testing/web-platform/tests/css/css-variables/variable-animation-to-only.html

   1 <!DOCTYPE html>
   2 <html>
   3 <head>
   4     <title>CSS Variables - Animation - From and To Values</title>
   5
   6     <meta rel="author" title="Kevin Babbitt">
   7     <meta rel="author" title="Greg Whitworth">
   8     <link rel="author" title="Microsoft Corporation" href="http://microsoft.com" />
   9     <link rel="help" href="http://www.w3.org/TR/css-variables-1/#syntax">
  10
  11     <script src="/resources/testharness.js"></script>
  12     <script src="/resources/testharnessreport.js"></script>
  13     <style>
  14         @keyframes valueanim
  15         {
  16             to { --value: green; }
  17         }
  18
  19         /* Start the animation in the paused state and fill at both ends so we can inspect values from both keyframes. */
  20         #target
  21         {
  22             animation-name: valueanim;
  23             animation-duration: 1s;
  24             animation-play-state: paused;
  25             animation-fill-mode: both;
  26         }
  27         #target
  28         {
  29             --value: blue;
  30         }
  31         #target span
  32         {
  33             color: var(--value);
  34         }
  35     </style>
  36 </head>
  37 <body>
  38
  39     <div id="target"><span>This text should animate from blue to green over a period of 1 second.</span></div>
  40
  41 <script type="text/javascript">
  42     "use strict";
  43
  44     // Force an initial layout pass
  45     document.documentElement.offsetHeight;
  46
  47     test(function() {
  48         assert_equals(window.getComputedStyle(document.getElementById("target")).getPropertyValue("--value").trim(), "blue", "--value is blue before animation runs");
  49         }, "Verify CSS variable value before animation");
  50
  51     var animationTest = async_test("Verify CSS variable value after animation");
  52
  53     animationTest.step(function() {
  54         // Set event handler
  55         document.getElementById("target").addEventListener("animationend", animationTest.step_func(function() {
  56             assert_equals(window.getComputedStyle(document.getElementById("target")).getPropertyValue("--value").trim(), "green", "--value is green after animation runs")
  57             animationTest.done();
  58             }));
  59
  60         // Trigger animation
  61         document.getElementById("target").style.animationPlayState = "running";
  62     });
  63 </script>
  64
  65 </body>
  66 </html>