"context" Overlay diff

--- core/src/widgets/overlay/overlay.js	2008-10-29 14:29:42.000000000 +0000
+++ trunk/src/widgets/overlay/overlay.js	2008-11-19 16:27:48.000000000 +0000
@@ -235,6 +235,9 @@
 			@param {glow.widgets.Mask} [opts.mask] Mask to use for modal overlays
 				used to indicate to the user that the overlay is modal. If provided then the modal property is set to true.
 			@param {Boolean} [opts.closeOnMaskClick="true"] if true then listens for a click event on the mask and hides when it fires
+			@param {selector|DOMElement|NodeList} [opts.context] Context for overlay positioning.
+				The overlay will be positioned so that it is centred over the specified element.
+				If the panel is modal, its Mask will inherit the context and so will only cover the context element.
 			@param {String|Function} [opts.anim="null"] A transition for showing / hiding the panel
 				Can be "fade" or "roll", or a function which returns a glow.anim.Animation or glow.anim.Timeline.
 				The function is passed the overlay as the first parameter, and 'true' if the overlay is showing, 'false' if it's hiding.
@@ -310,9 +313,13 @@
 			//assume modal if mask provided
 			if (opts.mask) { opts.modal = true; }
 
+			// Pass options through to mask
+			var maskOpts = opts.zIndex ? {zIndex: opts.zIndex-1} : {};
+			if(opts.context) maskOpts.context = opts.context;   
+			
 			this.opts = opts = glow.lang.apply({
 				modal: false,
-				mask: new glow.widgets.Mask(opts.zIndex ? {zIndex: opts.zIndex-1} : {}),
+				mask: new glow.widgets.Mask( maskOpts ),
 				closeOnMaskClick: true,
 				zIndex: 9990,
 				autoPosition: true,
@@ -325,6 +332,13 @@
 				hideWindowedFlash: true,
 				focusOnShow: false
 			}, opts);
+			
+			/*
+			  The context for this overlay
+			*/
+			if(opts.context) {
+				this.context = opts.context;
+			}
 
 			/**
 			@name glow.widgets.Overlay#content
@@ -440,7 +454,16 @@
 			@returns this
 			*/
 			setPosition: function(x, y) {
+				
+				// Set-up context
+				var context, hasContext = false;
+				if(this.context) {
+					context    = $(this.context);
+					hasContext = context.length > 0;
+				}
+				
 				var container = this.container;
+				
 				//don't use set position if autoPosition is false
 				if (this.autoPosition) {
 					//if values have been provided, set them. Make sure we're not being passed an event object!
@@ -448,6 +471,31 @@
 						this.opts.x = x;
 						this.opts.y = y;
 					}
+					
+					// If we've been give a context then
+					// work out the x,y of the overlay
+					// centred over this.
+					if(hasContext) {
+						var ctx, mid;
+						
+						var ctxOffset = context.offset();
+						ctx = {  x	: ctxOffset.left,
+							 y	: ctxOffset.top,
+							 width	: context.width(),
+							 height	: context.height()
+							};
+						
+						mid = { x: ctx.x + (ctx.width  / 2),
+							y: ctx.y + (ctx.height / 2)
+							};
+						
+						x = mid.x - (container.width()  / 2);
+						y = mid.y - (container.height() / 2);
+												
+						this.opts.x = x + "px";
+						this.opts.y = y + "px";
+					}
+
 					var win = $(window),
 						x = this.opts.x,
 						y = this.opts.y,
@@ -463,6 +511,11 @@
 						containerHeight;
 
 					useFixedThisTime && container.css("position", "fixed");
+					
+					// If we have a context then we set the position
+					// of the overlay to absolute, overriding the decision
+					// of usedFixed. This may cause problems?
+					if(hasContext) container.css("position", "absolute");
 
 					if (typeof x == "string" && x.indexOf("%") != -1) {
 						winWidth = win.width();
@@ -481,7 +534,11 @@
 							container.css("left", Math.max(((winWidth - containerWidth) * (xVal/100)) + extraOffset.x, extraOffset.x) + "px");
 						}
 					} else {
-						container.css("left", xVal + extraOffset.x + "px");
+						if(hasContext) {
+							container.css("left", xVal + "px");
+						} else {
+							container.css("left", xVal + extraOffset.x + "px");
+						}
 					}
 
 					if (typeof y == "string" && y.indexOf("%") != -1) {
@@ -501,7 +558,11 @@
 							container.css("top", Math.max(((winHeight - containerHeight) * (yVal/100)) + extraOffset.y, extraOffset.y) + "px");
 						}
 					} else {
-						container.css("top", yVal + extraOffset.y + "px");
+						if(hasContext) {
+							container.css("top", yVal + "px");
+						} else {
+							container.css("top", yVal + extraOffset.y + "px");
+						}
 					}
 				}
 
@@ -512,6 +573,7 @@
 								 css("width", container[0].offsetWidth + "px").
 								 css("height", container[0].offsetHeight + "px");
 				}
+				
 				return this;
 			},
 			/**