offscreencanvas.transfercontrol.to.offscreen.html

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This WPT test may be referenced by the following Test IDs:
- /html/canvas/offscreen/manual/the-offscreen-canvas/offscreencanvas.transfercontrol.to.offscreen.html - WPT Dashboard Interop Dashboard

<!DOCTYPE html>

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

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

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

<link rel="help" href="https://html.spec.whatwg.org/#dom-canvas-transfercontroltooffscreen">

<script>

test(function() {

    var placeholder = document.createElement('canvas');

    placeholder.width = 100;

    placeholder.height = 50;

    var offscreenCanvas = placeholder.transferControlToOffscreen();

    assert_equals(offscreenCanvas.width, 100);

    assert_equals(offscreenCanvas.height, 50);

}, "Test that an OffscreenCanvas generated by transferControlToOffscreen gets correct width and height");

test(function() {

    var placeholder = document.createElement('canvas');

    placeholder.width = 100;

    placeholder.height = 50;

    var offscreenCanvas = placeholder.transferControlToOffscreen();

    assert_throws_dom("InvalidStateError", function() { placeholder.getContext('2d'); });

}, "Test that calling getContext on a placeholder canvas that has already transferred its control throws an exception");

test(function() {

    var placeholder = document.createElement('canvas');

    placeholder.width = 100;

    placeholder.height = 50;

    var offscreenCanvas = placeholder.transferControlToOffscreen();

    assert_throws_dom("InvalidStateError", function() { placeholder.transferControlToOffscreen(); });

}, "Test that calling transferControlToOffscreen twice throws an exception");

</script>