dom/canvas/test/test_2d.clearRect.image.offscreen.html

   1 <!DOCTYPE HTML>
   2 <html>
   3 <head>
   4   <script src="/tests/SimpleTest/SimpleTest.js"></script>
   5   <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
   6 </head>
   7 <body onload="doTest()">
   8 <p id="display">
   9   <canvas id="c" width="1" height="1"></canvas>
  10   <img id="img" src="image_green-1x1.png">
  11 </p>
  12 <div id="content" style="display: none">
  13
  14 </div>
  15 <pre id="test">
  16 <script type="application/javascript">
  17
  18 var c = document.getElementById("c");
  19 var ctx = c.getContext("2d");
  20 var img = document.getElementById("img");
  21
  22 SimpleTest.waitForExplicitFinish();
  23
  24 function doTest() {
  25   ctx.fillStyle = "red";
  26   ctx.fillRect(0, 0, 1, 1);
  27   ctx.drawImage(img, -1, 0);
  28   ctx.clearRect(0, 0, 1, 1);
  29
  30   var data = ctx.getImageData(0, 0, 1, 1).data;
  31   is(data[0], 0, "Red channel should be 0");
  32   is(data[1], 0, "Green channel should be 0");
  33   is(data[2], 0, "Blue channel should be 0")
  34   is(data[3], 0, "Alpha channel should be 0");
  35
  36   SimpleTest.finish();
  37 }
  38
  39 </script>
  40 </pre>
  41 </body>
  42 </html>