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/SVGElementInstance.h"
  31 #include "core/svg/SVGLength.h"
  32 #include "core/svg/SVGTransformList.h"
  33
  34 namespace WebCore {
  35
  36 inline SVGLinearGradientElement::SVGLinearGradientElement(Document& document)
  37     : SVGGradientElement(SVGNames::linearGradientTag, document)
  38     , m_x1(SVGAnimatedLength::create(this, SVGNames::x1Attr, SVGLength::create(LengthModeWidth), AllowNegativeLengths))
  39     , m_y1(SVGAnimatedLength::create(this, SVGNames::y1Attr, SVGLength::create(LengthModeHeight), AllowNegativeLengths))
  40     , m_x2(SVGAnimatedLength::create(this, SVGNames::x2Attr, SVGLength::create(LengthModeWidth), AllowNegativeLengths))
  41     , m_y2(SVGAnimatedLength::create(this, SVGNames::y2Attr, SVGLength::create(LengthModeHeight), AllowNegativeLengths))
  42 {
  43     ScriptWrappable::init(this);
  44
  45     // Spec: If the x2 attribute is not specified, the effect is as if a value of "100%" were specified.
  46     m_x2->setDefaultValueAsString("100%");
  47
  48     addToPropertyMap(m_x1);
  49     addToPropertyMap(m_y1);
  50     addToPropertyMap(m_x2);
  51     addToPropertyMap(m_y2);
  52 }
  53
  54 PassRefPtr<SVGLinearGradientElement> SVGLinearGradientElement::create(Document& document)
  55 {
  56     return adoptRef(new SVGLinearGradientElement(document));
  57 }
  58
  59 bool SVGLinearGradientElement::isSupportedAttribute(const QualifiedName& attrName)
  60 {
  61     DEFINE_STATIC_LOCAL(HashSet<QualifiedName>, supportedAttributes, ());
  62     if (supportedAttributes.isEmpty()) {
  63         supportedAttributes.add(SVGNames::x1Attr);
  64         supportedAttributes.add(SVGNames::x2Attr);
  65         supportedAttributes.add(SVGNames::y1Attr);
  66         supportedAttributes.add(SVGNames::y2Attr);
  67     }
  68     return supportedAttributes.contains<SVGAttributeHashTranslator>(attrName);
  69 }
  70
  71 void SVGLinearGradientElement::parseAttribute(const QualifiedName& name, const AtomicString& value)
  72 {
  73     SVGParsingError parseError = NoError;
  74
  75     if (!isSupportedAttribute(name))
  76         SVGGradientElement::parseAttribute(name, value);
  77     else if (name == SVGNames::x1Attr)
  78         m_x1->setBaseValueAsString(value, parseError);
  79     else if (name == SVGNames::y1Attr)
  80         m_y1->setBaseValueAsString(value, parseError);
  81     else if (name == SVGNames::x2Attr)
  82         m_x2->setBaseValueAsString(value, parseError);
  83     else if (name == SVGNames::y2Attr)
  84         m_y2->setBaseValueAsString(value, parseError);
  85     else
  86         ASSERT_NOT_REACHED();
  87
  88     reportAttributeParsingError(parseError, name, value);
  89 }
  90
  91 void SVGLinearGradientElement::svgAttributeChanged(const QualifiedName& attrName)
  92 {
  93     if (!isSupportedAttribute(attrName)) {
  94         SVGGradientElement::svgAttributeChanged(attrName);
  95         return;
  96     }
  97
  98     SVGElement::InvalidationGuard invalidationGuard(this);
  99
 100     updateRelativeLengthsInformation();
 101
 102     RenderSVGResourceContainer* renderer = toRenderSVGResourceContainer(this->renderer());
 103     if (renderer)
 104         renderer->invalidateCacheAndMarkForLayout();
 105 }
 106
 107 RenderObject* SVGLinearGradientElement::createRenderer(RenderStyle*)
 108 {
 109     return new RenderSVGResourceLinearGradient(this);
 110 }
 111
 112 static void setGradientAttributes(SVGGradientElement* element, LinearGradientAttributes& attributes, bool isLinear = true)
 113 {
 114     if (!attributes.hasSpreadMethod() && element->spreadMethod()->isSpecified())
 115         attributes.setSpreadMethod(element->spreadMethod()->currentValue()->enumValue());
 116
 117     if (!attributes.hasGradientUnits() && element->gradientUnits()->isSpecified())
 118         attributes.setGradientUnits(element->gradientUnits()->currentValue()->enumValue());
 119
 120     if (!attributes.hasGradientTransform() && element->gradientTransform()->isSpecified()) {
 121         AffineTransform transform;
 122         element->gradientTransform()->currentValue()->concatenate(transform);
 123         attributes.setGradientTransform(transform);
 124     }
 125
 126     if (!attributes.hasStops()) {
 127         const Vector<Gradient::ColorStop>& stops(element->buildStops());
 128         if (!stops.isEmpty())
 129             attributes.setStops(stops);
 130     }
 131
 132     if (isLinear) {
 133         SVGLinearGradientElement* linear = toSVGLinearGradientElement(element);
 134
 135         if (!attributes.hasX1() && linear->x1()->isSpecified())
 136             attributes.setX1(linear->x1()->currentValue());
 137
 138         if (!attributes.hasY1() && linear->y1()->isSpecified())
 139             attributes.setY1(linear->y1()->currentValue());
 140
 141         if (!attributes.hasX2() && linear->x2()->isSpecified())
 142             attributes.setX2(linear->x2()->currentValue());
 143
 144         if (!attributes.hasY2() && linear->y2()->isSpecified())
 145             attributes.setY2(linear->y2()->currentValue());
 146     }
 147 }
 148
 149 bool SVGLinearGradientElement::collectGradientAttributes(LinearGradientAttributes& attributes)
 150 {
 151     if (!renderer())
 152         return false;
 153
 154     HashSet<SVGGradientElement*> processedGradients;
 155     SVGGradientElement* current = this;
 156
 157     setGradientAttributes(current, attributes);
 158     processedGradients.add(current);
 159
 160     while (true) {
 161         // Respect xlink:href, take attributes from referenced element
 162         Node* refNode = SVGURIReference::targetElementFromIRIString(current->href()->currentValue()->value(), treeScope());
 163         if (refNode && isSVGGradientElement(*refNode)) {
 164             current = toSVGGradientElement(refNode);
 165
 166             // Cycle detection
 167             if (processedGradients.contains(current))
 168                 return true;
 169
 170             if (!current->renderer())
 171                 return false;
 172
 173             setGradientAttributes(current, attributes, isSVGLinearGradientElement(*current));
 174             processedGradients.add(current);
 175         } else {
 176             return true;
 177         }
 178     }
 179
 180     ASSERT_NOT_REACHED();
 181     return false;
 182 }
 183
 184 bool SVGLinearGradientElement::selfHasRelativeLengths() const
 185 {
 186     return m_x1->currentValue()->isRelative()
 187         || m_y1->currentValue()->isRelative()
 188         || m_x2->currentValue()->isRelative()
 189         || m_y2->currentValue()->isRelative();
 190 }
 191
 192 }