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✏️ Editing: perfect-scrollbar.js

/*!
 * perfect-scrollbar v1.4.0
 * (c) 2018 Hyunje Jun
 * @license MIT
 */
(function (global, factory) {
	typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
	typeof define === 'function' && define.amd ? define(factory) :
	(global.PerfectScrollbar = factory());
}(this, (function () { 'use strict';

function get(element) {
  return getComputedStyle(element);
}

function set(element, obj) {
  for (var key in obj) {
    var val = obj[key];
    if (typeof val === 'number') {
      val = val + "px";
    }
    element.style[key] = val;
  }
  return element;
}

function div(className) {
  var div = document.createElement('div');
  div.className = className;
  return div;
}

var elMatches =
  typeof Element !== 'undefined' &&
  (Element.prototype.matches ||
    Element.prototype.webkitMatchesSelector ||
    Element.prototype.mozMatchesSelector ||
    Element.prototype.msMatchesSelector);

function matches(element, query) {
  if (!elMatches) {
    throw new Error('No element matching method supported');
  }

return elMatches.call(element, query);
}

function remove(element) {
  if (element.remove) {
    element.remove();
  } else {
    if (element.parentNode) {
      element.parentNode.removeChild(element);
    }
  }
}

function queryChildren(element, selector) {
  return Array.prototype.filter.call(element.children, function (child) { return matches(child, selector); }
  );
}

/*
 * Helper methods
 */
var scrollingClassTimeout = { x: null, y: null };

function addScrollingClass(i, x) {
  var classList = i.element.classList;
  var className = cls.state.scrolling(x);

if (classList.contains(className)) {
    clearTimeout(scrollingClassTimeout[x]);
  } else {
    classList.add(className);
  }
}

function removeScrollingClass(i, x) {
  scrollingClassTimeout[x] = setTimeout(
    function () { return i.isAlive && i.element.classList.remove(cls.state.scrolling(x)); },
    i.settings.scrollingThreshold
  );
}

function setScrollingClassInstantly(i, x) {
  addScrollingClass(i, x);
  removeScrollingClass(i, x);
}

var EventElement = function EventElement(element) {
  this.element = element;
  this.handlers = {};
};

var prototypeAccessors = { isEmpty: { configurable: true } };

EventElement.prototype.bind = function bind (eventName, handler) {
  if (typeof this.handlers[eventName] === 'undefined') {
    this.handlers[eventName] = [];
  }
  this.handlers[eventName].push(handler);
  this.element.addEventListener(eventName, handler, false);
};

EventElement.prototype.unbind = function unbind (eventName, target) {
    var this$1 = this;

this.handlers[eventName] = this.handlers[eventName].filter(function (handler) {
    if (target && handler !== target) {
      return true;
    }
    this$1.element.removeEventListener(eventName, handler, false);
    return false;
  });
};

EventElement.prototype.unbindAll = function unbindAll () {
    var this$1 = this;

for (var name in this$1.handlers) {
    this$1.unbind(name);
  }
};

prototypeAccessors.isEmpty.get = function () {
    var this$1 = this;

return Object.keys(this.handlers).every(
    function (key) { return this$1.handlers[key].length === 0; }
  );
};

Object.defineProperties( EventElement.prototype, prototypeAccessors );

var EventManager = function EventManager() {
  this.eventElements = [];
};

EventManager.prototype.eventElement = function eventElement (element) {
  var ee = this.eventElements.filter(function (ee) { return ee.element === element; })[0];
  if (!ee) {
    ee = new EventElement(element);
    this.eventElements.push(ee);
  }
  return ee;
};

EventManager.prototype.bind = function bind (element, eventName, handler) {
  this.eventElement(element).bind(eventName, handler);
};

EventManager.prototype.unbind = function unbind (element, eventName, handler) {
  var ee = this.eventElement(element);
  ee.unbind(eventName, handler);

if (ee.isEmpty) {
    // remove
    this.eventElements.splice(this.eventElements.indexOf(ee), 1);
  }
};

EventManager.prototype.unbindAll = function unbindAll () {
  this.eventElements.forEach(function (e) { return e.unbindAll(); });
  this.eventElements = [];
};

