react-magic-slider-dots/dist/index.js

React Magic Slider Dots Component for React Slick Carousel. Inspired by Instagram.

'use strict';

function _interopDefault (ex) { return (ex && (typeof ex === 'object') && 'default' in ex) ? ex['default'] : ex; }

var React = require('react');
var React__default = _interopDefault(React);
var PropTypes = _interopDefault(require('prop-types'));

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

var createClass = 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);
    }
  }

  return function (Constructor, protoProps, staticProps) {
    if (protoProps) defineProperties(Constructor.prototype, protoProps);
    if (staticProps) defineProperties(Constructor, staticProps);
    return Constructor;
  };
}();

var inherits = function (subClass, superClass) {
  if (typeof superClass !== "function" && superClass !== null) {
    throw new TypeError("Super expression must either be null or a function, not " + typeof superClass);
  }

  subClass.prototype = Object.create(superClass && superClass.prototype, {
    constructor: {
      value: subClass,
      enumerable: false,
      writable: true,
      configurable: true
    }
  });
  if (superClass) Object.setPrototypeOf ? Object.setPrototypeOf(subClass, superClass) : subClass.__proto__ = superClass;
};

var possibleConstructorReturn = function (self, call) {
  if (!self) {
    throw new ReferenceError("this hasn't been initialised - super() hasn't been called");
  }

  return call && (typeof call === "object" || typeof call === "function") ? call : self;
};

var toConsumableArray = function (arr) {
  if (Array.isArray(arr)) {
    for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) arr2[i] = arr[i];

    return arr2;
  } else {
    return Array.from(arr);
  }
};

var MagicSliderDots = function (_Component) {
  inherits(MagicSliderDots, _Component);

  function MagicSliderDots(props) {
    classCallCheck(this, MagicSliderDots);

    // init
    var _this = possibleConstructorReturn(this, (MagicSliderDots.__proto__ || Object.getPrototypeOf(MagicSliderDots)).call(this, props));

    _this.previousActiveIndex = 0;
    _this.hasAnimated = false;
    _this.minIndex = 0;
    _this.maxIndex = 0;
    _this.breakPointActiveIndex = 0;
    _this.addActiveClassToLastDot = false;
    return _this;
  }

  //handle react-slick breakpoints


  createClass(MagicSliderDots, [{
    key: 'componentDidUpdate',
    value: function componentDidUpdate(prevProps) {
      var prevDots = prevProps.dots;
      var _props = this.props,
          currentDots = _props.dots,
          activeDotClassName = _props.activeDotClassName,
          numDotsToShow = _props.numDotsToShow;

      //moving from more dots to less dots

      if (prevDots && currentDots && prevDots.length > currentDots.length) {
        //edge case - last dot was active
        if (prevDots[prevDots.length - 1].props.className === activeDotClassName) {
          this.breakPointActiveIndex = currentDots.length - 1;
          this.previousActiveIndex = this.breakPointActiveIndex - 1;
          this.addActiveClassToLastDot = true;
        }

        //edge case - last active index is at end of current dots or exceeds current dot length
        var lastActiveDot = prevDots.find(function (dot) {
          return dot.props.className === activeDotClassName;
        });
        var lastActiveIndex = parseInt(lastActiveDot.key);

        if (lastActiveIndex > currentDots.length - 1) {
          this.breakPointActiveIndex = currentDots.length - 1;
          this.previousActiveIndex = this.breakPointActiveIndex - 1;
          this.addActiveClassToLastDot = true;
        }

        //adjust minIndex and maxIndex if necessary
        if (this.minIndex < 0) {
          this.minIndex = 0;
          this.maxIndex = numDotsToShow - 1;
        }

        if (this.maxIndex > currentDots.length - 1) {
          this.maxIndex = currentDots.length - 1;
          this.minIndex = this.maxIndex - numDotsToShow + 1;
        }

        this.forceUpdate();
      } else if (prevDots && currentDots && prevDots.length < currentDots.length) {
        //edge case - adjust minIndex and maxIndex if active dot will be out of the View determined by min/max index
        var currentActiveDot = currentDots.find(function (dot) {
          return dot.props.className === activeDotClassName;
        });
        var currentActiveIndex = parseInt(currentActiveDot.key);

        if (currentActiveIndex >= this.maxIndex) {
          this.maxIndex = currentActiveIndex + 1;
          this.minIndex = this.maxIndex - numDotsToShow + 1;
        }

