jsbeans

/*!
 * Copyright (c) 2009 Francesco Mele jsbeans@francescomele.com
 *
 * Thi Software is licenced under the LGPL Licence (GNU Lesser General 
 * Public License).
 * In addition to the LGPL Licence the Software is subject to the 
 * following conditions:
 * 
 * 	i	every modification must be public and comunicated to the Author
 * 	ii	every "jsbean" added to this library must be self consistent 
 * 		except for the dependence from jsbeans-x.x.x.js
 * 	iii	copyright notice and this permission notice shall be included 
 * 		in all copies or substantial portions of the Software
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

/**
 * Invokes periodically a {@param} <code class="param">callback</code> every {@param} <code class="param">frequency</code> seconds.<br/>
 * Partially based upon prototype.js PeriodicalExecuter
 * @namespace jsbeans
 * @class Repeater
 * @constructor 
 * @param callback {Function}
 * @param frequency {Integer} interval in seconds between two subsequent calls
 * @param [args] {Object} arguments for callback
 * */
jsbeans.Repeater = function(callback, frequency /*, arguments*/) {
	this.callback = callback;
	this.frequency = frequency;
	this.args = arguments;
};

/**
 * Starts repeating
 * @method start
 * */
jsbeans.Repeater.prototype.start = function() {
	var args = new Array();
	for (var i = 2; i < this.args.length; i++) {
		args.push(this.args[i]);
	}
	this.args = args;
	this.callback.apply(this.callback, args);
	
	var _currentlyExecuting = this._currentlyExecuting;
	var callback = this.callback;

	var _starter = function() {
		if (!_currentlyExecuting) {
			try {
				_currentlyExecuting = true;
				callback.apply(callback, args);
			} 
			finally {
				_currentlyExecuting = false;
			}
		}
	};
	this._timerId = window.setInterval(_starter, this.frequency * 1000);
};

/**
 * Stops repeating.
 * @method stop
 * */
jsbeans.Repeater.prototype.stop = function() {
	window.clearInterval(this._timerId);
};


/**
 * After this call every Function will be added with a "repeatExtension" method.<br/>
 * Sample usage
 * <pre>
 * function myFun() { // my code here  }
 * 		myFun.repeatExtension(5000, 3) // execute myFun 3 times every 5 seconds
 * 		myFun.repeatExtension(5000, -1, 'ciccio') // exeute myFun every 5 seconds forever passing string "ciccio" as argument of myFun
 * </pre>
 * @method all
 * @static
 */
jsbeans.Repeater.all = function() {
	Function.prototype.repeatExtension = function () {
		var s = this;
		var _args;
		if (typeof arguments[0].callee != 'undefined'){
			_args = arguments[0];
		} 
		else {
			_args = arguments;
		}
		
		var delay = _args[0];
		var timesToExecute = _args[1];
		this._timerId = null;
		
		var args = new Array();
		for (var i = 2; i < _args.length; i++) {
			args.push(_args[i]);
		}
		
		s.apply(this, args);
		
		if (this._timerId) {
			clearTimeout(this._timerId);
		}
		
		if (timesToExecute == -1 || --timesToExecute > 0) {
			this._timerId = setTimeout(function (){
				_args[1] = timesToExecute;
				s.repeatExtension(_args);
			}, delay);
		}
		return s;
	};
};

/**
 * Instance method for static one.<br/>
 * It internally calls {@method} <code class="methd">jsbeans.Repeater.all()</code>
 * @method all
 * */
jsbeans.Repeater.prototype.all = function() {
	jsbeans.Repeater.all();
};