'use strict';

Object.defineProperty(exports, '__esModule', { value: true });

var React = require('react');
var utils = require('primereact/utils');

function _interopDefaultLegacy (e) { return e && typeof e === 'object' && 'default' in e ? e : { 'default': e }; }

var React__default = /*#__PURE__*/_interopDefaultLegacy(React);

function _classCallCheck(instance, Constructor) {
  if (!(instance instanceof Constructor)) {
    throw new TypeError("Cannot call a class as a function");
  }
}

function _defineProperties(target, props) {
  for (var i = 0; i < props.length; i++) {
    var descriptor = props[i];
    descriptor.enumerable = descriptor.enumerable || false;
    descriptor.configurable = true;
    if ("value" in descriptor) descriptor.writable = true;
    Object.defineProperty(target, descriptor.key, descriptor);
  }
}

function _createClass(Constructor, protoProps, staticProps) {
  if (protoProps) _defineProperties(Constructor.prototype, protoProps);
  if (staticProps) _defineProperties(Constructor, staticProps);
  Object.defineProperty(Constructor, "prototype", {
    writable: false
  });
  return Constructor;
}

function _assertThisInitialized(self) {
  if (self === void 0) {
    throw new ReferenceError("this hasn't been initialised - super() hasn't been called");
  }

  return self;
}

function _setPrototypeOf(o, p) {
  _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) {
    o.__proto__ = p;
    return o;
  };

  return _setPrototypeOf(o, p);
}

function _inherits(subClass, superClass) {
  if (typeof superClass !== "function" && superClass !== null) {
    throw new TypeError("Super expression must either be null or a function");
  }

  subClass.prototype = Object.create(superClass && superClass.prototype, {
    constructor: {
      value: subClass,
      writable: true,
      configurable: true
    }
  });
  Object.defineProperty(subClass, "prototype", {
    writable: false
  });
  if (superClass) _setPrototypeOf(subClass, superClass);
}

function _typeof(obj) {
  "@babel/helpers - typeof";

  return _typeof = "function" == typeof Symbol && "symbol" == typeof Symbol.iterator ? function (obj) {
    return typeof obj;
  } : function (obj) {
    return obj && "function" == typeof Symbol && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj;
  }, _typeof(obj);
}

function _possibleConstructorReturn(self, call) {
  if (call && (_typeof(call) === "object" || typeof call === "function")) {
    return call;
  } else if (call !== void 0) {
    throw new TypeError("Derived constructors may only return object or undefined");
  }

  return _assertThisInitialized(self);
}

function _getPrototypeOf(o) {
  _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) {
    return o.__proto__ || Object.getPrototypeOf(o);
  };
  return _getPrototypeOf(o);
}

function _defineProperty(obj, key, value) {
  if (key in obj) {
    Object.defineProperty(obj, key, {
      value: value,
      enumerable: true,
      configurable: true,
      writable: true
    });
  } else {
    obj[key] = value;
  }

  return obj;
}

function ownKeys(object, enumerableOnly) { var keys = Object.keys(object); if (Object.getOwnPropertySymbols) { var symbols = Object.getOwnPropertySymbols(object); enumerableOnly && (symbols = symbols.filter(function (sym) { return Object.getOwnPropertyDescriptor(object, sym).enumerable; })), keys.push.apply(keys, symbols); } return keys; }

function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { var source = null != arguments[i] ? arguments[i] : {}; i % 2 ? ownKeys(Object(source), !0).forEach(function (key) { _defineProperty(target, key, source[key]); }) : Object.getOwnPropertyDescriptors ? Object.defineProperties(target, Object.getOwnPropertyDescriptors(source)) : ownKeys(Object(source)).forEach(function (key) { Object.defineProperty(target, key, Object.getOwnPropertyDescriptor(source, key)); }); } return target; }

function _createSuper(Derived) { var hasNativeReflectConstruct = _isNativeReflectConstruct(); return function _createSuperInternal() { var Super = _getPrototypeOf(Derived), result; if (hasNativeReflectConstruct) { var NewTarget = _getPrototypeOf(this).constructor; result = Reflect.construct(Super, arguments, NewTarget); } else { result = Super.apply(this, arguments); } return _possibleConstructorReturn(this, result); }; }

function _isNativeReflectConstruct() { if (typeof Reflect === "undefined" || !Reflect.construct) return false; if (Reflect.construct.sham) return false; if (typeof Proxy === "function") return true; try { Boolean.prototype.valueOf.call(Reflect.construct(Boolean, [], function () {})); return true; } catch (e) { return false; } }
var VirtualScroller = /*#__PURE__*/function (_Component) {
  _inherits(VirtualScroller, _Component);

  var _super = _createSuper(VirtualScroller);

  function VirtualScroller(props) {
    var _this;