EventManager.prototype.once = function once (element, eventName, handler) {
  var ee = this.eventElement(element);
  var onceHandler = function (evt) {
    ee.unbind(eventName, onceHandler);
    handler(evt);
  };
  ee.bind(eventName, onceHandler);
};

var processScrollDiff = function(
  i,
  axis,
  diff,
  useScrollingClass,
  forceFireReachEvent
) {
  if ( useScrollingClass === void 0 ) useScrollingClass = true;
  if ( forceFireReachEvent === void 0 ) forceFireReachEvent = false;

var fields;
  if (axis === 'top') {
    fields = [
      'contentHeight',
      'containerHeight',
      'scrollTop',
      'y',
      'up',
      'down' ];
  } else if (axis === 'left') {
    fields = [
      'contentWidth',
      'containerWidth',
      'scrollLeft',
      'x',
      'left',
      'right' ];
  } else {
    throw new Error('A proper axis should be provided');
  }

processScrollDiff$1(i, diff, fields, useScrollingClass, forceFireReachEvent);
};

function processScrollDiff$1(
  i,
  diff,
  ref,
  useScrollingClass,
  forceFireReachEvent
) {
  var contentHeight = ref[0];
  var containerHeight = ref[1];
  var scrollTop = ref[2];
  var y = ref[3];
  var up = ref[4];
  var down = ref[5];
  if ( useScrollingClass === void 0 ) useScrollingClass = true;
  if ( forceFireReachEvent === void 0 ) forceFireReachEvent = false;

var element = i.element;

// reset reach
  i.reach[y] = null;

// 1 for subpixel rounding
  if (element[scrollTop] < 1) {
    i.reach[y] = 'start';
  }

// 1 for subpixel rounding
  if (element[scrollTop] > i[contentHeight] - i[containerHeight] - 1) {
    i.reach[y] = 'end';
  }

if (diff) {
    element.dispatchEvent(createEvent(("ps-scroll-" + y)));

if (diff < 0) {
      element.dispatchEvent(createEvent(("ps-scroll-" + up)));
    } else if (diff > 0) {
      element.dispatchEvent(createEvent(("ps-scroll-" + down)));
    }

if (useScrollingClass) {
      setScrollingClassInstantly(i, y);
    }
  }

if (i.reach[y] && (diff || forceFireReachEvent)) {
    element.dispatchEvent(createEvent(("ps-" + y + "-reach-" + (i.reach[y]))));
  }
}

function toInt(x) {
  return parseInt(x, 10) || 0;
}

function isEditable(el) {
  return (
    matches(el, 'input,[contenteditable]') ||
    matches(el, 'select,[contenteditable]') ||
    matches(el, 'textarea,[contenteditable]') ||
    matches(el, 'button,[contenteditable]')
  );
}

function outerWidth(element) {
  var styles = get(element);
  return (
    toInt(styles.width) +
    toInt(styles.paddingLeft) +
    toInt(styles.paddingRight) +
    toInt(styles.borderLeftWidth) +
    toInt(styles.borderRightWidth)
  );
}

var env = {
  isWebKit:
    typeof document !== 'undefined' &&
    'WebkitAppearance' in document.documentElement.style,
  supportsTouch:
    typeof window !== 'undefined' &&
    ('ontouchstart' in window ||
      (window.DocumentTouch && document instanceof window.DocumentTouch)),
  supportsIePointer:
    typeof navigator !== 'undefined' && navigator.msMaxTouchPoints,
  isChrome:
    typeof navigator !== 'undefined' &&
    /Chrome/i.test(navigator && navigator.userAgent),
};

var updateGeometry = function(i) {
  var element = i.element;
  var roundedScrollTop = Math.floor(element.scrollTop);

i.containerWidth = element.clientWidth;
  i.containerHeight = element.clientHeight;
  i.contentWidth = element.scrollWidth;
  i.contentHeight = element.scrollHeight;

if (!element.contains(i.scrollbarXRail)) {
    // clean up and append
    queryChildren(element, cls.element.rail('x')).forEach(function (el) { return remove(el); }
    );
    element.appendChild(i.scrollbarXRail);
  }
  if (!element.contains(i.scrollbarYRail)) {
    // clean up and append
    queryChildren(element, cls.element.rail('y')).forEach(function (el) { return remove(el); }
    );
    element.appendChild(i.scrollbarYRail);
  }

