OffscreenCanvas: contextrestored event

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

The contextrestored event of the OffscreenCanvas interface is fired if the browser restores a OffscreenCanvasRenderingContext2D context that was previously lost.

You can redraw, re-retrieve resources, and reinitialize the state of your context after receiving this event.

Syntax

Use the event name in methods like addEventListener(), or set an event handler property.

js
addEventListener("contextrestored", (event) => {});

oncontextrestored = (event) => {};

Event type

A generic Event.

Examples

The code fragment below detects the context restored event.

js
const canvas = new OffscreenCanvas(256, 256);
const gl = offscreen.getContext("2d");

canvas.addEventListener(
  "contextrestored",
  (e) => {
    console.log(e);
    // call to redrawCanvas() or similar
  },
  false,
);

Specifications

Specification
HTML
# event-contextrestored
HTML
# handler-offscreencanvas-oncontextrestored

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
contextrestored event

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support
No support
No support

See also