test_offscreencanvas_font.html

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<!DOCTYPE HTML>

<html>

<head>

<title>Serialization of font on OffscreenCanvas2d</title>

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

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

</head>

<body>

<canvas id="c">

<script>

SimpleTest.waitForExplicitFinish();

function testFontShorthand(ctx, font) {

  ctx.font = font;

  let w1 = ctx.measureText("Hello World").width;

  let f = ctx.font;

  ctx.font = f;

  let w2 = ctx.measureText("Hello World").width;

  ok(w1 === w2, "serialization and re-setting of \"" +

                font + "\" as \"" + f + "\" is idempotent");

const tests = [

  "12px serif",

  "12px/1.4 serif",

  "italic 12px serif",

  "oblique 12px serif",

  "bold 12px serif",

  "bold italic 12px serif",

  "condensed bold italic 12px serif",

  "500 italic 12px serif",

  "italic 500 12px serif",

];

function runTest() {

  let canvas = new OffscreenCanvas(100, 100);

  let ctx = canvas.getContext("2d");

  tests.forEach((t) => {

    testFontShorthand(ctx, t);

});

  // Although the bug that motivated this test was specific to offscreen canvas,

  // let's also check that it works with a <canvas> element.

  ctx = document.getElementById("c").getContext("2d");

  tests.forEach((t) => {

    testFontShorthand(ctx, t);

});

  SimpleTest.finish();

SpecialPowers.pushPrefEnv({'set': [

  ['gfx.offscreencanvas.enabled', true],

]}, runTest);

</script>

</body>

</html>