path: root/src/event/event.js

/*
 * A number of helper functions used for managing events.
 * Many of the ideas behind this code orignated from 
 * Dean Edwards' addEvent library.
 */
jQuery.event = {

	// Bind an event to an element
	// Original by Dean Edwards
	add: function(element, type, handler, data) {
		// For whatever reason, IE has trouble passing the window object
		// around, causing it to be cloned in the process
		if ( jQuery.browser.msie && element.setInterval != undefined )
			element = window;

		// Make sure that the function being executed has a unique ID
		if ( !handler.guid )
			handler.guid = this.guid++;
			
		// if data is passed, bind to handler 
		if( data != undefined ) { 
        		// Create temporary function pointer to original handler 
			var fn = handler; 

			// Create unique handler function, wrapped around original handler 
			handler = function() { 
				// Pass arguments and context to original handler 
				return fn.apply(this, arguments); 
			};

			// Store data in unique handler 
			handler.data = data;

			// Set the guid of unique handler to the same of original handler, so it can be removed 
			handler.guid = fn.guid;
		}

		// Namespaced event handlers
		var parts = type.split(".");
		type = parts[0];
		handler.type = parts[1];

		// Init the element's event structure
		if (!element.$events)
			element.$events = {};
		
		if (!element.$handle)
			element.$handle = function() {
				// returned undefined or false
				var val;

				// Handle the second event of a trigger and when
				// an event is called after a page has unloaded
				if ( typeof jQuery == "undefined" || jQuery.event.triggered )
				  return val;
				
				val = jQuery.event.handle.apply(element, arguments);
				
				return val;
			};

		// Get the current list of functions bound to this event
		var handlers = element.$events[type];

		// Init the event handler queue
		if (!handlers) {
			handlers = element.$events[type] = {};	
			
			// And bind the global event handler to the element
			if (element.addEventListener)
				element.addEventListener(type, element.$handle, false);
			else
				element.attachEvent("on" + type, element.$handle);
		}

		// Add the function to the element's handler list
		handlers[handler.guid] = handler;

		// Keep track of which events have been used, for global triggering
		this.global[type] = true;
	},

	guid: 1,
	global: {},

	// Detach an event or set of events from an element
	remove: function(element, type, handler) {
		var events = element.$events, ret, index;

		// Namespaced event handlers
		if ( typeof type == "string" ) {
			var parts = type.split(".");
			type = parts[0];
		}

		if ( events ) {
			// type is actually an event object here
			if ( type && type.type ) {
				handler = type.handler;
				type = type.type;
			}
			
			if ( !type ) {
				for ( type in events )
					this.remove( element, type );

			} else if ( events[type] ) {
				// remove the given handler for the given type
				if ( handler )
					delete events[type][handler.guid];
				
				// remove all handlers for the given type
				else
					for ( handler in element.$events[type] )
						// Handle the removal of namespaced events
						if ( !parts[1] || events[type][handler].type == parts[1] )
							delete events[type][handler];

				// remove generic event handler if no more handlers exist
				for ( ret in events[type] ) break;
				if ( !ret ) {
					if (element.removeEventListener)
						element.removeEventListener(type, element.$handle, false);
					else
						element.detachEvent("on" + type, element.$handle);
					ret = null;
					delete events[type];
				}
			}

			// Remove the expando if it's no longer used
			for ( ret in events ) break;
			if ( !ret )
				element.$handle = element.$events = null;
		}
	},

	trigger: function(type, data, element, donative, extra) {
		// Clone the incoming data, if any
		data = jQuery.makeArray(data || []);

		// Handle a global trigger
		if ( !element ) {
			// Only trigger if we've ever bound an event for it
			if ( this.global[type] )
				jQuery("*").add([window, document]).trigger(type, data);

		// Handle triggering a single element
		} else {
			var val, ret, fn = jQuery.isFunction( element[ type ] || null ),
				// Check to see if we need to provide a fake event, or not
				evt = !data[0] || !data[0].preventDefault;
			
			// Pass along a fake event
			if ( evt )
				data.unshift( this.fix({ type: type, target: element }) );

			// Trigger the event
			if ( jQuery.isFunction( element.$handle ) )
				val = element.$handle.apply( element, data );

			// Handle triggering native .onfoo handlers
			if ( !fn && element["on"+type] && element["on"+type].apply( element, data ) === false )
				val = false;

			// Extra functions don't get the custom event object
			if ( evt )
				data.shift();

