObject.isLowestNonOverhangingFloatInChild()) { |
| floatingObject.setShouldPaint(false); |
| shouldPaint = true; |
| } |
| // We create the floating object list lazily. |
| if (!m_floatingObjects) |
| createFloatingObjects(); |
| |
| m_floatingObjects->add( |
| floatingObject.copyToNewContainer(offset, shouldPaint, true)); |
| } |
| } else { |
| if (makeChildPaintOtherFloats && !floatingObject.shouldPaint() && |
| !floatingObject.layoutObject()->hasSelfPaintingLayer() && |
| !floatingObject.isLowestNonOverhangingFloatInChild() && |
| floatingObject.layoutObject()->isDescendantOf(child) && |
| floatingObject.layoutObject()->enclosingFloatPaintingLayer() == |
| child->enclosingFloatPaintingLayer()) { |
| // The float is not overhanging from this block, so if it is a |
| // descendant of the child, the child should paint it (the other case is |
| // that it is intruding into the child), unless it has its own layer or |
| // enclosing layer. |
| // If makeChildPaintOtherFloats is false, it means that the child must |
| // already know about all the floats it should paint. |
| floatingObject.setShouldPaint(true); |
| } |
| |
| // Since the float doesn't overhang, it didn't get put into our list. We |
| // need to go ahead and add its overflow in to the child now. |
| if (floatingObject.isDescendant()) |
| child->addOverflowFromChild( |
| floatingObject.layoutObject(), |
| LayoutSize(xPositionForFloatIncludingMargin(floatingObject), |
| yPositionForFloatIncludingMargin(floatingObject))); |
| } |
| } |
| } |
| |
| LayoutUnit LayoutBlockFlow::lowestFloatLogicalBottom(EClear clear) const { |
| if (clear == EClear::kNone || !m_floatingObjects) |
| return LayoutUnit(); |
| |
| FloatingObject::Type floatType = clear == EClear::kLeft |
| ? FloatingObject::FloatLeft |
| : clear == EClear::kRight |
| ? FloatingObject::FloatRight |
| : FloatingObject::FloatLeftRight; |
| return m_floatingObjects->lowestFloatLogicalBottom(floatType); |
| } |
| |
| LayoutUnit LayoutBlockFlow::nextFloatLogicalBottomBelow( |
| LayoutUnit logicalHeight) const { |
| if (!m_floatingObjects) |
| return logicalHeight; |
| return m_floatingObjects->findNextFloatLogicalBottomBelow(logicalHeight); |
| } |
| |
| LayoutUnit LayoutBlockFlow::nextFloatLogicalBottomBelowForBlock( |
| LayoutUnit logicalHeight) const { |
| if (!m_floatingObjects) |
| return logicalHeight; |
| |
| return m_floatingObjects->findNextFloatLogicalBottomBelowForBlock( |
| logicalHeight); |
| } |
| |
| LayoutUnit LayoutBlockFlow::logicalHeightWithVisibleOverflow() const { |
| LayoutUnit logicalHeight = LayoutBlock::logicalHeightWithVisibleOverflow(); |
| return std::max(logicalHeight, lowestFloatLogicalBottom()); |
| } |
| |
| Node* LayoutBlockFlow::nodeForHitTest() const { |
| // If we are in the margins of block elements that are part of a |
| // continuation we're actually still inside the enclosing element |
| // that was split. Use the appropriate inner node. |
| return isAnonymousBlockContinuation() ? continuation()->node() : node(); |
| } |
| |
| bool LayoutBlockFlow::hitTestChildren( |
| HitTestResult& result, |
| const HitTestLocation& locationInContainer, |
| const LayoutPoint& accumulatedOffset, |
| HitTestAction hitTestAction) { |
| LayoutPoint scrolledOffset(hasOverflowClip() |
| ? accumulatedOffset - scrolledContentOffset() |
| : accumulatedOffset); |
| |
| if (hitTestAction == HitTestFloat && |
| hitTestFloats(result, locationInContainer, scrolledOffset)) |
| return true; |
| |
| if (childrenInline()) { |
