react-native-easy-slider/MultiSlider.js

import React from "react";
import PropTypes from "prop-types";

import {
  StyleSheet,
  PanResponder,
  View,
  TouchableHighlight,
  Platform,
  I18nManager
} from "react-native";

import DefaultMarker from "./DefaultMarker";
import { createArray, valueToPosition, positionToValue } from "./converters";

const ViewPropTypes = require("react-native").ViewPropTypes || View.propTypes;

export default class MultiSlider extends React.Component {
  static defaultProps = {
    values: [0],
    onValuesChangeStart: () => {},
    onValuesChange: values => {},
    onValuesChangeFinish: values => {},
    step: 1,
    min: 0,
    max: 10,
    touchDimensions: {
      borderRadius: 15,
      slipDisplacement: 200
    },
    customMarker: DefaultMarker,
    customMarkerLeft: DefaultMarker,
    customMarkerRight: DefaultMarker,
    markerOffsetX: 0,
    markerOffsetY: 0,
    sliderLength: 280,
    onToggleOne: undefined,
    onToggleTwo: undefined,
    enabledOne: true,
    enabledTwo: true,
    allowOverlap: false,
    snapped: false,
    vertical: false,
    minMarkerOverlapDistance: 0
  };

  constructor(props) {
    super(props);

    this.optionsArray =
      this.props.optionsArray ||
      createArray(this.props.min, this.props.max, this.props.step);
    this.stepLength = this.props.sliderLength / this.optionsArray.length;

    var initialValues = this.props.values.map(value =>
      valueToPosition(value, this.optionsArray, this.props.sliderLength)
    );

    this.state = {
      pressedOne: true,
      valueOne: this.props.values[0],
      valueTwo: this.props.values[1],
      pastOne: initialValues[0],
      pastTwo: initialValues[1],
      positionOne: initialValues[0],
      positionTwo: initialValues[1]
    };
  }

  componentWillMount() {
    var customPanResponder = (start, move, end) => {
      return PanResponder.create({
        onStartShouldSetPanResponder: (evt, gestureState) => true,
        onStartShouldSetPanResponderCapture: (evt, gestureState) => true,
        onMoveShouldSetPanResponder: (evt, gestureState) => true,
        onMoveShouldSetPanResponderCapture: (evt, gestureState) => true,
        onPanResponderGrant: (evt, gestureState) => start(),
        onPanResponderMove: (evt, gestureState) => move(gestureState),
        onPanResponderTerminationRequest: (evt, gestureState) => false,
        onPanResponderRelease: (evt, gestureState) => end(gestureState),
        onPanResponderTerminate: (evt, gestureState) => end(gestureState),
        onShouldBlockNativeResponder: (evt, gestureState) => true
      });
    };

    this._panResponderOne = customPanResponder(
      this.startOne,
      this.moveOne,
      this.endOne
    );
    this._panResponderTwo = customPanResponder(
      this.startTwo,
      this.moveTwo,
      this.endTwo
    );
  }

  componentWillReceiveProps(nextProps) {
    if (this.state.onePressed || this.state.twoPressed) {
      return;
    }

    let nextState = {};
    if (
      nextProps.min !== this.props.min ||
      nextProps.max !== this.props.max ||
      nextProps.step !== this.props.step ||
      nextProps.values[0] !== this.state.valueOne ||
      nextProps.sliderLength !== this.props.sliderLength ||
      nextProps.values[1] !== this.state.valueTwo ||
      (nextProps.sliderLength !== this.props.sliderLength &&
        nextProps.values[1])
    ) {
      this.optionsArray =
        this.props.optionsArray ||
        createArray(nextProps.min, nextProps.max, nextProps.step);

      this.stepLength = this.props.sliderLength / this.optionsArray.length;

      var positionOne = valueToPosition(
        nextProps.values[0],
        this.optionsArray,
        nextProps.sliderLength
      );
      nextState.valueOne = nextProps.values[0];
      nextState.pastOne = positionOne;
      nextState.positionOne = positionOne;

      var positionTwo = valueToPosition(
        nextProps.values[1],
        this.optionsArray,
        nextProps.sliderLength
      );
      nextState.valueTwo = nextProps.values[1];
      nextState.pastTwo = positionTwo;
      nextState.positionTwo = positionTwo;
    }

    if (nextState != {}) {
      this.setState(nextState);
    }
  }

  startOne = () => {
    if (this.props.enabledOne) {
      this.props.onValuesChangeStart();
      this.setState({
        onePressed: !this.state.onePressed
      });
    }
  };

  startTwo = () => {
    if (this.props.enabledTwo) {
      this.props.onValuesChangeStart();
      this.setState({
        twoPressed: !this.state.twoPressed
      });
    }
  };

  moveOne = gestureState => {
    if (!this.props.enabledOne) {
      return;
    }

    const accumDistance = this.props.vertical
      ? -gestureState.dy
      : gestureState.dx;
    const accumDistanceDisplacement = this.props.vertical
      ? gestureState.dx
      : gestureState.dy;

