import React, { useState, useEffect } from 'react';
import { Animated, StyleSheet, View, LayoutChangeEvent, Text, TextInput, I18nManager, TextStyle, StyleProp } from 'react-native';
import { gestureHandlerRootHOC, GestureHandlerRootView, PanGestureHandler, PanGestureHandlerGestureEvent, State } from 'react-native-gesture-handler';
const osRtl = I18nManager.isRTL;
const SMALL_SIZE = 24;
const MEDIUM_SIZE = 34;
const LARGE_SIZE = 44;
const step = 1;
const min = 0;
export type itemType = {
value: number,
text: string
}
interface TextualSliderProps {
values: itemType[];
valueOnChange: (value: itemType) => void;
styleSize?: 'small' | 'medium' | 'large' | number;
knobColor?: string;
inRangeBarColor?: string;
outOfRangeBarColor?: string;
valueLabelsTextColor?: string;
valueLabelsBackgroundColor?: string;
rangeLabelsStyle?: StyleProp<TextStyle>;
showRangeLabels?: boolean;
showValueLabels?: boolean;
initialValue?: number;
}
const TextualSlider = gestureHandlerRootHOC(({
values, valueOnChange,
styleSize = 'medium',
knobColor = '#00a2ff',
inRangeBarColor = 'rgb(200,200,200)',
outOfRangeBarColor = 'rgb(100,100,100)',
valueLabelsTextColor = 'white',
valueLabelsBackgroundColor = '#3a4766',
rangeLabelsStyle,
showRangeLabels = true,
showValueLabels = true,
initialValue
}: TextualSliderProps) => {
// settings
const [stepInPixels, setStepInPixels] = useState(0);
const [knobSize, setknobSize] = useState(0);
const [max, setMax] = useState(1);
// rtl settings
const [flexDirection, setFlexDirection] = useState<"row" | "row-reverse" | "column" | "column-reverse" | undefined>('row');
const [svgOffset, setSvgOffset] = useState<object>({ left: (knobSize - 40) / 2 });
const [valueOffset, setValueOffset] = useState(0);
const [TextualSliderWidth, setTextualSliderWidth] = useState(0);
// animation values
const [translateX] = useState(new Animated.Value(0));
const [valueLabelScale] = useState(new Animated.Value(0.01));
const [inRangeScaleX] = useState(new Animated.Value(0.01));
// refs
const valueTextRef = React.createRef<TextInput>();
const opacity = React.useRef<Animated.Value>(new Animated.Value(0)).current;
// initalizing settings
useEffect(() => {
setMax(values.length - 1);
setFlexDirection(osRtl ? 'row-reverse' : 'row');
setSvgOffset(osRtl ? { right: (knobSize - 40) / 2 } : { left: (knobSize - 40) / 2 });
}, []);
useEffect(() => {
if (TextualSliderWidth > 0) {
const stepSize = setStepSize(max, min, step);
valueTextRef.current?.setNativeProps({ text: values[min].text });
if (typeof initialValue === 'number' && initialValue >= min && initialValue <= max) {
const offset = ((initialValue - min) / step) * stepSize - (knobSize / 2);
setValueStatic(offset, knobSize, stepSize);
setValueText(offset);
}
Animated.timing(opacity, {
toValue: 1,
duration: 64,
useNativeDriver: true
}).start();
}
}, [min, max, step, initialValue, TextualSliderWidth]);
useEffect(() => {
const size = typeof styleSize === 'number' ? styleSize : styleSize === 'small' ? SMALL_SIZE : styleSize === 'medium' ? MEDIUM_SIZE : LARGE_SIZE;
setknobSize(size);
translateX.setValue(-size / 4);
}, [styleSize]);
const setValueStatic = (newOffset: number, knobSize: number, stepInPixels: number) => {
newOffset = Math.round((newOffset + (knobSize / 2)) / stepInPixels) * stepInPixels - (knobSize / 2);
settingValue(newOffset);
setValueOffset(newOffset);
const index = Math.round(((newOffset + (knobSize / 2)) * (max - min) / TextualSliderWidth) / step) * step + min;
valueOnChange(values[index]);
}
const settingValue = (newOffset: number) => {
translateX.setValue(newOffset);
inRangeScaleX.setValue((newOffset + (knobSize / 2)) / TextualSliderWidth + 0.01);
}
const setValueText = (totalOffset: number) => {
const numericValue: number = Math.floor(((totalOffset + (knobSize / 2)) * (max - min) / TextualSliderWidth) / step) * step + min;
valueTextRef.current?.setNativeProps({ text: values[numericValue].text });
}
const setStepSize = (max: number, min: number, step: number) => {
const numberOfSteps = ((max - min) / step);
const stepSize = TextualSliderWidth / numberOfSteps;
setStepInPixels(stepSize);
return stepSize;
}
// value gesture events ------------------------------------------------------------------------
const onGestureEvent = (event: PanGestureHandlerGestureEvent) => {
