drawFocusIfNeeded_001.html

mozilla-central/testing/web-platform/tests/html/canvas/element/manual/drawing-paths-to-the-canvas/drawFocusIfNeeded_001.html

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Test Info:

This WPT test may be referenced by the following Test IDs:
- /html/canvas/element/manual/drawing-paths-to-the-canvas/drawFocusIfNeeded_001.html - WPT Dashboard Interop Dashboard

<!DOCTYPE html>

<html>

  <head>

    <title>drawFocusIfNeeded()</title>

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

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

    <link rel="author" title="W3C">

    <link rel="help" href="http://www.w3.org/TR/2dcontext/#dom-context-2d-drawFocusIfNeeded">

  </head>

  <body>

    <h1>Description</h1>

    <p>This test uses drawFocusIfNeeded to draw a focus ring in the canvas, then compare the ImageData before and after the invocation of the method to check that the focus ring was actually drawn.</p>

    <div>

      <p>Before:</p>

      <canvas height=100 width=100 id='original'>

      </canvas>

      <p>After:</p>

      <canvas height=100 width=100 id=canvas>

        <label><a href='http://www.w3.org' id='element'>Focus</a></label>

      </canvas>

    </div>

    <script>

      test(function() {

          var canvas = document.getElementById('canvas');

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

          var element = document.getElementById('element');

          element.focus();

          context.fillStyle = 'white';

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

          context.beginPath();

          context.strokeStyle = 'black';

          context.rect(10, 10, 80, 80);

          context.stroke();

          context.save();

          var refImage = context.getImageData(0, 0, 100, 100);

          assert_equals(40000, refImage.data.length, "ImageData.data.length is 40000");

          var original = document.getElementById('original');

          var o_context = original.getContext('2d');

          o_context.fillStyle = 'white';

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

          o_context.putImageData(refImage, 0, 0, 0, 0, 100, 100);

          context.rect(5, 5, 90, 90);

          context.drawFocusIfNeeded(element);

          var ringImage = context.getImageData(0, 0, 100, 100);

          assert_equals(40000, ringImage.data.length, "ImageData.data.length is 40000");

          // make sure refImage and ringImage are different

          var length = 40000;

          var index = length;

          var identical = true;

          while (--index > 0) {

            if (refImage.data[index] != ringImage.data[index]) identical = false;

          assert_false(identical, "The focus ring must appear in the canvas");

      }, 'drawFocusIfNeeded draws a focus ring.');

    </script>

    <div id="log"></div>

  </body>

</html>