    _classCallCheck(this, VirtualScroller);

    _this = _super.call(this, props);

    var isBoth = _this.isBoth();

    _this.state = {
      first: isBoth ? {
        rows: 0,
        cols: 0
      } : 0,
      last: isBoth ? {
        rows: 0,
        cols: 0
      } : 0,
      numItemsInViewport: isBoth ? {
        rows: 0,
        cols: 0
      } : 0,
      numToleratedItems: props.numToleratedItems,
      loading: props.loading,
      loaderArr: []
    };
    _this.onScroll = _this.onScroll.bind(_assertThisInitialized(_this));
    _this.lastScrollPos = isBoth ? {
      top: 0,
      left: 0
    } : 0;
    return _this;
  }

  _createClass(VirtualScroller, [{
    key: "scrollTo",
    value: function scrollTo(options) {
      this.el && this.el.scrollTo(options);
    }
  }, {
    key: "scrollToIndex",
    value: function scrollToIndex(index) {
      var _this2 = this;

      var behavior = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 'auto';
      var isBoth = this.isBoth();
      var isHorizontal = this.isHorizontal();
      var first = this.state.first;

      var _this$calculateNumIte = this.calculateNumItems(),
          numToleratedItems = _this$calculateNumIte.numToleratedItems;

      var itemSize = this.props.itemSize;
      var contentPos = this.getContentPosition();

      var calculateFirst = function calculateFirst() {
        var _index = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : 0;

        var _numT = arguments.length > 1 ? arguments[1] : undefined;

        return _index <= _numT ? 0 : _index;
      };

      var calculateCoord = function calculateCoord(_first, _size, _cpos) {
        return _first * _size + _cpos;
      };

      var scrollTo = function scrollTo() {
        var left = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : 0;
        var top = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 0;
        return _this2.scrollTo({
          left: left,
          top: top,
          behavior: behavior
        });
      };

      if (isBoth) {
        var newFirst = {
          rows: calculateFirst(index[0], numToleratedItems[0]),
          cols: calculateFirst(index[1], numToleratedItems[1])
        };

        if (newFirst.rows !== first.rows || newFirst.cols !== first.cols) {
          scrollTo(calculateCoord(newFirst.cols, itemSize[1], contentPos.left), calculateCoord(newFirst.rows, itemSize[0], contentPos.top));
          this.setState({
            first: newFirst
          });
        }
      } else {
        var _newFirst = calculateFirst(index, numToleratedItems);

        if (_newFirst !== first) {
          isHorizontal ? scrollTo(calculateCoord(_newFirst, itemSize, contentPos.left), 0) : scrollTo(0, calculateCoord(_newFirst, itemSize, contentPos.top));
          this.setState({
            first: _newFirst
          });
        }
      }
    }
  }, {
    key: "scrollInView",
    value: function scrollInView(index, to) {
      var _this3 = this;

      var behavior = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : 'auto';

      if (to) {
        var isBoth = this.isBoth();
        var isHorizontal = this.isHorizontal();

        var _this$getRenderedRang = this.getRenderedRange(),
            first = _this$getRenderedRang.first,
            viewport = _this$getRenderedRang.viewport;

        var itemSize = this.props.itemSize;

        var scrollTo = function scrollTo() {
          var left = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : 0;
          var top = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 0;
          return _this3.scrollTo({
            left: left,
            top: top,
            behavior: behavior
          });
        };

        var isToStart = to === 'to-start';
        var isToEnd = to === 'to-end';

