Observable.js

[app.Builder.js] / Observable.js

/*
 * Based on:
 * Ext JS Library 1.1.1
 * Copyright(c) 2006-2007, Ext JS, LLC.
 *
 * Originally Released Under LGPL - original licence link has changed is not relivant.
 *
 * Fork - LGPL
 * <script type="text/javascript">
 */
XObject = imports.XObject.XObject;
/**
 * @class Observable
 * Base class that provides a common interface for publishing events. Subclasses are expected to
 * to have a property "events" with all the events defined.<br>
 * For example:
 * <pre><code>
 Employee = XObject.define(
      function(name){
        this.name = name;
        this.addEvents({
            "fired" : true,
            "quit" : true
        });
     },
     Observable, {});
     
</code></pre>
 * @param {Object} config properties to use (incuding events / listeners)
 */
 
 
Observable = XObject.define(
    function(cfg){
        
        cfg = cfg|| {};
        this.addEvents(cfg.events || {});
        if (cfg.events) {
            delete cfg.events; // make sure
        }
         
        XObject.extend(this, cfg);
        
        if(this.listeners){
            this.on(this.listeners);
            delete this.listeners;
        }
    },
    Object,  
    {
        /** 
         * @cfg {Object} listeners  list of events and functions to call for this object, 
         * For example :
         * <pre><code>
            listeners :  { 
               'click' : function(e) {
                   ..... 
                } ,
                .... 
            } 
          </code></pre>
         */
            
        
        /**
         * Fires the specified event with the passed parameters (minus the event name).
         * @param {String} eventName
         * @param {Object...} args Variable number of parameters are passed to handlers
         * @return {Boolean} returns false if any of the handlers return false otherwise it returns true
         */
        fireEvent : function(){
            var ce = this.events[arguments[0].toLowerCase()];
            if(typeof ce == "object"){
                return ce.fire.apply(ce, Array.prototype.slice.call(arguments, 1));
            }else{
                return true;
            }
        },

        // private - blcoks these types of signals?
        filterOptRe : /^(?:scope|delay|buffer|single)$/,

        /**
         * Appends an event handler to this component
         * @param {String}   eventName The type of event to listen for
         * @param {Function} handler The method the event invokes
         * @param {Object}   scope (optional) The scope in which to execute the handler
         * function. The handler function's "this" context.
         * @param {Object}   options (optional) An object containing handler configuration
         * properties. This may contain any of the following properties:<ul>
         * <li>scope {Object} The scope in which to execute the handler function. The handler function's "this" context.</li>
         * <li>delay {Number} The number of milliseconds to delay the invocation of the handler after te event fires.</li>
         * <li>single {Boolean} True to add a handler to handle just the next firing of the event, and then remove itself.</li>
         * <li>buffer {Number} Causes the handler to be scheduled to run in an {@link Roo.DelayedTask} delayed
         * by the specified number of milliseconds. If the event fires again within that time, the original
         * handler is <em>not</em> invoked, but the new handler is scheduled in its place.</li>
         * </ul><br>
         * <p>
         * <b>Combining Options</b><br>
         * Using the options argument, it is possible to combine different types of listeners:<br>
         * <br>
         * A normalized, delayed, one-time listener that auto stops the event and passes a custom argument (forumId)
            <pre><code>
            el.on('click', this.onClick, this, {
                single: true,
                delay: 100,
                forumId: 4
            });
            </code></pre>
         * <p>
         * <b>Attaching multiple handlers in 1 call</b><br>
         * The method also allows for a single argument to be passed which is a config object containing properties
         * which specify multiple handlers.
         * <pre><code>
            el.on({
                'click': {
                    fn: this.onClick,
                    scope: this,
                    delay: 100
                }, 
                'mouseover': {
                    fn: this.onMouseOver,
                    scope: this
                },
                'mouseout': {
                    fn: this.onMouseOut,
                    scope: this
                }
            });
            </code></pre>
         * <p>
         * Or a shorthand syntax which passes the same scope object to all handlers:
            <pre><code>
            el.on({
                'click': this.onClick,
                'mouseover': this.onMouseOver,
                'mouseout': this.onMouseOut,
                scope: this
            });
            </code></pre>
         */
        on : function(eventName, fn, scope, o){
            if(typeof eventName == "object"){
                o = eventName;
                for(var e in o){
                    if(this.filterOptRe.test(e)){
                        continue;
                    }
                    if(typeof o[e] == "function"){
                        // shared options
                        this.on(e, o[e], o.scope,  o);
                    }else{
                        // individual options
                        this.on(e, o[e].fn, o[e].scope, o[e]);
                    }
                }
                return;
            }
            o = (!o || typeof o == "boolean") ? {} : o;
            eventName = eventName.toLowerCase();
            var ce = this.events[eventName] || true;
            if(typeof ce == "boolean"){
                ce = new Roo.Event(this, eventName);
                this.events[eventName] = ce;
            }
            ce.addListener(fn, scope, o);
        },

