| <!DOCTYPE html> |
| <link rel="help" href="https://drafts.csswg.org/css-scroll-snap-1/#scroll-snap-type" /> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <style> |
| div { |
| position: absolute; |
| margin: 0px; |
| } |
| #scroller { |
| width: 400px; |
| height: 350px; |
| overflow: scroll; |
| scroll-snap-type: both mandatory; |
| } |
| #space { |
| width: 1000px; |
| height: 1000px; |
| } |
| #target { |
| width: 200px; |
| height: 200px; |
| left: 300px; |
| top: 300px; |
| } |
| </style> |
| |
| <div id="scroller"> |
| <div id="space"></div> |
| <div id="target"></div> |
| </div> |
| |
| <script> |
| const scroller_width = scroller.clientWidth; |
| const scroller_height = scroller.clientHeight; |
| [ |
| ["horizontal-tb", 300, 500 - scroller_height], |
| ["vertical-lr", 500 - scroller_width, 300], |
| ["vertical-rl", scroller_width - 700, 300] |
| ].forEach(([writing_mode, left, top]) => { |
| test(() => { |
| const target_left = getComputedStyle(target).left; |
| scroller.style.writingMode = writing_mode; |
| target.style.scrollSnapAlign = "end start"; |
| if (writing_mode == "vertical-rl") { |
| target.style.left = (scroller_width - 700) + "px"; |
| scroller.scrollTo(-500, 0); |
| } else { |
| scroller.scrollTo(0, 0); |
| } |
| assert_equals(scroller.scrollLeft, left, "aligns correctly on x"); |
| assert_equals(scroller.scrollTop, top, "aligns correctly on y"); |
| target.style.left = target_left; |
| scroller.style.writingMode = ""; |
| }, "Snaps correctly for " + writing_mode + |
| " writing mode with 'scroll-snap-align: end start' alignment"); |
| }); |
| |
| [ |
| ["horizontal-tb", 500 - scroller_width, 300], |
| ["vertical-lr", 300, 500 - scroller_height], |
| ["vertical-rl", target.clientWidth - 700, 500 - scroller_height] |
| ].forEach(([writing_mode, left, top]) => { |
| test(() => { |
| const target_left = getComputedStyle(target).left; |
| scroller.style.writingMode = writing_mode; |
| target.style.scrollSnapAlign = "start end"; |
| if (writing_mode == "vertical-rl") { |
| target.style.left = (scroller_width - 700) + "px"; |
| scroller.scrollTo(-500, 0); |
| } else { |
| scroller.scrollTo(0, 0); |
| } |
| assert_equals(scroller.scrollLeft, left, "aligns correctly on x"); |
| assert_equals(scroller.scrollTop, top, "aligns correctly on y"); |
| target.style.left = target_left; |
| scroller.style.writingMode = ""; |
| }, "Snaps correctly for " + writing_mode + |
| " writing mode with 'scroll-snap-align: start end' alignment"); |
| }); |
| |
| test(() => { |
| const target_left = getComputedStyle(target).left; |
| scroller.style.direction = "rtl"; |
| target.style.scrollSnapAlign = "end start"; |
| target.style.left = (scroller_width - 700) + "px"; |
| |
| scroller.scrollTo(-500, 0); |
| assert_equals(scroller.scrollLeft, target.clientWidth - 700, |
| "aligns correctly on x"); |
| assert_equals(scroller.scrollTop, 500 - scroller_height, |
| "aligns correctly on y"); |
| |
| target.style.left = target_left; |
| scroller.style.direction = ""; |
| }, "Snaps correctly for 'direction: rtl' with 'scroll-snap-align: end start' " + |
| "alignment"); |
| |
| test(() => { |
| const target_left = getComputedStyle(target).left; |
| scroller.style.direction = "rtl"; |
| target.style.scrollSnapAlign = "start end"; |
| target.style.left = (scroller_width - 700) + "px"; |
| |
| scroller.scrollTo(-500, 0); |
| assert_equals(scroller.scrollLeft, scroller_width - 700, |
| "aligns correctly on x"); |
| assert_equals(scroller.scrollTop, 300, "aligns correctly on y"); |
| |
| target.style.left = target_left; |
| scroller.style.direction = ""; |
| }, "Snaps correctly for 'direction: rtl' with 'scroll-snap-align: start end' " + |
| "alignment"); |
| |
| </script> |
