| <!DOCTYPE html> |
| <html> |
| <head> |
| <meta charset="utf-8"> |
| <title>transition duration change</title> |
| <link rel="help" href="https://drafts.csswg.org/css-transitions-1/#starting"> |
| <style> |
| #box { |
| position: absolute; |
| height: 100px; |
| width: 100px; |
| left: 0px; |
| background-color: blue; |
| transition-duration: 1s; |
| transition-delay: -0.75s; |
| transition-timing-function: linear; |
| transition-property: left; |
| } |
| </style> |
| </head> |
| <body> |
| <div id="box"></div> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <script src="/css/css-transitions/support/helper.js"></script> |
| <script> |
| 'use strict'; |
| |
| window.onload = () => { |
| promise_test(async t => { |
| // Make sure we have rendered the page before making the style change |
| // to ensure we get transitions. |
| await waitForAnimationFrames(2); |
| |
| box.style.left = '400px'; |
| assert_equals( |
| getComputedStyle(box).left, '300px', |
| 'The transition progresses 75% immediately due to negative ' + |
| 'transition-delay'); |
| |
| box.style.transitionDuration = '7.5s'; |
| assert_equals( |
| getComputedStyle(box).left, '300px', |
| 'Changing the duration does not affect the current transition'); |
| |
| const anim = document.getAnimations()[0]; |
| anim.finish(); |
| |
| assert_equals( |
| getComputedStyle(box).left, '400px', |
| 'The final value has been reached when finished'); |
| box.style.left = '1400px'; |
| assert_equals( |
| getComputedStyle(box).left, '500px', |
| 'With the new duration taking effect, the transition progresses ' + |
| '10% immediately'); |
| }, 'Transition duration change should not affect transition in progress'); |
| }; |
| </script> |
| </body> |
| </html> |
