[New Multicolumn] Actual support for layout of column-span:all.

Source/core/rendering/RenderBox.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. 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
@@ skipping 28 matching lines @@
 #include "core/html/HTMLFrameOwnerElement.h"
 #include "core/page/AutoscrollController.h"
 #include "core/page/EventHandler.h"
 #include "core/page/Page.h"
 #include "core/paint/BackgroundImageGeometry.h"
 #include "core/paint/BoxPainter.h"
 #include "core/rendering/HitTestResult.h"
 #include "core/rendering/PaintInfo.h"
 #include "core/rendering/RenderDeprecatedFlexibleBox.h"
 #include "core/rendering/RenderFlexibleBox.h"
+#include "core/rendering/RenderFlowThread.h"
 #include "core/rendering/RenderGeometryMap.h"
 #include "core/rendering/RenderGrid.h"
 #include "core/rendering/RenderInline.h"
 #include "core/rendering/RenderLayer.h"
 #include "core/rendering/RenderListBox.h"
 #include "core/rendering/RenderListMarker.h"
 #include "core/rendering/RenderTableCell.h"
 #include "core/rendering/RenderView.h"
 #include "core/rendering/compositing/RenderLayerCompositor.h"
 #include "platform/LengthFunctions.h"
@@ skipping 1361 matching lines @@
     width += portionOfMarginNotConsumedByFloat(childMarginStart, startOffsetForContent, startOffsetForLine);
     width += portionOfMarginNotConsumedByFloat(childMarginEnd, endOffsetForContent, endOffsetForLine);
     return width;
 }
 
 LayoutUnit RenderBox::containingBlockLogicalWidthForContent() const
 {
     if (hasOverrideContainingBlockLogicalWidth())
         return overrideContainingBlockContentLogicalWidth();
 
-    RenderBlock* cb = containingBlock();
+    RenderBlock* cb;
+    if (isColumnSpanAll())
+        cb = flowThreadContainingBlock()->containingBlock();
+    else
+        cb = containingBlock();

[Julien - ping for review, 2014/11/17 23:47:11]

Why don't we patch containingBlock to return the right answer for
isColumnSpanAll()? Those 2 containing block changes seems very artificial.

[mstensho (USE GERRIT), 2014/11/18 13:29:26]

Done. A patch for this particular issue is uploaded separately, since it
entailed quite a few changes.

     return cb->availableLogicalWidth();
 }
 
 LayoutUnit RenderBox::containingBlockLogicalHeightForContent(AvailableLogicalHeightType heightType) const
 {
     if (hasOverrideContainingBlockLogicalHeight())
         return overrideContainingBlockContentLogicalHeight();
 
-    RenderBlock* cb = containingBlock();
+    RenderBlock* cb;
+    if (isColumnSpanAll())
+        cb = flowThreadContainingBlock()->containingBlock();
+    else
+        cb = containingBlock();
     return cb->availableLogicalHeight(heightType);
 }
 
 LayoutUnit RenderBox::containingBlockAvailableLineWidth() const
 {
     RenderBlock* cb = containingBlock();
     if (cb->isRenderBlockFlow())
         return toRenderBlockFlow(cb)->availableLogicalWidthForLine(logicalTop(), false, availableLogicalHeight(IncludeMarginBorderPadding));
     return 0;
 }
@@ skipping 2664 matching lines @@
     // Note this is just a heuristic, and it's still possible to have overflow under these
     // conditions, but it should work out to be good enough for common cases. Paginating overflow
     // with scrollbars present is not the end of the world and is what we used to do in the old model anyway.
     return !style()->logicalHeight().isIntrinsicOrAuto()
         || (!style()->logicalMaxHeight().isIntrinsicOrAuto() && !style()->logicalMaxHeight().isMaxSizeNone() && (!style()->logicalMaxHeight().isPercent() || percentageLogicalHeightIsResolvable(this)))
         || (!style()->logicalMinHeight().isIntrinsicOrAuto() && style()->logicalMinHeight().isPositive() && (!style()->logicalMinHeight().isPercent() || percentageLogicalHeightIsResolvable(this)));
 }
 
 bool RenderBox::isUnsplittableForPagination() const
 {
-    return isReplaced() || hasUnsplittableScrollingOverflow() || (parent() && isWritingModeRoot());
+    // FIXME: column spanners are only unsplittable (or rather: they do not participate in

[Julien - ping for review, 2014/11/17 23:47:11]

It's unclear what action needs to be taken to close this FIXME. We should make
it clear in case it goes stale.

[mstensho (USE GERRIT), 2014/11/18 13:29:26]

Done.

I just removed the column spanner condition for now. None of the tests depend on
it. Maybe I need it later. It would be fine to have the test here (as long as we
don't support nested fragmentation), although it's not exactly correct, as the
comment tried to communicate. :) If I need it later, I'll try to come up with a
better comment.

+    // fragmentation) in their nearest ancestor multicol container. If there are additional
+    // fragmentation contexts further up in the tree, spanners still need to take those into
+    // account.
+    return isReplaced() || hasUnsplittableScrollingOverflow() || (parent() && isWritingModeRoot()) || isColumnSpanAll();
 }
 
 LayoutUnit RenderBox::lineHeight(bool /*firstLine*/, LineDirectionMode direction, LinePositionMode /*linePositionMode*/) const
 {
     if (isReplaced())
         return direction == HorizontalLine ? m_marginBox.top() + height() + m_marginBox.bottom() : m_marginBox.right() + width() + m_marginBox.left();
     return 0;
 }
 
 int RenderBox::baselinePosition(FontBaseline baselineType, bool /*firstLine*/, LineDirectionMode direction, LinePositionMode linePositionMode) const
@@ skipping 304 matching lines @@
 
     setLogicalTop(oldLogicalTop);
     setLogicalWidth(oldLogicalWidth);
     setMarginLeft(oldMarginLeft);
     setMarginRight(oldMarginRight);
 
     return borderBox;
 }
 
 } // namespace blink