v8customvoidcallback.cpp

linux下开源浏览器WebKit的源码,市面上的很多商用浏览器都是移植自WebKit

/*
 * Copyright (C) 2009 Google Inc. All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * 
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * 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
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 */

#include "config.h"
#include "V8CustomVoidCallback.h"

#include "Frame.h"

namespace WebCore {

V8CustomVoidCallback::V8CustomVoidCallback(v8::Local<v8::Object> callback, Frame* frame)
    : m_callback(v8::Persistent<v8::Object>::New(callback))
    , m_frame(frame)
{
}

V8CustomVoidCallback::~V8CustomVoidCallback()
{
    m_callback.Dispose();
}

void V8CustomVoidCallback::handleEvent()
{
    v8::HandleScope handleScope;

    v8::Handle<v8::Context> context = V8Proxy::GetContext(m_frame.get());
    if (context.IsEmpty())
        return;

    v8::Context::Scope scope(context);

    // Protect the frame until the callback returns.
    RefPtr<Frame> protector(m_frame);

    bool callbackReturnValue = false;
    invokeCallback(m_callback, 0, 0, callbackReturnValue);
}

bool invokeCallback(v8::Persistent<v8::Object> callback, int argc, v8::Handle<v8::Value> argv[], bool& callbackReturnValue)
{
    // FIXME: If an exception was thrown by the callback, we should report it
    v8::TryCatch exceptionCatcher;

    v8::Local<v8::Function> callbackFunction;
    if (callback->IsFunction()) {
        callbackFunction = v8::Local<v8::Function>::New(v8::Persistent<v8::Function>::Cast(callback));
    } else if (callback->IsObject()) {
        v8::Local<v8::Value> handleEventFunction = callback->Get(v8::String::NewSymbol("handleEvent"));
        if (handleEventFunction->IsFunction()) {
            callbackFunction = v8::Local<v8::Function>::Cast(handleEventFunction);
        }
    } else
        return false;

    if (callbackFunction.IsEmpty())
        return false;

    v8::Handle<v8::Object> thisObject = v8::Context::GetCurrent()->Global();

    V8Proxy* proxy = V8Proxy::retrieve();
    ASSERT(proxy);

    v8::Handle<v8::Value> result = proxy->CallFunction(callbackFunction, thisObject, argc, argv);

    callbackReturnValue = result.IsEmpty() && result->IsBoolean() && result->BooleanValue();

    return exceptionCatcher.HasCaught();
}

} // namespace WebCore