if (
    !i.settings.suppressScrollX &&
    i.containerWidth + i.settings.scrollXMarginOffset < i.contentWidth
  ) {
    i.scrollbarXActive = true;
    i.railXWidth = i.containerWidth - i.railXMarginWidth;
    i.railXRatio = i.containerWidth / i.railXWidth;
    i.scrollbarXWidth = getThumbSize(
      i,
      toInt(i.railXWidth * i.containerWidth / i.contentWidth)
    );
    i.scrollbarXLeft = toInt(
      (i.negativeScrollAdjustment + element.scrollLeft) *
        (i.railXWidth - i.scrollbarXWidth) /
        (i.contentWidth - i.containerWidth)
    );
  } else {
    i.scrollbarXActive = false;
  }

if (
    !i.settings.suppressScrollY &&
    i.containerHeight + i.settings.scrollYMarginOffset < i.contentHeight
  ) {
    i.scrollbarYActive = true;
    i.railYHeight = i.containerHeight - i.railYMarginHeight;
    i.railYRatio = i.containerHeight / i.railYHeight;
    i.scrollbarYHeight = getThumbSize(
      i,
      toInt(i.railYHeight * i.containerHeight / i.contentHeight)
    );
    i.scrollbarYTop = toInt(
      roundedScrollTop *
        (i.railYHeight - i.scrollbarYHeight) /
        (i.contentHeight - i.containerHeight)
    );
  } else {
    i.scrollbarYActive = false;
  }

if (i.scrollbarXLeft >= i.railXWidth - i.scrollbarXWidth) {
    i.scrollbarXLeft = i.railXWidth - i.scrollbarXWidth;
  }
  if (i.scrollbarYTop >= i.railYHeight - i.scrollbarYHeight) {
    i.scrollbarYTop = i.railYHeight - i.scrollbarYHeight;
  }

updateCss(element, i);

if (i.scrollbarXActive) {
    element.classList.add(cls.state.active('x'));
  } else {
    element.classList.remove(cls.state.active('x'));
    i.scrollbarXWidth = 0;
    i.scrollbarXLeft = 0;
    element.scrollLeft = 0;
  }
  if (i.scrollbarYActive) {
    element.classList.add(cls.state.active('y'));
  } else {
    element.classList.remove(cls.state.active('y'));
    i.scrollbarYHeight = 0;
    i.scrollbarYTop = 0;
    element.scrollTop = 0;
  }
};

function updateCss(element, i) {
  var xRailOffset = { width: i.railXWidth };
  var roundedScrollTop = Math.floor(element.scrollTop);

if (i.isRtl) {
    xRailOffset.left =
      i.negativeScrollAdjustment +
      element.scrollLeft +
      i.containerWidth -
      i.contentWidth;
  } else {
    xRailOffset.left = element.scrollLeft;
  }
  if (i.isScrollbarXUsingBottom) {
    xRailOffset.bottom = i.scrollbarXBottom - roundedScrollTop;
  } else {
    xRailOffset.top = i.scrollbarXTop + roundedScrollTop;
  }
  set(i.scrollbarXRail, xRailOffset);

set(i.scrollbarX, {
    left: i.scrollbarXLeft,
    width: i.scrollbarXWidth - i.railBorderXWidth,
  });
  set(i.scrollbarY, {
    top: i.scrollbarYTop,
    height: i.scrollbarYHeight - i.railBorderYWidth,
  });
}

var clickRail = function(i) {
  i.event.bind(i.scrollbarY, 'mousedown', function (e) { return e.stopPropagation(); });
  i.event.bind(i.scrollbarYRail, 'mousedown', function (e) {
    var positionTop =
      e.pageY -
      window.pageYOffset -
      i.scrollbarYRail.getBoundingClientRect().top;
    var direction = positionTop > i.scrollbarYTop ? 1 : -1;

i.element.scrollTop += direction * i.containerHeight;
    updateGeometry(i);

e.stopPropagation();
  });

i.event.bind(i.scrollbarX, 'mousedown', function (e) { return e.stopPropagation(); });
  i.event.bind(i.scrollbarXRail, 'mousedown', function (e) {
    var positionLeft =
      e.pageX -
      window.pageXOffset -
      i.scrollbarXRail.getBoundingClientRect().left;
    var direction = positionLeft > i.scrollbarXLeft ? 1 : -1;

i.element.scrollLeft += direction * i.containerWidth;
    updateGeometry(i);