        if (isToStart) {
          if (isBoth) {
            if (viewport.first.rows - first.rows > index[0]) {
              scrollTo(viewport.first.cols * itemSize, (viewport.first.rows - 1) * itemSize);
            } else if (viewport.first.cols - first.cols > index[1]) {
              scrollTo((viewport.first.cols - 1) * itemSize, viewport.first.rows * itemSize);
            }
          } else {
            if (viewport.first - first > index) {
              var pos = (viewport.first - 1) * itemSize;
              isHorizontal ? scrollTo(pos, 0) : scrollTo(0, pos);
            }
          }
        } else if (isToEnd) {
          if (isBoth) {
            if (viewport.last.rows - first.rows <= index[0] + 1) {
              scrollTo(viewport.first.cols * itemSize, (viewport.first.rows + 1) * itemSize);
            } else if (viewport.last.cols - first.cols <= index[1] + 1) {
              scrollTo((viewport.first.cols + 1) * itemSize, viewport.first.rows * itemSize);
            }
          } else {
            if (viewport.last - first <= index + 1) {
              var _pos2 = (viewport.first + 1) * itemSize;

              isHorizontal ? scrollTo(_pos2, 0) : scrollTo(0, _pos2);
            }
          }
        }
      } else {
        this.scrollToIndex(index, behavior);
      }
    }
  }, {
    key: "getRows",
    value: function getRows() {
      return this.state.loading ? this.props.loaderDisabled ? this.state.loaderArr : [] : this.loadedItems();
    }
  }, {
    key: "getColumns",
    value: function getColumns() {
      if (this.props.columns) {
        var isBoth = this.isBoth();
        var isHorizontal = this.isHorizontal();

        if (isBoth || isHorizontal) {
          return this.state.loading && this.props.loaderDisabled ? isBoth ? this.state.loaderArr[0] : this.state.loaderArr : this.props.columns.slice(isBoth ? this.state.first.cols : this.state.first, isBoth ? this.state.last.cols : this.state.last);
        }
      }

      return this.props.columns;
    }
  }, {
    key: "getRenderedRange",
    value: function getRenderedRange() {
      var isBoth = this.isBoth();
      var isHorizontal = this.isHorizontal();
      var _this$state = this.state,
          first = _this$state.first,
          last = _this$state.last,
          numItemsInViewport = _this$state.numItemsInViewport;
      var itemSize = this.props.itemSize;

      var calculateFirstInViewport = function calculateFirstInViewport(_pos, _size) {
        return Math.floor(_pos / (_size || _pos));
      };

      var firstInViewport = first;
      var lastInViewport = 0;

      if (this.el) {
        var scrollTop = this.el.scrollTop;
        var scrollLeft = this.el.scrollLeft;

        if (isBoth) {
          firstInViewport = {
            rows: calculateFirstInViewport(scrollTop, itemSize[0]),
            cols: calculateFirstInViewport(scrollLeft, itemSize[1])
          };
          lastInViewport = {
            rows: firstInViewport.rows + numItemsInViewport.rows,
            cols: firstInViewport.cols + numItemsInViewport.cols
          };
        } else {
          var scrollPos = isHorizontal ? scrollLeft : scrollTop;
          firstInViewport = calculateFirstInViewport(scrollPos, itemSize);
          lastInViewport = firstInViewport + numItemsInViewport;
        }
      }

      return {
        first: first,
        last: last,
        viewport: {
          first: firstInViewport,
          last: lastInViewport
        }
      };
    }
  }, {
    key: "isVertical",
    value: function isVertical() {
      return this.props.orientation === 'vertical';
    }
  }, {
    key: "isHorizontal",
    value: function isHorizontal() {
      return this.props.orientation === 'horizontal';
    }
  }, {
    key: "isBoth",
    value: function isBoth() {
      return this.props.orientation === 'both';
    }
  }, {
    key: "calculateNumItems",
    value: function calculateNumItems() {
      var isBoth = this.isBoth();
      var isHorizontal = this.isHorizontal();
      var itemSize = this.props.itemSize;
      var contentPos = this.getContentPosition();
      var contentWidth = this.el ? this.el.offsetWidth - contentPos.left : 0;
      var contentHeight = this.el ? this.el.offsetHeight - contentPos.top : 0;

