<!DOCTYPE html>
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<title>ScrollTimeline current time algorithm - interaction with writing modes</title>
<link rel="help" href="https://wicg.github.io/scroll-animations/#current-time-algorithm">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>

<script src="./resources/scrolltimeline-utils.js"></script>

<body></body>

<script>
'use strict';

test(function() {
  const scrollerOverrides = new Map([['direction', 'rtl']]);
  const scroller = setupScrollTimelineTest(scrollerOverrides);

  // Set the timeRange such that currentTime maps directly to the value
  // scrolled. The contents and scroller are square, so it suffices to compute
  // one edge and use it for all the timelines.
  const scrollerSize = scroller.scrollHeight - scroller.clientHeight;

  const blockScrollTimeline = new ScrollTimeline(
      {scrollSource: scroller, timeRange: scrollerSize, orientation: 'block'});
  const inlineScrollTimeline = new ScrollTimeline(
      {scrollSource: scroller, timeRange: scrollerSize, orientation: 'inline'});
  const horizontalScrollTimeline = new ScrollTimeline({
    scrollSource: scroller,
    timeRange: scrollerSize,
    orientation: 'horizontal'
  });
  const verticalScrollTimeline = new ScrollTimeline({
    scrollSource: scroller,
    timeRange: scrollerSize,
    orientation: 'vertical'
  });

  // Unscrolled, all timelines should read a current time of 0 even though the
  // X-axis will have started at the right hand side for rtl.
  assert_equals(
      blockScrollTimeline.currentTime, 0, 'Unscrolled block timeline');
  assert_equals(
      inlineScrollTimeline.currentTime, 0, 'Unscrolled inline timeline');
  assert_equals(
      horizontalScrollTimeline.currentTime, 0,
      'Unscrolled horizontal timeline');
  assert_equals(
      verticalScrollTimeline.currentTime, 0, 'Unscrolled vertical timeline');

  // The offset in the inline/horizontal direction should be inverted. The
  // block/vertical direction should be unaffected.
  scroller.scrollTop = 50;
  scroller.scrollLeft = 75;

  assert_equals(blockScrollTimeline.currentTime, 50, 'Scrolled block timeline');
  assert_equals(
      inlineScrollTimeline.currentTime, scrollerSize - 75,
      'Scrolled inline timeline');
  assert_equals(
      horizontalScrollTimeline.currentTime, scrollerSize - 75,
      'Scrolled horizontal timeline');
  assert_equals(
      verticalScrollTimeline.currentTime, 50, 'Scrolled vertical timeline');
}, 'currentTime handles direction: rtl correctly');

test(function() {
  const scrollerOverrides = new Map([['writing-mode', 'vertical-rl']]);
  const scroller = setupScrollTimelineTest(scrollerOverrides);

  // Set the timeRange such that currentTime maps directly to the value
  // scrolled. The contents and scroller are square, so it suffices to compute
  // one edge and use it for all the timelines.
  const scrollerSize = scroller.scrollHeight - scroller.clientHeight;

  const blockScrollTimeline = new ScrollTimeline(
      {scrollSource: scroller, timeRange: scrollerSize, orientation: 'block'});
  const inlineScrollTimeline = new ScrollTimeline(
      {scrollSource: scroller, timeRange: scrollerSize, orientation: 'inline'});
  const horizontalScrollTimeline = new ScrollTimeline({
    scrollSource: scroller,
    timeRange: scrollerSize,
    orientation: 'horizontal'
  });
  const verticalScrollTimeline = new ScrollTimeline({
    scrollSource: scroller,
    timeRange: scrollerSize,
    orientation: 'vertical'
  });

  // Unscrolled, all timelines should read a current time of 0 even though the
  // X-axis will have started at the right hand side for vertical-rl.
  assert_equals(
      blockScrollTimeline.currentTime, 0, 'Unscrolled block timeline');
  assert_equals(
      inlineScrollTimeline.currentTime, 0, 'Unscrolled inline timeline');
  assert_equals(
      horizontalScrollTimeline.currentTime, 0,
      'Unscrolled horizontal timeline');
  assert_equals(
      verticalScrollTimeline.currentTime, 0, 'Unscrolled vertical timeline');

