<!DOCTYPE html>
<html>
<head>
<title>CSS Variables - Animation - From and To Values</title>
<meta rel="author" title="Kevin Babbitt">
<meta rel="author" title="Greg Whitworth">
<link rel="author" title="Microsoft Corporation" href="http://microsoft.com" />
<link rel="help" href="http://www.w3.org/TR/css-variables-1/#syntax">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style>
@keyframes valueanim
{
to { --value: green; }
}
/* Start the animation in the paused state and fill at both ends so we can inspect values from both keyframes. */
#target
{
animation-name: valueanim;
animation-duration: 1s;
animation-play-state: paused;
animation-fill-mode: both;
}
#target
{
--value: blue;
}
#target span
{
color: var(--value);
}
</style>
</head>
<body>
<div id="target"><span>This text should animate from blue to green over a period of 1 second.</span></div>
<script type="text/javascript">
"use strict";
// Force an initial layout pass
document.documentElement.offsetHeight;
test(function() {
assert_equals(window.getComputedStyle(document.getElementById("target")).getPropertyValue("--value").trim(), "blue", "--value is blue before animation runs");
}, "Verify CSS variable value before animation");
var animationTest = async_test("Verify CSS variable value after animation");
animationTest.step(function() {
// Set event handler
document.getElementById("target").addEventListener("animationend", animationTest.step_func(function() {
assert_equals(window.getComputedStyle(document.getElementById("target")).getPropertyValue("--value").trim(), "green", "--value is green after animation runs")
animationTest.done();
}));
// Trigger animation
document.getElementById("target").style.animationPlayState = "running";
});
</script>
</body>
</html>
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