test_offscreencanvas_neuter.html

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<!DOCTYPE HTML>

<html>

<head>

<title>OffscreenCanvas: Test neutering</title>

<script src="/tests/SimpleTest/SimpleTest.js"></script>

<link rel="stylesheet" href="/tests/SimpleTest/test.css">

</head>

<body>

<canvas id="c" width="64" height="64"></canvas>

<script>

SimpleTest.waitForExplicitFinish();

function runTest() {

  var htmlCanvas = document.getElementById("c");

  var worker = new Worker("offscreencanvas_neuter.js");

  ok(htmlCanvas, "Should have HTML canvas element");

  ok(worker, "Web worker successfully created");

  ok(htmlCanvas.transferControlToOffscreen, "HTMLCanvasElement has transferControlToOffscreen function");

  var offscreenCanvas = htmlCanvas.transferControlToOffscreen();

  ok(offscreenCanvas, "Expected transferControlToOffscreen to succeed");

  /* check html canvas is neuterd */

  is(htmlCanvas.width, 64, "HTML canvas has correct width");

  SimpleTest.doesThrow(

    function() { htmlCanvas.width = 128; },

    "Can't change html canvas' width after transferControlToOffscreen");

  SimpleTest.doesThrow(

    function() { htmlCanvas.height = 128; },

    "Can't change html canvas' height after transferControlToOffscreen");

  ok(!htmlCanvas.getContext("2d"), "Can't getContext after transferControlToOffscreen");

  ok(!htmlCanvas.getContext("webgl"), "Can't getContext after transferControlToOffscreen");

  ok(!htmlCanvas.getContext("webgl2"), "Can't getContext after transferControlToOffscreen");

  worker.postMessage(offscreenCanvas, [offscreenCanvas]);

  /* check parent offscreencanvas is neutered after being transfered */

  SimpleTest.doesThrow(

    function() { offscreenCanvas.width = 128; },

    "Can't change transfered worker canvas width");

  SimpleTest.doesThrow(

    function() { offscreenCanvas.height = 128; },

    "Can't change transfered worker canvas height");

  SimpleTest.doesThrow(

    function() { offscreenCanvas.getContext("2d") },

    "Can't getContext on transfered worker canvas");

  SimpleTest.doesThrow(

    function() { offscreenCanvas.getContext("webgl") },

    "Can't getContext on transfered worker canvas");

  SimpleTest.doesThrow(

    function() { offscreenCanvas.getContext("webgl2") },

    "Can't getContext on transfered worker canvas");

  // Transfer a neutered offscreencanvas should be ok.

  worker.postMessage(offscreenCanvas, [offscreenCanvas]);

  worker.terminate();

  SimpleTest.finish();

SpecialPowers.pushPrefEnv({'set': [

  ['webgl.force-enabled', true],

]}, runTest);

</script>

</body>

</html>