third_party/WebKit/LayoutTests/fast/canvas/canvas-lose-restore-max-int-size.html

   1 <!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN">
   2 <html>
   3 <head>
   4 <script src="../../resources/js-test.js"></script>
   5 </head>
   6 <body>
   7 <script>
   8 description("Tests to ensure correct behaviour of canvas loss and restoration when size is extremely large then, restored to a reasonable value.");
   9
  10 if (window.testRunner) {
  11     testRunner.dumpAsText();
  12     testRunner.waitUntilDone();
  13 }
  14
  15 var canvas = document.createElement('canvas')
  16 canvas.addEventListener('contextlost', contextLost);
  17 canvas.addEventListener('contextrestored', contextRestored);
  18 var ctx = canvas.getContext('2d');
  19 var lostEventHasFired = false;
  20 verifyContextLost(false);
  21
  22 // WebIDL defines width and height as int. 2147483647 is int max.
  23 var extremelyLargeNumber = 2147483647;
  24 canvas.width = extremelyLargeNumber;
  25 canvas.height = extremelyLargeNumber;
  26 verifyContextLost(true);
  27 canvas.width = extremelyLargeNumber;
  28 verifyContextLost(true);
  29 canvas.width = 100;
  30 canvas.height = 100;
  31 verifyContextLost(true); // Restoration is async.
  32 // Restore a sane dimension
  33
  34 function verifyContextLost(shouldBeLost) {
  35     // Verify context loss experimentally as well as isContextLost()
  36     ctx.fillStyle = '#0f0';
  37     ctx.fillRect(0, 0, 1, 1);
  38     contextLostTest = ctx.getImageData(0, 0, 1, 1).data[1] == 0;
  39     if (shouldBeLost) {
  40         shouldBeTrue('contextLostTest');
  41         shouldBeTrue('ctx.isContextLost()');
  42     } else {
  43         shouldBeFalse('contextLostTest');
  44         shouldBeFalse('ctx.isContextLost()');
  45     }
  46 }
  47
  48 function contextLost() {
  49     if (lostEventHasFired) {
  50         testFailed('Context lost event was dispatched more than once.');
  51     } else {
  52         testPassed('Graphics context lost event dispatched.');
  53     }
  54     lostEventHasFired = true;
  55     verifyContextLost(true);
  56 }
  57
  58 function contextRestored() {
  59     if (lostEventHasFired) {
  60         testPassed('Context restored event dispatched after context lost.');
  61     } else {
  62         testFailed('Context restored event was dispatched before a context lost event.');
  63     }
  64     verifyContextLost(false);
  65         if (window.testRunner) {
  66         testRunner.notifyDone();
  67     }
  68 }
  69 </script>
  70 </body>
  71 </html>