| if (m_lineBoxes.hitTest(LineLayoutBoxModel(this), result, |
| locationInContainer, scrolledOffset, |
| hitTestAction)) { |
| updateHitTestResult( |
| result, flipForWritingMode(toLayoutPoint(locationInContainer.point() - |
| accumulatedOffset))); |
| return true; |
| } |
| } else if (LayoutBlock::hitTestChildren(result, locationInContainer, |
| accumulatedOffset, hitTestAction)) { |
| return true; |
| } |
| |
| return false; |
| } |
| |
| bool LayoutBlockFlow::hitTestFloats(HitTestResult& result, |
| const HitTestLocation& locationInContainer, |
| const LayoutPoint& accumulatedOffset) { |
| if (!m_floatingObjects) |
| return false; |
| |
| LayoutPoint adjustedLocation = accumulatedOffset; |
| if (isLayoutView()) { |
| ScrollOffset offset = toLayoutView(this)->frameView()->getScrollOffset(); |
| adjustedLocation.move(LayoutSize(offset)); |
| } |
| |
| const FloatingObjectSet& floatingObjectSet = m_floatingObjects->set(); |
| FloatingObjectSetIterator begin = floatingObjectSet.begin(); |
| for (FloatingObjectSetIterator it = floatingObjectSet.end(); it != begin;) { |
| --it; |
| const FloatingObject& floatingObject = *it->get(); |
| if (floatingObject.shouldPaint() && |
| // TODO(wangxianzhu): Should this be a DCHECK? |
| !floatingObject.layoutObject()->hasSelfPaintingLayer()) { |
| LayoutUnit xOffset = xPositionForFloatIncludingMargin(floatingObject) - |
| floatingObject.layoutObject()->location().x(); |
| LayoutUnit yOffset = yPositionForFloatIncludingMargin(floatingObject) - |
| floatingObject.layoutObject()->location().y(); |
| LayoutPoint childPoint = flipFloatForWritingModeForChild( |
| floatingObject, adjustedLocation + LayoutSize(xOffset, yOffset)); |
| if (floatingObject.layoutObject()->hitTest(result, locationInContainer, |
| childPoint)) { |
| updateHitTestResult( |
| result, locationInContainer.point() - toLayoutSize(childPoint)); |
| return true; |
| } |
| } |
| } |
| |
| return false; |
| } |
| |
| LayoutSize LayoutBlockFlow::accumulateInFlowPositionOffsets() const { |
| if (!isAnonymousBlock() || !isInFlowPositioned()) |
| return LayoutSize(); |
| LayoutSize offset; |
| for (const LayoutObject* p = inlineElementContinuation(); |
| p && p->isLayoutInline(); p = p->parent()) { |
| if (p->isInFlowPositioned()) |
| offset += toLayoutInline(p)->offsetForInFlowPosition(); |
| } |
| return offset; |
| } |
| |
| LayoutUnit LayoutBlockFlow::logicalLeftFloatOffsetForLine( |
| LayoutUnit logicalTop, |
| LayoutUnit fixedOffset, |
| LayoutUnit logicalHeight) const { |
| if (m_floatingObjects && m_floatingObjects->hasLeftObjects()) |
| return m_floatingObjects->logicalLeftOffset(fixedOffset, logicalTop, |
| logicalHeight); |
| |
| return fixedOffset; |
| } |
| |
| LayoutUnit LayoutBlockFlow::logicalRightFloatOffsetForLine( |
| LayoutUnit logicalTop, |
| LayoutUnit fixedOffset, |
| LayoutUnit logicalHeight) const { |
| if (m_floatingObjects && m_floatingObjects->hasRightObjects()) |
| return m_floatingObjects->logicalRightOffset(fixedOffset, logicalTop, |
| logicalHeight); |
| |
| return fixedOffset; |
| } |
| |
| void LayoutBlockFlow::updateAncestorShouldPaintFloatingObject( |
| const LayoutBox& floatBox) { |
| ASSERT(floatBox.isFloating()); |
| bool floatBoxIsSelfPaintingLayer = |
| floatBox.hasLayer() && floatBox.layer()->isSelfPaintingLayer(); |
| for (LayoutObject* ancestor = floatBox.parent(); |
| ancestor && ancestor->isLayoutBlockFlow(); |
| ancestor = ancestor->parent()) { |
| LayoutBlockFlow* ancestorBlock = toLayoutBlockFlow(ancestor); |
