/*
 * jSwipe - jQuery Plugin
 * http://plugins.jquery.com/project/swipe
 * http://www.ryanscherf.com/demos/swipe/
 *
 * Copyright (c) 2009 Ryan Scherf (www.ryanscherf.com)
 * Licensed under the MIT license
 *
 * $Date: 2009-07-14 (Tue, 14 Jul 2009) $
 * $version: 0.1
 * 
 * This jQuery plugin will only run on devices running Mobile Safari
 * on iPhone or iPod Touch devices running iPhone OS 2.0 or later. 
 * http://developer.apple.com/iphone/library/documentation/AppleApplications/Reference/SafariWebContent/HandlingEvents/HandlingEvents.html#//apple_ref/doc/uid/TP40006511-SW5
 */
(function($) {
	$.fn.swipe = function(options) {
		
		// Default thresholds & swipe functions
		var defaults = {
			threshold: {
				x: 30,
				y: 10
			},
			swipeLeft: function() { alert('swiped left') },
			swipeRight: function() { alert('swiped right') }
		};
		
		var options = $.extend(defaults, options);
		
		if (!this) return false;
		
		return this.each(function() {
			
			var me = $(this)
			
			// Private variables for each element
			var originalCoord = { x: 0, y: 0 }
			var finalCoord = { x: 0, y: 0 }
			
			// Screen touched, store the original coordinate
			function touchStart(event) {
				console.log('Starting swipe gesture ('+event.targetTouches[0].pageX+','+event.targetTouches[0].pageY+')')
				originalCoord.x = event.targetTouches[0].pageX
				originalCoord.y = event.targetTouches[0].pageY
			}
			
			// Store coordinates as finger is swiping
			function touchMove(event) {
			    event.preventDefault();
				finalCoord.x = event.targetTouches[0].pageX // Updated X,Y coordinates
				finalCoord.y = event.targetTouches[0].pageY
			}
			
			// Done Swiping
			// Swipe should only be on X axis, ignore if swipe on Y axis
			// Calculate if the swipe was left or right
			function touchEnd(event) {
				var changeY = originalCoord.y - finalCoord.y
				var changeX = originalCoord.x - finalCoord.x
				//if(changeX < defaults.threshold.y && changeX > (defaults.threshold.x*-1)) {
					if(changeX > defaults.threshold.x) {
						defaults.swipeLeft()
					}
					if(changeX < (defaults.threshold.x*-1)) {
						defaults.swipeRight()
					}
					console.log('Ending swipe gesture ('+changeX+','+changeY+')')
				//}
				//else console.log('Ending swipe gesture (no movement)')
			}
			
			// Swipe was canceled
			function touchCancel(event) { 
				console.log('Canceling swipe gesture...')
			}
			
			// Add gestures to all swipable areas
			AttachEvent(this,"touchstart", touchStart, false);
			AttachEvent(this,"touchmove", touchMove, false);
			AttachEvent(this,"touchend", touchEnd, false);
			AttachEvent(this,"touchcancel", touchCancel, false);
				
		});
	};
})(jQuery);


//Cross Browser Event Handling
function AttachEvent(obj,evt,fnc,useCapture){
	if (!useCapture) useCapture=false;
	if (obj.addEventListener){
		obj.addEventListener(evt,fnc,useCapture);
		return true;
	} else if (obj.attachEvent) return obj.attachEvent("on"+evt,fnc);
	else{
		MyAttachEvent(obj,evt,fnc);
		obj['on'+evt]=function(){ MyFireEvent(obj,evt) };
	}
} 

//The following are for browsers like NS4 or IE5Mac which don't support either
//attachEvent or addEventListener
function MyAttachEvent(obj,evt,fnc){
	if (!obj.myEvents) obj.myEvents={};
	if (!obj.myEvents[evt]) obj.myEvents[evt]=[];
	var evts = obj.myEvents[evt];
	evts[evts.length]=fnc;
}
function MyFireEvent(obj,evt){
	if (!obj || !obj.myEvents || !obj.myEvents[evt]) return;
	var evts = obj.myEvents[evt];
	for (var i=0,len=evts.length;i<len;i++) evts[i]();
}