chromium/third_party/blink/web_tests/external/wpt/html/editing/dnd/canvas/001.html

<!doctype html>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/resources/testdriver.js"></script>
<script src="/resources/testdriver-vendor.js"></script>
<script src="/resources/testdriver-actions.js"></script>
<script src="../resources/test-helper.js"></script>
<head>
<title>Canvas drag and drop carrying image as dataURL</title>
<style type="text/css">
div[ondragenter]
  {width:105px;
  min-height:105px;
  text-align:center;
  margin-top:20px;
  padding:10px;
  border:solid thin navy;}
p:first-child
  {padding-left:12px;}
</style>
<script type="application/ecmascript">
function addImage(event)
  {var c = document.createElement('img');
  c.setAttribute('src',event.dataTransfer.getData('text/uri-list'));
  document.querySelector('div').appendChild(c);}
function start(event)
  {event.dataTransfer.effectAllowed = 'copy';
  event.dataTransfer.setData('text/uri-list', document.querySelector('canvas').toDataURL('image/png'));}
</script>
</head>
<body>
<p>
  <canvas width="100" height="100" draggable="true" ondragstart="start(event)">Canvas</canvas>
</p>
<p>Drag canvas pattern above to the box below. It should be copied to the box once you drop it there.</p>
<div
  ondragenter="event.preventDefault()"
  ondragover="return false"
/>
<script type="application/ecmascript">
var canvas = document.querySelector('canvas'),
c = canvas.getContext('2d');
for(var x = 0; x != 50; x++)
  {c.fillStyle = (x%2 == 0)?'navy':'white';
  c.beginPath();
  c.moveTo(x,x);
  c.lineTo(100-x,x);
  c.lineTo(100-x,100-x);
  c.lineTo(x,100-x);
  c.closePath();
  c.fill();}
async function test() {
  const canvas = document.querySelector('canvas');
  const div = document.querySelector('div');
  function onDropCallBack(event) {
    addImage(event);
    const img = document.querySelector('img');
    assert_equals(img.src, canvas.toDataURL('image/png'));
    return true;
  }

  dragDropTest(canvas, div, onDropCallBack, 'Dragging the canvas to the bottom div should turn it green');
}
test();
</script>
</body>
</html>