        /**
         * Removes a listener
         * @param {String}   eventName     The type of event to listen for
         * @param {Function} handler        The handler to remove
         * @param {Object}   scope  (optional) The scope (this object) for the handler
         */
        un : function(eventName, fn, scope){
            var ce = this.events[eventName.toLowerCase()];
            if(typeof ce == "object"){
                ce.removeListener(fn, scope);
            }
        },

        /**
         * Removes all listeners for this object
         */
        purgeListeners : function(){
            for(var evt in this.events){
                if(typeof this.events[evt] == "object"){
                     this.events[evt].clearListeners();
                }
            }
        },

        relayEvents : function(o, events){
            var createHandler = function(ename){
                return function(){
                    return this.fireEvent.apply(this, Roo.combine(ename, Array.prototype.slice.call(arguments, 0)));
                };
            };
            for(var i = 0, len = events.length; i < len; i++){
                var ename = events[i];
                if(!this.events[ename]){ this.events[ename] = true; };
                o.on(ename, createHandler(ename), this);
            }
        },

        /**
         * Used to define events on this Observable
         * @param {Object} object The object with the events defined
         */
        addEvents : function(o){
            if(!this.events){
                this.events = {};
            }
            Roo.applyIf(this.events, o);
        },

        /**
         * Checks to see if this object has any listeners for a specified event
         * @param {String} eventName The name of the event to check for
         * @return {Boolean} True if the event is being listened for, else false
         */
        hasListener : function(eventName){
            var e = this.events[eventName];
            return typeof e == "object" && e.listeners.length > 0;
        }
};
 
/**
 * Starts capture on the specified Observable. All events will be passed
 * to the supplied function with the event name + standard signature of the event
 * <b>before</b> the event is fired. If the supplied function returns false,
 * the event will not fire.
 * @param {Observable} o The Observable to capture
 * @param {Function} fn The function to call
 * @param {Object} scope (optional) The scope (this object) for the fn
 * @static
 */
Observable.capture = function(o, fn, scope){
    o.fireEvent = o.fireEvent.createInterceptor(fn, scope);
};

/**
 * Removes <b>all</b> added captures from the Observable.
 * @param {Observable} o The Observable to release
 * @static
 */
Observable.releaseCapture = function(o){
    o.fireEvent = Observable.prototype.fireEvent;
};

(function(){

    var createBuffered = function(h, o, scope){
        var task = new Roo.DelayedTask();
        return function(){
            task.delay(o.buffer, h, scope, Array.prototype.slice.call(arguments, 0));
        };
    };

    var createSingle = function(h, e, fn, scope){
        return function(){
            e.removeListener(fn, scope);
            return h.apply(scope, arguments);
        };
    };

    var createDelayed = function(h, o, scope){
        return function(){
            var args = Array.prototype.slice.call(arguments, 0);
            setTimeout(function(){
                h.apply(scope, args);
            }, o.delay || 10);
        };
    };

    Roo.Event = function(obj, name){
        this.name = name;
        this.obj = obj;
        this.listeners = [];
    };

    Roo.Event.prototype = {
        addListener : function(fn, scope, options){
            var o = options || {};
            scope = scope || this.obj;
            if(!this.isListening(fn, scope)){
                var l = {fn: fn, scope: scope, options: o};
                var h = fn;
                if(o.delay){
                    h = createDelayed(h, o, scope);
                }
                if(o.single){
                    h = createSingle(h, this, fn, scope);
                }
                if(o.buffer){
                    h = createBuffered(h, o, scope);
                }
                l.fireFn = h;
                if(!this.firing){ // if we are currently firing this event, don't disturb the listener loop
                    this.listeners.push(l);
                }else{
                    this.listeners = this.listeners.slice(0);
                    this.listeners.push(l);
                }
            }
        },

        findListener : function(fn, scope){
            scope = scope || this.obj;
            var ls = this.listeners;
            for(var i = 0, len = ls.length; i < len; i++){
                var l = ls[i];
                if(l.fn == fn && l.scope == scope){
                    return i;
                }
            }
            return -1;
        },

        isListening : function(fn, scope){
            return this.findListener(fn, scope) != -1;
        },

        removeListener : function(fn, scope){
            var index;
            if((index = this.findListener(fn, scope)) != -1){
                if(!this.firing){
                    this.listeners.splice(index, 1);
                }else{
                    this.listeners = this.listeners.slice(0);
                    this.listeners.splice(index, 1);
                }
                return true;
            }
            return false;
        },

        clearListeners : function(){
            this.listeners = [];
        },

        fire : function(){
            var ls = this.listeners, scope, len = ls.length;
            if(len > 0){
                this.firing = true;
                var args = Array.prototype.slice.call(arguments, 0);
                for(var i = 0; i < len; i++){
                    var l = ls[i];
                    if(l.fireFn.apply(l.scope||this.obj||window, arguments) === false){
                        this.firing = false;
                        return false;
                    }
                }
                this.firing = false;
            }
            return true;
        }
    };
})();