third_party/WebKit/LayoutTests/fast/canvas/canvas-font-cache.html

   1 <script src="../../resources/js-test.js"></script>
   2 <canvas id='c'></canvas>
   3 <script>
   4 // The reason this is implemented as a layout test instead of a unit test (see CanvasFontCacheTest.cpp)
   5 // is to exercise interactions with animation frames.
   6
   7 var cacheLimit = 0;
   8 if (!window.internals || !window.testRunner) {
   9         testFailed('This test requires the window.internals and window.testRunner interfaces');
  10 } else {
  11         cacheLimit = internals.canvasFontCacheMaxFonts();
  12         testRunner.waitUntilDone();
  13         testRunner.dumpAsText();
  14         requestAnimationFrame(step1);
  15 }
  16
  17 var ctx = document.getElementById('c').getContext('2d');
  18
  19 function step1()
  20 {
  21         for (var i = 0; i < cacheLimit + 1; i ++) {
  22                 ctx.font = (1 + i) + 'px sans-serif';
  23                 ctx.fillText('a', 0, 50);
  24         }
  25         shouldBeTrue('internals.isInCanvasFontCache(document, "1px sans-serif")');
  26         requestAnimationFrame(step2);
  27 }
  28
  29 function step2()
  30 {
  31         // Pruning of the cache is expected to happen between tasks
  32         shouldBeFalse('internals.isInCanvasFontCache(document, "1px sans-serif")');
  33         shouldBeTrue('internals.isInCanvasFontCache(document, "2px sans-serif")');
  34         testRunner.notifyDone();
  35 }
  36
  37 </script>