2d.text.drawing.style.letterSpacing.change.font.html

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This WPT test may be referenced by the following Test IDs:
- /html/canvas/offscreen/text/2d.text.drawing.style.letterSpacing.change.font.html - WPT Dashboard Interop Dashboard

<!DOCTYPE html>

<!-- DO NOT EDIT! This test has been generated by /html/canvas/tools/gentest.py. -->

<meta charset="UTF-8">

<title>OffscreenCanvas test: 2d.text.drawing.style.letterSpacing.change.font</title>

<script src="/resources/testharness.js"></script>

<script src="/resources/testharnessreport.js"></script>

<script src="/html/canvas/resources/canvas-tests.js"></script>

<h1>2d.text.drawing.style.letterSpacing.change.font</h1>

<p class="desc">Set letter spacing and word spacing to font dependent value and verify it works after font change.</p>

<script>

var t = async_test("Set letter spacing and word spacing to font dependent value and verify it works after font change.");

var t_pass = t.done.bind(t);

var t_fail = t.step_func(function(reason) {

    throw reason;

});

t.step(function() {

  var canvas = new OffscreenCanvas(100, 50);

  var ctx = canvas.getContext('2d');

  _assertSame(ctx.letterSpacing, '0px', "ctx.letterSpacing", "'0px'");

  _assertSame(ctx.wordSpacing, '0px', "ctx.wordSpacing", "'0px'");

  // Get the width for 'Hello World' at default size, 10px.

  var width_normal = ctx.measureText('Hello World').width;

  ctx.letterSpacing = '1em';

  _assertSame(ctx.letterSpacing, '1em', "ctx.letterSpacing", "'1em'");

  // 1em = 10px. Add 10px after each letter in "Hello World",

  // makes it 110px longer.

  var width_with_spacing = ctx.measureText('Hello World').width;

  assert_approx_equals(width_with_spacing, width_normal + 110, 0.1, "letter-spacing error");

  // Changing font to 20px. Without resetting the spacing, 1em letterSpacing

  // is now 20px, so it's suppose to be 220px longer without any letterSpacing set.

  ctx.font = '20px serif';

  width_with_spacing = ctx.measureText('Hello World').width;

  // Now calculate the reference spacing for "Hello World" with no spacing.

  ctx.letterSpacing = '0em';

  width_normal = ctx.measureText('Hello World').width;

  assert_approx_equals(width_with_spacing, width_normal + 220, 0.1, "letter-spacing error after font change");

  t.done();

});

</script>