chromium/third_party/blink/web_tests/fast/overflow/scrollbar-drag-origin.html

<!DOCTYPE html>
<title>Scrollbar interaction gutter</title>
<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<style>
#container {
    position: absolute;
    left: 200px;
    top: 195px;
    width: 300px;
    height: 200px;
    overflow: scroll;
}

#content {
    width: 1000px;
    height: 1000px;
}
</style>
<div id="container">
    <div id="content">
    </div>
</div>
This test verifies scroll position restores/snaps correctly when a thumb drag
has been cancelled.<br/>
The general behavior is that the cancelling behavior is only for the
scrollbar's non-scrolling direction.<br/>
This test is expected to behave differently on Mac and Linux because those
platforms don't cancel scrolling when mouse cursor is out of a certain
range.<br/>
<script>
  const leftButton = 0;

  function dragWithoutUp(from, to) {
    assert_own_property(window, 'chrome');
    assert_own_property(window.chrome, 'gpuBenchmarking');
    return new Promise((resolve) => {
      chrome.gpuBenchmarking.pointerActionSequence(
        [{
          source: 'mouse',
          actions: [
            {name: 'pointerMove', x: from.x, y: from.y},
            {name: 'pointerDown', x: from.x, y: from.y, button: leftButton},
            {name: 'pointerMove', x: to.x, y: to.y}
          ]
        }],
        resolve);
    });
  }

  function sendUp(at) {
    assert_own_property(window, 'chrome');
    assert_own_property(window.chrome, 'gpuBenchmarking');
    return new Promise((resolve) => {
      chrome.gpuBenchmarking.pointerActionSequence(
        [{
          source: 'mouse',
          actions: [
            // Need to send a down with the up or pointerActionSequence will
            // refuse to send the up because the sequence believes the button
            // is not currently down.
            {name: 'pointerDown', x: at.x, y: at.y, button: leftButton},
            {name: 'pointerUp', button: leftButton}
          ]
        }],
        resolve);
    });
  }

  function resetScroller() {
    var container = document.getElementById("container");
    container.scrollLeft = 350;
    container.scrollTop = 350;
  }

  var onMacPlatform = navigator.userAgent.search(/\bMac OS X\b/) != -1;
  var onLinuxPlatform = navigator.userAgent.search(/\bLinux\b/) != -1;

  promise_test(async t => {
    let from = { x: 490, y: 285 };
    let to = { x: 490, y: 50 };
    t.add_cleanup(async c => { await sendUp(to); });

    resetScroller();
    await dragWithoutUp(from, to);
    assert_equals(container.scrollTop, 0);
  }, document.title + ', drag vertical scrollbar out top');

  promise_test(async t => {
    let from = { x: 490, y: 285 };
    let to = { x: 490, y: 560 };
    t.add_cleanup(async c => { await sendUp(to); });

    resetScroller();
    await dragWithoutUp(from, to);
    assert_equals(container.scrollTop, 815);
  }, document.title + ', drag vertical scrollbar out bottom');

  promise_test(async t => {
    let from = { x: 490, y: 285 };
    let to = { x: 230, y: 560 };
    t.add_cleanup(async c => { await sendUp(to); });

    resetScroller();
    await dragWithoutUp(from, to);
    if (onMacPlatform || onLinuxPlatform) {
      // Mac and Linux/Android should not snap
      assert_equals(container.scrollTop, 815);
    }
    else {
      // Dragging out left should cause snapping even though we're not
      // snapping due to the vertical position.
      assert_equals(container.scrollTop, 350);
    }
  }, document.title + ', drag vertical scrollbar out left');

  promise_test(async t => {
    let from = { x: 490, y: 285 };
    let to = { x: 650, y: 560 };
    t.add_cleanup(async c => { await sendUp(to); });

    resetScroller();
    await dragWithoutUp(from, to);
    if (onMacPlatform || onLinuxPlatform) {
      // Mac and Linux/Android should not snap
      assert_equals(container.scrollTop, 815);
    }
    else {
      // Dragging out right should cause snapping even though we're not
      // snapping due to the vertical position.
      assert_equals(container.scrollTop, 350);
    }
  }, document.title + ', drag vertical scrollbar out right');

  promise_test(async t => {
    let from = { x: 340, y: 390 };
    let to = { x: 25, y: 390 };
    t.add_cleanup(async c => { await sendUp(to); });

    resetScroller();
    await dragWithoutUp(from, to);
    assert_equals(container.scrollLeft, 0);
  }, document.title + ', drag horizontal scrollbar out left');

  promise_test(async t => {
    let from = { x: 340, y: 390 };
    let to = { x: 560, y: 390 };
    t.add_cleanup(async c => { await sendUp(to); });

    resetScroller();
    await dragWithoutUp(from, to);
    assert_equals(container.scrollLeft, 715);
  }, document.title + ', drag horizontal scrollbar out right');

  promise_test(async t => {
    let from = { x: 340, y: 390 };
    let to = { x: 560, y: 190 };
    t.add_cleanup(async c => { await sendUp(to); });

    resetScroller();
    await dragWithoutUp(from, to);
    if (onMacPlatform || onLinuxPlatform) {
      // Mac and Linux/Android should not snap
      assert_equals(container.scrollLeft, 715);
    }
    else {
      // Dragging out the top should cause snapping even though we're not
      // snapping due to the right position.
      assert_equals(container.scrollLeft, 350);
    }
  }, document.title + ', drag horizontal scrollbar out top');

  promise_test(async t => {
    let from = { x: 340, y: 390 };
    let to = { x: 560, y: 590 };
    t.add_cleanup(async c => { await sendUp(to); });

    resetScroller();
    await dragWithoutUp(from, to);
    if (onMacPlatform || onLinuxPlatform) {
      // Mac and Linux/Android should not snap
      assert_equals(container.scrollLeft, 715);
    }
    else {
      // Dragging out the bottom should cause snapping even though we're not
      // snapping due to the right position.
      assert_equals(container.scrollLeft, 350);
    }
  }, document.title + ', drag horizontal scrollbar out bottom');
</script>