| <!DOCTYPE html> |
| <html> |
| <head> |
| <style> |
| #container { |
| position: absolute; |
| width: 400px; |
| height: 400px; |
| top: 0; |
| left: 0; |
| scroll-snap-type: y mandatory; |
| overflow-x: hidden; |
| overflow-y: scroll; |
| border: 1px black dashed; |
| opacity: 0.75; |
| background-color: #EEE; |
| } |
| |
| .child { |
| width: 400px; |
| height: 400px; |
| scroll-snap-align: start; |
| position: absolute; |
| left: 0; |
| } |
| </style> |
| <script> |
| let write = s => output.innerHTML += s + "<br>"; |
| if (window.testRunner) { |
| testRunner.dumpAsText(); |
| testRunner.waitUntilDone(); |
| } |
| |
| function deflateScrollSnapMargins(amount) { |
| for (let child of document.querySelectorAll(".child")) { |
| let currentMargin = parseInt(child.style.scrollSnapMargin.replace(/px/, "")); |
| child.style.scrollSnapMargin = `${currentMargin - amount}px`; |
| } |
| } |
| |
| function zeroDelayTimeout(action) { |
| return new Promise((resolve) => { |
| setTimeout(() => { |
| action(); |
| resolve(); |
| }); |
| }); |
| } |
| |
| function run() |
| { |
| if (!window.testRunner || !window.internals) { |
| write(`To manually test, verify that scrolling snaps somewhere above each colored box. As you scroll further |
| down, the distance between the snapped position and the top of the colored box should increase.`); |
| return; |
| } |
| |
| zeroDelayTimeout(() => { |
| write("Scroll-snap offsets are: " + internals.scrollSnapOffsets(container)); |
| container.scrollTop += 100; |
| container.style.width = "500px"; |
| }) |
| .then(() => { |
| zeroDelayTimeout(() => { |
| write("After resizing, the offsets should not have changed: " + internals.scrollSnapOffsets(container)); |
| container.scrollTop += 100; |
| deflateScrollSnapMargins(10); |
| }); |
| }) |
| .then(() => { |
| zeroDelayTimeout(() => { |
| write("After deflating scroll-snap-margin by 10px, the offsets are: " + internals.scrollSnapOffsets(container)); |
| container.scrollTop += 100; |
| container.style.width = "400px"; |
| }); |
| }) |
| .then(() => { |
| zeroDelayTimeout(() => { |
| write("After resizing, the offsets should not have changed: " + internals.scrollSnapOffsets(container)); |
| testRunner.notifyDone(); |
| }); |
| }); |
| } |
| </script> |
| </head> |
| <body onload=run()> |
| <div id="container"> |
| <div class="child" style="background-color: red; top: 0px; scroll-snap-margin: 10px;"></div> |
| <div class="child" style="background-color: green; top: 720px; scroll-snap-margin: 20px;"></div> |
| <div class="child" style="background-color: blue; top: 1440px; scroll-snap-margin: 30px;"></div> |
| <div class="child" style="background-color: aqua; top: 2160px; scroll-snap-margin: 40px;"></div> |
| <div class="child" style="background-color: yellow; top: 2880px; scroll-snap-margin: 50px;"></div> |
| <div class="child" style="background-color: fuchsia; top: 3600px; scroll-snap-margin: 60px;"></div> |
| </div> |
| <div id="output"></div> |
| </body> |
| </html> |
