Use Length for the stroke-dasharray property in SVGLayoutStyle

Source/core/layout/svg/SVGLayoutSupport.cpp

 /*
  * Copyright (C) 2007, 2008 Rob Buis <buis@kde.org>
  * Copyright (C) 2007 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2007 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2009 Google, Inc.  All rights reserved.
  * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
  * Copyright (C) Research In Motion Limited 2009-2010. 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
@@ skipping 330 matching lines @@
 }
 
 bool SVGLayoutSupport::transformToUserSpaceAndCheckClipping(LayoutObject* object, const AffineTransform& localTransform, const FloatPoint& pointInParent, FloatPoint& localPoint)
 {
     if (!localTransform.isInvertible())
         return false;
     localPoint = localTransform.inverse().mapPoint(pointInParent);
     return pointInClippingArea(object, localPoint);
 }
 
+DashArray SVGLayoutSupport::resolveSVGDashArray(const SVGDashArray& svgDashArray, const LayoutStyle& style, const SVGLengthContext& lengthContext)
+{
+    DashArray dashArray;
+    for (const Length& dashLength : svgDashArray.vector())
+        dashArray.append(lengthContext.valueForLength(dashLength, style));
+    return dashArray;
+}
+
 void SVGLayoutSupport::applyStrokeStyleToContext(GraphicsContext& context, const LayoutStyle& style, const LayoutObject& object)
 {
     ASSERT(object.node());
     ASSERT(object.node()->isSVGElement());
 
     const SVGLayoutStyle& svgStyle = style.svgStyle();
 
     SVGLengthContext lengthContext(toSVGElement(object.node()));
     context.setStrokeThickness(svgStyle.strokeWidth()->value(lengthContext));
     context.setLineCap(svgStyle.capStyle());
     context.setLineJoin(svgStyle.joinStyle());
     context.setMiterLimit(svgStyle.strokeMiterLimit());
 
-    RefPtrWillBeRawPtr<SVGLengthList> dashes = svgStyle.strokeDashArray();
-    DashArray dashArray;
-    if (!dashes->isEmpty()) {
-        SVGLengthList::ConstIterator it = dashes->begin();
-        SVGLengthList::ConstIterator itEnd = dashes->end();
-        for (; it != itEnd; ++it)
-            dashArray.append(it->value(lengthContext));
-    }
+    DashArray dashArray = resolveSVGDashArray(*svgStyle.strokeDashArray(), style, lengthContext);

[pdr., 2015/03/05 21:35:59]

Can we save an unnecessary copy by using a const ref here?

[fs, 2015/03/06 11:27:46]

There's no unnecessary copy here - for the instances in this compilation unit it
appears to just be inlined, and in the other callsite it's RVO'd.

     context.setLineDash(dashArray, lengthContext.valueForLength(svgStyle.strokeDashOffset(), style));
 }
 
 void SVGLayoutSupport::applyStrokeStyleToStrokeData(StrokeData& strokeData, const LayoutStyle& style, const LayoutObject& object)
 {
     ASSERT(object.node());
     ASSERT(object.node()->isSVGElement());
 
     const SVGLayoutStyle& svgStyle = style.svgStyle();
 
     SVGLengthContext lengthContext(toSVGElement(object.node()));
     strokeData.setThickness(svgStyle.strokeWidth()->value(lengthContext));
     strokeData.setLineCap(svgStyle.capStyle());
     strokeData.setLineJoin(svgStyle.joinStyle());
     strokeData.setMiterLimit(svgStyle.strokeMiterLimit());
 
-    RefPtrWillBeRawPtr<SVGLengthList> dashes = svgStyle.strokeDashArray();
-    DashArray dashArray;
-    if (!dashes->isEmpty()) {
-        SVGLengthList::ConstIterator it = dashes->begin();
-        SVGLengthList::ConstIterator itEnd = dashes->end();
-        for (; it != itEnd; ++it)
-            dashArray.append(it->value(lengthContext));
-    }
+    DashArray dashArray = resolveSVGDashArray(*svgStyle.strokeDashArray(), style, lengthContext);
     strokeData.setLineDash(dashArray, lengthContext.valueForLength(svgStyle.strokeDashOffset(), style));
 }
 
 bool SVGLayoutSupport::updateGraphicsContext(const PaintInfo& paintInfo, GraphicsContextStateSaver& stateSaver, const LayoutStyle& style, LayoutObject& renderer, LayoutSVGResourceMode resourceMode, const AffineTransform* additionalPaintServerTransform)
 {
     ASSERT(paintInfo.context == stateSaver.context());
 
     GraphicsContext& context = *paintInfo.context;
     if (paintInfo.isRenderingClipPathAsMaskImage()) {
         if (resourceMode == ApplyToStrokeMode)
@@ skipping 104 matching lines @@
 
         layer = layer->parent();
     }
 
     ctm.scale(deviceScaleFactor);
 
     return narrowPrecisionToFloat(sqrt((pow(ctm.xScale(), 2) + pow(ctm.yScale(), 2)) / 2));
 }
 
 }