  // For vertical-rl, the X-axis starts on the right-hand-side and is the block
  // axis. The Y-axis is normal but is the inline axis. For the
  // horizontal/vertical cases, horizontal starts on the right-hand-side and
  // vertical is normal.
  scroller.scrollTop = 50;
  scroller.scrollLeft = 75;

  assert_equals(
      blockScrollTimeline.currentTime, scrollerSize - 75,
      'Scrolled block timeline');
  assert_equals(
      inlineScrollTimeline.currentTime, 50, 'SCrolled inline timeline');
  assert_equals(
      horizontalScrollTimeline.currentTime, scrollerSize - 75,
      'Scrolled horizontal timeline');
  assert_equals(
      verticalScrollTimeline.currentTime, 50, 'Scrolled vertical timeline');
}, 'currentTime handles writing-mode: vertical-rl correctly');

test(function() {
  const scrollerOverrides = new Map([['writing-mode', 'vertical-lr']]);
  const scroller = setupScrollTimelineTest(scrollerOverrides);

  // Set the timeRange such that currentTime maps directly to the value
  // scrolled. The contents and scroller are square, so it suffices to compute
  // one edge and use it for all the timelines.
  const scrollerSize = scroller.scrollHeight - scroller.clientHeight;

  const blockScrollTimeline = new ScrollTimeline(
      {scrollSource: scroller, timeRange: scrollerSize, orientation: 'block'});
  const inlineScrollTimeline = new ScrollTimeline(
      {scrollSource: scroller, timeRange: scrollerSize, orientation: 'inline'});
  const horizontalScrollTimeline = new ScrollTimeline({
    scrollSource: scroller,
    timeRange: scrollerSize,
    orientation: 'horizontal'
  });
  const verticalScrollTimeline = new ScrollTimeline({
    scrollSource: scroller,
    timeRange: scrollerSize,
    orientation: 'vertical'
  });

  // Unscrolled, all timelines should read a current time of 0.
  assert_equals(
      blockScrollTimeline.currentTime, 0, 'Unscrolled block timeline');
  assert_equals(
      inlineScrollTimeline.currentTime, 0, 'Unscrolled inline timeline');
  assert_equals(
      horizontalScrollTimeline.currentTime, 0,
      'Unscrolled horizontal timeline');
  assert_equals(
      verticalScrollTimeline.currentTime, 0, 'Unscrolled vertical timeline');

  // For vertical-lr, both axes start at their 'normal' positions but the X-axis
  // is the block direction and the Y-axis is the inline direction. This does
  // not affect horizontal/vertical.
  scroller.scrollTop = 50;
  scroller.scrollLeft = 75;

  assert_equals(blockScrollTimeline.currentTime, 75, 'Scrolled block timeline');
  assert_equals(
      inlineScrollTimeline.currentTime, 50, 'Scrolled inline timeline');
  assert_equals(
      horizontalScrollTimeline.currentTime, 75, 'Scrolled horizontal timeline');
  assert_equals(
      verticalScrollTimeline.currentTime, 50, 'Scrolled vertical timeline');
}, 'currentTime handles writing-mode: vertical-lr correctly');

test(function() {
  const scrollerOverrides = new Map([['direction', 'rtl']]);
  const scroller = setupScrollTimelineTest(scrollerOverrides);
  // Set the timeRange such that currentTime maps directly to the value
  // scrolled. The contents and scroller are square, so it suffices to compute
  // one edge and use it for all the timelines.
  const scrollerSize = scroller.scrollHeight - scroller.clientHeight;

  const lengthScrollTimeline = new ScrollTimeline({
    scrollSource: scroller,
    timeRange: scrollerSize,
    orientation: 'horizontal',
    startScrollOffset: '20px'
  });
  const percentageScrollTimeline = new ScrollTimeline({
    scrollSource: scroller,
    timeRange: scrollerSize,
    orientation: 'horizontal',
    startScrollOffset: '20%'
  });
  const calcScrollTimeline = new ScrollTimeline({
    scrollSource: scroller,
    timeRange: scrollerSize,
    orientation: 'horizontal',
    startScrollOffset: 'calc(20% - 5px)'
  });

  // Unscrolled, all timelines should read a current time of unresolved, since
  // the current offset (0) will be less than the startScrollOffset.
  assert_equals(
      lengthScrollTimeline.currentTime, null,
      'Unscrolled length-based timeline');
  assert_equals(
      percentageScrollTimeline.currentTime, null,
      'Unscrolled percentage-based timeline');
  assert_equals(
      calcScrollTimeline.currentTime, null, 'Unscrolled calc-based timeline');

  // With direction rtl offsets are inverted, such that scrollLeft ==
  // scrollerSize is the 'zero' point for currentTime. However the
  // startScrollOffset is an absolute distance along the offset, so doesn't
  // need adjusting.

