| <!DOCTYPE html> |
| <title>Testing scroll positions when scrolling an element with smooth behavior</title> |
| <meta name="timeout" content="long"/> |
| <link rel="author" title="Frédéric Wang" href="mailto:fwang@igalia.com"> |
| <link rel="help" href="https://drafts.csswg.org/cssom-view/#propdef-scroll-behavior"> |
| <link rel="help" href="https://drafts.csswg.org/cssom-view/#scrolling-box"> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <script src="support/scroll-behavior.js"></script> |
| <style> |
| .scrollable { |
| overflow: auto; |
| width: 400px; |
| height: 200px; |
| scroll-behavior: smooth; |
| } |
| </style> |
| <div id="log"> |
| </div> |
| <div id="overflowNode" class="scrollable"> |
| <div style="width: 2000px; height: 1000px; background: linear-gradient(135deg, red, green);"> |
| <span style="display: inline-block; width: 500px; height: 250px;"></span><span id="elementToReveal" style="display: inline-block; vertical-align: -15px; width: 10px; height: 15px; background: black;"></span> |
| </div> |
| </div> |
| <script> |
| // For smooth behavior, evolution of scroll positions over time is not specified by CSSOM View. |
| // This test relies on the minimal assumption that scroll position functions are monotonic. |
| ["scroll", "scrollTo", "scrollBy", "scrollIntoView"].forEach(function(scrollFunction) { |
| [{left:0, top:0}, {left:1000, top:0}, {left:0, top:500}, {left:1000, top:500}].forEach((initial) => { |
| var finalLeft = 500; |
| var finalTop = 250; |
| promise_test(() => { |
| return new Promise(function(resolve, reject) { |
| scrollNode(overflowNode, "scroll", "instant", initial.left, initial.top); |
| var oldLeft = overflowNode.scrollLeft; |
| var oldTop = overflowNode.scrollTop; |
| assert_equals(oldLeft, initial.left, "ScrollLeft should be at initial position"); |
| assert_equals(oldTop, initial.top, "ScrollTop should be at initial position"); |
| if (scrollFunction === "scrollBy") |
| scrollNode(overflowNode, scrollFunction, "smooth", finalLeft - initial.left, finalTop - initial.top); |
| else |
| scrollNode(overflowNode, scrollFunction, "smooth", finalLeft, finalTop); |
| observeScrolling(overflowNode, function(done) { |
| try { |
| var newLeft = overflowNode.scrollLeft; |
| var newTop = overflowNode.scrollTop; |
| assert_less_than_equal(Math.hypot(finalLeft - newLeft, finalTop - newTop), Math.hypot(finalLeft - oldLeft, finalTop - oldTop), "Scroll position should move towards the final position"); |
| if (done) { |
| assert_equals(newLeft, finalLeft, "ScrollLeft should reach final position"); |
| assert_equals(newTop, finalTop, "ScrollTop should reach final position"); |
| } |
| oldLeft = newLeft; |
| oldTop = newTop; |
| } catch(e) { |
| reject(e); |
| } |
| if (done) |
| resolve(); |
| }); |
| }); |
| }, `Scroll positions when performing smooth scrolling from (${initial.left}, ${initial.top}) to (${finalLeft}, ${finalTop}) using ${scrollFunction}() `); |
| }); |
| }); |
| |
| [{scrollAttribute: "scrollLeft", scrollValue: 500}, {scrollAttribute: "scrollTop", scrollValue: 250}].forEach(function(scrollTest) { |
| var initialPosition = Number(scrollTest.scrollValue) * 2; |
| [0, initialPosition].forEach((initial) => { |
| promise_test(() => { |
| return new Promise(function(resolve, reject) { |
| scrollNode(overflowNode, "scroll", "instant", initial, initial); |
| var oldValue = overflowNode[scrollTest.scrollAttribute]; |
| assert_equals(oldValue, initial, `${scrollTest.scrollAttribute} should be at initial position`); |
| var expectedValue = Number(scrollTest.scrollValue); |
| overflowNode[scrollTest.scrollAttribute] = expectedValue; |
| observeScrolling(overflowNode, function(done) { |
| try { |