      var calculateNumItemsInViewport = function calculateNumItemsInViewport(_contentSize, _itemSize) {
        return Math.ceil(_contentSize / (_itemSize || _contentSize));
      };

      var calculateNumToleratedItems = function calculateNumToleratedItems(_numItems) {
        return Math.ceil(_numItems / 2);
      };

      var numItemsInViewport = isBoth ? {
        rows: calculateNumItemsInViewport(contentHeight, itemSize[0]),
        cols: calculateNumItemsInViewport(contentWidth, itemSize[1])
      } : calculateNumItemsInViewport(isHorizontal ? contentWidth : contentHeight, itemSize);
      var numToleratedItems = this.state.numToleratedItems || (isBoth ? [calculateNumToleratedItems(numItemsInViewport.rows), calculateNumToleratedItems(numItemsInViewport.cols)] : calculateNumToleratedItems(numItemsInViewport));
      return {
        numItemsInViewport: numItemsInViewport,
        numToleratedItems: numToleratedItems
      };
    }
  }, {
    key: "calculateOptions",
    value: function calculateOptions() {
      var _this4 = this;

      var isBoth = this.isBoth();
      var first = this.state.first;

      var _this$calculateNumIte2 = this.calculateNumItems(),
          numItemsInViewport = _this$calculateNumIte2.numItemsInViewport,
          numToleratedItems = _this$calculateNumIte2.numToleratedItems;

      var calculateLast = function calculateLast(_first, _num, _numT, _isCols) {
        return _this4.getLast(_first + _num + (_first < _numT ? 2 : 3) * _numT, _isCols);
      };

      var last = isBoth ? {
        rows: calculateLast(first.rows, numItemsInViewport.rows, numToleratedItems[0]),
        cols: calculateLast(first.cols, numItemsInViewport.cols, numToleratedItems[1], true)
      } : calculateLast(first, numItemsInViewport, numToleratedItems);
      var state = {
        numItemsInViewport: numItemsInViewport,
        last: last,
        numToleratedItems: numToleratedItems
      };

      if (this.props.showLoader) {
        state['loaderArr'] = isBoth ? Array.from({
          length: numItemsInViewport.rows
        }).map(function () {
          return Array.from({
            length: numItemsInViewport.cols
          });
        }) : Array.from({
          length: numItemsInViewport
        });
      }

      this.setState(state, function () {
        if (_this4.props.lazy) {
          _this4.props.onLazyLoad && _this4.props.onLazyLoad({
            first: _this4.state.first,
            last: _this4.state.last
          });
        }
      });
    }
  }, {
    key: "getLast",
    value: function getLast() {
      var last = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : 0;
      var isCols = arguments.length > 1 ? arguments[1] : undefined;

      if (this.props.items) {
        return Math.min(isCols ? (this.props.columns || this.props.items[0]).length : this.props.items.length, last);
      }

      return 0;
    }
  }, {
    key: "getContentPosition",
    value: function getContentPosition() {
      if (this.content) {
        var style = getComputedStyle(this.content);
        var left = parseInt(style.paddingLeft, 10) + Math.max(parseInt(style.left, 10), 0);
        var right = parseInt(style.paddingRight, 10) + Math.max(parseInt(style.right, 10), 0);
        var top = parseInt(style.paddingTop, 10) + Math.max(parseInt(style.top, 10), 0);
        var bottom = parseInt(style.paddingBottom, 10) + Math.max(parseInt(style.bottom, 10), 0);
        return {
          left: left,
          right: right,
          top: top,
          bottom: bottom,
          x: left + right,
          y: top + bottom
        };
      }

      return {
        left: 0,
        right: 0,
        top: 0,
        bottom: 0,
        x: 0,
        y: 0
      };
    }
  }, {
    key: "setSize",
    value: function setSize() {
      var _this5 = this;

      if (this.el) {
        var isBoth = this.isBoth();
        var isHorizontal = this.isHorizontal();
        var parentElement = this.el.parentElement;
        var width = this.props.scrollWidth || "".concat(this.el.offsetWidth || parentElement.offsetWidth, "px");
        var height = this.props.scrollHeight || "".concat(this.el.offsetHeight || parentElement.offsetHeight, "px");

