Diff for "context" Mask

--- core/src/widgets/mask/mask.js	2008-09-22 11:27:44.000000000 +0100
+++ trunk/src/widgets/mask/mask.js	2008-11-17 11:13:51.000000000 +0000
@@ -65,6 +65,15 @@
 				zIndex: 9900,
 				disableScroll: false
 			}, opts || {});
+			
+			/*
+			Property: context
+				If context is specified, the mask is restricted in size
+				to cover the width and height of the context element.
+			*/
+			if(this.opts.context) {
+				this.context = opts.context;
+			}
 
 			/*
 			Property: maskElement
@@ -139,9 +148,31 @@
 
 				function resizeMask() {
 					var bodyHeight = body.height();
+					
+					var hasContext, context, contextHeight, contextWidth, contextOffset;
+					
+					if(that.context) {
+						context = $(that.context);
+						hasContext = context.length > 0;
+					}
+						
+					if(hasContext) {
+						contextOffset = context.offset();
+						contextHeight = context.height() + "px";
+						contextWidth  = context.width()  + "px";
+					} else {
+						contextWidth  = "100%";
+						contextHeight = (that.opts.disableScroll ? noScrollContainer.height() : Math.max(bodyHeight, win.height())) + "px";
+					}
+					
 					for (var i = 0; i < 2; i++) {
-						that.maskElement.css("width", "100%").
-								  css("height", (that.opts.disableScroll ? noScrollContainer.height() : Math.max(bodyHeight, win.height())) + "px");
+						that.maskElement.css("width", contextWidth).
+								  css("height",  contextHeight);
+						
+						// position mask over context element		  
+						if(hasContext) {
+							that.maskElement.css("top", contextOffset.top + "px").css("left", contextOffset.left + "px");
+						}
 					}
 					if (glow.env.ie < 7) {
 						var maskStyle = that.maskElement[0].style;