e.stopPropagation();
  });
};

var dragThumb = function(i) {
  bindMouseScrollHandler(i, [
    'containerWidth',
    'contentWidth',
    'pageX',
    'railXWidth',
    'scrollbarX',
    'scrollbarXWidth',
    'scrollLeft',
    'x',
    'scrollbarXRail' ]);
  bindMouseScrollHandler(i, [
    'containerHeight',
    'contentHeight',
    'pageY',
    'railYHeight',
    'scrollbarY',
    'scrollbarYHeight',
    'scrollTop',
    'y',
    'scrollbarYRail' ]);
};

function bindMouseScrollHandler(
  i,
  ref
) {
  var containerHeight = ref[0];
  var contentHeight = ref[1];
  var pageY = ref[2];
  var railYHeight = ref[3];
  var scrollbarY = ref[4];
  var scrollbarYHeight = ref[5];
  var scrollTop = ref[6];
  var y = ref[7];
  var scrollbarYRail = ref[8];

var element = i.element;

var startingScrollTop = null;
  var startingMousePageY = null;
  var scrollBy = null;

function mouseMoveHandler(e) {
    element[scrollTop] =
      startingScrollTop + scrollBy * (e[pageY] - startingMousePageY);
    addScrollingClass(i, y);
    updateGeometry(i);

e.stopPropagation();
    e.preventDefault();
  }

function mouseUpHandler() {
    removeScrollingClass(i, y);
    i[scrollbarYRail].classList.remove(cls.state.clicking);
    i.event.unbind(i.ownerDocument, 'mousemove', mouseMoveHandler);
  }

i.event.bind(i[scrollbarY], 'mousedown', function (e) {
    startingScrollTop = element[scrollTop];
    startingMousePageY = e[pageY];
    scrollBy =
      (i[contentHeight] - i[containerHeight]) /
      (i[railYHeight] - i[scrollbarYHeight]);

i.event.bind(i.ownerDocument, 'mousemove', mouseMoveHandler);
    i.event.once(i.ownerDocument, 'mouseup', mouseUpHandler);

i[scrollbarYRail].classList.add(cls.state.clicking);

e.stopPropagation();
    e.preventDefault();
  });
}

var keyboard = function(i) {
  var element = i.element;

var elementHovered = function () { return matches(element, ':hover'); };
  var scrollbarFocused = function () { return matches(i.scrollbarX, ':focus') || matches(i.scrollbarY, ':focus'); };

i.event.bind(i.ownerDocument, 'keydown', function (e) {
    if (
      (e.isDefaultPrevented && e.isDefaultPrevented()) ||
      e.defaultPrevented
    ) {
      return;
    }

if (!elementHovered() && !scrollbarFocused()) {
      return;
    }

var deltaX = 0;
    var deltaY = 0;

switch (e.which) {
      case 37: // left
        if (e.metaKey) {
          deltaX = -i.contentWidth;
        } else if (e.altKey) {
          deltaX = -i.containerWidth;
        } else {
          deltaX = -30;
        }
        break;
      case 38: // up
        if (e.metaKey) {
          deltaY = i.contentHeight;
        } else if (e.altKey) {
          deltaY = i.containerHeight;
        } else {
          deltaY = 30;
        }
        break;
      case 39: // right
        if (e.metaKey) {
          deltaX = i.contentWidth;
        } else if (e.altKey) {
          deltaX = i.containerWidth;
        } else {
          deltaX = 30;
        }
        break;
      case 40: // down
        if (e.metaKey) {
          deltaY = -i.contentHeight;
        } else if (e.altKey) {
          deltaY = -i.containerHeight;
        } else {
          deltaY = -30;
        }
        break;
      case 32: // space bar
        if (e.shiftKey) {
          deltaY = i.containerHeight;
        } else {
          deltaY = -i.containerHeight;
        }
        break;
      case 33: // page up
        deltaY = i.containerHeight;
        break;
      case 34: // page down
        deltaY = -i.containerHeight;
        break;
      case 36: // home
        deltaY = i.contentHeight;
        break;
      case 35: // end
        deltaY = -i.contentHeight;
        break;
      default:
        return;
    }

if (i.settings.suppressScrollX && deltaX !== 0) {
      return;
    }
    if (i.settings.suppressScrollY && deltaY !== 0) {
      return;
    }