| FloatingObjects* ancestorFloatingObjects = |
| ancestorBlock->m_floatingObjects.get(); |
| if (!ancestorFloatingObjects) |
| break; |
| FloatingObjectSet::iterator it = ancestorFloatingObjects->mutableSet() |
| .find<FloatingObjectHashTranslator>( |
| const_cast<LayoutBox*>(&floatBox)); |
| if (it == ancestorFloatingObjects->mutableSet().end()) |
| break; |
| |
| FloatingObject& floatingObject = **it; |
| if (!floatBoxIsSelfPaintingLayer) { |
| // This repeats the logic in addOverhangingFloats() about shouldPaint |
| // flag: |
| // - The nearest enclosing block in which the float doesn't overhang |
| // paints the float; |
| // - Or even if the float overhangs, if the ancestor block has |
| // self-painting layer, it paints the float. |
| if (ancestorBlock->hasSelfPaintingLayer() || |
| !ancestorBlock->isOverhangingFloat(floatingObject)) { |
| floatingObject.setShouldPaint(true); |
| return; |
| } |
| } else { |
| floatingObject.setShouldPaint(false); |
| } |
| } |
| } |
| |
| bool LayoutBlockFlow::allowsPaginationStrut() const { |
| // The block needs to be contained by a LayoutBlockFlow (and not by e.g. a |
| // flexbox, grid, or a table (the latter being the case for table cell or |
| // table caption)). The reason for this limitation is simply that |
| // LayoutBlockFlow child layout code is the only place where we pick up the |
| // struts and handle them. We handle floats and regular in-flow children, and |
| // that's all. We could handle this in other layout modes as well (and even |
| // for out-of-flow children), but currently we don't. |
| // TODO(mstensho): But we *should*. |
| if (isOutOfFlowPositioned()) |
| return false; |
| if (isLayoutFlowThread()) { |
| // Don't let the strut escape the fragmentation context and get lost. |
| // TODO(mstensho): If we're in a nested fragmentation context, we should |
| // ideally convert and propagate the strut to the outer fragmentation |
| // context, so that the inner one is fully pushed to the next outer |
| // fragmentainer, instead of taking up unusable space in the previous one. |
| // But currently we have no mechanism in place to handle this. |
| return false; |
| } |
| const LayoutBlock* containingBlock = this->containingBlock(); |
| if (!containingBlock || !containingBlock->isLayoutBlockFlow()) |
| return false; |
| const LayoutBlockFlow* containingBlockFlow = |
| toLayoutBlockFlow(containingBlock); |
| // If children are inline, allow the strut. We are probably a float. |
| if (containingBlockFlow->childrenInline()) |
| return true; |
| for (LayoutBox* sibling = previousSiblingBox(); sibling; |
| sibling = sibling->previousSiblingBox()) { |
| // What happens on the other side of a spanner is none of our concern, so |
| // stop here. Since there's no in-flow box between the previous spanner and |
| // us, there's no class A break point in front of us. We cannot even |
| // re-propagate pagination struts to our containing block, since the |
| // containing block starts in a different column row. |
| if (sibling->isColumnSpanAll()) |
| return false; |
| // If this isn't the first in-flow object, there's a break opportunity |
| // before us, which means that we can allow the strut. |
| if (!sibling->isFloatingOrOutOfFlowPositioned()) |
| return true; |
| } |
| // This is a first in-flow child. We'll still allow the strut if it can be |
| // re-propagated to our containing block. |
| return containingBlockFlow->allowsPaginationStrut(); |
| } |
| |
