jquery/src/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
		var events = jQuery.data(element, "events") || jQuery.data(element, "events", {});
		
		var handle = jQuery.data(element, "handle") || jQuery.data(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 = events[type];

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

			// Remove the expando if it's no longer used
			for ( ret in events ) break;
			if ( !ret ) {
				jQuery.removeData( element, "events" );
				jQuery.removeData( element, "handle" );
			}
		}
	},

	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
				event = !data[0] || !data[0].preventDefault;
			
			// Pass along a fake event
			if ( event )
				data.unshift( this.fix({ type: type, target: element }) );

			// Enforce the right trigger type
			data[0].type = type;

			// Trigger the event
			if ( jQuery.isFunction( jQuery.data(element, "handle") ) )
				val = jQuery.data(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 ( event )
				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 handlers = jQuery.data(this, "events") && jQuery.data(this, "events")[event.type], args = Array.prototype.slice.call( arguments, 1 );
		args.unshift( event );

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

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

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

				if ( ret === 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.target = event.srcElement || document; // Fixes #1925 where srcElement might not be defined either
				
		// check if target is a textnode (safari)
		if ( 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 doc = document.documentElement, body = document.body;
			event.pageX = event.clientX + (doc && doc.scrollLeft || body && body.scrollLeft || 0) - (doc.clientLeft || 0);
			event.pageY = event.clientY + (doc && doc.scrollTop  || body && body.scrollTop  || 0) - (doc.clientLeft || 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 args = arguments;

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

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

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


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, name){
	
	// Handle event binding
	jQuery.fn[name] = function(fn){
		return fn ? this.bind(name, fn) : this.trigger(name);
	};
});

var readyBound = false;

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

	// Mozilla, Opera and webkit nightlies currently support this event
	if ( document.addEventListener )
		// Use the handy event callback
		document.addEventListener( "DOMContentLoaded", jQuery.ready, false );
	
	// If Safari or IE is used
	// Continually check to see if the document is ready
	if  (jQuery.browser.msie || jQuery.browser.safari ) (function(){
		try {
			// If IE is used, use the trick by Diego Perini
			// http://javascript.nwbox.com/IEContentLoaded/
			if ( jQuery.browser.msie || document.readyState != "loaded" && document.readyState != "complete" )
				document.documentElement.doScroll("left");
		} catch( error ) {
			return setTimeout( arguments.callee, 0 );
		}

		// and execute any waiting functions
		jQuery.ready();
	})();

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

// Prevent memory leaks in IE
// And prevent errors on refresh with events like mouseover
// Window isn't included so as not to unbind existing unload events
jQuery(window).bind("unload", function() {
	jQuery("*").add(document).unbind();
});