        var setProp = function setProp(_name, _value) {
          return _this5.el.style[_name] = _value;
        };

        if (isBoth || isHorizontal) {
          setProp('height', height);
          setProp('width', width);
        } else {
          setProp('height', height);
        }
      }
    }
  }, {
    key: "setSpacerSize",
    value: function setSpacerSize() {
      var _this6 = this;

      var items = this.props.items;

      if (this.spacer && items) {
        var isBoth = this.isBoth();
        var isHorizontal = this.isHorizontal();
        var itemSize = this.props.itemSize;
        var contentPos = this.getContentPosition();

        var setProp = function setProp(_name, _value, _size) {
          var _cpos = arguments.length > 3 && arguments[3] !== undefined ? arguments[3] : 0;

          return _this6.spacer.style[_name] = (_value || []).length * _size + _cpos + 'px';
        };

        if (isBoth) {
          setProp('height', items, itemSize[0], contentPos.y);
          setProp('width', this.props.columns || items[1], itemSize[1], contentPos.x);
        } else {
          isHorizontal ? setProp('width', this.props.columns || items, itemSize, contentPos.x) : setProp('height', items, itemSize, contentPos.y);
        }
      }
    }
  }, {
    key: "setContentPosition",
    value: function setContentPosition(pos) {
      var _this7 = this;

      if (this.content) {
        var isBoth = this.isBoth();
        var isHorizontal = this.isHorizontal();
        var first = pos ? pos.first : this.state.first;
        var itemSize = this.props.itemSize;

        var calculateTranslateVal = function calculateTranslateVal(_first, _size) {
          return _first * _size;
        };

        var setTransform = function setTransform() {
          var _x = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : 0;

          var _y = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 0;

          _this7.sticky && (_this7.sticky.style.top = "-".concat(_y, "px"));
          _this7.content.style.transform = "translate3d(".concat(_x, "px, ").concat(_y, "px, 0)");
        };

        if (isBoth) {
          setTransform(calculateTranslateVal(first.cols, itemSize[1]), calculateTranslateVal(first.rows, itemSize[0]));
        } else {
          var translateVal = calculateTranslateVal(first, itemSize);
          isHorizontal ? setTransform(translateVal, 0) : setTransform(0, translateVal);
        }
      }
    }
  }, {
    key: "onScrollPositionChange",
    value: function onScrollPositionChange(event) {
      var _this8 = this;

      var target = event.target;
      var isBoth = this.isBoth();
      var isHorizontal = this.isHorizontal();
      var _this$state2 = this.state,
          first = _this$state2.first,
          last = _this$state2.last,
          numItemsInViewport = _this$state2.numItemsInViewport,
          numToleratedItems = _this$state2.numToleratedItems;
      var itemSize = this.props.itemSize;
      var contentPos = this.getContentPosition();

      var calculateScrollPos = function calculateScrollPos(_pos, _cpos) {
        return _pos ? _pos > _cpos ? _pos - _cpos : _pos : 0;
      };

      var calculateCurrentIndex = function calculateCurrentIndex(_pos, _size) {
        return Math.floor(_pos / (_size || _pos));
      };

      var calculateTriggerIndex = function calculateTriggerIndex(_currentIndex, _first, _last, _num, _numT, _isScrollDownOrRight) {
        return _currentIndex <= _numT ? _numT : _isScrollDownOrRight ? _last - _num - _numT : _first + _numT - 1;
      };

      var calculateFirst = function calculateFirst(_currentIndex, _triggerIndex, _first, _last, _num, _numT, _isScrollDownOrRight) {
        if (_currentIndex <= _numT) return 0;else return Math.max(0, _isScrollDownOrRight ? _currentIndex < _triggerIndex ? _first : _currentIndex - _numT : _currentIndex > _triggerIndex ? _first : _currentIndex - 2 * _numT);
      };

      var calculateLast = function calculateLast(_currentIndex, _first, _last, _num, _numT, _isCols) {
        var lastValue = _first + _num + 2 * _numT;

        if (_currentIndex >= _numT) {
          lastValue += _numT + 1;
        }

        return _this8.getLast(lastValue, _isCols);
      };

