| <!DOCTYPE html> |
| <title> |
| Moving the current snap target should make the scroller resnap to it. |
| </title> |
| <link rel="help" href="https://drafts.csswg.org/css-scroll-snap/#re-snap" /> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <style> |
| div { |
| position: relative; |
| margin: 0; |
| } |
| |
| #block { |
| height: 100px; |
| width: 100px; |
| } |
| |
| #scroller { |
| height: 500px; |
| width: 500px; |
| overflow: hidden; |
| scroll-snap-type: both mandatory; |
| } |
| |
| #initial-target { |
| width: 300px; |
| height: 300px; |
| left: 100px; |
| top: 0; |
| transform: none; |
| background-color: green; |
| scroll-snap-align: start; |
| } |
| |
| #other-target { |
| width: 300px; |
| height: 300px; |
| left: 300px; |
| background-color: red; |
| scroll-snap-align: start; |
| } |
| |
| .area { |
| width: 2000px; |
| height: 2000px; |
| } |
| </style> |
| |
| <div id="scroller"> |
| <div id="block"></div> |
| <div id="initial-target"></div> |
| <div id="other-target"></div> |
| <div class="area"></div> |
| </div> |
| |
| <script> |
| const initial_target = document.getElementById("initial-target"); |
| const other_target = document.getElementById("other-target"); |
| const block = document.getElementById("block"); |
| const scroller = document.getElementById("scroller"); |
| |
| function cleanup() { |
| initial_target.style.setProperty("transform", "none"); |
| initial_target.style.setProperty("top", "0"); |
| block.style.setProperty("height", "100px"); |
| } |
| |
| test(t => { |
| t.add_cleanup(cleanup); |
| scroller.scrollTo(0,0); |
| assert_equals(scroller.scrollTop, 100); |
| assert_equals(scroller.scrollLeft, 100); |
| |
| initial_target.style.setProperty("top", "300px"); |
| assert_equals(scroller.scrollTop, 400); |
| assert_equals(scroller.scrollLeft, 100); |
| }, "Moving the current snap target should make the scroller resnap to it."); |
| |
| test(t => { |
| t.add_cleanup(cleanup); |
| scroller.scrollTo(0,0); |
| assert_equals(scroller.scrollTop, 100); |
| assert_equals(scroller.scrollLeft, 100); |
| |
| block.style.setProperty("height", "200px"); |
| assert_equals(scroller.scrollTop, 200); |
| assert_equals(scroller.scrollLeft, 100); |
| }, "Changing the layout of other elements should be able to cause resnapping to \ |
| the target."); |
| |
| test(t => { |
| t.add_cleanup(cleanup); |
| scroller.scrollTo(0,0); |
| assert_equals(scroller.scrollTop, 100); |
| assert_equals(scroller.scrollLeft, 100); |
| |
| initial_target.style.setProperty("transform", "translate(0,100px)"); |
| assert_equals(scroller.scrollTop, 200); |
| assert_equals(scroller.scrollLeft, 100); |
| }, "Transforming the current snap target should make the scroller resnap to it."); |
| |
| test(t => { |
| t.add_cleanup(cleanup); |
| initial_target.style.setProperty("top", "100px"); |
| scroller.scrollTo(0,0); |
| assert_equals(scroller.scrollTop, 200); |
| assert_equals(scroller.scrollLeft, 100); |
| |
| initial_target.style.setProperty("transform", "translate(0,100px)"); |
| initial_target.style.setProperty("top", "0"); |
| assert_equals(scroller.scrollTop, 200); |
| assert_equals(scroller.scrollLeft, 100); |
| }, "Applying two property changes that do not change the visual offset of the \ |
| target should not change the scroll offset."); |
| </script> |
