What is the getCSSCanvasContext() method of an HTML5 element?

What is the getCSSCanvasContext() method? I saw it in Chrome’s debuging console, but I cannot find any decent开发者_Go百科 documentation for it.

Does it mean we can draw using canvas commands on any element?

The method is implemented in WebKit (meaning you can also use it in Safari) and returns an object that lets you draw into a CSS image. See this blog post for an example:

In the latest nightlies, you can try out a new feature: the ability to specify named image buffers in CSS and then to draw into them programmatically from JavaScript. Here’s how it works.

background: -webkit-canvas(mycanvas);

Instead of specifying an image URL, you specify a canvas and an identifier to use for that canvas. The following new API on documents can then be used to obtain a drawing context for that canvas.

CanvasRenderingContext getCSSCanvasContext(in DOMString contextType, in DOMString identifier, in long width, in long height);

also don't use ctx.clearRect(0, 0, w, h); for IE9 - it doesn't work after this code if you try to draw something after clearRect() you will get empty canvas anyway