| void LayoutBlockFlow::setPaginationStrutPropagatedFromChild(LayoutUnit strut) { |
| strut = std::max(strut, LayoutUnit()); |
| if (!m_rareData) { |
| if (!strut) |
| return; |
| m_rareData = WTF::makeUnique<LayoutBlockFlowRareData>(this); |
| } |
| m_rareData->m_paginationStrutPropagatedFromChild = strut; |
| } |
| |
| void LayoutBlockFlow::setFirstForcedBreakOffset(LayoutUnit blockOffset) { |
| if (!m_rareData) { |
| if (!blockOffset) |
| return; |
| m_rareData = WTF::makeUnique<LayoutBlockFlowRareData>(this); |
| } |
| m_rareData->m_firstForcedBreakOffset = blockOffset; |
| } |
| |
| void LayoutBlockFlow::positionSpannerDescendant( |
| LayoutMultiColumnSpannerPlaceholder& child) { |
| LayoutBox& spanner = *child.layoutObjectInFlowThread(); |
| // FIXME: |spanner| is a descendant, but never a direct child, so the names |
| // here are bad, if nothing else. |
| setLogicalTopForChild(spanner, child.logicalTop()); |
| determineLogicalLeftPositionForChild(spanner); |
| } |
| |
| bool LayoutBlockFlow::avoidsFloats() const { |
| // Floats can't intrude into our box if we have a non-auto column count or |
| // width. |
| // Note: we need to use LayoutBox::avoidsFloats here since |
| // LayoutBlock::avoidsFloats is always true. |
| return LayoutBox::avoidsFloats() || !style()->hasAutoColumnCount() || |
| !style()->hasAutoColumnWidth(); |
| } |
| |
| void LayoutBlockFlow::moveChildrenTo(LayoutBoxModelObject* toBoxModelObject, |
| LayoutObject* startChild, |
| LayoutObject* endChild, |
| LayoutObject* beforeChild, |
| bool fullRemoveInsert) { |
| if (childrenInline()) |
| deleteLineBoxTree(); |
| LayoutBoxModelObject::moveChildrenTo(toBoxModelObject, startChild, endChild, |
| beforeChild, fullRemoveInsert); |
| } |
| |
| LayoutUnit LayoutBlockFlow::logicalLeftSelectionOffset( |
| const LayoutBlock* rootBlock, |
| LayoutUnit position) const { |
| LayoutUnit logicalLeft = logicalLeftOffsetForLine(position, DoNotIndentText); |
| if (logicalLeft == logicalLeftOffsetForContent()) |
| return LayoutBlock::logicalLeftSelectionOffset(rootBlock, position); |
| |
| const LayoutBlock* cb = this; |
| while (cb != rootBlock) { |
| logicalLeft += cb->logicalLeft(); |
| cb = cb->containingBlock(); |
| } |
| return logicalLeft; |
| } |
| |
| LayoutUnit LayoutBlockFlow::logicalRightSelectionOffset( |
| const LayoutBlock* rootBlock, |
| LayoutUnit position) const { |
| LayoutUnit logicalRight = |
| logicalRightOffsetForLine(position, DoNotIndentText); |
| if (logicalRight == logicalRightOffsetForContent()) |
| return LayoutBlock::logicalRightSelectionOffset(rootBlock, position); |
| |
| const LayoutBlock* cb = this; |
| while (cb != rootBlock) { |
| logicalRight += cb->logicalLeft(); |
| cb = cb->containingBlock(); |
| } |
| return logicalRight; |
| } |
| |
| RootInlineBox* LayoutBlockFlow::createRootInlineBox() { |
| return new RootInlineBox(LineLayoutItem(this)); |
| } |
| |
| bool LayoutBlockFlow::isPagedOverflow(const ComputedStyle& style) { |
| return style.isOverflowPaged() && |
| node() != document().viewportDefiningElement(); |
| } |
| |
| LayoutBlockFlow::FlowThreadType LayoutBlockFlow::getFlowThreadType( |
| const ComputedStyle& style) { |
| if (isPagedOverflow(style)) |
| return PagedFlowThread; |
| if (style.specifiesColumns()) |
| return MultiColumnFlowThread; |
| return NoFlowThread; |
| } |
| |
| LayoutMultiColumnFlowThread* LayoutBlockFlow::createMultiColumnFlowThread( |
| FlowThreadType type) { |
| switch (type) { |
| case MultiColumnFlowThread: |
