added event handler base class

WebContent/OSRM.EventHandler.js

@@ -0,0 +1,61 @@
+/*
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU AFFERO General Public License as published by
+the Free Software Foundation; either version 3 of the License, or
+any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+or see http://www.gnu.org/licenses/agpl.txt.
+*/
+
+// OSRM EventHandler
+// [adds simple event handling: other classes can derive from this class to acquire custom event handling]
+
+
+OSRM.EventHandler = function() {
+	this._listeners = {};
+};
+
+OSRM.extend( OSRM.EventHandler, {
+	
+	// add listener
+	addListener: function(type, listener) {
+		if( typeof this._listeners[type] == "undefined" )
+			this._listeners[type] = [];
+		this._listeners[type].push(listener);
+	},
+	
+	//remove event listener
+	removeListener: function(type, listener) {
+		if( this._listeners[type] instanceof Array) {
+			for(var i=0; i<this._listeners[type].length; i++)
+				if( this._listeners[type][i] == listener) {
+					this._listeners[type].splice(i,1);
+					break;
+				}
+		}
+	},
+	
+	// fire event
+	fire: function(event) {
+		if( typeof event == "string")
+			event = {type:event};
+		if( !event.target )
+			event.target = this;
+		
+		if( !event.type )
+			throw new Error("event object missing type property!");
+		
+		if( this._listeners[event.type] instanceof Array)
+			for(var listener in this._listeners[event.type])
+				listener.call(this, event);
+	}
+	
+});