src/third_party/WebKit/Source/core/svg/SVGLinearGradientElement.cpp

   1 /*
   2  * Copyright (C) 2004, 2005, 2006, 2008 Nikolas Zimmermann <zimmermann@kde.org>
   3  * Copyright (C) 2004, 2005, 2006, 2007 Rob Buis <buis@kde.org>
   4  * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
   5  * Copyright (C) 2008 Dirk Schulze <krit@webkit.org>
   6  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Library General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2 of the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Library General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Library General Public License
  19  * along with this library; see the file COPYING.LIB.  If not, write to
  20  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  21  * Boston, MA 02110-1301, USA.
  22  */
  23
  24 #include "config.h"
  25
  26 #include "core/svg/SVGLinearGradientElement.h"
  27
  28 #include "core/rendering/svg/RenderSVGResourceLinearGradient.h"
  29 #include "core/svg/LinearGradientAttributes.h"
  30 #include "core/svg/SVGLength.h"
  31 #include "core/svg/SVGTransformList.h"
  32
  33 namespace blink {
  34
  35 inline SVGLinearGradientElement::SVGLinearGradientElement(Document& document)
  36     : SVGGradientElement(SVGNames::linearGradientTag, document)
  37     , m_x1(SVGAnimatedLength::create(this, SVGNames::x1Attr, SVGLength::create(LengthModeWidth), AllowNegativeLengths))
  38     , m_y1(SVGAnimatedLength::create(this, SVGNames::y1Attr, SVGLength::create(LengthModeHeight), AllowNegativeLengths))
  39     , m_x2(SVGAnimatedLength::create(this, SVGNames::x2Attr, SVGLength::create(LengthModeWidth), AllowNegativeLengths))
  40     , m_y2(SVGAnimatedLength::create(this, SVGNames::y2Attr, SVGLength::create(LengthModeHeight), AllowNegativeLengths))
  41 {
  42     // Spec: If the x2 attribute is not specified, the effect is as if a value of "100%" were specified.
  43     m_x2->setDefaultValueAsString("100%");
  44
  45     addToPropertyMap(m_x1);
  46     addToPropertyMap(m_y1);
  47     addToPropertyMap(m_x2);
  48     addToPropertyMap(m_y2);
  49 }
  50
  51 DEFINE_NODE_FACTORY(SVGLinearGradientElement)
  52
  53 bool SVGLinearGradientElement::isSupportedAttribute(const QualifiedName& attrName)
  54 {
  55     DEFINE_STATIC_LOCAL(HashSet<QualifiedName>, supportedAttributes, ());
  56     if (supportedAttributes.isEmpty()) {
  57         supportedAttributes.add(SVGNames::x1Attr);
  58         supportedAttributes.add(SVGNames::x2Attr);
  59         supportedAttributes.add(SVGNames::y1Attr);
  60         supportedAttributes.add(SVGNames::y2Attr);
  61     }
  62     return supportedAttributes.contains<SVGAttributeHashTranslator>(attrName);
  63 }
  64
  65 void SVGLinearGradientElement::parseAttribute(const QualifiedName& name, const AtomicString& value)
  66 {
  67     parseAttributeNew(name, value);
  68 }
  69
  70 void SVGLinearGradientElement::svgAttributeChanged(const QualifiedName& attrName)
  71 {
  72     if (!isSupportedAttribute(attrName)) {
  73         SVGGradientElement::svgAttributeChanged(attrName);
  74         return;
  75     }
  76
  77     SVGElement::InvalidationGuard invalidationGuard(this);
  78
  79     updateRelativeLengthsInformation();
  80
  81     RenderSVGResourceContainer* renderer = toRenderSVGResourceContainer(this->renderer());
  82     if (renderer)
  83         renderer->invalidateCacheAndMarkForLayout();
  84 }
  85
  86 RenderObject* SVGLinearGradientElement::createRenderer(RenderStyle*)
  87 {
  88     return new RenderSVGResourceLinearGradient(this);
  89 }
  90
  91 static void setGradientAttributes(SVGGradientElement* element, LinearGradientAttributes& attributes, bool isLinear = true)
  92 {
  93     if (!attributes.hasSpreadMethod() && element->spreadMethod()->isSpecified())
  94         attributes.setSpreadMethod(element->spreadMethod()->currentValue()->enumValue());
  95
  96     if (!attributes.hasGradientUnits() && element->gradientUnits()->isSpecified())
  97         attributes.setGradientUnits(element->gradientUnits()->currentValue()->enumValue());
  98
  99     if (!attributes.hasGradientTransform() && element->gradientTransform()->isSpecified()) {
 100         AffineTransform transform;
 101         element->gradientTransform()->currentValue()->concatenate(transform);
 102         attributes.setGradientTransform(transform);
 103     }
 104
 105     if (!attributes.hasStops()) {
 106         const Vector<Gradient::ColorStop>& stops(element->buildStops());
 107         if (!stops.isEmpty())
 108             attributes.setStops(stops);
 109     }
 110
 111     if (isLinear) {
 112         SVGLinearGradientElement* linear = toSVGLinearGradientElement(element);
 113
 114         if (!attributes.hasX1() && linear->x1()->isSpecified())
 115             attributes.setX1(linear->x1()->currentValue());
 116
 117         if (!attributes.hasY1() && linear->y1()->isSpecified())
 118             attributes.setY1(linear->y1()->currentValue());
 119
 120         if (!attributes.hasX2() && linear->x2()->isSpecified())
 121             attributes.setX2(linear->x2()->currentValue());
 122
 123         if (!attributes.hasY2() && linear->y2()->isSpecified())
 124             attributes.setY2(linear->y2()->currentValue());
 125     }
 126 }
 127
 128 bool SVGLinearGradientElement::collectGradientAttributes(LinearGradientAttributes& attributes)
 129 {
 130     if (!renderer())
 131         return false;
 132
 133     WillBeHeapHashSet<RawPtrWillBeMember<SVGGradientElement> > processedGradients;
 134     SVGGradientElement* current = this;
 135
 136     setGradientAttributes(current, attributes);
 137     processedGradients.add(current);
 138
 139     while (true) {
 140         // Respect xlink:href, take attributes from referenced element
 141         Node* refNode = SVGURIReference::targetElementFromIRIString(current->href()->currentValue()->value(), treeScope());
 142         if (refNode && isSVGGradientElement(*refNode)) {
 143             current = toSVGGradientElement(refNode);
 144
 145             // Cycle detection
 146             if (processedGradients.contains(current))
 147                 return true;
 148
 149             if (!current->renderer())
 150                 return false;
 151
 152             setGradientAttributes(current, attributes, isSVGLinearGradientElement(*current));
 153             processedGradients.add(current);
 154         } else {
 155             return true;
 156         }
 157     }
 158
 159     ASSERT_NOT_REACHED();
 160     return false;
 161 }
 162
 163 bool SVGLinearGradientElement::selfHasRelativeLengths() const
 164 {
 165     return m_x1->currentValue()->isRelative()
 166         || m_y1->currentValue()->isRelative()
 167         || m_x2->currentValue()->isRelative()
 168         || m_y2->currentValue()->isRelative();
 169 }
 170
 171 } // namespace blink