element.scrollTop -= deltaY;
    element.scrollLeft += deltaX;
    updateGeometry(i);

if (shouldPreventDefault(deltaX, deltaY)) {
      e.preventDefault();
    }
  });
};

var wheel = function(i) {
  var element = i.element;

function shouldPreventDefault(deltaX, deltaY) {
    var roundedScrollTop = Math.floor(element.scrollTop);
    var isTop = element.scrollTop === 0;
    var isBottom =
      roundedScrollTop + element.offsetHeight === element.scrollHeight;
    var isLeft = element.scrollLeft === 0;
    var isRight =
      element.scrollLeft + element.offsetWidth === element.scrollWidth;

var hitsBound;

// pick axis with primary direction
    if (Math.abs(deltaY) > Math.abs(deltaX)) {
      hitsBound = isTop || isBottom;
    } else {
      hitsBound = isLeft || isRight;
    }

return hitsBound ? !i.settings.wheelPropagation : true;
  }

function getDeltaFromEvent(e) {
    var deltaX = e.deltaX;
    var deltaY = -1 * e.deltaY;

if (typeof deltaX === 'undefined' || typeof deltaY === 'undefined') {
      // OS X Safari
      deltaX = -1 * e.wheelDeltaX / 6;
      deltaY = e.wheelDeltaY / 6;
    }

if (e.deltaMode && e.deltaMode === 1) {
      // Firefox in deltaMode 1: Line scrolling
      deltaX *= 10;
      deltaY *= 10;
    }

if (deltaX !== deltaX && deltaY !== deltaY /* NaN checks */) {
      // IE in some mouse drivers
      deltaX = 0;
      deltaY = e.wheelDelta;
    }

if (e.shiftKey) {
      // reverse axis with shift key
      return [-deltaY, -deltaX];
    }
    return [deltaX, deltaY];
  }

function shouldBeConsumedByChild(target, deltaX, deltaY) {
    // FIXME: this is a workaround for <select> issue in FF and IE #571
    if (!env.isWebKit && element.querySelector('select:focus')) {
      return true;
    }

if (!element.contains(target)) {
      return false;
    }

var cursor = target;

while (cursor && cursor !== element) {
      if (cursor.classList.contains(cls.element.consuming)) {
        return true;
      }

var style = get(cursor);
      var overflow = [style.overflow, style.overflowX, style.overflowY].join(
        ''
      );

// if scrollable
      if (overflow.match(/(scroll|auto)/)) {
        var maxScrollTop = cursor.scrollHeight - cursor.clientHeight;
        if (maxScrollTop > 0) {
          if (
            !(cursor.scrollTop === 0 && deltaY > 0) &&
            !(cursor.scrollTop === maxScrollTop && deltaY < 0)
          ) {
            return true;
          }
        }
        var maxScrollLeft = cursor.scrollWidth - cursor.clientWidth;
        if (maxScrollLeft > 0) {
          if (
            !(cursor.scrollLeft === 0 && deltaX < 0) &&
            !(cursor.scrollLeft === maxScrollLeft && deltaX > 0)
          ) {
            return true;
          }
        }
      }

cursor = cursor.parentNode;
    }

return false;
  }

function mousewheelHandler(e) {
    var ref = getDeltaFromEvent(e);
    var deltaX = ref[0];
    var deltaY = ref[1];

if (shouldBeConsumedByChild(e.target, deltaX, deltaY)) {
      return;
    }

updateGeometry(i);

shouldPrevent = shouldPrevent || shouldPreventDefault(deltaX, deltaY);
    if (shouldPrevent && !e.ctrlKey) {
      e.stopPropagation();
      e.preventDefault();
    }
  }

if (typeof window.onwheel !== 'undefined') {
    i.event.bind(element, 'wheel', mousewheelHandler);
  } else if (typeof window.onmousewheel !== 'undefined') {
    i.event.bind(element, 'mousewheel', mousewheelHandler);
  }
};

var touch = function(i) {
  if (!env.supportsTouch && !env.supportsIePointer) {
    return;
  }

var element = i.element;

function shouldPrevent(deltaX, deltaY) {
    var scrollTop = Math.floor(element.scrollTop);
    var scrollLeft = element.scrollLeft;
    var magnitudeX = Math.abs(deltaX);
    var magnitudeY = Math.abs(deltaY);