			// Handle triggering of extra function
			if ( extra && extra.apply( element, data ) === false )
				val = false;

			// Trigger the native events (except for clicks on links)
			if ( fn && donative !== false && val !== false && !(jQuery.nodeName(element, 'a') && type == "click") ) {
				this.triggered = true;
				element[ type ]();
			}

			this.triggered = false;
		}

		return val;
	},

	handle: function(event) {
		// returned undefined or false
		var val;

		// Empty object is for triggered events with no data
		event = jQuery.event.fix( event || window.event || {} ); 

		// Namespaced event handlers
		var parts = event.type.split(".");
		event.type = parts[0];

		var c = this.$events && this.$events[event.type], args = Array.prototype.slice.call( arguments, 1 );
		args.unshift( event );

		for ( var j in c ) {
			// Pass in a reference to the handler function itself
			// So that we can later remove it
			args[0].handler = c[j];
			args[0].data = c[j].data;

			// Filter the functions by class
			if ( !parts[1] || c[j].type == parts[1] ) {
				var tmp = c[j].apply( this, args );

				if ( val !== false )
					val = tmp;

				if ( tmp === false ) {
					event.preventDefault();
					event.stopPropagation();
				}
			}
		}

		// Clean up added properties in IE to prevent memory leak
		if (jQuery.browser.msie)
			event.target = event.preventDefault = event.stopPropagation =
				event.handler = event.data = null;

		return val;
	},

	fix: function(event) {
		// store a copy of the original event object 
		// and clone to set read-only properties
		var originalEvent = event;
		event = jQuery.extend({}, originalEvent);
		
		// add preventDefault and stopPropagation since 
		// they will not work on the clone
		event.preventDefault = function() {
			// if preventDefault exists run it on the original event
			if (originalEvent.preventDefault)
				originalEvent.preventDefault();
			// otherwise set the returnValue property of the original event to false (IE)
			originalEvent.returnValue = false;
		};
		event.stopPropagation = function() {
			// if stopPropagation exists run it on the original event
			if (originalEvent.stopPropagation)
				originalEvent.stopPropagation();
			// otherwise set the cancelBubble property of the original event to true (IE)
			originalEvent.cancelBubble = true;
		};
		
		// Fix target property, if necessary
		if ( !event.target && event.srcElement )
			event.target = event.srcElement;
				
		// check if target is a textnode (safari)
		if (jQuery.browser.safari && event.target.nodeType == 3)
			event.target = originalEvent.target.parentNode;

		// Add relatedTarget, if necessary
		if ( !event.relatedTarget && event.fromElement )
			event.relatedTarget = event.fromElement == event.target ? event.toElement : event.fromElement;

		// Calculate pageX/Y if missing and clientX/Y available
		if ( event.pageX == null && event.clientX != null ) {
			var e = document.documentElement, b = document.body;
			event.pageX = event.clientX + (e && e.scrollLeft || b.scrollLeft || 0);
			event.pageY = event.clientY + (e && e.scrollTop || b.scrollTop || 0);
		}
			
		// Add which for key events
		if ( !event.which && (event.charCode || event.keyCode) )
			event.which = event.charCode || event.keyCode;
		
		// Add metaKey to non-Mac browsers (use ctrl for PC's and Meta for Macs)
		if ( !event.metaKey && event.ctrlKey )
			event.metaKey = event.ctrlKey;

		// Add which for click: 1 == left; 2 == middle; 3 == right
		// Note: button is not normalized, so don't use it
		if ( !event.which && event.button )
			event.which = (event.button & 1 ? 1 : ( event.button & 2 ? 3 : ( event.button & 4 ? 2 : 0 ) ));
			
		return event;
	}
};

jQuery.fn.extend({
	bind: function( type, data, fn ) {
		return type == "unload" ? this.one(type, data, fn) : this.each(function(){
			jQuery.event.add( this, type, fn || data, fn && data );
		});
	},
	
	one: function( type, data, fn ) {
		return this.each(function(){
			jQuery.event.add( this, type, function(event) {
				jQuery(this).unbind(event);
				return (fn || data).apply( this, arguments);
			}, fn && data);
		});
	},

	unbind: function( type, fn ) {
		return this.each(function(){
			jQuery.event.remove( this, type, fn );
		});
	},

	trigger: function( type, data, fn ) {
		return this.each(function(){
			jQuery.event.trigger( type, data, this, true, fn );
		});
	},

	triggerHandler: function( type, data, fn ) {
		if ( this[0] )
			return jQuery.event.trigger( type, data, this[0], false, fn );
	},

	toggle: function() {
		// Save reference to arguments for access in closure
		var a = arguments;

		return this.click(function(e) {
			// Figure out which function to execute
			this.lastToggle = 0 == this.lastToggle ? 1 : 0;
			
