third_party/WebKit/LayoutTests/webaudio/onstatechange.html

   1 <!doctype html>
   2 <html>
   3   <head>
   4     <title>Test statechange event</title>
   5     <script src="../resources/js-test.js"></script>
   6     <script src="resources/audio-testing.js"/>
   7     <script src="resources/compatibility.js"></script>
   8   </head>
   9
  10   <body>
  11     <script>
  12       description("Test statechange event is properly signaled")
  13
  14       window.jsTestIsAsync = true;
  15
  16       var secondsToRender = 2;
  17       var sampleRate = 48000;
  18
  19       var stateChangeCount = 0;
  20       var context;
  21       var contextState;
  22
  23       function checkStateChange (e) {
  24         contextState = e.currentTarget.state;
  25
  26         switch (stateChangeCount) {
  27         case 0:
  28           shouldBeEqualToString("contextState", "running");
  29           break;
  30         case 1:
  31           shouldBeEqualToString("contextState", "closed");
  32           break;
  33         default:
  34           testFailed("Expected only two state changes but got " + stateChangeCount);
  35         }
  36         ++stateChangeCount;
  37       }
  38
  39       function finalCheck() {
  40         // Final check that we got the right number of state changes and the correct final state.
  41         shouldBeEqualToNumber("stateChangeCount", 2);
  42         shouldBeEqualToString("context.state", "closed");
  43         finishJSTest();
  44       }
  45
  46       function runTest() {
  47         // Create an offline context with a source passing through a convolver.  The convolver is
  48         // just to waste some time.
  49         context = new OfflineAudioContext(1, secondsToRender * sampleRate, sampleRate);
  50         var buffer = createImpulseBuffer(context, sampleRate);
  51         var source = context.createBufferSource();
  52         var conv = context.createConvolver();
  53
  54         source.buffer = buffer;
  55         conv.normalize = false;
  56         conv.buffer = buffer;
  57
  58         source.connect(conv);
  59         conv.connect(context.destination);
  60
  61         source.start();
  62
  63         context.onstatechange = checkStateChange;
  64
  65         context.startRendering().then(function () {
  66           testPassed("context finished rendering")
  67         });
  68
  69         // Don't want to set an oncomplete for the context and don't want to use the promise because
  70         // the order of the state change event and resolving the promise is not specified.  Thus,
  71         // just wait for a bit and then finish the test.  We assume the offline context runs faster
  72         // than realtime.
  73         setTimeout(finalCheck, secondsToRender * 1000);
  74       }
  75
  76       runTest();
  77     </script>
  78   </body>
  79 </html>