| var newValue = overflowNode[scrollTest.scrollAttribute]; |
| assert_less_than_equal(Math.abs(expectedValue - newValue), Math.abs(expectedValue - oldValue), "Scroll position should move towards the final position"); |
| if (done) |
| assert_equals(newValue, expectedValue, `${scrollTest.scrollAttribute} should reach final position`); |
| oldValue = newValue; |
| } catch(e) { |
| reject(e); |
| } |
| if (done) |
| resolve(); |
| }); |
| }); |
| }, `Scroll positions when performing smooth scrolling from ${initial} to ${scrollTest.scrollValue} by setting ${scrollTest.scrollAttribute} `); |
| }); |
| }); |
| |
| promise_test(() => { |
| return new Promise(function(resolve, reject) { |
| resetScroll(overflowNode); |
| var initialScrollAborted = false; |
| var scrollDirectionChanged = false; |
| var oldLeft = overflowNode.scrollLeft; |
| var oldTop = overflowNode.scrollTop; |
| assert_equals(oldLeft, 0); |
| assert_equals(oldTop, 0); |
| scrollNode(overflowNode, "scroll", "smooth", 1500, 750); |
| observeScrolling(overflowNode, function(done) { |
| try { |
| var newLeft = overflowNode.scrollLeft; |
| var newTop = overflowNode.scrollTop; |
| if (initialScrollAborted) { |
| if (scrollDirectionChanged) { |
| assert_greater_than_equal(oldLeft, newLeft, "ScrollLeft keeps decreasing"); |
| assert_greater_than_equal(oldTop, newTop, "ScrollTop keeps decreasing"); |
| } else |
| scrollDirectionChanged = newLeft <= oldLeft && newTop <= oldTop; |
| } else { |
| assert_less_than_equal(oldLeft, newLeft, "ScrollLeft keeps increasing"); |
| assert_less_than_equal(oldTop, newTop, "ScrollTop keeps increasing"); |
| if (newLeft > 1000 && newTop > 500) { |
| // Abort the initial scroll. |
| initialScrollAborted = true; |
| scrollNode(overflowNode, "scroll", "smooth", 500, 250); |
| newLeft = overflowNode.scrollLeft; |
| newTop = overflowNode.scrollTop; |
| } |
| } |
| if (done) { |
| assert_equals(newLeft, 500, "ScrollLeft should reach final position"); |
| assert_equals(newTop, 250, "ScrollTop should reach final position"); |
| } |
| oldLeft = newLeft; |
| oldTop = newTop; |
| } catch(e) { |
| reject(e); |
| } |
| if (done) |
| resolve(); |
| }); |
| }); |
| }, "Scroll positions when aborting a smooth scrolling with another smooth scrolling"); |
| |
| promise_test(() => { |
| return new Promise(function(resolve, reject) { |
| resetScroll(overflowNode); |
| var initialScrollAborted = false; |
| var oldLeft = overflowNode.scrollLeft; |
| var oldTop = overflowNode.scrollTop; |
| assert_equals(oldLeft, 0); |
| assert_equals(oldTop, 0); |
| scrollNode(overflowNode, "scroll", "smooth", 1500, 750); |
| observeScrolling(overflowNode, function(done) { |
| try { |
| var newLeft = overflowNode.scrollLeft; |
| var newTop = overflowNode.scrollTop; |
| if (!initialScrollAborted) { |
| assert_less_than_equal(oldLeft, newLeft, "ScrollLeft keeps increasing"); |
| assert_less_than_equal(oldTop, newTop, "ScrollTop keeps increasing"); |
| if (newLeft > 1000 && newTop > 500) { |
| // Abort the initial scroll. |
| initialScrollAborted = true; |
| scrollNode(overflowNode, "scroll", "instant", 500, 250); |
| newLeft = overflowNode.scrollLeft; |
| newTop = overflowNode.scrollTop; |
| assert_equals(newLeft, 500, "ScrollLeft should reach final position"); |
| assert_equals(newTop, 250, "ScrollTop should reach final position"); |
| } |
| } |
| if (done) { |
| assert_equals(newLeft, 500, "ScrollLeft should stay at final position"); |
| assert_equals(newTop, 250, "ScrollTop should stay at final position"); |
| } |
| oldLeft = newLeft; |
| oldTop = newTop; |
| } catch(e) { |
| reject(e); |
| } |
| if (done) |
| resolve(); |
| }); |
| }); |
| }, "Scroll positions when aborting a smooth scrolling with an instant scrolling"); |
| </script> |