| return LayoutMultiColumnFlowThread::createAnonymous(document(), |
| styleRef()); |
| case PagedFlowThread: |
| // Paged overflow is currently done using the multicol implementation. |
| UseCounter::count(document(), UseCounter::CSSOverflowPaged); |
| return LayoutPagedFlowThread::createAnonymous(document(), styleRef()); |
| default: |
| NOTREACHED(); |
| return nullptr; |
| } |
| } |
| |
| void LayoutBlockFlow::createOrDestroyMultiColumnFlowThreadIfNeeded( |
| const ComputedStyle* oldStyle) { |
| // Paged overflow trumps multicol in this implementation. Ideally, it should |
| // be possible to have both paged overflow and multicol on the same element, |
| // but then we need two flow threads. Anyway, this is nothing to worry about |
| // until we can actually nest multicol properly inside other fragmentation |
| // contexts. |
| FlowThreadType type = getFlowThreadType(styleRef()); |
| |
| if (multiColumnFlowThread()) { |
| ASSERT(oldStyle); |
| if (type != getFlowThreadType(*oldStyle)) { |
| // If we're no longer to be multicol/paged, destroy the flow thread. Also |
| // destroy it when switching between multicol and paged, since that |
| // affects the column set structure (multicol containers may have |
| // spanners, paged containers may not). |
| multiColumnFlowThread()->evacuateAndDestroy(); |
| ASSERT(!multiColumnFlowThread()); |
| m_paginationStateChanged = true; |
| } |
| } |
| |
| if (type == NoFlowThread || multiColumnFlowThread()) |
| return; |
| |
| // Ruby elements manage child insertion in a special way, and would mess up |
| // insertion of the flow thread. The flow thread needs to be a direct child of |
| // the multicol block (|this|). |
| if (isRuby()) |
| return; |
| |
| // Fieldsets look for a legend special child (layoutSpecialExcludedChild()). |
| // We currently only support one special child per layout object, and the |
| // flow thread would make for a second one. |
| if (isFieldset()) |
| return; |
| |
| // Form controls are replaced content, and are therefore not supposed to |
| // support multicol. |
| if (isFileUploadControl() || isTextControl() || isListBox()) |
| return; |
| |
| LayoutMultiColumnFlowThread* flowThread = createMultiColumnFlowThread(type); |
| addChild(flowThread); |
| m_paginationStateChanged = true; |
| |
| // Check that addChild() put the flow thread as a direct child, and didn't do |
| // fancy things. |
| ASSERT(flowThread->parent() == this); |
| |
| flowThread->populate(); |
| LayoutBlockFlowRareData& rareData = ensureRareData(); |
| ASSERT(!rareData.m_multiColumnFlowThread); |
| rareData.m_multiColumnFlowThread = flowThread; |
| } |
| |
| LayoutBlockFlow::LayoutBlockFlowRareData& LayoutBlockFlow::ensureRareData() { |
| if (m_rareData) |
| return *m_rareData; |
| |
| m_rareData = WTF::makeUnique<LayoutBlockFlowRareData>(this); |
| return *m_rareData; |
| } |
| |
| void LayoutBlockFlow::positionDialog() { |
| HTMLDialogElement* dialog = toHTMLDialogElement(node()); |
| if (dialog->getCenteringMode() == HTMLDialogElement::NotCentered) |
| return; |
| |
| bool canCenterDialog = (style()->position() == EPosition::kAbsolute || |
| style()->position() == EPosition::kFixed) && |
| style()->hasAutoTopAndBottom(); |
| |
| if (dialog->getCenteringMode() == HTMLDialogElement::Centered) { |
| if (canCenterDialog) |
| setY(dialog->centeredPosition()); |
| return; |
| } |
| |
| ASSERT(dialog->getCenteringMode() == HTMLDialogElement::NeedsCentering); |
| if (!canCenterDialog) { |
| dialog->setNotCentered(); |