    const unconfined = I18nManager.isRTL
      ? this.state.pastOne - accumDistance
      : accumDistance + this.state.pastOne;
    var bottom = 0;
    var trueTop =
      this.state.positionTwo -
      (this.props.allowOverlap
        ? 0
        : this.props.minMarkerOverlapDistance > 0
        ? this.props.minMarkerOverlapDistance
        : this.stepLength);
    var top = trueTop === 0 ? 0 : trueTop || this.props.sliderLength;
    var confined =
      unconfined < bottom ? bottom : unconfined > top ? top : unconfined;
    var slipDisplacement = this.props.touchDimensions.slipDisplacement;

    if (
      Math.abs(accumDistanceDisplacement) < slipDisplacement ||
      !slipDisplacement
    ) {
      var value = positionToValue(
        confined,
        this.optionsArray,
        this.props.sliderLength
      );
      var snapped = valueToPosition(
        value,
        this.optionsArray,
        this.props.sliderLength
      );
      this.setState({
        positionOne: this.props.snapped ? snapped : confined
      });

      if (value !== this.state.valueOne) {
        this.setState(
          {
            valueOne: value
          },
          () => {
            var change = [this.state.valueOne];
            if (this.state.valueTwo) {
              change.push(this.state.valueTwo);
            }
            this.props.onValuesChange(change);
          }
        );
      }
    }
  };

  moveTwo = gestureState => {
    if (!this.props.enabledTwo) {
      return;
    }

    const accumDistance = this.props.vertical
      ? -gestureState.dy
      : gestureState.dx;
    const accumDistanceDisplacement = this.props.vertical
      ? gestureState.dx
      : gestureState.dy;

    const unconfined = I18nManager.isRTL
      ? this.state.pastTwo - accumDistance
      : accumDistance + this.state.pastTwo;
    var bottom =
      this.state.positionOne +
      (this.props.allowOverlap
        ? 0
        : this.props.minMarkerOverlapDistance > 0
        ? this.props.minMarkerOverlapDistance
        : this.stepLength);
    var top = this.props.sliderLength;
    var confined =
      unconfined < bottom ? bottom : unconfined > top ? top : unconfined;
    var slipDisplacement = this.props.touchDimensions.slipDisplacement;

    if (
      Math.abs(accumDistanceDisplacement) < slipDisplacement ||
      !slipDisplacement
    ) {
      var value = positionToValue(
        confined,
        this.optionsArray,
        this.props.sliderLength
      );
      var snapped = valueToPosition(
        value,
        this.optionsArray,
        this.props.sliderLength
      );

      this.setState({
        positionTwo: this.props.snapped ? snapped : confined
      });

      if (value !== this.state.valueTwo) {
        this.setState(
          {
            valueTwo: value
          },
          () => {
            this.props.onValuesChange([
              this.state.valueOne,
              this.state.valueTwo
            ]);
          }
        );
      }
    }
  };

  endOne = gestureState => {
    if (gestureState.moveX === 0 && this.props.onToggleOne) {
      this.props.onToggleOne();
      return;
    }

    this.setState(
      {
        pastOne: this.state.positionOne,
        onePressed: !this.state.onePressed
      },
      () => {
        var change = [this.state.valueOne];
        if (this.state.valueTwo) {
          change.push(this.state.valueTwo);
        }
        this.props.onValuesChangeFinish(change);
      }
    );
  };

  endTwo = gestureState => {
    if (gestureState.moveX === 0 && this.props.onToggleTwo) {
      this.props.onToggleTwo();
      return;
    }

    this.setState(
      {
        twoPressed: !this.state.twoPressed,
        pastTwo: this.state.positionTwo
      },
      () => {
        this.props.onValuesChangeFinish([
          this.state.valueOne,
          this.state.valueTwo
        ]);
      }
    );
  };

  render() {
    const { positionOne, positionTwo } = this.state;
    const {
      selectedStyle,
      unselectedStyle,
      sliderLength,
      markerOffsetX,
      markerOffsetY
    } = this.props;
    const twoMarkers = this.props.values.length == 2; // when allowOverlap, positionTwo could be 0, identified as string '0' and throwing 'RawText 0 needs to be wrapped in <Text>' error

    const trackOneLength = positionOne;
    const trackOneStyle = twoMarkers
      ? unselectedStyle
      : selectedStyle || styles.selectedTrack;
    const trackThreeLength = twoMarkers ? sliderLength - positionTwo : 0;
    const trackThreeStyle = unselectedStyle;
    const trackTwoLength = sliderLength - trackOneLength - trackThreeLength;
    const trackTwoStyle = twoMarkers
      ? selectedStyle || styles.selectedTrack
      : unselectedStyle;
    const Marker = this.props.customMarker;

    const MarkerLeft = this.props.customMarkerLeft;
    const MarkerRight = this.props.customMarkerRight;
    const isMarkersSeparated = this.props.isMarkersSeparated || false;