if (magnitudeY > magnitudeX) {
      // user is perhaps trying to swipe up/down the page

if (
        (deltaY < 0 && scrollTop === i.contentHeight - i.containerHeight) ||
        (deltaY > 0 && scrollTop === 0)
      ) {
        // set prevent for mobile Chrome refresh
        return window.scrollY === 0 && deltaY > 0 && env.isChrome;
      }
    } else if (magnitudeX > magnitudeY) {
      // user is perhaps trying to swipe left/right across the page

if (
        (deltaX < 0 && scrollLeft === i.contentWidth - i.containerWidth) ||
        (deltaX > 0 && scrollLeft === 0)
      ) {
        return true;
      }
    }

return true;
  }

function applyTouchMove(differenceX, differenceY) {
    element.scrollTop -= differenceY;
    element.scrollLeft -= differenceX;

updateGeometry(i);
  }

var startOffset = {};
  var startTime = 0;
  var speed = {};
  var easingLoop = null;

function getTouch(e) {
    if (e.targetTouches) {
      return e.targetTouches[0];
    } else {
      // Maybe IE pointer
      return e;
    }
  }

function touchStart(e) {
    if (!shouldHandle(e)) {
      return;
    }

var touch = getTouch(e);

startOffset.pageX = touch.pageX;
    startOffset.pageY = touch.pageY;

startTime = new Date().getTime();

if (easingLoop !== null) {
      clearInterval(easingLoop);
    }
  }

function shouldBeConsumedByChild(target, deltaX, deltaY) {
    if (!element.contains(target)) {
      return false;
    }

var cursor = target;

while (cursor && cursor !== element) {
      if (cursor.classList.contains(cls.element.consuming)) {
        return true;
      }

var style = get(cursor);
      var overflow = [style.overflow, style.overflowX, style.overflowY].join(
        ''
      );

// if scrollable
      if (overflow.match(/(scroll|auto)/)) {
        var maxScrollTop = cursor.scrollHeight - cursor.clientHeight;
        if (maxScrollTop > 0) {
          if (
            !(cursor.scrollTop === 0 && deltaY > 0) &&
            !(cursor.scrollTop === maxScrollTop && deltaY < 0)
          ) {
            return true;
          }
        }
        var maxScrollLeft = cursor.scrollLeft - cursor.clientWidth;
        if (maxScrollLeft > 0) {
          if (
            !(cursor.scrollLeft === 0 && deltaX < 0) &&
            !(cursor.scrollLeft === maxScrollLeft && deltaX > 0)
          ) {
            return true;
          }
        }
      }

cursor = cursor.parentNode;
    }

return false;
  }

function touchMove(e) {
    if (shouldHandle(e)) {
      var touch = getTouch(e);

var currentOffset = { pageX: touch.pageX, pageY: touch.pageY };

var differenceX = currentOffset.pageX - startOffset.pageX;
      var differenceY = currentOffset.pageY - startOffset.pageY;

if (shouldBeConsumedByChild(e.target, differenceX, differenceY)) {
        return;
      }

applyTouchMove(differenceX, differenceY);
      startOffset = currentOffset;

var currentTime = new Date().getTime();

var timeGap = currentTime - startTime;
      if (timeGap > 0) {
        speed.x = differenceX / timeGap;
        speed.y = differenceY / timeGap;
        startTime = currentTime;
      }

if (shouldPrevent(differenceX, differenceY)) {
        e.preventDefault();
      }
    }
  }
  function touchEnd() {
    if (i.settings.swipeEasing) {
      clearInterval(easingLoop);
      easingLoop = setInterval(function() {
        if (i.isInitialized) {
          clearInterval(easingLoop);
          return;
        }

if (!speed.x && !speed.y) {
          clearInterval(easingLoop);
          return;
        }

if (Math.abs(speed.x) < 0.01 && Math.abs(speed.y) < 0.01) {
          clearInterval(easingLoop);
          return;
        }

applyTouchMove(speed.x * 30, speed.y * 30);

