WebCore/svg/SVGElementInstance.cpp

   1 /*
   2     Copyright (C) 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
   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 #include "config.h"
  21
  22 #if ENABLE(SVG)
  23 #include "SVGElementInstance.h"
  24
  25 #include "ContainerNodeAlgorithms.h"
  26 #include "Event.h"
  27 #include "EventException.h"
  28 #include "EventListener.h"
  29 #include "EventNames.h"
  30 #include "FrameView.h"
  31 #include "SVGElementInstanceList.h"
  32 #include "SVGUseElement.h"
  33
  34 #include <wtf/RefCountedLeakCounter.h>
  35
  36 #if USE(JSC)
  37 #include "GCController.h"
  38 #endif
  39
  40 namespace WebCore {
  41
  42 #ifndef NDEBUG
  43 static WTF::RefCountedLeakCounter instanceCounter("WebCoreSVGElementInstance");
  44 #endif
  45
  46 static EventTargetData& dummyEventTargetData()
  47 {
  48     DEFINE_STATIC_LOCAL(EventTargetData, dummyEventTargetData, ());
  49     dummyEventTargetData.eventListenerMap.clear();
  50     return dummyEventTargetData;
  51 }
  52
  53 SVGElementInstance::SVGElementInstance(SVGUseElement* useElement, PassRefPtr<SVGElement> originalElement)
  54     : m_needsUpdate(false)
  55     , m_useElement(useElement)
  56     , m_element(originalElement)
  57     , m_previousSibling(0)
  58     , m_nextSibling(0)
  59     , m_firstChild(0)
  60     , m_lastChild(0)
  61 {
  62     ASSERT(m_useElement);
  63     ASSERT(m_element);
  64
  65     // Register as instance for passed element.
  66     m_element->mapInstanceToElement(this);
  67
  68 #ifndef NDEBUG
  69     instanceCounter.increment();
  70 #endif
  71 }
  72
  73 SVGElementInstance::~SVGElementInstance()
  74 {
  75 #ifndef NDEBUG
  76     instanceCounter.decrement();
  77 #endif
  78
  79     // Deregister as instance for passed element.
  80     m_element->removeInstanceMapping(this);
  81
  82     removeAllChildrenInContainer<SVGElementInstance, SVGElementInstance>(this);
  83 }
  84
  85 PassRefPtr<SVGElementInstanceList> SVGElementInstance::childNodes()
  86 {
  87     return SVGElementInstanceList::create(this);
  88 }
  89
  90 void SVGElementInstance::setShadowTreeElement(SVGElement* element)
  91 {
  92     ASSERT(element);
  93     m_shadowTreeElement = element;
  94 }
  95
  96 void SVGElementInstance::forgetWrapper()
  97 {
  98 #if USE(JSC)
  99     // FIXME: This is fragile, as discussed with Sam. Need to find a better solution.
 100     // Think about the case where JS explicitely holds "var root = useElement.instanceRoot;".
 101     // We still have to recreate this wrapper somehow. The gc collection below, won't catch it.
 102
 103     // If the use shadow tree has been rebuilt, just the JSSVGElementInstance objects
 104     // are still holding RefPtrs of SVGElementInstance objects, which prevent us to
 105     // be deleted (and the shadow tree is not destructed as well). Force JS GC.
 106     gcController().garbageCollectNow();
 107 #endif
 108 }
 109
 110 void SVGElementInstance::appendChild(PassRefPtr<SVGElementInstance> child)
 111 {
 112     appendChildToContainer<SVGElementInstance, SVGElementInstance>(child.get(), this);
 113 }
 114
 115 void SVGElementInstance::invalidateAllInstancesOfElement(SVGElement* element)
 116 {
 117     if (!element)
 118         return;
 119
 120     HashSet<SVGElementInstance*> set = element->instancesForElement();
 121     if (set.isEmpty())
 122         return;
 123
 124     // Find all use elements referencing the instances - ask them _once_ to rebuild.
 125     HashSet<SVGElementInstance*>::const_iterator it = set.begin();
 126     const HashSet<SVGElementInstance*>::const_iterator end = set.end();
 127
 128     for (; it != end; ++it)
 129         (*it)->setNeedsUpdate(true);
 130 }
 131
 132 void SVGElementInstance::setNeedsUpdate(bool value)
 133 {
 134     m_needsUpdate = value;
 135
 136     if (m_needsUpdate)
 137         correspondingUseElement()->setNeedsStyleRecalc();
 138 }
 139
 140 ScriptExecutionContext* SVGElementInstance::scriptExecutionContext() const
 141 {
 142     if (SVGElement* element = correspondingElement())
 143         return element->document();
 144     return 0;
 145 }
 146
 147 bool SVGElementInstance::addEventListener(const AtomicString& eventType, PassRefPtr<EventListener> listener, bool useCapture)
 148 {
 149     if (!correspondingElement())
 150         return false;
 151     return correspondingElement()->addEventListener(eventType, listener, useCapture);
 152 }
 153
 154 bool SVGElementInstance::removeEventListener(const AtomicString& eventType, EventListener* listener, bool useCapture)
 155 {
 156     if (!correspondingElement())
 157         return false;
 158     return correspondingElement()->removeEventListener(eventType, listener, useCapture);
 159 }
 160
 161 void SVGElementInstance::removeAllEventListeners()
 162 {
 163     if (!correspondingElement())
 164         return;
 165     correspondingElement()->removeAllEventListeners();
 166 }
 167
 168 bool SVGElementInstance::dispatchEvent(PassRefPtr<Event> prpEvent)
 169 {
 170     RefPtr<EventTarget> protect = this;
 171     RefPtr<Event> event = prpEvent;
 172
 173     event->setTarget(this);
 174
 175     SVGElement* element = shadowTreeElement();
 176     if (!element)
 177         return false;
 178
 179     RefPtr<FrameView> view = element->document()->view();
 180     return element->dispatchGenericEvent(event.release());
 181 }
 182
 183 EventTargetData* SVGElementInstance::eventTargetData()
 184 {
 185     return correspondingElement() ? correspondingElement()->eventTargetData() : 0;
 186 }
 187
 188 EventTargetData* SVGElementInstance::ensureEventTargetData()
 189 {
 190     return &dummyEventTargetData(); // return something, so we don't crash
 191 }
 192
 193 } // namespace WebCore
 194
 195 #endif // ENABLE(SVG)