        //adjust minIndex and maxIndex if necessary
        if (this.maxIndex > currentDots.length - 1) {
          this.maxIndex = currentDots.length - 1;
          this.minIndex = this.maxIndex - numDotsToShow + 1;
        }

        this.forceUpdate();
      }
    }
  }, {
    key: 'render',
    value: function render() {
      var _props2 = this.props,
          dots = _props2.dots,
          numDotsToShow = _props2.numDotsToShow,
          dotWidth = _props2.dotWidth,
          dotContainerClassName = _props2.dotContainerClassName,
          activeDotClassName = _props2.activeDotClassName,
          prevNextDotClassName = _props2.prevNextDotClassName;


      var active = dots.find(function (dot) {
        return dot.props.className === activeDotClassName;
      });
      var adjustedDots = [].concat(toConsumableArray(dots));
      //if no current activeIndex, then due to react-slick breakpoint - use generated breakPointActiveIndex
      var activeIndex = active ? parseInt(active.key) : this.breakPointActiveIndex;
      //consider '>=' as moving forward to support react-slick breakpoint use case
      var isMovingForward = activeIndex >= this.previousActiveIndex;

      // need to subtract 2 from numDotsToShow since array index are zero-based
      if (activeIndex > numDotsToShow - 2 && adjustedDots.length > numDotsToShow || this.hasAnimated) {
        if (isMovingForward) {
          if (activeIndex === this.maxIndex && activeIndex !== dots.length - 1) {
            // list will move left
            this.minIndex = activeIndex - (numDotsToShow - 2);
            this.maxIndex = activeIndex + 1;
          } else {
            // special case - handle if initialSlide from react-slick has a value greater than 0
            if (this.minIndex === 0 && this.maxIndex === 0) {
              if (activeIndex === dots.length - 1) {
                this.maxIndex = activeIndex;
                this.minIndex = this.maxIndex - (numDotsToShow - 1);
              } else {
                this.minIndex = activeIndex - 1 < 0 ? 0 : activeIndex - 1;
                this.maxIndex = this.minIndex + (numDotsToShow - 1) > dots.length - 1 ? dots.length - 1 : this.minIndex + (numDotsToShow - 1);
              }
            } else {
              if (activeIndex === dots.length - 1) {
                // moving carousel backward from 0 to max index
                this.maxIndex = dots.length - 1;
                this.minIndex = dots.length - numDotsToShow;
              }
            }
          }
        } else {
          // movingBackwards
          if (activeIndex === this.minIndex && activeIndex !== 0) {
            // list will move right
            this.minIndex = activeIndex - 1;
            this.maxIndex = this.minIndex + (numDotsToShow - 1);
          } else {
            if (activeIndex === 0) {
              // moving carousel forward from max index to 0
              this.maxIndex = numDotsToShow - 1;
              this.minIndex = 0;
            }
          }
        }

        this.hasAnimated = true;
        var firstViewableDotIndex = this.minIndex;
        var firstViewableDot = adjustedDots[firstViewableDotIndex];
        var lastViewableDotIndex = this.maxIndex;
        var lastViewableDot = adjustedDots[lastViewableDotIndex];

        //outside of bounds check - can be caused when using react-slick breakpoints
        //return null and dots will correctly re-render once componentDidUpdate lifecycle recalculates indexes
        if (!firstViewableDot || !lastViewableDot) {
          console.log('rendering null - outside of bounds', firstViewableDot, lastViewableDot);
          return null;
        }

