| <!DOCTYPE html> |
| <html> |
| <head> |
| <meta charset="utf-8"> |
| <title>CSS Animations: Expansion of shorthand properties</title> |
| <link rel="help" href="https://www.w3.org/TR/web-animations-1/#calculating-computed-keyframes"> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <style> |
| #block { |
| background: green; |
| background-position-x: 10px; |
| height: 100px; |
| width: 100px; |
| } |
| </style> |
| <body> |
| <div id="block"></div> |
| </body> |
| <script> |
| function assert_background_position_at(time, x, y) { |
| document.getAnimations()[0].currentTime = time; |
| const target = document.getElementById('block'); |
| const style = getComputedStyle(target); |
| assert_equals(style.backgroundPositionX, x, |
| `background-position-x @${time/10}% progress`); |
| assert_equals(style.backgroundPositionY, y, |
| `background-position-y @${time/10}% progress`); |
| } |
| |
| test(() => { |
| const target = document.getElementById('block'); |
| target.animate([ |
| { background: 'red' }, |
| { backgroundPositionY: '10px', background: 'blue' } |
| ], { duration: 1000 }); |
| // Animation is active in the semi-closed interval [0, 1000). |
| // The background shorthand expands to its longhand counterparts with |
| // background-position-(x|y) picking up the default value of 0%. |
| // The explicit background-property-y in the second keyframe takes priority |
| // over the value from expansion of the shorthand. |
| const test_cases = [ |
| { time: -100, x: "10px", y: "0%" }, |
| { time: 0, x: "0%", y: "0%" }, |
| { time: 200, x: "0%", y: "calc(0% + 2px)" }, |
| { time: 500, x: "0%", y: "calc(0% + 5px)" }, |
| { time: 800, x: "0%", y: "calc(0% + 8px)" }, |
| { time: 1100, x: "10px", y: "0%" } |
| ]; |
| test_cases.forEach(test => { |
| assert_background_position_at(test.time, test.x, test.y); |
| }); |
| }, 'Shorthand properties expand to longhand counterparts in computed ' + |
| 'keyframes.'); |
| </script> |