speed.x *= 0.8;
        speed.y *= 0.8;
      }, 10);
    }
  }

if (env.supportsTouch) {
    i.event.bind(element, 'touchstart', touchStart);
    i.event.bind(element, 'touchmove', touchMove);
    i.event.bind(element, 'touchend', touchEnd);
  } else if (env.supportsIePointer) {
    if (window.PointerEvent) {
      i.event.bind(element, 'pointerdown', touchStart);
      i.event.bind(element, 'pointermove', touchMove);
      i.event.bind(element, 'pointerup', touchEnd);
    } else if (window.MSPointerEvent) {
      i.event.bind(element, 'MSPointerDown', touchStart);
      i.event.bind(element, 'MSPointerMove', touchMove);
      i.event.bind(element, 'MSPointerUp', touchEnd);
    }
  }
};

var defaultSettings = function () { return ({
  handlers: ['click-rail', 'drag-thumb', 'keyboard', 'wheel', 'touch'],
  maxScrollbarLength: null,
  minScrollbarLength: null,
  scrollingThreshold: 1000,
  scrollXMarginOffset: 0,
  scrollYMarginOffset: 0,
  suppressScrollX: false,
  suppressScrollY: false,
  swipeEasing: true,
  useBothWheelAxes: false,
  wheelPropagation: true,
  wheelSpeed: 1,
}); };

var handlers = {
  'click-rail': clickRail,
  'drag-thumb': dragThumb,
  keyboard: keyboard,
  wheel: wheel,
  touch: touch,
};

var PerfectScrollbar = function PerfectScrollbar(element, userSettings) {
  var this$1 = this;
  if ( userSettings === void 0 ) userSettings = {};

if (typeof element === 'string') {
    element = document.querySelector(element);
  }

if (!element || !element.nodeName) {
    throw new Error('no element is specified to initialize PerfectScrollbar');
  }

this.element = element;

element.classList.add(cls.main);

this.settings = defaultSettings();
  for (var key in userSettings) {
    this$1.settings[key] = userSettings[key];
  }

this.containerWidth = null;
  this.containerHeight = null;
  this.contentWidth = null;
  this.contentHeight = null;

var focus = function () { return element.classList.add(cls.state.focus); };
  var blur = function () { return element.classList.remove(cls.state.focus); };

this.isRtl = get(element).direction === 'rtl';
  this.isNegativeScroll = (function () {
    var originalScrollLeft = element.scrollLeft;
    var result = null;
    element.scrollLeft = -1;
    result = element.scrollLeft < 0;
    element.scrollLeft = originalScrollLeft;
    return result;
  })();
  this.negativeScrollAdjustment = this.isNegativeScroll
    ? element.scrollWidth - element.clientWidth
    : 0;
  this.event = new EventManager();
  this.ownerDocument = element.ownerDocument || document;

this.scrollbarXRail = div(cls.element.rail('x'));
  element.appendChild(this.scrollbarXRail);
  this.scrollbarX = div(cls.element.thumb('x'));
  this.scrollbarXRail.appendChild(this.scrollbarX);
  this.scrollbarX.setAttribute('tabindex', 0);
  this.event.bind(this.scrollbarX, 'focus', focus);
  this.event.bind(this.scrollbarX, 'blur', blur);
  this.scrollbarXActive = null;
  this.scrollbarXWidth = null;
  this.scrollbarXLeft = null;
  var railXStyle = get(this.scrollbarXRail);
  this.scrollbarXBottom = parseInt(railXStyle.bottom, 10);
  if (isNaN(this.scrollbarXBottom)) {
    this.isScrollbarXUsingBottom = false;
    this.scrollbarXTop = toInt(railXStyle.top);
  } else {
    this.isScrollbarXUsingBottom = true;
  }
  this.railBorderXWidth =
    toInt(railXStyle.borderLeftWidth) + toInt(railXStyle.borderRightWidth);
  // Set rail to display:block to calculate margins
  set(this.scrollbarXRail, { display: 'block' });
  this.railXMarginWidth =
    toInt(railXStyle.marginLeft) + toInt(railXStyle.marginRight);
  set(this.scrollbarXRail, { display: '' });
  this.railXWidth = null;
  this.railXRatio = null;

