The webglcontextlost event of the WebGL API is fired if the user agent detects that the drawing buffer associated with a WebGLRenderingContext object has been lost.
| Bubbles | Yes |
| Cancelable | Yes |
| Target objects | HTMLCanvasElement |
| Interface | WebGLContextEvent |
Example
With the help of the WEBGL_lose_context extension, you can simulate the webglcontextlost event:
var canvas = document.getElementById("canvas");
var gl = canvas.getContext("webgl");
canvas.addEventListener("webglcontextlost", function(e) {
console.log(e);
}, false);
gl.getExtension('WEBGL_lose_context').loseContext();
// "webglcontextlost" event is logged.
Inheritance
The webglcontextlost event implements the WebGLContextEvent interface, which inherits from Event. You can use the properties and methods defined on these interfaces.
<div id="interfaceDiagram" style="display: inline-block; position: relative; width: 100%; padding-bottom: 11.666666666666666%; vertical-align: middle; overflow: hidden;"><svg style="display: inline-block; position: absolute; top: 0; left: 0;" viewbox="-50 0 600 70" preserveAspectRatio="xMinYMin meet"><a xlink:href="https://developer.mozilla.org/en-US/docs/Web/API/Event" target="_top"><rect x="1" y="1" width="75" height="50" fill="#fff" stroke="#D4DDE4" stroke-width="2px" /><text x="38.5" y="30" font-size="12px" font-family="Consolas,Monaco,Andale Mono,monospace" fill="#4D4E53" text-anchor="middle" alignment-baseline="middle">Event</text></a><polyline points="76,25 86,20 86,30 76,25" stroke="#D4DDE4" fill="none"/><line x1="86" y1="25" x2="116" y2="25" stroke="#D4DDE4"/><a xlink:href="https://developer.mozilla.org/en-US/docs/Web/API/WebGLContextEvent" target="_top"><rect x="116" y="1" width="170" height="50" fill="#F4F7F8" stroke="#D4DDE4" stroke-width="2px" /><text x="201" y="30" font-size="12px" font-family="Consolas,Monaco,Andale Mono,monospace" fill="#4D4E53" text-anchor="middle" alignment-baseline="middle">WebGLContextEvent</text></a></svg></div>
a:hover text { fill: #0095DD; pointer-events: all;}
Specifications
| Specification | Status | Comment |
|---|---|---|
| WebGL 1.0 The definition of 'webglcontextlost' in that specification. |
Recommendation | Initial definition. |
Browser compatibility
| Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|
| Basic support | 9 | 4.0 (2.0) | 11 | 12 | 5.1 |
| Feature | Android | Chrome for Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
|---|---|---|---|---|---|---|
| Basic support | ? | 25 | 4.0 (2.0) | ? | 12 | 8.0 |