| return; |
| } |
| |
| FrameView* frameView = document().view(); |
| LayoutUnit top = LayoutUnit((style()->position() == EPosition::kFixed) |
| ? 0 |
| : frameView->scrollOffsetInt().height()); |
| int visibleHeight = frameView->visibleContentRect(IncludeScrollbars).height(); |
| if (size().height() < visibleHeight) |
| top += (visibleHeight - size().height()) / 2; |
| setY(top); |
| dialog->setCentered(top); |
| } |
| |
| void LayoutBlockFlow::simplifiedNormalFlowInlineLayout() { |
| ASSERT(childrenInline()); |
| ListHashSet<RootInlineBox*> lineBoxes; |
| for (InlineWalker walker(LineLayoutBlockFlow(this)); !walker.atEnd(); |
| walker.advance()) { |
| LayoutObject* o = walker.current().layoutObject(); |
| if (!o->isOutOfFlowPositioned() && |
| (o->isAtomicInlineLevel() || o->isFloating())) { |
| o->layoutIfNeeded(); |
| if (toLayoutBox(o)->inlineBoxWrapper()) { |
| RootInlineBox& box = toLayoutBox(o)->inlineBoxWrapper()->root(); |
| lineBoxes.insert(&box); |
| } |
| } else if (o->isText() || |
| (o->isLayoutInline() && !walker.atEndOfInline())) { |
| o->clearNeedsLayout(); |
| } |
| } |
| |
| // FIXME: Glyph overflow will get lost in this case, but not really a big |
| // deal. |
| GlyphOverflowAndFallbackFontsMap textBoxDataMap; |
| for (ListHashSet<RootInlineBox*>::const_iterator it = lineBoxes.begin(); |
| it != lineBoxes.end(); ++it) { |
| RootInlineBox* box = *it; |
| box->computeOverflow(box->lineTop(), box->lineBottom(), textBoxDataMap); |
| } |
| } |
| |
| bool LayoutBlockFlow::recalcInlineChildrenOverflowAfterStyleChange() { |
| ASSERT(childrenInline()); |
| bool childrenOverflowChanged = false; |
| ListHashSet<RootInlineBox*> lineBoxes; |
| for (InlineWalker walker(LineLayoutBlockFlow(this)); !walker.atEnd(); |
| walker.advance()) { |
| LayoutObject* layoutObject = walker.current().layoutObject(); |
| if (recalcNormalFlowChildOverflowIfNeeded(layoutObject)) { |
| childrenOverflowChanged = true; |
| if (InlineBox* inlineBoxWrapper = |
| toLayoutBlock(layoutObject)->inlineBoxWrapper()) |
| lineBoxes.insert(&inlineBoxWrapper->root()); |
| } |
| } |
| |
| // FIXME: Glyph overflow will get lost in this case, but not really a big |
| // deal. |
| GlyphOverflowAndFallbackFontsMap textBoxDataMap; |
| for (ListHashSet<RootInlineBox*>::const_iterator it = lineBoxes.begin(); |
| it != lineBoxes.end(); ++it) { |
| RootInlineBox* box = *it; |
| box->clearKnownToHaveNoOverflow(); |
| box->computeOverflow(box->lineTop(), box->lineBottom(), textBoxDataMap); |
| } |
| return childrenOverflowChanged; |
| } |
| |
| PositionWithAffinity LayoutBlockFlow::positionForPoint( |
| const LayoutPoint& point) { |
| if (isAtomicInlineLevel()) { |
| PositionWithAffinity position = |
| positionForPointIfOutsideAtomicInlineLevel(point); |
| if (!position.isNull()) |
| return position; |
| } |
| if (!childrenInline()) |
| return LayoutBlock::positionForPoint(point); |
| |
| LayoutPoint pointInContents = point; |
| offsetForContents(pointInContents); |
| LayoutPoint pointInLogicalContents(pointInContents); |
| if (!isHorizontalWritingMode()) |
| pointInLogicalContents = pointInLogicalContents.transposedPoint(); |
| |
| if (!firstRootBox()) |
| return createPositionWithAffinity(0); |
| |
| bool linesAreFlipped = style()->isFlippedLinesWritingMode(); |
| bool blocksAreFlipped = style()->isFlippedBlocksWritingMode(); |
| |
| // look for the closest line box in the root box which is at the passed-in y |
| // coordinate |
| InlineBox* closestBox = nullptr; |
