standardise event cancellation

client/dcwebui.js

@@ -243,8 +243,7 @@ var userMenu = function(u, ev) {
 	usermenu.show();
 	
 	//
-	ev.preventDefault();
-	return false;
+	return noprop(ev);
 };
 
 var userlist = {
@@ -525,6 +524,20 @@ var tab_free = function(id) {
 	}
 };
 
+var noprop = function(ev) {
+	if (ev.preventDefault) {
+		ev.preventDefault();
+	}
+	
+	if (ev.stopPropagation) {
+		ev.stopPropagation();
+	} else {
+		ev.cancelBubble = true; // oldIE
+	}
+	
+	return false;
+}
+
 var tab_addHandlers = function() {
 	var tabitems = $(".tabitem");
 	for (var i = 0; i < tabitems.length; i++) {
@@ -533,13 +546,7 @@ var tab_addHandlers = function() {
 		tabitems[i].onclick = function(ev) {
 			tab_set( this.getAttribute('data-tab') );
 			
-			// 360nobubble
-			if (ev.stopPropagation) {
-				ev.stopPropagation();
-			} else {
-				ev.cancelBubble = true; // oldIE
-			}
-			return false;
+			return noprop(ev);
 		};
 	}
 	
@@ -550,13 +557,7 @@ var tab_addHandlers = function() {
 		tabclosers[i].onclick = function(ev) {
 			tab_free( this.getAttribute('data-tab') );
 			
-			// 360nobubble
-			if (ev.stopPropagation) {
-				ev.stopPropagation();
-			} else {
-				ev.cancelBubble = true; // oldIE
-			}
-			return false;
+			return noprop(ev);
 		};
 	}
 };
@@ -949,26 +950,21 @@ window.onload = function() {
 	$("#form-none").onsubmit = function(ev) {
 		submit();
 		
-		// don't submit form
-		ev.preventDefault();
-		return false;
+		return noprop(ev); // don't submit form
 	};
 	
 	$("#chatbox").onkeydown = function(ev) {
 		if (ev.keyCode === 9 /* Tab */) {
 			tabcompletion_start( ev.shiftKey ? -1 : 1 );
-			ev.preventDefault();
-			return false;
+			return noprop(ev);
 				
 		} else if (ev.keyCode == 38 /* ArrowUp */ && ev.ctrlKey) {
 			scrollback_move(-1);
-			ev.preventDefault();
-			return false;
+			return noprop(ev);
 			
 		} else if (ev.keyCode == 40 /* ArrowDown */ && ev.ctrlKey) {
 			scrollback_move(1);
-			ev.preventDefault();
-			return false;
+			return noprop(ev);
 			
 		} else {
 			tabcompletion_inactive();
@@ -987,9 +983,7 @@ window.onload = function() {
 	
 	$("#menubutton").onclick = function(ev) {
 		menu.toggle();
-		ev.preventDefault();
-		ev.stopPropagation();
-		return false;
+		return noprop(ev);
 	};
 	
 	window.onclick = function() {