1 files changed, 74 insertions, 59 deletions

diff --git a/Source/WebCore/svg/SVGTRefElement.cpp b/Source/WebCore/svg/SVGTRefElement.cpp
index 836cfbbd4..dc023162e 100644
--- a/Source/WebCore/svg/SVGTRefElement.cpp
+++ b/Source/WebCore/svg/SVGTRefElement.cpp
@@ -49,13 +49,6 @@ BEGIN_REGISTER_ANIMATED_PROPERTIES(SVGTRefElement)
     REGISTER_PARENT_ANIMATED_PROPERTIES(SVGTextPositioningElement)
 END_REGISTER_ANIMATED_PROPERTIES
 
-inline SVGTRefElement::SVGTRefElement(const QualifiedName& tagName, Document* document)
-    : SVGTextPositioningElement(tagName, document)
-{
-    ASSERT(hasTagName(SVGNames::trefTag));
-    registerAnimatedPropertiesForSVGTRefElement();
-}
-
 PassRefPtr<SVGTRefElement> SVGTRefElement::create(const QualifiedName& tagName, Document* document)
 {
     RefPtr<SVGTRefElement> element = adoptRef(new SVGTRefElement(tagName, document));
@@ -63,59 +56,83 @@ PassRefPtr<SVGTRefElement> SVGTRefElement::create(const QualifiedName& tagName,
     return element.release();
 }
 
-class TargetListener : public EventListener {
+class SVGTRefTargetEventListener : public EventListener {
 public:
-    static PassRefPtr<TargetListener> create(SVGTRefElement* trefElement, String targetId)
+    static PassRefPtr<SVGTRefTargetEventListener> create(SVGTRefElement* trefElement)
     {
-        return adoptRef(new TargetListener(trefElement, targetId));
+        return adoptRef(new SVGTRefTargetEventListener(trefElement));
     }
 
-    static const TargetListener* cast(const EventListener* listener)
+    static const SVGTRefTargetEventListener* cast(const EventListener* listener)
     {
-        return listener->type() == CPPEventListenerType ? static_cast<const TargetListener*>(listener) : 0;
+        return listener->type() == SVGTRefTargetEventListenerType
+                ? static_cast<const SVGTRefTargetEventListener*>(listener) : 0;
     }
 
-    virtual bool operator==(const EventListener&);
-
-    void clear()
-    {
-        Element* target = m_trefElement->treeScope()->getElementById(m_targetId);
-        if (target) {
-            target->removeEventListener(eventNames().DOMSubtreeModifiedEvent, this, false);
-            target->removeEventListener(eventNames().DOMNodeRemovedFromDocumentEvent, this, false);
-        }
-        
-        m_trefElement = 0;
-        m_targetId = String();
-    }
+    void attach(Element* target, String& targetId);
+    void detach();
+    bool isAttached() const { return m_attached; }
 
 private:
-    TargetListener(SVGTRefElement* trefElement, String targetId)
-        : EventListener(CPPEventListenerType)
-        , m_trefElement(trefElement)
-        , m_targetId(targetId)
-    {
-    }
+    SVGTRefTargetEventListener(SVGTRefElement* trefElement);
 
-    virtual void handleEvent(ScriptExecutionContext*, Event*);
+    virtual void handleEvent(ScriptExecutionContext*, Event*) OVERRIDE;
+    virtual bool operator==(const EventListener&) OVERRIDE;
 
     SVGTRefElement* m_trefElement;
     String m_targetId;
+    bool m_attached;
 };
 
-bool TargetListener::operator==(const EventListener& listener)
+SVGTRefTargetEventListener::SVGTRefTargetEventListener(SVGTRefElement* trefElement)
+    : EventListener(SVGTRefTargetEventListenerType)
+    , m_trefElement(trefElement)
+    , m_attached(false)
 {
-    if (const TargetListener* subtreeModificationEventListener = TargetListener::cast(&listener))
-        return m_trefElement == subtreeModificationEventListener->m_trefElement;
+    ASSERT(m_trefElement);
+}
+
+void SVGTRefTargetEventListener::attach(Element* target, String& targetId)
+{
+    ASSERT(!isAttached());
+    ASSERT(target);
+    ASSERT(target->inDocument());
+    ASSERT(!targetId.isEmpty());
+
+    target->addEventListener(eventNames().DOMSubtreeModifiedEvent, this, false);
+    target->addEventListener(eventNames().DOMNodeRemovedFromDocumentEvent, this, false);
+    m_targetId = targetId;
+    m_attached = true;
+}
+
+void SVGTRefTargetEventListener::detach()
+{
+    if (!isAttached())
+        return;
+
+    if (Element* target = m_trefElement->treeScope()->getElementById(m_targetId)) {
+        target->removeEventListener(eventNames().DOMSubtreeModifiedEvent, this, false);
+        target->removeEventListener(eventNames().DOMNodeRemovedFromDocumentEvent, this, false);
+    }
+
+    m_targetId = emptyString();
+    m_attached = false;
+}
+
+bool SVGTRefTargetEventListener::operator==(const EventListener& listener)
+{
+    if (const SVGTRefTargetEventListener* targetListener = SVGTRefTargetEventListener::cast(&listener))
+        return m_trefElement == targetListener->m_trefElement;
     return false;
 }
 
