mousemove-becomes-drag.html (1836B)
1 <!DOCTYPE html> 2 <title>Layout Instability: no shift in mouse moves with a button pressed</title> 3 <link rel="help" href="https://wicg.github.io/layout-instability/" /> 4 <style> 5 6 body { margin: 0; height: 2000px; } 7 #draggable { 8 top:50px; 9 left:50px; 10 width:50px; 11 height:50px; 12 background-color:blue; 13 position:absolute 14 } 15 16 </style> 17 <div id="draggable" ></div> 18 <script src="/resources/testharness.js"></script> 19 <script src="/resources/testharnessreport.js"></script> 20 <script src="/resources/testdriver.js"></script> 21 <script src="/resources/testdriver-actions.js"></script> 22 <script src="/resources/testdriver-vendor.js"></script> 23 <script src="resources/util.js"></script> 24 <script> 25 26 const draggable = document.getElementById("draggable"); 27 draggable.addEventListener('mousemove', function(event) { 28 // Move the element when the mouse moves. 29 draggable.style.top = event.pageY - 25 + 'px'; 30 event.preventDefault(); 31 }, false); 32 33 generateMouseMoveSequence = () => new test_driver.Actions() 34 .pointerMove(0, 0, {origin: draggable}) 35 .pointerDown() 36 .pointerMove(0, 15, {origin: draggable}) 37 .pause(100) 38 .pointerMove(0, 30, {origin: draggable}) 39 .pause(100) 40 .pointerMove(0, 45, {origin: draggable}) 41 .pause(100) 42 .pointerUp() 43 .pause(100); 44 45 promise_test(async () => { 46 47 const watcher = new ScoreWatcher; 48 49 // Wait for the initial render to complete. 50 await waitForAnimationFrames(2); 51 52 // Send pointer events for a sequence of mouse actions, mouse down, mouse moves and mouse up. 53 await generateMouseMoveSequence().send(); 54 55 // Mouse moves which drag the objects should be counted as the excluding inputs 56 // for the layout shift. 57 assert_greater_than(watcher.score, 0); 58 assert_equals(watcher.scoreWithInputExclusion, 0); 59 60 }, "No layout shift when mouse moves with a button pressed."); 61 62 </script>