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32 #include "bindings/v8/V8AbstractEventListener.h"
35 #include "V8EventTarget.h"
36 #include "bindings/v8/V8Binding.h"
37 #include "bindings/v8/V8EventListenerList.h"
38 #include "core/events/BeforeUnloadEvent.h"
39 #include "core/events/Event.h"
40 #include "core/events/ThreadLocalEventNames.h"
41 #include "core/inspector/InspectorCounters.h"
42 #include "core/workers/WorkerGlobalScope.h"
46 V8AbstractEventListener::V8AbstractEventListener(bool isAttribute, PassRefPtr<DOMWrapperWorld> world, v8::Isolate* isolate)
47 : EventListener(JSEventListenerType)
48 , m_isAttribute(isAttribute)
53 InspectorCounters::incrementCounter(InspectorCounters::JSEventListenerCounter);
56 V8AbstractEventListener::~V8AbstractEventListener()
58 if (!m_listener.isEmpty()) {
59 v8::HandleScope scope(m_isolate);
60 V8EventListenerList::clearWrapper(m_listener.newLocal(m_isolate), m_isAttribute, m_isolate);
63 InspectorCounters::decrementCounter(InspectorCounters::JSEventListenerCounter);
66 void V8AbstractEventListener::handleEvent(ExecutionContext* context, Event* event)
68 // Don't reenter V8 if execution was terminated in this instance of V8.
69 if (context->isJSExecutionForbidden())
74 // The callback function on XMLHttpRequest can clear the event listener and destroys 'this' object. Keep a local reference to it.
76 RefPtr<V8AbstractEventListener> protect(this);
78 v8::HandleScope handleScope(m_isolate);
80 v8::Local<v8::Context> v8Context = toV8Context(context, world());
81 if (v8Context.IsEmpty())
84 // Enter the V8 context in which to perform the event handling.
85 v8::Context::Scope scope(v8Context);
87 // Get the V8 wrapper for the event object.
88 v8::Isolate* isolate = v8Context->GetIsolate();
89 v8::Handle<v8::Value> jsEvent = toV8(event, v8::Handle<v8::Object>(), isolate);
90 if (jsEvent.IsEmpty())
92 invokeEventHandler(context, event, v8::Local<v8::Value>::New(isolate, jsEvent));
95 void V8AbstractEventListener::setListenerObject(v8::Handle<v8::Object> listener)
97 m_listener.set(m_isolate, listener);
98 m_listener.setWeak(this, &setWeakCallback);
101 void V8AbstractEventListener::invokeEventHandler(ExecutionContext* context, Event* event, v8::Local<v8::Value> jsEvent)
103 // If jsEvent is empty, attempt to set it as a hidden value would crash v8.
104 if (jsEvent.IsEmpty())
107 v8::Local<v8::Context> v8Context = toV8Context(context, world());
108 if (v8Context.IsEmpty())
111 // We push the event being processed into the global object, so that it can be exposed by DOMWindow's bindings.
112 v8::Handle<v8::String> eventSymbol = v8AtomicString(v8Context->GetIsolate(), "event");
113 v8::Local<v8::Value> returnValue;
116 // Catch exceptions thrown in the event handler so they do not propagate to javascript code that caused the event to fire.
117 v8::TryCatch tryCatch;
118 tryCatch.SetVerbose(true);
120 // Save the old 'event' property so we can restore it later.
121 v8::Local<v8::Value> savedEvent = getHiddenValue(v8Context->GetIsolate(), v8Context->Global(), eventSymbol);
124 // Make the event available in the global object, so DOMWindow can expose it.
125 setHiddenValue(v8Context->GetIsolate(), v8Context->Global(), eventSymbol, jsEvent);
128 returnValue = callListenerFunction(context, jsEvent, event);
129 if (tryCatch.HasCaught())
130 event->target()->uncaughtExceptionInEventHandler();
132 if (!tryCatch.CanContinue()) { // Result of TerminateExecution().
133 if (context->isWorkerGlobalScope())
134 toWorkerGlobalScope(context)->script()->forbidExecution();
139 // Restore the old event. This must be done for all exit paths through this method.
140 if (savedEvent.IsEmpty())
141 setHiddenValue(v8Context->GetIsolate(), v8Context->Global(), eventSymbol, v8::Undefined(v8Context->GetIsolate()));
143 setHiddenValue(v8Context->GetIsolate(), v8Context->Global(), eventSymbol, savedEvent);
147 ASSERT(!handleOutOfMemory() || returnValue.IsEmpty());
149 if (returnValue.IsEmpty())
152 if (!returnValue->IsNull() && !returnValue->IsUndefined() && event->isBeforeUnloadEvent()) {
153 V8TRYCATCH_FOR_V8STRINGRESOURCE_VOID(V8StringResource<>, stringReturnValue, returnValue);
154 toBeforeUnloadEvent(event)->setReturnValue(stringReturnValue);
157 if (m_isAttribute && shouldPreventDefault(returnValue))
158 event->preventDefault();
161 bool V8AbstractEventListener::shouldPreventDefault(v8::Local<v8::Value> returnValue)
163 // Prevent default action if the return value is false in accord with the spec
164 // http://www.w3.org/TR/html5/webappapis.html#event-handler-attributes
165 return returnValue->IsBoolean() && !returnValue->BooleanValue();
168 v8::Local<v8::Object> V8AbstractEventListener::getReceiverObject(ExecutionContext* context, Event* event)
170 v8::Isolate* isolate = toV8Context(context, world())->GetIsolate();
171 v8::Local<v8::Object> listener = m_listener.newLocal(isolate);
172 if (!m_listener.isEmpty() && !listener->IsFunction())
175 EventTarget* target = event->currentTarget();
176 v8::Handle<v8::Value> value = toV8(target, v8::Handle<v8::Object>(), isolate);
178 return v8::Local<v8::Object>();
179 return v8::Local<v8::Object>::New(isolate, v8::Handle<v8::Object>::Cast(value));
182 void V8AbstractEventListener::setWeakCallback(const v8::WeakCallbackData<v8::Object, V8AbstractEventListener> &data)
184 data.GetParameter()->m_listener.clear();
187 } // namespace WebCore