This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.

The non-standard and internal only CanvasRenderingContext2D.drawWidgetAsOnScreen() method of the Canvas 2D API renders the root widget of a window into the canvas. Unlike drawWindow(), this API uses the operating system to snapshot the widget on-screen, rather than reading from Gecko's own compositor.

This API cannot be used by Web content. It is only supported on Windows, only on widgets that use OMTC, and only from within the chrome process.


void ctx.drawWidgetAsOnScreen(window);


The Window to render.


Not part of any current specification or draft. This is a non-standard and internal only API.

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support No No41 No No No
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support No No No41 No No No

See also

Document Tags and Contributors

Contributors to this page: fscholz, Jedipedia
Last updated by: fscholz,