third_party/WebKit/LayoutTests/fast/events/wheelevent-handler-count.html

   1 <script src="../../resources/js-test.js"></script>
   2 <script>
   3 description("This test checks that we correctly update the wheel event handler count as event handlers are added and removed");
   4
   5 (function() {
   6     // Test addEventListener/removeEventListener on the document.
   7     var listener = function() { }
   8
   9     shouldBe('window.internals.wheelEventHandlerCount(document)', '0');
  10     document.addEventListener('mousewheel', listener, true);
  11     shouldBe('window.internals.wheelEventHandlerCount(document)', '1');
  12     document.addEventListener('mousewheel', listener, false);
  13     shouldBe('window.internals.wheelEventHandlerCount(document)', '2');
  14     document.removeEventListener('mousewheel', listener, true);
  15     shouldBe('window.internals.wheelEventHandlerCount(document)', '1');
  16
  17     // Try removing the capturing listener again.
  18     document.removeEventListener('mousewheel', listener, true);
  19     shouldBe('window.internals.wheelEventHandlerCount(document)', '1');
  20
  21     document.removeEventListener('mousewheel', listener, false);
  22     shouldBe('window.internals.wheelEventHandlerCount(document)', '0');
  23 })();
  24
  25 (function() {
  26     // Test setting onmousewheel on the document.
  27
  28     shouldBe('window.internals.wheelEventHandlerCount(document)', '0');
  29     document.onmousewheel = function() { }
  30     shouldBe('window.internals.wheelEventHandlerCount(document)', '1');
  31     document.onmousewheel = function() { }
  32     shouldBe('window.internals.wheelEventHandlerCount(document)', '1');
  33     document.onmousewheel = null;
  34     shouldBe('window.internals.wheelEventHandlerCount(document)', '0');
  35 })();
  36
  37 (function() {
  38     // Test addEventListener/removeEventListener on the window.
  39     var listener = function() { }
  40
  41     shouldBe('window.internals.wheelEventHandlerCount(document)', '0');
  42     window.addEventListener('mousewheel', listener, true);
  43     shouldBe('window.internals.wheelEventHandlerCount(document)', '1');
  44     window.addEventListener('mousewheel', listener, false);
  45     shouldBe('window.internals.wheelEventHandlerCount(document)', '2');
  46     window.removeEventListener('mousewheel', listener, true);
  47     shouldBe('window.internals.wheelEventHandlerCount(document)', '1');
  48
  49     // Try removing the capturing listener again.
  50     window.removeEventListener('mousewheel', listener, true);
  51     shouldBe('window.internals.wheelEventHandlerCount(document)', '1');
  52
  53     window.removeEventListener('mousewheel', listener, false);
  54     shouldBe('window.internals.wheelEventHandlerCount(document)', '0');
  55 })();
  56
  57 (function() {
  58     // Test setting onmousewheel on the window.
  59     shouldBe('window.internals.wheelEventHandlerCount(document)', '0');
  60     window.onmousewheel = function() { }
  61     shouldBe('window.internals.wheelEventHandlerCount(document)', '1');
  62     window.onmousewheel = function() { }
  63     shouldBe('window.internals.wheelEventHandlerCount(document)', '1');
  64     window.onmousewheel = null;
  65     shouldBe('window.internals.wheelEventHandlerCount(document)', '0');
  66 })();
  67
  68 </script>
  69 </body>