Annotatable canvas element - text and drawing in html5

I'm looking for an annotatable canvas element that will be integrated into an existing html5 mobile application, with the ability for the user to draw on it, and drag a text area onto it as well to type in. The functionality needed would be an html file, which has a button /link to pull up the functionality. When this is clicked, a transparent should pop up to 100% of the screen space. This div would contain a header (div) (30 or 40px high), and the remaining screen space would be a transparent canvas element. The header needs 4 buttons. One to place a box that the user can type in on top of the canvas element, a close button, a clear canvas button, and a button for additional functionality I'll add later. The canvas needs allow users to draw on it using an ontouch event. If the user clicks the button to add a text box up on top, a text area needs to be added to the screen on top of the canvas, which can then be moved around via an ontouch/ontouchmove/ontouchend event, and then typed into. Multiple text areas may need to be added to the DOM, so that would need to be accounted for. Lastly, there would need to be a way to clear off the drawn items and text areas, using the clear canvas button in the header. Thanks for looking.