react-slick/src/dots.js

"use strict";

import React from "react";
import classnames from "classnames";
import { clamp } from "./utils/innerSliderUtils";

const getDotCount = spec => {
  let dots;

  if (spec.infinite) {
    dots = Math.ceil(spec.slideCount / spec.slidesToScroll);
  } else {
    dots =
      Math.ceil((spec.slideCount - spec.slidesToShow) / spec.slidesToScroll) +
      1;
  }

  return dots;
};

export class Dots extends React.PureComponent {
  clickHandler(options, e) {
    // In Autoplay the focus stays on clicked button even after transition
    // to next slide. That only goes away by click somewhere outside
    e.preventDefault();
    this.props.clickHandler(options);
  }
  render() {
    const {
      onMouseEnter,
      onMouseOver,
      onMouseLeave,
      infinite,
      slidesToScroll,
      slidesToShow,
      slideCount,
      currentSlide
    } = this.props;
    let dotCount = getDotCount({
      slideCount,
      slidesToScroll,
      slidesToShow,
      infinite
    });

    const mouseEvents = { onMouseEnter, onMouseOver, onMouseLeave };
    let dots = [];
    for (let i = 0; i < dotCount; i++) {
      let _rightBound = (i + 1) * slidesToScroll - 1;
      let rightBound = infinite
        ? _rightBound
        : clamp(_rightBound, 0, slideCount - 1);
      let _leftBound = rightBound - (slidesToScroll - 1);
      let leftBound = infinite
        ? _leftBound
        : clamp(_leftBound, 0, slideCount - 1);

      let className = classnames({
        "slick-active": infinite
          ? currentSlide >= leftBound && currentSlide <= rightBound
          : currentSlide === leftBound
      });

      let dotOptions = {
        message: "dots",
        index: i,
        slidesToScroll,
        currentSlide
      };

      let onClick = this.clickHandler.bind(this, dotOptions);
      dots = dots.concat(
        <li key={i} className={className}>
          {React.cloneElement(this.props.customPaging(i), { onClick })}
        </li>
      );
    }

    return React.cloneElement(this.props.appendDots(dots), {
      className: this.props.dotsClass,
      ...mouseEvents
    });
  }
}