-void TargetListener::handleEvent(ScriptExecutionContext*, Event* event)
+void SVGTRefTargetEventListener::handleEvent(ScriptExecutionContext*, Event* event)
 {
-    if (m_trefElement && event->type() == eventNames().DOMSubtreeModifiedEvent && m_trefElement != event->target())
-        m_trefElement->updateReferencedText();
+    ASSERT(isAttached());
 
-    if (m_trefElement && event->type() == eventNames().DOMNodeRemovedFromDocumentEvent)
+    if (event->type() == eventNames().DOMSubtreeModifiedEvent && m_trefElement != event->target())
+        m_trefElement->updateReferencedText();
+    else if (event->type() == eventNames().DOMNodeRemovedFromDocumentEvent)
         m_trefElement->detachTarget();
 }
 
@@ -148,9 +165,17 @@ void SVGShadowText::willRecalcTextStyle(StyleChange change)
     }
 }
 
+inline SVGTRefElement::SVGTRefElement(const QualifiedName& tagName, Document* document)
+    : SVGTextPositioningElement(tagName, document)
+    , m_targetListener(SVGTRefTargetEventListener::create(this))
+{
+    ASSERT(hasTagName(SVGNames::trefTag));
+    registerAnimatedPropertiesForSVGTRefElement();
+}
+
 SVGTRefElement::~SVGTRefElement()
 {
-    clearEventListener();
+    m_targetListener->detach();
 }
 
 void SVGTRefElement::createShadowSubtree()
@@ -175,7 +200,7 @@ void SVGTRefElement::updateReferencedText()
 void SVGTRefElement::detachTarget()
 {
     // Remove active listeners and clear the text content.
-    clearEventListener();
+    m_targetListener->detach();
 
     String emptyContent;
     ExceptionCode ignore = 0;
@@ -185,7 +210,8 @@ void SVGTRefElement::detachTarget()
     if (container)
         container->setTextContent(emptyContent, ignore);
 
-    ASSERT(inDocument());
+    if (!inDocument())
+        return;
 
     // Mark the referenced ID as pending.
     String id;
@@ -263,7 +289,7 @@ bool SVGTRefElement::rendererIsNeeded(const NodeRenderingContext& context)
 void SVGTRefElement::buildPendingResource()
 {
     // Remove any existing event listener.
-    clearEventListener();
+    m_targetListener->detach();
 
     // If we're not yet in a document, this function will be called again from insertedInto().
     if (!inDocument())
@@ -280,17 +306,14 @@ void SVGTRefElement::buildPendingResource()
         return;
     }
 
-    updateReferencedText();
-
     // Don't set up event listeners if this is a shadow tree node.
     // SVGUseElement::transferEventListenersToShadowTree() handles this task, and addEventListener()
     // expects every element instance to have an associated shadow tree element - which is not the
     // case when we land here from SVGUseElement::buildShadowTree().
-    if (!isInShadowTree()) {
-        m_eventListener = TargetListener::create(this, id);
-        target->addEventListener(eventNames().DOMSubtreeModifiedEvent, m_eventListener.get(), false);
-        target->addEventListener(eventNames().DOMNodeRemovedFromDocumentEvent, m_eventListener.get(), false);
-    }
+    if (!isInShadowTree())
+        m_targetListener->attach(target, id);
+
+    updateReferencedText();
 }
 
 Node::InsertionNotificationRequest SVGTRefElement::insertedInto(ContainerNode* rootParent)
@@ -305,15 +328,7 @@ void SVGTRefElement::removedFrom(ContainerNode* rootParent)
 {
     SVGStyledElement::removedFrom(rootParent);
     if (rootParent->inDocument())
-        clearEventListener();
-}
-
-void SVGTRefElement::clearEventListener()
-{
-    if (m_eventListener) {
-        m_eventListener->clear();
-        m_eventListener = 0;
-    }
+        m_targetListener->detach();
 }
 
 }