| RootInlineBox* firstRootBoxWithChildren = nullptr; |
| RootInlineBox* lastRootBoxWithChildren = nullptr; |
| for (RootInlineBox* root = firstRootBox(); root; root = root->nextRootBox()) { |
| if (!root->firstLeafChild()) |
| continue; |
| if (!firstRootBoxWithChildren) |
| firstRootBoxWithChildren = root; |
| |
| if (!linesAreFlipped && root->isFirstAfterPageBreak() && |
| (pointInLogicalContents.y() < root->lineTopWithLeading() || |
| (blocksAreFlipped && |
| pointInLogicalContents.y() == root->lineTopWithLeading()))) |
| break; |
| |
| lastRootBoxWithChildren = root; |
| |
| // check if this root line box is located at this y coordinate |
| if (pointInLogicalContents.y() < root->selectionBottom() || |
| (blocksAreFlipped && |
| pointInLogicalContents.y() == root->selectionBottom())) { |
| if (linesAreFlipped) { |
| RootInlineBox* nextRootBoxWithChildren = root->nextRootBox(); |
| while (nextRootBoxWithChildren && |
| !nextRootBoxWithChildren->firstLeafChild()) |
| nextRootBoxWithChildren = nextRootBoxWithChildren->nextRootBox(); |
| |
| if (nextRootBoxWithChildren && |
| nextRootBoxWithChildren->isFirstAfterPageBreak() && |
| (pointInLogicalContents.y() > |
| nextRootBoxWithChildren->lineTopWithLeading() || |
| (!blocksAreFlipped && |
| pointInLogicalContents.y() == |
| nextRootBoxWithChildren->lineTopWithLeading()))) |
| continue; |
| } |
| closestBox = root->closestLeafChildForLogicalLeftPosition( |
| pointInLogicalContents.x()); |
| if (closestBox) |
| break; |
| } |
| } |
| |
| bool moveCaretToBoundary = |
| document() |
| .frame() |
| ->editor() |
| .behavior() |
| .shouldMoveCaretToHorizontalBoundaryWhenPastTopOrBottom(); |
| |
| if (!moveCaretToBoundary && !closestBox && lastRootBoxWithChildren) { |
| // y coordinate is below last root line box, pretend we hit it |
| closestBox = |
| lastRootBoxWithChildren->closestLeafChildForLogicalLeftPosition( |
| pointInLogicalContents.x()); |
| } |
| |
| if (closestBox) { |
| if (moveCaretToBoundary) { |
| LayoutUnit firstRootBoxWithChildrenTop = |
| std::min<LayoutUnit>(firstRootBoxWithChildren->selectionTop(), |
| firstRootBoxWithChildren->logicalTop()); |
| if (pointInLogicalContents.y() < firstRootBoxWithChildrenTop || |
| (blocksAreFlipped && |
| pointInLogicalContents.y() == firstRootBoxWithChildrenTop)) { |
| InlineBox* box = firstRootBoxWithChildren->firstLeafChild(); |
| if (box->isLineBreak()) { |
| if (InlineBox* newBox = box->nextLeafChildIgnoringLineBreak()) |
| box = newBox; |
| } |
| // y coordinate is above first root line box, so return the start of the |
| // first |
| return PositionWithAffinity(positionForBox(box, true)); |
| } |
| } |
| |
| // pass the box a top position that is inside it |
| LayoutPoint point(pointInLogicalContents.x(), |
| closestBox->root().blockDirectionPointInLine()); |
| if (!isHorizontalWritingMode()) |
| point = point.transposedPoint(); |
| if (closestBox->getLineLayoutItem().isAtomicInlineLevel()) |
| return positionForPointRespectingEditingBoundaries( |
| LineLayoutBox(closestBox->getLineLayoutItem()), point); |
| return closestBox->getLineLayoutItem().positionForPoint(point); |
| } |
| |
| if (lastRootBoxWithChildren) { |
| // We hit this case for Mac behavior when the Y coordinate is below the last |
| // box. |
| ASSERT(moveCaretToBoundary); |
| InlineBox* logicallyLastBox; |
| if (lastRootBoxWithChildren->getLogicalEndBoxWithNode(logicallyLastBox)) |
| return PositionWithAffinity(positionForBox(logicallyLastBox, false)); |
| } |
