containertiming-with-child-canvas.html

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This WPT test may be referenced by the following Test IDs:
- /container-timing/tentative/containertiming-with-child-canvas.html - WPT Dashboard Interop Dashboard

<!DOCTYPE HTML>

<meta charset=utf-8>

<title>Container Timing: observe with a node with containertiming and a canvas child</title>

<body>

<style>

body {

  margin: 0;

</style>

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

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

<script src="/container-timing/resources/container-timing-helpers.js"></script>

<script>

  let beforeRender;

  async_test(function (t) {

    assert_implements(window.PerformanceContainerTiming, "PerformanceContainerTiming is not implemented");

    const observer = new PerformanceObserver(

      t.step_func_done(function(entryList) {

        assert_equals(entryList.getEntries().length, 1);

        const entry = entryList.getEntries()[0];

        checkContainerEntry(entry, 'div_ct', 'canvas_id', beforeRender);

        checkContainerSize(entry, 10000);

})

);

    observer.observe({entryTypes: ['container']});

    // Add a div that is the container timing root

    const div = document.createElement('div');

    div.setAttribute('containertiming', 'div_ct');

    document.body.appendChild(div);

    // Add canvas of width equal to 100 and height equal to 100.

    const canvas = document.createElement('canvas');

    canvas.width = 100;

    canvas.height = 100;

    canvas.setAttribute('id', 'canvas_id');

    div.appendChild(canvas);

    // Draw something on the canvas to make it "contentful"

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

    ctx.fillStyle = 'red';

    ctx.fillRect(0, 0, 100, 100);

    beforeRender = performance.now();

  }, 'Paint of the canvas child of container timing is reported.');

</script>

</body>