			// Make sure that clicks stop
			e.preventDefault();
			
			// and execute the function
			return a[this.lastToggle].apply( this, [e] ) || false;
		});
	},

	hover: function(f,g) {
		
		// A private function for handling mouse 'hovering'
		function handleHover(e) {
			// Check if mouse(over|out) are still within the same parent element
			var p = e.relatedTarget;
	
			// Traverse up the tree
			while ( p && p != this ) try { p = p.parentNode; } catch(e) { p = this; };
			
			// If we actually just moused on to a sub-element, ignore it
			if ( p == this ) return false;
			
			// Execute the right function
			return (e.type == "mouseover" ? f : g).apply(this, [e]);
		}
		
		// Bind the function to the two event listeners
		return this.mouseover(handleHover).mouseout(handleHover);
	},
	
	ready: function(f) {
		// Attach the listeners
		bindReady();

		// If the DOM is already ready
		if ( jQuery.isReady )
			// Execute the function immediately
			f.apply( document, [jQuery] );
			
		// Otherwise, remember the function for later
		else
			// Add the function to the wait list
			jQuery.readyList.push( function() { return f.apply(this, [jQuery]); } );
	
		return this;
	}
});

jQuery.extend({
	/*
	 * All the code that makes DOM Ready work nicely.
	 */
	isReady: false,
	readyList: [],
	
	// Handle when the DOM is ready
	ready: function() {
		// Make sure that the DOM is not already loaded
		if ( !jQuery.isReady ) {
			// Remember that the DOM is ready
			jQuery.isReady = true;
			
			// If there are functions bound, to execute
			if ( jQuery.readyList ) {
				// Execute all of them
				jQuery.each( jQuery.readyList, function(){
					this.apply( document );
				});
				
				// Reset the list of functions
				jQuery.readyList = null;
			}
			// Remove event listener to avoid memory leak
			if ( jQuery.browser.mozilla || jQuery.browser.opera )
				document.removeEventListener( "DOMContentLoaded", jQuery.ready, false );
			
			// Remove script element used by IE hack
			if( !window.frames.length ) // don't remove if frames are present (#1187)
				jQuery(window).load(function(){ jQuery("#__ie_init").remove(); });
		}
	}
});


jQuery.each( ("blur,focus,load,resize,scroll,unload,click,dblclick," +
	"mousedown,mouseup,mousemove,mouseover,mouseout,change,select," + 
	"submit,keydown,keypress,keyup,error").split(","), function(i,o){
	
	// Handle event binding
	jQuery.fn[o] = function(f){
		return f ? this.bind(o, f) : this.trigger(o);
	};
});

var readyBound = false;

function bindReady(){
	if ( readyBound ) return;
	readyBound = true;

	// If Mozilla is used
	if ( jQuery.browser.mozilla || jQuery.browser.opera )
		// Use the handy event callback
		document.addEventListener( "DOMContentLoaded", jQuery.ready, false );
	
	// If IE is used, use the excellent hack by Matthias Miller
	// http://www.outofhanwell.com/blog/index.php?title=the_window_onload_problem_revisited
	else if ( jQuery.browser.msie ) {
	
		// Only works if you document.write() it
		document.write("<scr" + "ipt id=__ie_init defer=true " + 
			"src=//:><\/script>");
	
		// Use the defer script hack
		var script = document.getElementById("__ie_init");
		
		// script does not exist if jQuery is loaded dynamically
		if ( script ) 
			script.onreadystatechange = function() {
				if ( this.readyState != "complete" ) return;
				jQuery.ready();
			};
	
		// Clear from memory
		script = null;
	
	// If Safari  is used
	} else if ( jQuery.browser.safari )
		// Continually check to see if the document.readyState is valid
		jQuery.safariTimer = setInterval(function(){
			// loaded and complete are both valid states
			if ( document.readyState == "loaded" || 
				document.readyState == "complete" ) {
	
				// If either one are found, remove the timer
				clearInterval( jQuery.safariTimer );
				jQuery.safariTimer = null;
	
				// and execute any waiting functions
				jQuery.ready();
			}
		}, 10); 

	// A fallback to window.onload, that will always work
	jQuery.event.add( window, "load", jQuery.ready );
}