third_party/WebKit/LayoutTests/fast/canvas/painting-on-bad-canvas.html

   1 <!DOCTYPE html>
   2 <canvas id="mycanvas"><button id="button"></button></canvas>
   3 <script src="../../resources/js-test.js"></script>
   4 <script>
   5 description("This tests verifies that canvas API calls on a canvas with no backing or no visibility do not crash or throw exceptions.");
   6
   7 if (window.testRunner) {
   8     testRunner.dumpAsText();
   9 }
  10
  11 var canvas = document.getElementById('mycanvas');
  12 var ctx = canvas.getContext('2d');
  13 var button = document.getElementById('button');
  14 button.focus();
  15
  16 function testAPICalls() {
  17     try {
  18         ctx.beginPath();
  19         ctx.rect(0, 0, 10, 10);
  20         ctx.fill();
  21         ctx.stroke();
  22         ctx.drawFocusIfNeeded(button);
  23         ctx.isPointInPath(0,0);
  24         ctx.isPointInStroke(0,0);
  25         ctx.clearRect(0, 0, 5, 5);
  26         ctx.fillRect(0, 0, 5, 5);
  27         ctx.strokeRect(0, 0, 5, 5);
  28         ctx.scrollPathIntoView();
  29         data = ctx.createImageData(5, 5);
  30         ctx.putImageData(data, 0, 0);
  31         ctx.font = "20px arial";
  32         ctx.fillText("Test", 20, 20);
  33         ctx.strokeText("Test", 20, 20);
  34         ctx.measureText("Test");
  35         ctx.clip();
  36         ctx.drawImage(canvas, 0, 0);
  37         ctx.getImageData(0, 0, 5, 5);
  38         canvas.toDataURL();
  39     } catch(err) {
  40         testFailed("Unexpected exception.");
  41     }
  42 }
  43
  44 // First pass: normal conditions
  45 testAPICalls();
  46
  47 // Test a zero size canvas
  48 canvas.width = 0;
  49 testAPICalls();
  50
  51 // Test a canvas so large that it has no chance of successfull allocating a backing
  52 canvas.width = 10000000;
  53 canvas.height = 10000000;
  54 testAPICalls();
  55
  56 // Test a canvas that is valid, but detached from the DOM
  57 canvas.width = 100;
  58 canvas.height = 100;
  59 canvas.remove();
  60 testAPICalls();
  61
  62 </script>