        if (lastViewableDotIndex < adjustedDots.length - 1 && isMovingForward) {
          // moving foward - but not on the last dot
          adjustedDots = [].concat(toConsumableArray(adjustedDots.slice(0, firstViewableDotIndex)), [React__default.cloneElement(firstViewableDot, {
            className: prevNextDotClassName
          })], toConsumableArray(adjustedDots.slice(firstViewableDotIndex + 1, lastViewableDotIndex)), [React__default.cloneElement(lastViewableDot, {
            className: prevNextDotClassName
          })], toConsumableArray(adjustedDots.slice(lastViewableDotIndex + 1)));
        } else if (lastViewableDotIndex === adjustedDots.length - 1) {
          // moving foward or backward - last dot visible - should appear not small
          adjustedDots = [].concat(toConsumableArray(adjustedDots.slice(0, firstViewableDotIndex)), [React__default.cloneElement(firstViewableDot, {
            className: prevNextDotClassName
          })], toConsumableArray(adjustedDots.slice(firstViewableDotIndex + 1, lastViewableDotIndex)), [this.addActiveClassToLastDot || activeIndex === lastViewableDotIndex ? React__default.cloneElement(lastViewableDot, {
            className: this.props.activeDotClassName
          }) : lastViewableDot]);
        } else if (activeIndex > 1 && !isMovingForward) {
          // moving backwards the left
          adjustedDots = [].concat(toConsumableArray(adjustedDots.slice(0, firstViewableDotIndex)), [React__default.cloneElement(firstViewableDot, {
            className: prevNextDotClassName
          })], toConsumableArray(adjustedDots.slice(firstViewableDotIndex + 1, lastViewableDotIndex)), [React__default.cloneElement(lastViewableDot, {
            className: prevNextDotClassName
          })], toConsumableArray(adjustedDots.slice(lastViewableDotIndex + 1)));
        } else {
          this.hasAnimated = false;
          // moving backwards on first dot - should appear not small
          // eq: (activeIndex === 1 || activeIndex === 0) && !isMovingForward
          adjustedDots = [].concat(toConsumableArray(adjustedDots.slice(0, lastViewableDotIndex)), [React__default.cloneElement(lastViewableDot, {
            className: prevNextDotClassName
          })], toConsumableArray(adjustedDots.slice(lastViewableDotIndex + 1)));
        }
      }
      // no leftOffset in place, just render the dots
      else {
          var _lastViewableDotIndex = Math.min(numDotsToShow, dots.length) - 1;
          this.minIndex = 0;
          this.maxIndex = _lastViewableDotIndex;

          if (_lastViewableDotIndex < adjustedDots.length - 1) {
            var _lastViewableDot = adjustedDots[_lastViewableDotIndex];

            adjustedDots = [].concat(toConsumableArray(adjustedDots.slice(0, _lastViewableDotIndex)), [React__default.cloneElement(_lastViewableDot, {
              className: prevNextDotClassName
            })], toConsumableArray(adjustedDots.slice(_lastViewableDotIndex + 1)));
          }
        }

      // track active index
      this.previousActiveIndex = activeIndex;
      this.addActiveClassToLastDot = false;
      // calculate container width
      var containerWidth = dots.length < numDotsToShow ? dots.length * dotWidth : numDotsToShow * dotWidth;

      var midIndex = (this.minIndex + this.maxIndex) / 2;

      // only give leftOffset if number of dots exceeds number of dots to show at one time
      var leftOffset = dots.length < numDotsToShow ? 0 : (dotWidth * numDotsToShow - dotWidth) / 2 - midIndex * dotWidth;

      return React__default.createElement(
        'div',
        {
          className: dotContainerClassName,
          style: {
            position: 'relative',
            overflow: 'hidden',
            margin: 'auto',
            width: containerWidth + 'px'
          }
        },
        React__default.createElement(
          'ul',
          { style: { transform: 'translateX(' + leftOffset + 'px)' } },
          ' ',
          adjustedDots,
          ' '
        )
      );
    }
  }]);
  return MagicSliderDots;
}(React.Component);


MagicSliderDots.propTypes = {
  /** array of HTML li elements representing the slider dot.   */
  dots: PropTypes.array.isRequired,
  /** number of slider dots to show. */
  numDotsToShow: PropTypes.number.isRequired,
  /** width, in pixels, of a slider dot including any margins/padding. */
  dotWidth: PropTypes.number.isRequired,
  /** class name of parent div. */
  dotContainerClassName: PropTypes.string,
  /** class name of active slider dot. */
  activeDotClassName: PropTypes.string,
  /** class name of left-most (prev) and right-most (next) slider dot. */
  prevNextDotClassName: PropTypes.string
};

MagicSliderDots.defaultProps = {
  dotContainerClassName: 'magic-dots slick-dots',
  activeDotClassName: 'slick-active',
  prevNextDotClassName: 'small'
};

module.exports = MagicSliderDots;
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