OffscreenCanvas: contextrestored event

The contextrestored event of the OffscreenCanvas interface is fired if the browser restores an 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
});

Specifications

See also