Fix pointer-events:all when stroke="none"

Source/core/layout/svg/LayoutSVGPath.cpp

 /*
  * Copyright (C) 2004, 2005, 2007 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2008 Rob Buis <buis@kde.org>
  * Copyright (C) 2005, 2007 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2009 Google, Inc.
  * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  * Copyright (C) 2009 Jeff Schiller <codedread@gmail.com>
  * Copyright (C) 2011 Renata Hodovan <reni@webkit.org>
  * Copyright (C) 2011 University of Szeged
@@ skipping 17 matching lines @@
 #include "config.h"
 
 #include "core/layout/svg/LayoutSVGPath.h"
 
 #include "core/layout/svg/LayoutSVGResourceMarker.h"
 #include "core/layout/svg/SVGResources.h"
 #include "core/layout/svg/SVGResourcesCache.h"
 #include "core/layout/svg/SVGSubpathData.h"
 #include "core/svg/SVGGraphicsElement.h"
 
+#include <cmath>

[fs, 2015/03/31 14:53:59]

(I think it's pretty common to just pull in wtf/MathExtras.h for this, but I
don't particularly mind either way.)

+
 namespace blink {
 
 LayoutSVGPath::LayoutSVGPath(SVGGraphicsElement* node)
     : LayoutSVGShape(node)
 {
 }
 
 LayoutSVGPath::~LayoutSVGPath()
 {
 }
 
 void LayoutSVGPath::updateShapeFromElement()
 {
     LayoutSVGShape::updateShapeFromElement();
     processMarkerPositions();
     updateZeroLengthSubpaths();
 
     m_strokeBoundingBox = calculateUpdatedStrokeBoundingBox();
 }
 
+FloatRect LayoutSVGPath::hitTestStrokeBoundingBox() const
+{
+    const SVGLayoutStyle& svgStyle = style()->svgStyle();
+    if (svgStyle.hasStroke())
+        return m_strokeBoundingBox;
+
+    FloatRect result = m_fillBoundingBox;
+    const float strokeWidth = this->strokeWidth();
+
+    if (svgStyle.joinStyle() == MiterJoin) {

[fs, 2015/03/31 14:54:00]

Could you pull this out into a helper?

http://dev.w3.org/fxtf/css-masking-1/#compute-stroke-bounding-box might be worth
looking at and implementing for this (also contains adjustment for square caps).

(Could probably also reference crbug.com/435097 which is sort of related.)

+        // We need to consider the miterlimit, because the would-be stroke
+        // bounding box could extend outward quite far at a sharp angle along
+        // the path.
+        //
+        // Per http://www.w3.org/TR/SVG/painting.html#StrokeMiterlimitProperty
+        // the maximum miterLength is:
+        //     stroke-width * miterlimit
+        // Inflate the result by the maximum of that amount and half the
+        // stroke-width.
+        //
+        // Note that because the miterLength is the distance between the outer
+        // tip and the inner corner of the miter, this technically overshoots
+        // a bit.
+        result.inflate(std::max(strokeWidth * svgStyle.strokeMiterLimit(), strokeWidth / 2));
+    } else {
+        result.inflate(strokeWidth / 2);
+    }
+
+    for (size_t i = 0; i < m_zeroLengthLinecapLocations.size(); ++i)
+        result.unite(zeroLengthSubpathRect(m_zeroLengthLinecapLocations[i], strokeWidth));
+
+    return result;
+}
+
 FloatRect LayoutSVGPath::calculateUpdatedStrokeBoundingBox() const
 {
     FloatRect strokeBoundingBox = m_strokeBoundingBox;
 
     if (!m_markerPositions.isEmpty())
         strokeBoundingBox.unite(markerRect(strokeWidth()));
 
     if (style()->svgStyle().hasStroke()) {
         // FIXME: zero-length subpaths do not respect vector-effect = non-scaling-stroke.
         float strokeWidth = this->strokeWidth();
         for (size_t i = 0; i < m_zeroLengthLinecapLocations.size(); ++i)
             strokeBoundingBox.unite(zeroLengthSubpathRect(m_zeroLengthLinecapLocations[i], strokeWidth));
     }
 
     return strokeBoundingBox;
 }
 
 bool LayoutSVGPath::shapeDependentStrokeContains(const FloatPoint& point)
 {
     if (LayoutSVGShape::shapeDependentStrokeContains(point))
         return true;
 
     const SVGLayoutStyle& svgStyle = style()->svgStyle();
+    const float strokeWidth = this->strokeWidth();
     for (size_t i = 0; i < m_zeroLengthLinecapLocations.size(); ++i) {
         ASSERT(svgStyle.hasStroke());
-        float strokeWidth = this->strokeWidth();
         if (svgStyle.capStyle() == SquareCap) {
             if (zeroLengthSubpathRect(m_zeroLengthLinecapLocations[i], strokeWidth).contains(point))
                 return true;
         } else {
             ASSERT(svgStyle.capStyle() == RoundCap);
             FloatPoint radiusVector(point.x() - m_zeroLengthLinecapLocations[i].x(), point.y() -  m_zeroLengthLinecapLocations[i].y());
             if (radiusVector.lengthSquared() < strokeWidth * strokeWidth * .25f)
                 return true;
         }
     }
@@ skipping 71 matching lines @@
     ASSERT(resources);
 
     LayoutSVGResourceMarker* markerStart = resources->markerStart();
 
     SVGMarkerData markerData(m_markerPositions, markerStart ? markerStart->orientType() == SVGMarkerOrientAutoStartReverse : false);
     path().apply(&markerData, SVGMarkerData::updateFromPathElement);
     markerData.pathIsDone();
 }
 
 }