    const {
      slipDisplacement,
      height,
      width,
      borderRadius
    } = this.props.touchDimensions;
    const touchStyle = {
      borderRadius: borderRadius || 0
    };

    const markerContainerOne = {
      top: markerOffsetY - 24,
      left: trackOneLength + markerOffsetX - 24
    };

    const markerContainerTwo = {
      top: markerOffsetY - 24,
      right: trackThreeLength - markerOffsetX - 24
    };

    const containerStyle = [styles.container, this.props.containerStyle];

    if (this.props.vertical) {
      containerStyle.push({
        transform: [{ rotate: "-90deg" }]
      });
    }

    return (
      <View style={containerStyle}>
        <View style={[styles.fullTrack, { width: sliderLength }]}>
          <View
            style={[
              styles.track,
              this.props.trackStyle,
              trackOneStyle,
              { width: trackOneLength }
            ]}
          />
          <View
            style={[
              styles.track,
              this.props.trackStyle,
              trackTwoStyle,
              { width: trackTwoLength }
            ]}
          />
          {twoMarkers && (
            <View
              style={[
                styles.track,
                this.props.trackStyle,
                trackThreeStyle,
                { width: trackThreeLength }
              ]}
            />
          )}
          <View
            style={[
              styles.markerContainer,
              markerContainerOne,
              this.props.markerContainerStyle,
              positionOne > sliderLength / 2 && styles.topMarkerContainer
            ]}
          >
            <View
              style={[styles.touch, touchStyle]}
              ref={component => (this._markerOne = component)}
              {...this._panResponderOne.panHandlers}
            >
              {isMarkersSeparated === false ? (
                <Marker
                  enabled={this.props.enabledOne}
                  pressed={this.state.onePressed}
                  markerStyle={[styles.marker, this.props.markerStyle]}
                  pressedMarkerStyle={this.props.pressedMarkerStyle}
                  currentValue={this.state.valueOne}
                  valuePrefix={this.props.valuePrefix}
                  valueSuffix={this.props.valueSuffix}
                />
              ) : (
                <MarkerLeft
                  enabled={this.props.enabledOne}
                  pressed={this.state.onePressed}
                  markerStyle={[styles.marker, this.props.markerStyle]}
                  pressedMarkerStyle={this.props.pressedMarkerStyle}
                  currentValue={this.state.valueOne}
                  valuePrefix={this.props.valuePrefix}
                  valueSuffix={this.props.valueSuffix}
                />
              )}
            </View>
          </View>
          {twoMarkers && positionOne !== this.props.sliderLength && (
            <View
              style={[
                styles.markerContainer,
                markerContainerTwo,
                this.props.markerContainerStyle
              ]}
            >
              <View
                style={[styles.touch, touchStyle]}
                ref={component => (this._markerTwo = component)}
                {...this._panResponderTwo.panHandlers}
              >
                {isMarkersSeparated === false ? (
                  <Marker
                    pressed={this.state.twoPressed}
                    markerStyle={this.props.markerStyle}
                    pressedMarkerStyle={this.props.pressedMarkerStyle}
                    currentValue={this.state.valueTwo}
                    enabled={this.props.enabledTwo}
                    valuePrefix={this.props.valuePrefix}
                    valueSuffix={this.props.valueSuffix}
                  />
                ) : (
                  <MarkerRight
                    pressed={this.state.twoPressed}
                    markerStyle={this.props.markerStyle}
                    pressedMarkerStyle={this.props.pressedMarkerStyle}
                    currentValue={this.state.valueTwo}
                    enabled={this.props.enabledTwo}
                    valuePrefix={this.props.valuePrefix}
                    valueSuffix={this.props.valueSuffix}
                  />
                )}
              </View>
            </View>
          )}
        </View>
      </View>
    );
  }
}

const styles = StyleSheet.create({
  container: {
    position: "relative",
    height: 50,
    justifyContent: "center"
  },
  fullTrack: {
    flexDirection: "row"
  },
  track: {
    ...Platform.select({
      ios: {
        height: 2,
        borderRadius: 2,
        backgroundColor: "#A7A7A7"
      },
      android: {
        height: 2,
        backgroundColor: "#CECECE"
      },
      web: {
        height: 2,
        borderRadius: 2,
        backgroundColor: "#A7A7A7"
      }
    })
  },
  selectedTrack: {
    ...Platform.select({
      ios: {
        backgroundColor: "#095FFF"
      },
      android: {
        backgroundColor: "#0D8675"
      },
      web: {
        backgroundColor: "#095FFF"
      }
    })
  },
  markerContainer: {
    position: "absolute",
    width: 48,
    height: 48,
    backgroundColor: "transparent",
    justifyContent: "center",
    alignItems: "center"
  },
  topMarkerContainer: {
    zIndex: 1
  },
  touch: {
    backgroundColor: "transparent",
    justifyContent: "center",
    alignItems: "center",
    alignSelf: "stretch"
  }
});