  // Check the length-based ScrollTimeline.
  scroller.scrollLeft = scrollerSize;
  assert_equals(
      lengthScrollTimeline.currentTime, null,
      'Length-based timeline before the startScrollOffset point');
  scroller.scrollLeft = scrollerSize - 20;
  assert_equals(
      lengthScrollTimeline.currentTime, 0,
      'Length-based timeline at the startScrollOffset point');
  scroller.scrollLeft = scrollerSize - 50;
  assert_equals(
      lengthScrollTimeline.currentTime,
      calculateCurrentTime(50, 20, scrollerSize, scrollerSize),
      'Length-based timeline after the startScrollOffset point');

  // Check the percentage-based ScrollTimeline.
  scroller.scrollLeft = scrollerSize - (0.19 * scrollerSize);
  assert_equals(
      percentageScrollTimeline.currentTime, null,
      'Percentage-based timeline before the startScrollOffset point');
  scroller.scrollLeft = scrollerSize - (0.20 * scrollerSize);
  assert_equals(
      percentageScrollTimeline.currentTime, 0,
      'Percentage-based timeline at the startScrollOffset point');
  scroller.scrollLeft = scrollerSize - (0.4 * scrollerSize);
  assert_equals(
      percentageScrollTimeline.currentTime,
      calculateCurrentTime(
          0.4 * scrollerSize, 0.2 * scrollerSize, scrollerSize, scrollerSize),
      'Percentage-based timeline after the startScrollOffset point');

  // Check the calc-based ScrollTimeline.
  scroller.scrollLeft = scrollerSize - (0.2 * scrollerSize - 10);
  assert_equals(
      calcScrollTimeline.currentTime, null,
      'Calc-based timeline before the startScrollOffset point');
  scroller.scrollLeft = scrollerSize - (0.2 * scrollerSize - 5);
  assert_equals(
      calcScrollTimeline.currentTime, 0,
      'Calc-based timeline at the startScrollOffset point');
  scroller.scrollLeft = scrollerSize - (0.2 * scrollerSize);
  assert_equals(
      calcScrollTimeline.currentTime,
      calculateCurrentTime(
          0.2 * scrollerSize, 0.2 * scrollerSize - 5, scrollerSize,
          scrollerSize),
      'Calc-based timeline after the startScrollOffset point');
}, 'currentTime handles startScrollOffset with direction: rtl correctly');

test(function() {
  const scrollerOverrides = new Map([['direction', 'rtl']]);
  const scroller = setupScrollTimelineTest(scrollerOverrides);
  // Set the timeRange such that currentTime maps directly to the value
  // scrolled. The contents and scroller are square, so it suffices to compute
  // one edge and use it for all the timelines.
  const scrollerSize = scroller.scrollHeight - scroller.clientHeight;

  const lengthScrollTimeline = new ScrollTimeline({
    scrollSource: scroller,
    timeRange: scrollerSize,
    orientation: 'horizontal',
    endScrollOffset: (scrollerSize - 20) + 'px'
  });
  const percentageScrollTimeline = new ScrollTimeline({
    scrollSource: scroller,
    timeRange: scrollerSize,
    orientation: 'horizontal',
    endScrollOffset: '80%'
  });
  const calcScrollTimeline = new ScrollTimeline({
    scrollSource: scroller,
    timeRange: scrollerSize,
    orientation: 'horizontal',
    endScrollOffset: 'calc(80% + 5px)'
  });

  // With direction rtl offsets are inverted, such that scrollLeft ==
  // scrollerSize is the 'zero' point for currentTime. However the
  // endScrollOffset is an absolute distance along the offset, so doesn't need
  // adjusting.