      var scrollTop = calculateScrollPos(target.scrollTop, contentPos.top);
      var scrollLeft = calculateScrollPos(target.scrollLeft, contentPos.left);
      var newFirst = 0;
      var newLast = last;
      var isRangeChanged = false;

      if (isBoth) {
        var isScrollDown = this.lastScrollPos.top <= scrollTop;
        var isScrollRight = this.lastScrollPos.left <= scrollLeft;
        var currentIndex = {
          rows: calculateCurrentIndex(scrollTop, itemSize[0]),
          cols: calculateCurrentIndex(scrollLeft, itemSize[1])
        };
        var triggerIndex = {
          rows: calculateTriggerIndex(currentIndex.rows, first.rows, last.rows, numItemsInViewport.rows, numToleratedItems[0], isScrollDown),
          cols: calculateTriggerIndex(currentIndex.cols, first.cols, last.cols, numItemsInViewport.cols, numToleratedItems[1], isScrollRight)
        };
        newFirst = {
          rows: calculateFirst(currentIndex.rows, triggerIndex.rows, first.rows, last.rows, numItemsInViewport.rows, numToleratedItems[0], isScrollDown),
          cols: calculateFirst(currentIndex.cols, triggerIndex.cols, first.cols, last.cols, numItemsInViewport.cols, numToleratedItems[1], isScrollRight)
        };
        newLast = {
          rows: calculateLast(currentIndex.rows, newFirst.rows, last.rows, numItemsInViewport.rows, numToleratedItems[0]),
          cols: calculateLast(currentIndex.cols, newFirst.cols, last.cols, numItemsInViewport.cols, numToleratedItems[1], true)
        };
        isRangeChanged = newFirst.rows !== first.rows && newLast.rows !== last.rows || newFirst.cols !== first.cols && newLast.cols !== last.cols;
        this.lastScrollPos = {
          top: scrollTop,
          left: scrollLeft
        };
      } else {
        var scrollPos = isHorizontal ? scrollLeft : scrollTop;
        var isScrollDownOrRight = this.lastScrollPos <= scrollPos;

        var _currentIndex2 = calculateCurrentIndex(scrollPos, itemSize);

        var _triggerIndex2 = calculateTriggerIndex(_currentIndex2, first, last, numItemsInViewport, numToleratedItems, isScrollDownOrRight);

        newFirst = calculateFirst(_currentIndex2, _triggerIndex2, first, last, numItemsInViewport, numToleratedItems, isScrollDownOrRight);
        newLast = calculateLast(_currentIndex2, newFirst, last, numItemsInViewport, numToleratedItems);
        isRangeChanged = newFirst !== first && newLast !== last;
        this.lastScrollPos = scrollPos;
      }

      return {
        first: newFirst,
        last: newLast,
        isRangeChanged: isRangeChanged
      };
    }
  }, {
    key: "onScrollChange",
    value: function onScrollChange(event) {
      var _this9 = this;

      var _this$onScrollPositio = this.onScrollPositionChange(event),
          first = _this$onScrollPositio.first,
          last = _this$onScrollPositio.last,
          isRangeChanged = _this$onScrollPositio.isRangeChanged;

      if (isRangeChanged) {
        var newState = {
          first: first,
          last: last
        };
        this.setContentPosition(newState);
        this.setState(newState, function () {
          _this9.props.onScrollIndexChange && _this9.props.onScrollIndexChange(newState);

          if (_this9.props.lazy) {
            _this9.props.onLazyLoad && _this9.props.onLazyLoad(newState);
          }
        });
      }
    }
  }, {
    key: "onScroll",
    value: function onScroll(event) {
      var _this10 = this;

      this.props.onScroll && this.props.onScroll(event);

      if (this.props.delay) {
        if (this.scrollTimeout) {
          clearTimeout(this.scrollTimeout);
        }

        if (!this.state.loading && this.props.showLoader) {
          var _this$onScrollPositio2 = this.onScrollPositionChange(event),
              changed = _this$onScrollPositio2.isRangeChanged;

          changed && this.setState({
            loading: true
          });
        }

        this.scrollTimeout = setTimeout(function () {
          _this10.onScrollChange(event);

