root/Source/bindings/v8/V8EventListener.cpp

DEFINITIONS

1. getListenerFunction
2. callListenerFunction

/*
 * Copyright (C) 2006, 2007, 2008, 2009 Google Inc. All rights reserved.
 *
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 * modification, are permitted provided that the following conditions are
 * met:
 *
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 * notice, this list of conditions and the following disclaimer.
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 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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#include "config.h"
#include "bindings/v8/V8EventListener.h"

#include "bindings/v8/ScriptController.h"
#include "bindings/v8/V8Binding.h"
#include "core/dom/Document.h"
#include "core/frame/LocalFrame.h"

namespace WebCore {

V8EventListener::V8EventListener(v8::Local<v8::Object> listener, bool isAttribute, v8::Isolate* isolate)
    : V8AbstractEventListener(isAttribute, DOMWrapperWorld::current(isolate), isolate)
{
    setListenerObject(listener);
}

v8::Local<v8::Function> V8EventListener::getListenerFunction(ExecutionContext* context)
{
    v8::Local<v8::Object> listener = getListenerObject(context);

    // Has the listener been disposed?
    if (listener.IsEmpty())
        return v8::Local<v8::Function>();

    if (listener->IsFunction())
        return v8::Local<v8::Function>::Cast(listener);

    if (listener->IsObject()) {
        ASSERT_WITH_MESSAGE(!isAttribute(), "EventHandler attributes should only accept JS Functions as input.");
        v8::Local<v8::Value> property = listener->Get(v8AtomicString(isolate(), "handleEvent"));
        // Check that no exceptions were thrown when getting the
        // handleEvent property and that the value is a function.
        if (!property.IsEmpty() && property->IsFunction())
            return v8::Local<v8::Function>::Cast(property);
    }

    return v8::Local<v8::Function>();
}

v8::Local<v8::Value> V8EventListener::callListenerFunction(ExecutionContext* context, v8::Handle<v8::Value> jsEvent, Event* event)
{

    v8::Local<v8::Function> handlerFunction = getListenerFunction(context);
    v8::Local<v8::Object> receiver = getReceiverObject(context, event);
    if (handlerFunction.IsEmpty() || receiver.IsEmpty())
        return v8::Local<v8::Value>();

    // FIXME: Can |context| be 0 here?
    if (!context)
        return v8::Local<v8::Value>();

    if (!context->isDocument())
        return v8::Local<v8::Value>();

    LocalFrame* frame = toDocument(context)->frame();
    if (!frame)
        return v8::Local<v8::Value>();

    if (!frame->script().canExecuteScripts(AboutToExecuteScript))
        return v8::Local<v8::Value>();

    v8::Handle<v8::Value> parameters[1] = { jsEvent };
    return frame->script().callFunction(handlerFunction, receiver, WTF_ARRAY_LENGTH(parameters), parameters);
}

} // namespace WebCore