A user account is required in order to edit this wiki, but we've had to disable public user registrations due to spam.

To request an account, ask an autoconfirmed user on Chat (such as one of these permanent autoconfirmed members).

WorkerCanvas

From WHATWG Wiki
Revision as of 23:53, 23 October 2013 by Kenrussell (talk | contribs) (added Category:Proposals using HotCat)
Jump to navigation Jump to search

WebIDL

[Constructor(unsigned long width, unsigned long height)]
interface WorkerCanvas {
  attribute unsigned long width;
  attribute unsigned long height;
  RenderingContext? getContext(DOMString contextId, any... arguments); 
  void toBlob(FileCallback? _callback, optional DOMString type, any... arguments);
  ImageBitmap transferToImageBitmap();
};

partial interface RenderingContext {
  void commit();
};

WorkerCanvas implements Transferable;
ImageBitmap implements Transferable;

partial interface HTMLCanvasElement {
  WorkerCanvas transferControlToWorker();
};

partial interface ImageBitmap {
  void transferToImage(HTMLImageElement image);
};

Spec changes

Transferring of ImageBitmaps has to be defined. It should neuter the ImageBitmap in the sending thread. Neutering sets the ImageBitmap's width and height to 0.

HTMLCanvasElement.transferControlToWorker behaves like transferControlToProxy in the current WHATWG spec. WorkerCanvas is Transferable, but transfer fails if transferred other than from the main thread to a worker. All its methods throw if not called on a worker, or if it's neutered.

ImageBitmap.transferToImage removes the image element's "src" attribute and makes the image display the contents of the ImageBitmap (until the next transferToImage to that image, or until the image's "src" attribute is set). The ImageBitmap is neutered.