          if (_this10.state.loading && _this10.props.showLoader && !_this10.props.lazy) {
            _this10.setState({
              loading: false
            });
          }
        }, this.props.delay);
      } else {
        this.onScrollChange(event);
      }
    }
  }, {
    key: "getOptions",
    value: function getOptions(renderedIndex) {
      var first = this.state.first;
      var count = (this.props.items || []).length;
      var index = this.isBoth() ? first.rows + renderedIndex : first + renderedIndex;
      return {
        index: index,
        count: count,
        first: index === 0,
        last: index === count - 1,
        even: index % 2 === 0,
        odd: index % 2 !== 0,
        props: this.props
      };
    }
  }, {
    key: "loaderOptions",
    value: function loaderOptions(index, extOptions) {
      var count = this.state.loaderArr.length;
      return _objectSpread({
        index: index,
        count: count,
        first: index === 0,
        last: index === count - 1,
        even: index % 2 === 0,
        odd: index % 2 !== 0,
        props: this.props
      }, extOptions);
    }
  }, {
    key: "loadedItems",
    value: function loadedItems() {
      var _this11 = this;

      var items = this.props.items;

      if (items && !this.state.loading) {
        var isBoth = this.isBoth();
        var isHorizontal = this.isHorizontal();
        var _this$state3 = this.state,
            first = _this$state3.first,
            last = _this$state3.last;
        if (isBoth) return items.slice(first.rows, last.rows).map(function (item) {
          return _this11.props.columns ? item : item.slice(first.cols, last.cols);
        });else if (isHorizontal && this.props.columns) return items;else return items.slice(first, last);
      }

      return [];
    }
  }, {
    key: "isPropChanged",
    value: function isPropChanged(prevProps) {
      var _this12 = this;

      var props = ['itemSize', 'scrollHeight'];
      return props.some(function (p) {
        return !utils.ObjectUtils.equals(prevProps[p], _this12.props[p]);
      });
    }
  }, {
    key: "init",
    value: function init() {
      this.setSize();
      this.calculateOptions();
      this.setSpacerSize();
    }
  }, {
    key: "componentDidMount",
    value: function componentDidMount() {
      this.init();
    }
  }, {
    key: "componentDidUpdate",
    value: function componentDidUpdate(prevProps, prevState) {
      if (!prevProps.items || prevProps.items.length !== (this.props.items || []).length || this.isPropChanged(prevProps)) {
        this.init();
      }

      if (this.props.lazy && prevProps.loading !== this.props.loading && this.state.loading !== this.props.loading) {
        this.setState({
          loading: this.props.loading
        });
      }

      if (prevProps.orientation !== this.props.orientation) {
        this.lastScrollPos = this.isBoth() ? {
          top: 0,
          left: 0
        } : 0;
      }
    }
  }, {
    key: "renderLoaderItem",
    value: function renderLoaderItem(index) {
      var extOptions = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {};
      var options = this.loaderOptions(index, extOptions);
      var content = utils.ObjectUtils.getJSXElement(this.props.loadingTemplate, options);
      return /*#__PURE__*/React__default["default"].createElement(React__default["default"].Fragment, {
        key: index
      }, content);
    }
  }, {
    key: "renderLoader",
    value: function renderLoader() {
      var _this13 = this;

      if (!this.props.loaderDisabled && this.props.showLoader && this.state.loading) {
        var className = utils.classNames('p-virtualscroller-loader', {
          'p-component-overlay': !this.props.loadingTemplate
        });
        var content = /*#__PURE__*/React__default["default"].createElement("i", {
          className: "p-virtualscroller-loading-icon pi pi-spinner pi-spin"
        });

        if (this.props.loadingTemplate) {
          var isBoth = this.isBoth();
          var numItemsInViewport = this.state.numItemsInViewport;
          content = this.state.loaderArr.map(function (_, index) {
            return _this13.renderLoaderItem(index, isBoth && {
              numCols: numItemsInViewport.cols
            });
          });
        }

        return /*#__PURE__*/React__default["default"].createElement("div", {
          className: className
        }, content);
      }

