| <!DOCTYPE html> |
| <title> |
| A test case that scrolling to a point on large element where the snap area |
| doesn't cover over the snapport |
| </title> |
| <link rel="help" href="https://drafts.csswg.org/css-scroll-snap-1/#snap-overflow"/> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <style> |
| div { |
| position: absolute; |
| width: 100%; |
| } |
| #scroller { |
| left: 10px; |
| height: 200px; |
| width: 100px; |
| overflow-y: scroll; |
| overflow-x: hidden; |
| scroll-snap-type: y mandatory; |
| } |
| .snap { |
| scroll-snap-align: start; |
| background-color: green; |
| } |
| .target { |
| background-color: red; |
| border-radius: 100%; |
| height: 88px; |
| top: 536px; |
| } |
| </style> |
| <div id="scroller"> |
| <div style="height: 2000px;"></div> |
| <div class="snap" style="top: 0px; height: 40px;">1</div> |
| <div class="snap" style="top: 40px; height: 40px;">2</div> |
| <div class="snap" style="top: 80px; height: 1000px;">3</div> |
| <div class="snap" style="top: 1080px; height: 40px;">4</div> |
| <div class="snap" style="top: 1120px; height: 40px;">5</div> |
| <div class="target"></div> |
| </div> |
| <script> |
| test(() => { |
| const scroller = document.getElementById("scroller"); |
| |
| scroller.scrollBy(0, 10); |
| // Snap to the first snap point. |
| assert_equals(scroller.scrollLeft, 0); |
| assert_equals(scroller.scrollTop, 40); |
| |
| scroller.scrollBy(0, 10); |
| // Snap to the second snap point. |
| assert_equals(scroller.scrollLeft, 0); |
| assert_equals(scroller.scrollTop, 80); |
| |
| scroller.scrollBy(0, 100); |
| // Snap to the given scrolling position since the third snap target element |
| // is larger than the snapport. |
| assert_equals(scroller.scrollLeft, 0); |
| assert_equals(scroller.scrollTop, 180); |
| |
| scroller.scrollBy(0, 100); |
| // Again, snap to the given scrolling position. |
| assert_equals(scroller.scrollLeft, 0); |
| assert_equals(scroller.scrollTop, 280); |
| |
| // Scroll to a point where the third target element is still covering over the |
| // snapport. |
| scroller.scrollBy(0, 600); |
| assert_equals(scroller.scrollLeft, 0); |
| // Again, snap to the given scrolling position. |
| assert_equals(scroller.scrollTop, 880); |
| |
| // Scroll to a point where the third target element is no longer convering |
| // over the snapport, rather the forth snap point is in the snapport. |
| scroller.scrollBy(0, 10); |
| // Now, snap to the forth snap point. |
| assert_equals(scroller.scrollLeft, 0); |
| assert_equals(scroller.scrollTop, 1080); |
| |
| // Scroll back a bit. |
| scroller.scrollBy(0, -10); |
| // This should snap to the bottom of the 3rd snap area and not all the way |
| // back up to its top. |
| assert_equals(scroller.scrollLeft, 0); |
| assert_equals(scroller.scrollTop, 880); |
| }, "snaps to bottom edge of large snap area that doesn't cover the snap port."); |
| </script> |