1/* 2 * Copyright (C) Research In Motion Limited 2010. All rights reserved. 3 * 4 * This library is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU Library General Public 6 * License as published by the Free Software Foundation; either 7 * version 2 of the License, or (at your option) any later version. 8 * 9 * This library is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 * Library General Public License for more details. 13 * 14 * You should have received a copy of the GNU Library General Public License 15 * along with this library; see the file COPYING.LIB. If not, write to 16 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 17 * Boston, MA 02110-1301, USA. 18 */ 19 20#ifndef SVGPropertyTearOff_h 21#define SVGPropertyTearOff_h 22 23#if ENABLE(SVG) 24#include "SVGAnimatedProperty.h" 25#include "SVGElement.h" 26#include "SVGProperty.h" 27#include <wtf/WeakPtr.h> 28 29namespace WebCore { 30 31class SVGPropertyTearOffBase : public SVGProperty { 32public: 33 virtual void detachWrapper() = 0; 34}; 35 36template<typename PropertyType> 37class SVGPropertyTearOff : public SVGPropertyTearOffBase { 38public: 39 typedef SVGPropertyTearOff<PropertyType> Self; 40 41 // Used for child types (baseVal/animVal) of a SVGAnimated* property (for example: SVGAnimatedLength::baseVal()). 42 // Also used for list tear offs (for example: text.x.baseVal.getItem(0)). 43 static PassRefPtr<Self> create(SVGAnimatedProperty* animatedProperty, SVGPropertyRole role, PropertyType& value) 44 { 45 ASSERT(animatedProperty); 46 return adoptRef(new Self(animatedProperty, role, value)); 47 } 48 49 // Used for non-animated POD types (for example: SVGSVGElement::createSVGLength()). 50 static PassRefPtr<Self> create(const PropertyType& initialValue) 51 { 52 return adoptRef(new Self(initialValue)); 53 } 54 55 PropertyType& propertyReference() { return *m_value; } 56 SVGAnimatedProperty* animatedProperty() const { return m_animatedProperty; } 57 58 void setValue(PropertyType& value) 59 { 60 if (m_valueIsCopy) { 61 detachChildren(); 62 delete m_value; 63 } 64 m_valueIsCopy = false; 65 m_value = &value; 66 } 67 68 void setAnimatedProperty(SVGAnimatedProperty* animatedProperty) 69 { 70 m_animatedProperty = animatedProperty; 71 72 if (m_animatedProperty) 73 m_contextElement = m_animatedProperty->contextElement(); 74 } 75 76 SVGElement* contextElement() const 77 { 78 if (!m_animatedProperty || m_valueIsCopy) 79 return 0; 80 return m_contextElement.get(); 81 } 82 83 void addChild(WeakPtr<SVGPropertyTearOffBase> child) 84 { 85 m_childTearOffs.append(child); 86 } 87 88 virtual void detachWrapper() override 89 { 90 if (m_valueIsCopy) 91 return; 92 93 detachChildren(); 94 95 // Switch from a live value, to a non-live value. 96 // For example: <text x="50"/> 97 // var item = text.x.baseVal.getItem(0); 98 // text.setAttribute("x", "100"); 99 // item.value still has to report '50' and it has to be possible to modify 'item' 100 // w/o changing the "new item" (with x=100) in the text element. 101 // Whenever the XML DOM modifies the "x" attribute, all existing wrappers are detached, using this function. 102 m_value = new PropertyType(*m_value); 103 m_valueIsCopy = true; 104 m_animatedProperty = 0; 105 } 106 107 virtual void commitChange() 108 { 109 if (!m_animatedProperty || m_valueIsCopy) 110 return; 111 m_animatedProperty->commitChange(); 112 } 113 114 virtual bool isReadOnly() const 115 { 116 if (m_role == AnimValRole) 117 return true; 118 if (m_animatedProperty && m_animatedProperty->isReadOnly()) 119 return true; 120 return false; 121 } 122 123protected: 124 SVGPropertyTearOff(SVGAnimatedProperty* animatedProperty, SVGPropertyRole role, PropertyType& value) 125 : m_animatedProperty(animatedProperty) 126 , m_role(role) 127 , m_value(&value) 128 , m_valueIsCopy(false) 129 { 130 // Using operator & is completely fine, as SVGAnimatedProperty owns this reference, 131 // and we're guaranteed to live as long as SVGAnimatedProperty does. 132 133 if (m_animatedProperty) 134 m_contextElement = m_animatedProperty->contextElement(); 135 } 136 137 SVGPropertyTearOff(const PropertyType& initialValue) 138 : m_animatedProperty(0) 139 , m_role(UndefinedRole) 140 , m_value(new PropertyType(initialValue)) 141 , m_valueIsCopy(true) 142 { 143 } 144 145 virtual ~SVGPropertyTearOff() 146 { 147 if (m_valueIsCopy) { 148 detachChildren(); 149 delete m_value; 150 } 151 } 152 153 void detachChildren() 154 { 155 for (const auto& childTearOff : m_childTearOffs) { 156 if (childTearOff.get()) 157 childTearOff.get()->detachWrapper(); 158 } 159 m_childTearOffs.clear(); 160 } 161 162 RefPtr<SVGElement> m_contextElement; 163 SVGAnimatedProperty* m_animatedProperty; 164 SVGPropertyRole m_role; 165 PropertyType* m_value; 166 Vector<WeakPtr<SVGPropertyTearOffBase>> m_childTearOffs; 167 bool m_valueIsCopy : 1; 168}; 169 170} 171 172#endif // ENABLE(SVG) 173#endif // SVGPropertyTearOff_h 174