dojo_app/js/library/dojox/drawing/manager/Canvas.js

define(["dojo", "../util/oo", "dojox/gfx"], 
function(dojo, oo, gfx){

	//dojox.drawing.manager.Canvas = 
	return oo.declare(
		function(/*Object*/options){
			dojo.mixin(this, options);
			
			var dim = dojo.contentBox(this.srcRefNode);
			this.height = this.parentHeight = options.height || dim.h;
			this.width = this.parentWidth = options.width || dim.w;
			this.domNode = dojo.create("div", {id:"canvasNode"}, this.srcRefNode);
			dojo.style(this.domNode, {
				width:this.width,
				height:"auto"
			});
			
			dojo.setSelectable(this.domNode, false);
			
			this.id = this.id || this.util.uid("surface");
			
			console.info("create canvas");
			this.gfxSurface = gfx.createSurface(this.domNode, this.width, this.height);
			this.gfxSurface.whenLoaded(this, function(){
				setTimeout(dojo.hitch(this, function(){
					this.surfaceReady = true;
					if(dojo.isIE){
						//this.gfxSurface.rawNode.parentNode.id = this.id;
					}else if(gfx.renderer == "silverlight"){
						this.id = this.domNode.firstChild.id
					}else{
						//this.gfxSurface.rawNode.id = this.id;
					}
					
					this.underlay = this.gfxSurface.createGroup();
					this.surface = this.gfxSurface.createGroup();
					this.overlay = this.gfxSurface.createGroup();
					this.surface.setTransform({dx:0, dy:0,xx:1,yy:1});
					
					this.gfxSurface.getDimensions = dojo.hitch(this.gfxSurface, "getDimensions");
					if(options.callback){
						options.callback(this.domNode);
					}
				}),500);
			});
			this._mouseHandle = this.mouse.register(this);
		},
		{
			// summary:
			//		Creates a dojox.gfx.surface to be used for Drawing. Note that
			//		The 'surface' that Drawing uses is actually a dojox.gfx.group.
			//		This allows for more versatility.
			//
			//		Called internally from a dojox.Drawing.
			//
			//		Note: Surface creation is asynchronous. Connect to
			//		onSurfaceReady in Drawing.

			// zoom: [readonly] Number
			//		The amount the canvas is zoomed
			zoom:1,
						
			useScrollbars: true,
			baseClass:"drawingCanvas",
			
			resize: function(width, height){
				// summary:
				//		Method used to change size of canvas. Potentially
				//		called from a container like ContentPane. May be
				//		called directly.

				this.parentWidth = width;
				this.parentHeight = height;
				this.setDimensions(width, height);
			},
			
			setDimensions: function(width, height, scrollx, scrolly){
				// summary:
				//		Internal. Changes canvas size and sets scroll position.
				//		Do not call this, use resize().

				// changing the size of the surface and setting scroll
				// if items are off screen
				var sw = this.getScrollWidth(); //+ 10;
				this.width = Math.max(width, this.parentWidth);
				this.height = Math.max(height, this.parentHeight);
				
				if(this.height>this.parentHeight){
					this.width -= sw;
				}
				if(this.width>this.parentWidth){
					this.height -= sw;
				}
				
				this.mouse.resize(this.width,this.height);
				this.gfxSurface.setDimensions(this.width, this.height);

			
				this.domNode.parentNode.scrollTop = scrolly || 0;
				this.domNode.parentNode.scrollLeft = scrollx || 0;
				
				
				if(this.useScrollbars){
					//console.info("Set Canvas Scroll", (this.height > this.parentHeight), this.height, this.parentHeight)
					dojo.style(this.domNode.parentNode, {
						overflowY: this.height > this.parentHeight ? "scroll" : "hidden",
						overflowX: this.width > this.parentWidth ? "scroll" : "hidden"
					});
				}else{
					dojo.style(this.domNode.parentNode, {
						overflowY: "hidden",
						overflowX: "hidden"
					});
				}
			},
			
			
			setZoom: function(zoom){
				// summary:
				//		Internal. Zooms canvas in and out.
				this.zoom = zoom;
				this.surface.setTransform({xx:zoom, yy:zoom});
				this.setDimensions(this.width*zoom, this.height*zoom)
			},
			
			onScroll: function(){
				// summary:
				//		Event fires on scroll.NOT IMPLEMENTED
			},
			
			getScrollOffset: function(){
				// summary:
				//		Get the scroll position of the canvas
				return {
					top:this.domNode.parentNode.scrollTop,
					left:this.domNode.parentNode.scrollLeft
				}; // Object
			},
			
			getScrollWidth: function(){
				// summary:
				//		Special method used to detect the width (and height)
				//		of the browser scrollbars. Becomes memoized.

				var p = dojo.create('div');
				p.innerHTML = '<div style="width:50px;height:50px;overflow:hidden;position:absolute;top:0;left:-1000px;"><div style="height:100px;"></div>';
				var div = p.firstChild;
				dojo.body().appendChild(div);
				var noscroll = dojo.contentBox(div).h;
				dojo.style(div, "overflow", "scroll");
				var scrollWidth = noscroll - dojo.contentBox(div).h;
				dojo.destroy(div);
				this.getScrollWidth = function(){
					return scrollWidth;
				};
				return scrollWidth; // Object
			}
		}
	);
	
});