| <!DOCTYPE html> |
| <title> |
| Snap to an area where the element's scroll-margin is visible but not the |
| element itself (using x-axis snap type) |
| </title> |
| <link rel="help" href="https://drafts.csswg.org/css-scroll-snap-1/#snap-scope"/> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <style> |
| div { |
| position: absolute; |
| margin: 0px; |
| } |
| |
| #scroller { |
| height: 600px; |
| width: 600px; |
| overflow: scroll; |
| scroll-snap-type: x mandatory; |
| } |
| |
| #space { |
| width: 2000px; |
| height: 2000px; |
| } |
| |
| .snap { |
| width: 200px; |
| height: 200px; |
| background-color: blue; |
| scroll-snap-align: start; |
| } |
| |
| #left-visible { |
| left: 0px; |
| top: 0px; |
| } |
| |
| #right-visible { |
| left: 800px; |
| top: 0px; |
| } |
| |
| #middle-margin-visible { |
| left: 700px; |
| top: 800px; |
| /* 300px makes snap area visible with margin but non-visible without it */ |
| scroll-margin-top: 300px; |
| } |
| |
| </style> |
| <div id="scroller"> |
| <div id="space"></div> |
| <div id="left-visible" class="snap"></div> |
| <div id="middle-margin-visible" class="snap"></div> |
| <div id="right-visible" class="snap"></div> |
| </div> |
| <script> |
| test(() => { |
| const scroller = document.getElementById("scroller"); |
| scroller.scrollTo(0, 0); |
| assert_equals(scroller.scrollLeft, 0); |
| assert_equals(scroller.scrollTop, 0); |
| scroller.scrollTo(500, 0); |
| assert_equals(scroller.scrollLeft, 700); |
| assert_equals(scroller.scrollTop, 0); |
| }, 'Scroll margin should be considered when calculating snap area visibilty \ |
| while snapping on the x-axis'); |
| </script> |
