/*
 * Copyright (C) 2008 Apple 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:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 APPLE INC. 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, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * @constructor
 * @implements {WebInspector.EventTarget}
 */
WebInspector.Object = function() {
}

WebInspector.Object.prototype = {
    /**
     * @override
     * @param {string} eventType
     * @param {function(!WebInspector.Event)} listener
     * @param {!Object=} thisObject
     * @return {!WebInspector.EventTarget.EventDescriptor}
     */
    addEventListener: function(eventType, listener, thisObject)
    {
        if (!listener)
            console.assert(false);

        if (!this._listeners)
            this._listeners = new Map();
        if (!this._listeners.has(eventType))
            this._listeners.set(eventType, []);
        this._listeners.get(eventType).push({ thisObject: thisObject, listener: listener });
        return new WebInspector.EventTarget.EventDescriptor(this, eventType, thisObject, listener);
    },

    /**
     * @override
     * @param {string} eventType
     * @param {function(!WebInspector.Event)} listener
     * @param {!Object=} thisObject
     */
    removeEventListener: function(eventType, listener, thisObject)
    {
        console.assert(listener);

        if (!this._listeners || !this._listeners.has(eventType))
            return;
        var listeners = this._listeners.get(eventType);
        for (var i = 0; i < listeners.length; ++i) {
            if (listeners[i].listener === listener && listeners[i].thisObject === thisObject)
                listeners.splice(i--, 1);
        }

        if (!listeners.length)
            this._listeners.delete(eventType);
    },

    /**
     * @override
     */
    removeAllListeners: function()
    {
        delete this._listeners;
    },

    /**
     * @override
     * @param {string} eventType
     * @return {boolean}
     */
    hasEventListeners: function(eventType)
    {
        if (!this._listeners || !this._listeners.has(eventType))
            return false;
        return true;
    },

    /**
     * @override
     * @param {string} eventType
     * @param {*=} eventData
     * @return {boolean}
     */
    dispatchEventToListeners: function(eventType, eventData)
    {
        if (!this._listeners || !this._listeners.has(eventType))
            return false;

        var event = new WebInspector.Event(this, eventType, eventData);
        var listeners = this._listeners.get(eventType).slice(0);
        for (var i = 0; i < listeners.length; ++i) {
            listeners[i].listener.call(listeners[i].thisObject, event);
            if (event._stoppedPropagation)
                break;
        }

        return event.defaultPrevented;
    }
}

/**
 * @constructor
 * @param {!WebInspector.EventTarget} target
 * @param {string} type
 * @param {*=} data
 */
WebInspector.Event = function(target, type, data)
{
    this.target = target;
    this.type = type;
    this.data = data;
    this.defaultPrevented = false;
    this._stoppedPropagation = false;
}

WebInspector.Event.prototype = {
    stopPropagation: function()
    {
        this._stoppedPropagation = true;
    },

    preventDefault: function()
    {
        this.defaultPrevented = true;
    },

    /**
     * @param {boolean=} preventDefault
     */
    consume: function(preventDefault)
    {
        this.stopPropagation();
        if (preventDefault)
            this.preventDefault();
    }
}

/**
 * @interface
 */
WebInspector.EventTarget = function()
{
}

/**
 * @param {!Array<!WebInspector.EventTarget.EventDescriptor>} eventList
 */
WebInspector.EventTarget.removeEventListeners = function(eventList)
{
    for (var i = 0; i < eventList.length; ++i) {
        var eventInfo = eventList[i];
        eventInfo.eventTarget.removeEventListener(eventInfo.eventType, eventInfo.method, eventInfo.receiver);
    }
}

WebInspector.EventTarget.prototype = {
    /**
     * @param {string} eventType
     * @param {function(!WebInspector.Event)} listener
     * @param {!Object=} thisObject
     * @return {!WebInspector.EventTarget.EventDescriptor}
     */
    addEventListener: function(eventType, listener, thisObject) { },

    /**
     * @param {string} eventType
     * @param {function(!WebInspector.Event)} listener
     * @param {!Object=} thisObject
     */
    removeEventListener: function(eventType, listener, thisObject) { },

    removeAllListeners: function() { },

    /**
     * @param {string} eventType
     * @return {boolean}
     */
    hasEventListeners: function(eventType) { },

    /**
     * @param {string} eventType
     * @param {*=} eventData
     * @return {boolean}
     */
    dispatchEventToListeners: function(eventType, eventData) { },
}

/**
 * @constructor
 * @param {!WebInspector.EventTarget} eventTarget
 * @param {string} eventType
 * @param {(!Object|undefined)} receiver
 * @param {function(?):?} method
 */
WebInspector.EventTarget.EventDescriptor = function(eventTarget, eventType, receiver, method)
{
    this.eventTarget = eventTarget;
    this.eventType = eventType;
    this.receiver = receiver;
    this.method = method;
}