let totalOffset = event.nativeEvent.translationX + valueOffset;
if (totalOffset >= - knobSize / 2 && totalOffset <= TextualSliderWidth - knobSize / 2) {
translateX.setValue(totalOffset);
if (valueTextRef != null) {
const index = Math.round(((totalOffset + (knobSize / 2)) * (max - min) / TextualSliderWidth) / step) * step + min;
valueTextRef.current?.setNativeProps({ text: values[index].text });
}
inRangeScaleX.setValue((totalOffset + (knobSize / 2)) / TextualSliderWidth + 0.01);
}
}
const onHandlerStateChange = (event: PanGestureHandlerGestureEvent) => {
if (event.nativeEvent.state === State.BEGAN) {
scaleTo(valueLabelScale, 1);
}
if (event.nativeEvent.state === State.END) {
let newOffset = event.nativeEvent.translationX + valueOffset;
newOffset = Math.round((newOffset + (knobSize / 2)) / stepInPixels) * stepInPixels - (knobSize / 2);
if (newOffset < -knobSize / 2) {
newOffset = -knobSize / 2;
} else if (newOffset >= TextualSliderWidth - knobSize / 2) {
newOffset = TextualSliderWidth - knobSize / 2;
}
setValueStatic(newOffset, knobSize, stepInPixels);
scaleTo(valueLabelScale, 0.01);
}
}
// ------------------------------------------------------------------------------------------------
// gesture events help functions ------------------------------------------------------------------
const scaleTo = (param: Animated.Value, toValue: number) => Animated.timing(param,
{
toValue,
duration: 150,
useNativeDriver: true
}
).start();
// ------------------------------------------------------------------------------------------------
// setting bar width ------------------------------------------------------------------------------
const onLayout = (event: LayoutChangeEvent) => {
setTextualSliderWidth(event.nativeEvent.layout.width);
}
// ------------------------------------------------------------------------------------------------
const labelOpacity = valueLabelScale.interpolate({
inputRange: [0.1, 1],
outputRange: [0, 1]
})
return (
<GestureHandlerRootView>
<Animated.View style={[styles.container, { opacity, padding: styleSize === 'large' ? 7 : styleSize === 'medium' ? 14 : 21 }]}>
{
showValueLabels &&
<View style={{ width: '100%', flexDirection }}>
<Animated.View
style={{ position: 'absolute', bottom: 0, left: 0, opacity: labelOpacity, transform: [{ translateX }, { scale: valueLabelScale }] }}
>
<View style={{ width: '100%', alignItems: 'center' }}>
<TextInput style={{ ...svgOffset, color: valueLabelsTextColor, fontWeight: 'bold', backgroundColor: valueLabelsBackgroundColor, paddingHorizontal: 20, paddingVertical: 5, borderRadius: 3 }} ref={valueTextRef} />
</View>
</Animated.View>
</View>
}
<View style={{ width: '100%', height: knobSize, marginVertical: 4, position: 'relative', flexDirection, alignItems: 'center' }}>
<View style={[styles.bar, { backgroundColor: inRangeBarColor, left: knobSize / 4, marginLeft: -knobSize / 4, right: knobSize / 4, height: knobSize / 3 }]} onLayout={onLayout} />
<Animated.View style={{ width: TextualSliderWidth, height: knobSize / 3, backgroundColor: outOfRangeBarColor, transform: [{ translateX: -TextualSliderWidth / 2 }, { scaleX: inRangeScaleX }, { translateX: TextualSliderWidth / 2 }] }} />
<Animated.View style={{ position: 'absolute', left: -knobSize / 4, width: knobSize / 2.5, height: knobSize / 3, borderRadius: knobSize / 3, backgroundColor: outOfRangeBarColor }} />
<PanGestureHandler {...{ onGestureEvent, onHandlerStateChange }}>
<Animated.View style={[styles.knob, { height: knobSize, width: knobSize, borderRadius: knobSize, backgroundColor: knobColor, transform: [{ translateX }] }]} />
</PanGestureHandler>
</View>
{
showRangeLabels &&
<View style={{ width: '100%', flexDirection, justifyContent: 'space-between' }}>
<Text style={[rangeLabelsStyle, { fontWeight: "bold", marginLeft: -7 }]}>{values.length > 1 ? values[0].text : ''}</Text>
<Text style={[rangeLabelsStyle, { fontWeight: "bold" }]}>{values.length > 1 ? values[max].text : ''}</Text>
</View>
}
</Animated.View>
</GestureHandlerRootView>
);
});
const styles = StyleSheet.create({
container: {
height: 100,
width: '100%',
overflow: 'visible'
},
knob: {
position: 'absolute',
elevation: 4
},
bar: {
position: 'absolute',
borderBottomRightRadius: 100,
borderTopRightRadius: 100
}
});
export default TextualSlider;
