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     SVGParsingError parseError = NoError;
  68
  69     if (!isSupportedAttribute(name))
  70         SVGGradientElement::parseAttribute(name, value);
  71     else if (name == SVGNames::x1Attr)
  72         m_x1->setBaseValueAsString(value, parseError);
  73     else if (name == SVGNames::y1Attr)
  74         m_y1->setBaseValueAsString(value, parseError);
  75     else if (name == SVGNames::x2Attr)
  76         m_x2->setBaseValueAsString(value, parseError);
  77     else if (name == SVGNames::y2Attr)
  78         m_y2->setBaseValueAsString(value, parseError);
  79     else
  80         ASSERT_NOT_REACHED();
  81
  82     reportAttributeParsingError(parseError, name, value);
  83 }
  84
  85 void SVGLinearGradientElement::svgAttributeChanged(const QualifiedName& attrName)
  86 {
  87     if (!isSupportedAttribute(attrName)) {
  88         SVGGradientElement::svgAttributeChanged(attrName);
  89         return;
  90     }
  91
  92     SVGElement::InvalidationGuard invalidationGuard(this);
  93
  94     updateRelativeLengthsInformation();
  95
  96     RenderSVGResourceContainer* renderer = toRenderSVGResourceContainer(this->renderer());
  97     if (renderer)
  98         renderer->invalidateCacheAndMarkForLayout();
  99 }
 100
 101 RenderObject* SVGLinearGradientElement::createRenderer(RenderStyle*)
 102 {
 103     return new RenderSVGResourceLinearGradient(this);
 104 }
 105
 106 static void setGradientAttributes(SVGGradientElement* element, LinearGradientAttributes& attributes, bool isLinear = true)
 107 {
 108     if (!attributes.hasSpreadMethod() && element->spreadMethod()->isSpecified())
 109         attributes.setSpreadMethod(element->spreadMethod()->currentValue()->enumValue());
 110
 111     if (!attributes.hasGradientUnits() && element->gradientUnits()->isSpecified())
 112         attributes.setGradientUnits(element->gradientUnits()->currentValue()->enumValue());
 113
 114     if (!attributes.hasGradientTransform() && element->gradientTransform()->isSpecified()) {
 115         AffineTransform transform;
 116         element->gradientTransform()->currentValue()->concatenate(transform);
 117         attributes.setGradientTransform(transform);
 118     }
 119
 120     if (!attributes.hasStops()) {
 121         const Vector<Gradient::ColorStop>& stops(element->buildStops());
 122         if (!stops.isEmpty())
 123             attributes.setStops(stops);
 124     }
 125
 126     if (isLinear) {
 127         SVGLinearGradientElement* linear = toSVGLinearGradientElement(element);
 128
 129         if (!attributes.hasX1() && linear->x1()->isSpecified())
 130             attributes.setX1(linear->x1()->currentValue());
 131
 132         if (!attributes.hasY1() && linear->y1()->isSpecified())
 133             attributes.setY1(linear->y1()->currentValue());
 134
 135         if (!attributes.hasX2() && linear->x2()->isSpecified())
 136             attributes.setX2(linear->x2()->currentValue());
 137
 138         if (!attributes.hasY2() && linear->y2()->isSpecified())
 139             attributes.setY2(linear->y2()->currentValue());
 140     }
 141 }
 142
 143 bool SVGLinearGradientElement::collectGradientAttributes(LinearGradientAttributes& attributes)
 144 {
 145     if (!renderer())
 146         return false;
 147
 148     WillBeHeapHashSet<RawPtrWillBeMember<SVGGradientElement> > processedGradients;
 149     SVGGradientElement* current = this;
 150
 151     setGradientAttributes(current, attributes);
 152     processedGradients.add(current);
 153
 154     while (true) {
 155         // Respect xlink:href, take attributes from referenced element
 156         Node* refNode = SVGURIReference::targetElementFromIRIString(current->href()->currentValue()->value(), treeScope());
 157         if (refNode && isSVGGradientElement(*refNode)) {
 158             current = toSVGGradientElement(refNode);
 159
 160             // Cycle detection
 161             if (processedGradients.contains(current))
 162                 return true;
 163
 164             if (!current->renderer())
 165                 return false;
 166
 167             setGradientAttributes(current, attributes, isSVGLinearGradientElement(*current));
 168             processedGradients.add(current);
 169         } else {
 170             return true;
 171         }
 172     }
 173
 174     ASSERT_NOT_REACHED();
 175     return false;
 176 }
 177
 178 bool SVGLinearGradientElement::selfHasRelativeLengths() const
 179 {
 180     return m_x1->currentValue()->isRelative()
 181         || m_y1->currentValue()->isRelative()
 182         || m_x2->currentValue()->isRelative()
 183         || m_y2->currentValue()->isRelative();
 184 }
 185
 186 } // namespace blink