MultiSlider.js

import React from 'react';

import {
  StyleSheet,
  PanResponder,
  View,
  Platform,
  Dimensions,
  I18nManager,
  ImageBackground
} from 'react-native';

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

export default class MultiSlider extends React.Component {
  static defaultProps = {
    values: [0],
    onValuesChangeStart: () => {},
    onValuesChange: values => {},
    onValuesChangeFinish: values => {},
    onMarkersPosition: values => {},
    step: 1,
    min: 0,
    max: 10,
    touchDimensions: {
      height: 50,
      width: 50,
      borderRadius: 15,
      slipDisplacement: 200,
    },
    customMarker: DefaultMarker,
    customMarkerLeft: DefaultMarker,
    customMarkerRight: DefaultMarker,
    customLabel: DefaultLabel,
    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);

      if (typeof nextState.positionOne !== 'undefined' && typeof nextState.positionTwo !== 'undefined') {
          this.props.onMarkersPosition([nextState.positionOne, nextState.positionTwo]);
      }
    }
  }

  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);

            this.props.onMarkersPosition([this.state.positionOne, this.state.positionTwo]);
          },
        );
      }
    }
  };

  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]);

            this.props.onMarkersPosition([this.state.positionOne, this.state.positionTwo]);
          },
        );
      }
    }
  };

  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 Label = this.props.customLabel;

    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' }],
      });
    }

    const body = (<React.Fragment>
      <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,
                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>
    </React.Fragment>);
    const leftDiff = (Dimensions.get('window').width - this.props.sliderLength) / 2;
    return (
      <View>
        <Label
          leftDiff={leftDiff}
          oneMarkerValue={this.state.valueOne}
          twoMarkerValue={this.state.valueTwo}
          oneMarkerLeftPosition={positionOne}
          twoMarkerLeftPosition={positionTwo}
        />
        {this.props.imageBackgroundSource && 
          <ImageBackground source={this.props.imageBackgroundSource} style={[{width: '100%', height: '100%'}, containerStyle]}>
            {body}
          </ImageBackground>
        }
        {!this.props.imageBackgroundSource &&
          <View style={containerStyle}>
            {body}
          </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',
      },
    }),
  },
  selectedTrack: {
    ...Platform.select({
      ios: {
        backgroundColor: '#095FFF',
      },
      android: {
        backgroundColor: '#0D8675',
      },
    }),
  },
  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',
  },
});