New utility functions to add and remove event handlers

1 files changed, 65 insertions, 0 deletions

diff --git a/itjs/it.js b/itjs/it.js
index 090d28f..a48d829 100644
--- a/itjs/it.js
+++ b/itjs/it.js
@@ -103,6 +103,71 @@ function it_event(p)
 	p.element["on" + p.event].oldhandler = oldhandler;
 }
 
+function it_add_event(p)
+{
+	if (!p.object || !p.method)  // not enough arguments
+		return;
+	if (!p.element)
+		p.element = document;
+
+	if (!p.object._it_events)
+		p.object._it_events = [];
+	
+	var evt = p.event;
+	var key = p.event + '*' + p.method;
+	var p_closure = p;	// Needed for Konqueror 3.4.2 as p is (wrongly) shadowed by global input element named p
+	if (!p.object._it_events[key])
+		p.object._it_events[key] = function(e){ return p_closure.object[p_closure.method](e, p_closure); };
+
+	if (p.element.addEventListener)
+		p.element.addEventListener(evt, p.object._it_events[key], false);
+	else if (p.element.attachEvent)
+		p.element.attachEvent('on'+evt, p.object._it_events[key]);
+	else
+	{
+		p.element['on'+evt] = function(e)
+		{
+			var ret = true;
+			for (var k in p_closure.object._it_events)
+				if (p_closure.object._it_events[k] && k.indexOf(evt) == 0)
+					ret = p_closure.object._it_events[k](e);
+			return ret;
+		};
+	}
+}
+
+function it_remove_event(p)
+{
+	if (!p.element)
+		p.element = document;
+
+	var key = p.event + '*' + p.method;
+	if (p.object && p.object._it_events && p.object._it_events[key]) {
+		if (p.element.removeEventListener)
+			p.element.removeEventListener(p.event, p.object._it_events[key], false);
+		else if (p.element.detachEvent)
+			p.element.detachEvent('on'+p.event, p.object._it_events[key]);
+
+		p.object._it_events[key] = null;
+	}
+}
+
+/**
+ * Prevent event propagation and bubbeling
+ */
+function it_event_void(evt)
+{
+	var e = evt ? evt : window.event;
+	if (e.preventDefault)
+		e.preventDefault();
+	if (e.stopPropagation)
+		e.stopPropagation();
+
+	e.cancelBubble = true;
+	e.returnValue = false;
+	return false;
+}
+
 /* Get object pixel position. Based on quirksmode.org's code */
 function it_get_obj_x(obj)
 {