Slider: add handles in single DOM operation. Fixed #7259 - optimize handle creation.

(cherry picked from commit 7fb6ca1)

Author: adambaratz

ui/jquery.ui.slider.js

@@ -36,7 +36,11 @@ $.widget( "ui.slider", $.ui.mouse, {
 
 	_create: function() {
 		var self = this,
-			o = this.options;
+			o = this.options,
+			existingHandles = this.element.find( ".ui-slider-handle" ).addClass( "ui-state-default ui-corner-all" ),
+			handle = "<a class='ui-slider-handle ui-state-default ui-corner-all' href='#'></a>",
+			handleCount = ( o.values && o.values.length ) || 1,
+			handles = [];
 
 		this._keySliding = false;
 		this._mouseSliding = false;
@@ -50,57 +54,35 @@ $.widget( "ui.slider", $.ui.mouse, {
 				" ui-slider-" + this.orientation +
 				" ui-widget" +
 				" ui-widget-content" +
-				" ui-corner-all" );
-		
-		if ( o.disabled ) {
-			this.element.addClass( "ui-slider-disabled ui-disabled" );
-		}
+				" ui-corner-all" +
+				( o.disabled ? " ui-slider-disabled ui-disabled" : "" ) );
 
 		this.range = $([]);
 
 		if ( o.range ) {
 			if ( o.range === true ) {
-				this.range = $( "<div></div>" );
 				if ( !o.values ) {
 					o.values = [ this._valueMin(), this._valueMin() ];
 				}
 				if ( o.values.length && o.values.length !== 2 ) {
 					o.values = [ o.values[0], o.values[0] ];
 				}
-			} else {
-				this.range = $( "<div></div>" );
-			}
-
-			this.range
-				.appendTo( this.element )
-				.addClass( "ui-slider-range" );
-
-			if ( o.range === "min" || o.range === "max" ) {
-				this.range.addClass( "ui-slider-range-" + o.range );
 			}
 
-			// note: this isn't the most fittingly semantic framework class for this element,
-			// but worked best visually with a variety of themes
-			this.range.addClass( "ui-widget-header" );
-		}
-
-		if ( $( ".ui-slider-handle", this.element ).length === 0 ) {
-			$( "<a href='#'></a>" )
+			this.range = $( "<div></div>" )
 				.appendTo( this.element )
-				.addClass( "ui-slider-handle" );
+				.addClass( "ui-slider-range" +
+				// note: this isn't the most fittingly semantic framework class for this element,
+				// but worked best visually with a variety of themes
+				" ui-widget-header" + 
+				( ( o.range === "min" || o.range === "max" ) ? " ui-slider-range-" + o.range : "" ) );
 		}
 
-		if ( o.values && o.values.length ) {
-			while ( $(".ui-slider-handle", this.element).length < o.values.length ) {
-				$( "<a href='#'></a>" )
-					.appendTo( this.element )
-					.addClass( "ui-slider-handle" );
-			}
+		for ( var i = existingHandles.length; i < handleCount; i += 1 ) {
+			handles.push( handle );
 		}
 
-		this.handles = $( ".ui-slider-handle", this.element )
-			.addClass( "ui-state-default" +
-				" ui-corner-all" );
+		this.handles = existingHandles.add( $( handles.join( "" ) ).appendTo( self.element ) );
 
 		this.handle = this.handles.eq( 0 );