      return null;
    }
  }, {
    key: "renderSpacer",
    value: function renderSpacer() {
      var _this14 = this;

      if (this.props.showSpacer) {
        return /*#__PURE__*/React__default["default"].createElement("div", {
          ref: function ref(el) {
            return _this14.spacer = el;
          },
          className: "p-virtualscroller-spacer"
        });
      }

      return null;
    }
  }, {
    key: "renderItem",
    value: function renderItem(item, index) {
      var options = this.getOptions(index);
      var content = utils.ObjectUtils.getJSXElement(this.props.itemTemplate, item, options);
      return /*#__PURE__*/React__default["default"].createElement(React__default["default"].Fragment, {
        key: options.index
      }, content);
    }
  }, {
    key: "renderItems",
    value: function renderItems(loadedItems) {
      var _this15 = this;

      return loadedItems.map(function (item, index) {
        return _this15.renderItem(item, index);
      });
    }
  }, {
    key: "renderContent",
    value: function renderContent() {
      var _this16 = this;

      var loadedItems = this.loadedItems();
      var items = this.renderItems(loadedItems);
      var className = utils.classNames('p-virtualscroller-content', {
        'p-virtualscroller-loading': this.state.loading
      });
      var content = /*#__PURE__*/React__default["default"].createElement("div", {
        className: className,
        ref: function ref(el) {
          return _this16.content = el;
        }
      }, items);

      if (this.props.contentTemplate) {
        var defaultOptions = {
          className: className,
          contentRef: function contentRef(el) {
            return _this16.content = el;
          },
          spacerRef: function spacerRef(el) {
            return _this16.spacer = el;
          },
          stickyRef: function stickyRef(el) {
            return _this16.sticky = el;
          },
          items: loadedItems,
          getItemOptions: function getItemOptions(index) {
            return _this16.getOptions(index);
          },
          children: items,
          element: content,
          props: this.props,
          loading: this.state.loading,
          getLoaderOptions: function getLoaderOptions(index, ext) {
            return _this16.loaderOptions(index, ext);
          },
          loadingTemplate: this.props.loadingTemplate,
          itemSize: this.props.itemSize,
          rows: this.getRows(),
          columns: this.getColumns(),
          vertical: this.isVertical(),
          horizontal: this.isHorizontal(),
          both: this.isBoth()
        };
        return utils.ObjectUtils.getJSXElement(this.props.contentTemplate, defaultOptions);
      }

      return content;
    }
  }, {
    key: "render",
    value: function render() {
      var _this17 = this;

      if (this.props.disabled) {
        var content = utils.ObjectUtils.getJSXElement(this.props.contentTemplate, {
          items: this.props.items,
          rows: this.props.items,
          columns: this.props.columns
        });
        return /*#__PURE__*/React__default["default"].createElement(React__default["default"].Fragment, null, this.props.children, content);
      } else {
        var isBoth = this.isBoth();
        var isHorizontal = this.isHorizontal();
        var className = utils.classNames('p-virtualscroller', {
          'p-both-scroll': isBoth,
          'p-horizontal-scroll': isHorizontal
        }, this.props.className);
        var loader = this.renderLoader();

        var _content = this.renderContent();

        var spacer = this.renderSpacer();
        return /*#__PURE__*/React__default["default"].createElement("div", {
          ref: function ref(el) {
            return _this17.el = el;
          },
          className: className,
          tabIndex: 0,
          style: this.props.style,
          onScroll: this.onScroll
        }, _content, spacer, loader);
      }
    }
  }]);

  return VirtualScroller;
}(React.Component);

_defineProperty(VirtualScroller, "defaultProps", {
  id: null,
  style: null,
  className: null,
  items: null,
  itemSize: 0,
  scrollHeight: null,
  scrollWidth: null,
  orientation: 'vertical',
  numToleratedItems: null,
  delay: 0,
  lazy: false,
  disabled: false,
  loaderDisabled: false,
  columns: null,
  loading: false,
  showSpacer: true,
  showLoader: false,
  loadingTemplate: null,
  itemTemplate: null,
  contentTemplate: null,
  onScroll: null,
  onScrollIndexChange: null,
  onLazyLoad: null
});

exports.VirtualScroller = VirtualScroller;