Implement Layout Containment

third_party/WebKit/Source/core/layout/LayoutBlock.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 989 matching lines @@
 
     IntRect inflatedRect = pixelSnappedBorderBoxRect();
     LayoutTheme::theme().addVisualOverflow(*this, inflatedRect);
     addVisualOverflow(LayoutRect(inflatedRect));
 }
 
 bool LayoutBlock::createsNewFormattingContext() const
 {
     return isInlineBlockOrInlineTable() || isFloatingOrOutOfFlowPositioned() || hasOverflowClip() || isFlexItemIncludingDeprecated()
         || style()->specifiesColumns() || isLayoutFlowThread() || isTableCell() || isTableCaption() || isFieldset() || isWritingModeRoot()
-        || isDocumentElement() || isColumnSpanAll() || isGridItem() || style()->containsPaint();
+        || isDocumentElement() || isColumnSpanAll() || isGridItem() || style()->containsPaint() || style()->containsLayout();
 }
 
 void LayoutBlock::updateBlockChildDirtyBitsBeforeLayout(bool relayoutChildren, LayoutBox& child)
 {
     if (child.isOutOfFlowPositioned()) {
         // It's rather useless to mark out-of-flow children at this point. We may not be their
         // containing block (and if we are, it's just pure luck), so this would be the wrong place
         // for it. Furthermore, it would cause trouble for out-of-flow descendants of column
         // spanners, if the containing block is outside the spanner but inside the multicol container.
         return;
@@ skipping 929 matching lines @@
 
 int LayoutBlock::columnGap() const
 {
     if (style()->hasNormalColumnGap())
         return style()->fontDescription().computedPixelSize(); // "1em" is recommended as the normal gap setting. Matches <p> margins.
     return static_cast<int>(style()->columnGap());
 }
 
 void LayoutBlock::computeIntrinsicLogicalWidths(LayoutUnit& minLogicalWidth, LayoutUnit& maxLogicalWidth) const
 {
+    // Layout-contained elements don't consider their contents for preferred sizing.
+    if (style()->containsLayout())
+        return;
+
     if (childrenInline()) {
         // FIXME: Remove this const_cast.
         toLayoutBlockFlow(const_cast<LayoutBlock*>(this))->computeInlinePreferredLogicalWidths(minLogicalWidth, maxLogicalWidth);
     } else {
         computeBlockPreferredLogicalWidths(minLogicalWidth, maxLogicalWidth);
     }
 
     maxLogicalWidth = std::max(minLogicalWidth, maxLogicalWidth);
 
     if (isHTMLMarqueeElement(node()) && toHTMLMarqueeElement(node())->isHorizontal())
@@ skipping 260 matching lines @@
     return -1;
 }
 
 int LayoutBlock::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 layout containment,
+    // where the block's contents shouldn't be considered when laying out its
+    // ancestors or siblings.
 
-    if (!style()->isOverflowVisible() && !shouldIgnoreOverflowPropertyForInlineBlockBaseline()) {
+    if ((!style()->isOverflowVisible() && !shouldIgnoreOverflowPropertyForInlineBlockBaseline()) || style()->containsLayout()) {
         // We are not calling LayoutBox::baselinePosition here because the caller should add the margin-top/margin-right, not us.
         return lineDirection == HorizontalLine ? size().height() + marginBottom() : size().width() + marginLeft();
     }
 
     if (isWritingModeRoot() && !isRubyRun())
         return -1;
 
     if (childrenInline()) {
         if (!firstLineBox() && hasLineIfEmpty()) {
             const FontMetrics& fontMetrics = firstLineStyle()->fontMetrics();
@@ skipping 640 matching lines @@
 void LayoutBlock::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
 
 } // namespace blink