  // Check the length-based ScrollTimeline.
  scroller.scrollLeft = 0;
  assert_equals(
      lengthScrollTimeline.currentTime, null,
      'Length-based timeline after the endScrollOffset point');
  scroller.scrollLeft = 20;
  assert_equals(
      lengthScrollTimeline.currentTime, null,
      'Length-based timeline at the endScrollOffset point');
  scroller.scrollLeft = 50;
  assert_equals(
      lengthScrollTimeline.currentTime,
      calculateCurrentTime(
          scrollerSize - 50, 0, scrollerSize - 20, scrollerSize),
      'Length-based timeline before the endScrollOffset point');

  // Check the percentage-based ScrollTimeline.
  scroller.scrollLeft = 0.19 * scrollerSize;
  assert_equals(
      percentageScrollTimeline.currentTime, null,
      'Percentage-based timeline after the endScrollOffset point');
  scroller.scrollLeft = 0.20 * scrollerSize;
  assert_equals(
      percentageScrollTimeline.currentTime, null,
      'Percentage-based timeline at the endScrollOffset point');
  scroller.scrollLeft = 0.4 * scrollerSize;
  assert_equals(
      percentageScrollTimeline.currentTime,
      calculateCurrentTime(
          0.6 * scrollerSize, 0, 0.8 * scrollerSize, scrollerSize),
      'Percentage-based timeline before the endScrollOffset point');

  // Check the calc-based ScrollTimeline. 80% + 5px
  scroller.scrollLeft = 0.2 * scrollerSize - 10;
  assert_equals(
      calcScrollTimeline.currentTime, null,
      'Calc-based timeline after the endScrollOffset point');
  scroller.scrollLeft = 0.2 * scrollerSize - 5;
  assert_equals(
      calcScrollTimeline.currentTime, null,
      'Calc-based timeline at the endScrollOffset point');
  scroller.scrollLeft = 0.2 * scrollerSize;
  assert_equals(
      calcScrollTimeline.currentTime,
      calculateCurrentTime(
          0.8 * scrollerSize, 0, 0.8 * scrollerSize + 5, scrollerSize),
      'Calc-based timeline before the endScrollOffset point');
}, 'currentTime handles endScrollOffset with direction: rtl correctly');

test(function() {
  const scrollerOverrides = new Map([['direction', 'rtl']]);
  const scroller = setupScrollTimelineTest(scrollerOverrides);
  // Set the timeRange such that currentTime maps directly to the value
  // scrolled. The contents and scroller are square, so it suffices to compute
  // one edge and use it for all the timelines.
  const scrollerSize = scroller.scrollHeight - scroller.clientHeight;

  // When the endScrollOffset is equal to the maximum scroll offset (and there
  // are no fill modes), the endScrollOffset is treated as inclusive.
  const inclusiveAutoScrollTimeline = new ScrollTimeline({
    scrollSource: scroller,
    timeRange: scrollerSize,
    orientation: 'block',
    endScrollOffset: 'auto'
  });
  const inclusiveLengthScrollTimeline = new ScrollTimeline({
    scrollSource: scroller,
    timeRange: scrollerSize,
    orientation: 'block',
    endScrollOffset: scrollerSize + 'px'
  });
  const inclusivePercentageScrollTimeline = new ScrollTimeline({
    scrollSource: scroller,
    timeRange: scrollerSize,
    orientation: 'block',
    endScrollOffset: '100%'
  });
  const inclusiveCalcScrollTimeline = new ScrollTimeline({
    scrollSource: scroller,
    timeRange: scrollerSize,
    orientation: 'block',
    endScrollOffset: 'calc(80% + ' + (0.2 * scrollerSize) + 'px)'
  });

  // With direction rtl offsets are inverted, such that scrollLeft ==
  // scrollerSize is the 'zero' point for currentTime. However the
  // endScrollOffset is an absolute distance along the offset, so doesn't need
  // adjusting.

  scroller.scrollLeft = 0;
  let expectedCurrentTime = calculateCurrentTime(
      scroller.scrollLeft, 0, scrollerSize, scrollerSize);

  assert_equals(
    inclusiveAutoScrollTimeline.currentTime, expectedCurrentTime,
    'Inclusive auto timeline at the endScrollOffset point');
  assert_equals(
    inclusiveLengthScrollTimeline.currentTime, expectedCurrentTime,
    'Inclusive length-based timeline at the endScrollOffset point');
  assert_equals(
    inclusivePercentageScrollTimeline.currentTime, expectedCurrentTime,
    'Inclusive percentage-based timeline at the endScrollOffset point');
  assert_equals(
    inclusiveCalcScrollTimeline.currentTime, expectedCurrentTime,
    'Inclusive calc-based timeline at the endScrollOffset point');
}, 'currentTime handles endScrollOffset (inclusive case) with direction: rtl correctly');
</script>