Use jquery.debounce instead of custom code to speed up navigation scroll and resize handlers

js/jquery/jquery.debounce-1.0.5.js

@@ -0,0 +1,71 @@
+/**
+ * Debounce and throttle function's decorator plugin 1.0.5
+ *
+ * Copyright (c) 2009 Filatov Dmitry (alpha@zforms.ru)
+ * Dual licensed under the MIT and GPL licenses:
+ * http://www.opensource.org/licenses/mit-license.php
+ * http://www.gnu.org/licenses/gpl.html
+ *
+ */
+
+(function($) {
+
+$.extend({
+
+	debounce : function(fn, timeout, invokeAsap, ctx) {
+
+		if(arguments.length == 3 && typeof invokeAsap != 'boolean') {
+			ctx = invokeAsap;
+			invokeAsap = false;
+		}
+
+		var timer;
+
+		return function() {
+
+			var args = arguments;
+            ctx = ctx || this;
+
+			invokeAsap && !timer && fn.apply(ctx, args);
+
+			clearTimeout(timer);
+
+			timer = setTimeout(function() {
+				!invokeAsap && fn.apply(ctx, args);
+				timer = null;
+			}, timeout);
+
+		};
+
+	},
+
+	throttle : function(fn, timeout, ctx) {
+
+		var timer, args, needInvoke;
+
+		return function() {
+
+			args = arguments;
+			needInvoke = true;
+			ctx = ctx || this;
+
+			if(!timer) {
+				(function() {
+					if(needInvoke) {
+						fn.apply(ctx, args);
+						needInvoke = false;
+						timer = setTimeout(arguments.callee, timeout);
+					}
+					else {
+						timer = null;
+					}
+				})();
+			}
+
+		};
+
+	}
+
+});
+
+})(jQuery);

js/navigation.js

@@ -432,15 +432,18 @@ var ScrollHandler = {
         };
         this.displayScrollbar();
         $(window).bind('resize', this.displayScrollbar);
-        this.elms.$handle.live('drag', function (event, drag) {
-            var elms = ScrollHandler.elms;
-            var scrollbarOffset = elms.$scrollbar.offset().top;
-            var pos = drag.offsetY - scrollbarOffset;
-            var height = $(window).height() - scrollbarOffset - elms.$handle.height();
-            value = ScrollHandler.sanitize(pos / height);
-            ScrollHandler.setScrollbar(value);
-            ScrollHandler.setContent(value);
-        });
+        this.elms.$handle.live(
+            'drag',
+            $.throttle(function (event, drag) {
+                var elms = ScrollHandler.elms;
+                var scrollbarOffset = elms.$scrollbar.offset().top;
+                var pos = drag.offsetY - scrollbarOffset;
+                var height = $(window).height() - scrollbarOffset - elms.$handle.height();
+                value = ScrollHandler.sanitize(pos / height);
+                ScrollHandler.setScrollbar(value);
+                ScrollHandler.setContent(value);
+            }, 4)
+        );
         this.elms.$scrollbar.live('click', function (event) {
             if($(event.target).attr('id') === $(this).attr('id')) {
                 var $scrollbar = ScrollHandler.elms.$scrollbar;
@@ -642,7 +645,7 @@ var ResizeHandler = function () {
         .live('mousedown', {'resize_handler':this}, this.mousedown);
     $(document)
         .bind('mouseup', {'resize_handler':this}, this.mouseup)
-        .bind('mousemove', {'resize_handler':this}, this.mousemove);
+        .bind('mousemove', {'resize_handler':this}, $.throttle(this.mousemove, 4));
     var $collapser = $('#pma_navigation_collapser');
     $collapser.live('click', {'resize_handler':this}, this.collapse);
     // Add the correct arrow symbol to the collapser

libraries/Header.class.php

@@ -153,6 +153,7 @@ class PMA_Header
         $this->_scripts->addFile('jquery/jquery.event.drag-2.0.js');
         $this->_scripts->addFile('jquery/timepicker.js');
         $this->_scripts->addFile('jquery/jquery.ba-hashchange-1.3.js');
+        $this->_scripts->addFile('jquery/jquery.debounce-1.0.5.js');
 
         $this->_scripts->addFile('jquery/jquery.qtip-1.0.0-rc3.js');
         if ($GLOBALS['cfg']['CodemirrorEnable']) {