Add a border radius property to inherit it from a parent in a fallback content

third_party/WebKit/Source/core/layout/line/InlineFlowBox.cpp

 /*
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. 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
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 1015 matching lines @@
             if (culledParent == lineLayoutItem() || (hasSibling && prev && prev->lineLayoutItem().isDescendantOf(culledParent)))
                 break;
 
             if (culledParent.isLayoutInline() && LineLayoutInline(culledParent).hitTestCulledInline(result, locationInContainer, accumulatedOffset))
                 return true;
 
             currLayoutItem = culledParent;
         }
     }
 
     if (lineLayoutItem().style()->hasBorderRadius()) {

[pdr., 2016/03/07 21:15:51]

I agree that the code in InlineBox::nodeAtPoint is wrong, but I don't understand
why the code here is correct.

Why can't we change includeLogicalLeftEdge to look like:
bool includeLogicalLeftEdge() const { return lineLayoutItem().isBox() ?
m_includeLogicalLeftEdge : false; }

I guess it's just not clear why this isBox check is correct, since I don't see
similar calls elsewhere.

[Miyoung Shin(c), 2016/03/09 12:28:07]

<img> has a <div> child with inline-block for a fallback image, and <img>
inlinebox is a rootInlineBox.
Then, we will set the position in RootInlineBox::alignBoxesInBlockDirection and
the position of <img> is updated by the child's maxAscent.
So, <img>, rootInlineBox(inlineflowbox), has the different position from
LayoutBox's position.
If <img> doesn't have any child or the child's size is none, <img> position is
not updated.
As I know, in general <img> doesn't have chidren.
I've seen the only case that <img> has a child when shadow dom is created for a
fallback image.

Considering this case, I thought we should check borderRadius with <img>
LayoutBox's position.

If I'm wrong, could you please correct me ?

[pdr., 2016/03/21 05:26:10]

I think you're getting stuck on the <img> case when the issue here is unrelated
to images. I would recommend getting everything working for the common case of
divs, then see if images need special handling.

Hit testing and painting are very similar problems so one way to approach this
is to look at how rounded rects are painted, and use the same functions here.
Another approach might be to directly call
LayoutBox::hitTestClippedOutByRoundedBorder.

[Miyoung Shin(c), 2016/03/29 22:49:40]

As you suggested, I've looked at how rounded rects are painted. In case of IMG,
we use the overflow rectangle applied with lineTop and lineBottom to paint the
rounded border, but in case of a general inlineflowbox such as text, we use the
frameRect moved by the paint offset in
InlineFlowBoxPainter::paintBoxDecorationBackground. Currently in this function,
we check hitTest with overflowRect but for borderRadius we use frameRect.
So I think it is inconsistent, and LayoutBox::hitTestClippedOutByRoundedBorder
will be reasonable to use here.

-        LayoutRect borderRect = logicalFrameRect();
+        LayoutRect borderRect;
+        bool includeLeftEdge = true;
+        bool includeRightEdge = true;
+        if (lineLayoutItem().isBox()) {
+            borderRect = toLayoutBox(lineLayoutItem())->borderBoxRect();
+        } else {
+            borderRect = logicalFrameRect();
+            includeLeftEdge = includeLogicalLeftEdge();
+            includeRightEdge = includeLogicalRightEdge();
+        }
+
         borderRect.moveBy(accumulatedOffset);
-        FloatRoundedRect border = lineLayoutItem().style()->getRoundedBorderFor(borderRect, includeLogicalLeftEdge(), includeLogicalRightEdge());
+        FloatRoundedRect border = lineLayoutItem().style()->getRoundedBorderFor(borderRect, includeLeftEdge, includeRightEdge);
         if (!locationInContainer.intersects(border))
             return false;
     }
 
     // Now check ourselves.
     LayoutRect rect = InlineFlowBoxPainter(*this).frameRectClampedToLineTopAndBottomIfNeeded();
 
     flipForWritingMode(rect);
     rect.moveBy(accumulatedOffset);
 
@@ skipping 264 matching lines @@
         ASSERT(child->prevOnLine() == prev);
         prev = child;
     }
     ASSERT(prev == m_lastChild);
 #endif
 }
 
 #endif
 
 } // namespace blink