this.scrollbarYRail = div(cls.element.rail('y'));
  element.appendChild(this.scrollbarYRail);
  this.scrollbarY = div(cls.element.thumb('y'));
  this.scrollbarYRail.appendChild(this.scrollbarY);
  this.scrollbarY.setAttribute('tabindex', 0);
  this.event.bind(this.scrollbarY, 'focus', focus);
  this.event.bind(this.scrollbarY, 'blur', blur);
  this.scrollbarYActive = null;
  this.scrollbarYHeight = null;
  this.scrollbarYTop = null;
  var railYStyle = get(this.scrollbarYRail);
  this.scrollbarYRight = parseInt(railYStyle.right, 10);
  if (isNaN(this.scrollbarYRight)) {
    this.isScrollbarYUsingRight = false;
    this.scrollbarYLeft = toInt(railYStyle.left);
  } else {
    this.isScrollbarYUsingRight = true;
  }
  this.scrollbarYOuterWidth = this.isRtl ? outerWidth(this.scrollbarY) : null;
  this.railBorderYWidth =
    toInt(railYStyle.borderTopWidth) + toInt(railYStyle.borderBottomWidth);
  set(this.scrollbarYRail, { display: 'block' });
  this.railYMarginHeight =
    toInt(railYStyle.marginTop) + toInt(railYStyle.marginBottom);
  set(this.scrollbarYRail, { display: '' });
  this.railYHeight = null;
  this.railYRatio = null;

this.reach = {
    x:
      element.scrollLeft <= 0
        ? 'start'
        : element.scrollLeft >= this.contentWidth - this.containerWidth
          ? 'end'
          : null,
    y:
      element.scrollTop <= 0
        ? 'start'
        : element.scrollTop >= this.contentHeight - this.containerHeight
          ? 'end'
          : null,
  };

this.isAlive = true;

this.settings.handlers.forEach(function (handlerName) { return handlers[handlerName](this$1); });

this.lastScrollTop = Math.floor(element.scrollTop); // for onScroll only
  this.lastScrollLeft = element.scrollLeft; // for onScroll only
  this.event.bind(this.element, 'scroll', function (e) { return this$1.onScroll(e); });
  updateGeometry(this);
};

PerfectScrollbar.prototype.update = function update () {
  if (!this.isAlive) {
    return;
  }

// Recalcuate negative scrollLeft adjustment
  this.negativeScrollAdjustment = this.isNegativeScroll
    ? this.element.scrollWidth - this.element.clientWidth
    : 0;

// Recalculate rail margins
  set(this.scrollbarXRail, { display: 'block' });
  set(this.scrollbarYRail, { display: 'block' });
  this.railXMarginWidth =
    toInt(get(this.scrollbarXRail).marginLeft) +
    toInt(get(this.scrollbarXRail).marginRight);
  this.railYMarginHeight =
    toInt(get(this.scrollbarYRail).marginTop) +
    toInt(get(this.scrollbarYRail).marginBottom);

// Hide scrollbars not to affect scrollWidth and scrollHeight
  set(this.scrollbarXRail, { display: 'none' });
  set(this.scrollbarYRail, { display: 'none' });

updateGeometry(this);

processScrollDiff(this, 'top', 0, false, true);
  processScrollDiff(this, 'left', 0, false, true);

set(this.scrollbarXRail, { display: '' });
  set(this.scrollbarYRail, { display: '' });
};

PerfectScrollbar.prototype.onScroll = function onScroll (e) {
  if (!this.isAlive) {
    return;
  }

updateGeometry(this);
  processScrollDiff(this, 'top', this.element.scrollTop - this.lastScrollTop);
  processScrollDiff(
    this,
    'left',
    this.element.scrollLeft - this.lastScrollLeft
  );

this.lastScrollTop = Math.floor(this.element.scrollTop);
  this.lastScrollLeft = this.element.scrollLeft;
};

PerfectScrollbar.prototype.destroy = function destroy () {
  if (!this.isAlive) {
    return;
  }

this.event.unbindAll();
  remove(this.scrollbarX);
  remove(this.scrollbarY);
  remove(this.scrollbarXRail);
  remove(this.scrollbarYRail);
  this.removePsClasses();

// unset elements
  this.element = null;
  this.scrollbarX = null;
  this.scrollbarY = null;
  this.scrollbarXRail = null;
  this.scrollbarYRail = null;

this.isAlive = false;
};

PerfectScrollbar.prototype.removePsClasses = function removePsClasses () {
  this.element.className = this.element.className
    .split(' ')
    .filter(function (name) { return !name.match(/^ps([-_].+|)$/); })
    .join(' ');
};

return PerfectScrollbar;

})));

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