dojo.provide("dijit.DialogUnderlay");

dojo.require("dojo.window");

dojo.require("dijit._Widget");
dojo.require("dijit._Templated");

dojo.declare(
	"dijit.DialogUnderlay",
	[dijit._Widget, dijit._Templated],
	{
		// summary:
		//		The component that blocks the screen behind a `dijit.Dialog`
		//
		// description:
		// 		A component used to block input behind a `dijit.Dialog`. Only a single
		//		instance of this widget is created by `dijit.Dialog`, and saved as
		//		a reference to be shared between all Dialogs as `dijit._underlay`
		//
		//		The underlay itself can be styled based on and id:
		//	|	#myDialog_underlay { background-color:red; }
		//
		//		In the case of `dijit.Dialog`, this id is based on the id of the Dialog,
		//		suffixed with _underlay.

		// Template has two divs; outer div is used for fade-in/fade-out, and also to hold background iframe.
		// Inner div has opacity specified in CSS file.
		templateString: "<div class='dijitDialogUnderlayWrapper'><div class='dijitDialogUnderlay' dojoAttachPoint='node'></div></div>",

		// Parameters on creation or updatable later

		// dialogId: String
		//		Id of the dialog.... DialogUnderlay's id is based on this id
		dialogId: "",

		// class: String
		//		This class name is used on the DialogUnderlay node, in addition to dijitDialogUnderlay
		"class": "",

		attributeMap: { id: "domNode" },

		_setDialogIdAttr: function(id){
			dojo.attr(this.node, "id", id + "_underlay");
		},

		_setClassAttr: function(clazz){
			this.node.className = "dijitDialogUnderlay " + clazz;
		},

		postCreate: function(){
			// summary:
			//		Append the underlay to the body
			dojo.body().appendChild(this.domNode);
		},

		layout: function(){
			// summary:
			//		Sets the background to the size of the viewport
			//
			// description:
			//		Sets the background to the size of the viewport (rather than the size
			//		of the document) since we need to cover the whole browser window, even
			//		if the document is only a few lines long.
			// tags:
			//		private

			var is = this.node.style,
				os = this.domNode.style;

			// hide the background temporarily, so that the background itself isn't
			// causing scrollbars to appear (might happen when user shrinks browser
			// window and then we are called to resize)
			os.display = "none";

			// then resize and show
			var viewport = dojo.window.getBox();
			os.top = viewport.t + "px";
			os.left = viewport.l + "px";
			is.width = viewport.w + "px";
			is.height = viewport.h + "px";
			os.display = "block";
		},

		show: function(){
			// summary:
			//		Show the dialog underlay
			this.domNode.style.display = "block";
			this.layout();
			this.bgIframe = new dijit.BackgroundIframe(this.domNode);
		},

		hide: function(){
			// summary:
			//		Hides the dialog underlay
			this.bgIframe.destroy();
			delete this.bgIframe;
			this.domNode.style.display = "none";
		}
	}
);