| |
| // Can't reach this. We have a root line box, but it has no kids. |
| // FIXME: This should NOTREACHED(), but clicking on placeholder text |
| // seems to hit this code path. |
| return createPositionWithAffinity(0); |
| } |
| |
| #ifndef NDEBUG |
| |
| void LayoutBlockFlow::showLineTreeAndMark(const InlineBox* markedBox1, |
| const char* markedLabel1, |
| const InlineBox* markedBox2, |
| const char* markedLabel2, |
| const LayoutObject* obj) const { |
| showLayoutObject(); |
| for (const RootInlineBox* root = firstRootBox(); root; |
| root = root->nextRootBox()) |
| root->showLineTreeAndMark(markedBox1, markedLabel1, markedBox2, |
| markedLabel2, obj, 1); |
| } |
| |
| #endif |
| |
| void LayoutBlockFlow::addOutlineRects( |
| Vector<LayoutRect>& rects, |
| const LayoutPoint& additionalOffset, |
| IncludeBlockVisualOverflowOrNot includeBlockOverflows) const { |
| // For blocks inside inlines, we go ahead and include margins so that we run |
| // right up to the inline boxes above and below us (thus getting merged with |
| // them to form a single irregular shape). |
| const LayoutInline* inlineElementContinuation = |
| this->inlineElementContinuation(); |
| if (inlineElementContinuation) { |
| // FIXME: This check really isn't accurate. |
| bool nextInlineHasLineBox = inlineElementContinuation->firstLineBox(); |
| // FIXME: This is wrong. The principal layoutObject may not be the |
| // continuation preceding this block. |
| // FIXME: This is wrong for vertical writing-modes. |
| // https://bugs.webkit.org/show_bug.cgi?id=46781 |
| bool prevInlineHasLineBox = |
| toLayoutInline(inlineElementContinuation->node()->layoutObject()) |
| ->firstLineBox(); |
| LayoutUnit topMargin = |
| prevInlineHasLineBox ? collapsedMarginBefore() : LayoutUnit(); |
| LayoutUnit bottomMargin = |
| nextInlineHasLineBox ? collapsedMarginAfter() : LayoutUnit(); |
| if (topMargin || bottomMargin) { |
| LayoutRect rect(additionalOffset, size()); |
| rect.expandEdges(topMargin, LayoutUnit(), bottomMargin, LayoutUnit()); |
| rects.push_back(rect); |
| } |
| } |
| |
| LayoutBlock::addOutlineRects(rects, additionalOffset, includeBlockOverflows); |
| |
| if (includeBlockOverflows == IncludeBlockVisualOverflow && |
| !hasOverflowClip() && !hasControlClip()) { |
| for (RootInlineBox* curr = firstRootBox(); curr; |
| curr = curr->nextRootBox()) { |
| LayoutUnit top = std::max<LayoutUnit>(curr->lineTop(), curr->y()); |
| LayoutUnit bottom = |
| std::min<LayoutUnit>(curr->lineBottom(), curr->y() + curr->height()); |
| LayoutRect rect(additionalOffset.x() + curr->x(), |
| additionalOffset.y() + top, curr->width(), bottom - top); |
| if (!rect.isEmpty()) |
| rects.push_back(rect); |
| } |
| } |
| |
| if (inlineElementContinuation) |
| inlineElementContinuation->addOutlineRects( |
| rects, additionalOffset + |
| (inlineElementContinuation->containingBlock()->location() - |
| location()), |
| includeBlockOverflows); |
| } |
| |
| PaintInvalidationReason LayoutBlockFlow::invalidatePaintIfNeeded( |
| const PaintInvalidationState& paintInvalidationState) { |
| if (containsFloats()) |
| paintInvalidationState.paintingLayer().setNeedsPaintPhaseFloat(); |
| |
| return LayoutBlock::invalidatePaintIfNeeded(paintInvalidationState); |
| } |
| |
| void LayoutBlockFlow::invalidateDisplayItemClients( |
| PaintInvalidationReason invalidationReason) const { |
| BlockFlowPaintInvalidator(*this).invalidateDisplayItemClients( |
| invalidationReason); |
| } |
| |
| } // namespace blink |