react-native-dates-picker
Version:
Customizable date picker for React Native
170 lines (168 loc) • 6.17 kB
JavaScript
function _extends() { _extends = Object.assign ? Object.assign.bind() : function (target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i]; for (var key in source) { if (Object.prototype.hasOwnProperty.call(source, key)) { target[key] = source[key]; } } } return target; }; return _extends.apply(this, arguments); }
import React, { useEffect, useMemo, useRef, useState, memo } from 'react';
import { Animated, View, Platform, StyleSheet } from 'react-native';
import WheelPickerItem from './wheel-picker-item';
import { useCalendarContext } from '../../../CalendarContext';
const WheelPicker = ({
value,
options,
onChange,
itemHeight = 40,
scaleFunction = x => 1.0 ** x,
rotationFunction = x => 1 - Math.pow(1 / 2, x),
opacityFunction = x => Math.pow(1 / 3, x),
visibleRest = 2,
decelerationRate = 'normal',
containerProps = {}
}) => {
const {
theme
} = useCalendarContext();
const momentumStarted = useRef(false);
const selectedIndex = options.findIndex(item => item.value === value);
const flatListRef = useRef(null);
const [scrollY] = useState(new Animated.Value(selectedIndex * itemHeight));
const containerHeight = (1 + visibleRest * 2) * itemHeight;
const paddedOptions = useMemo(() => {
const array = [...options];
for (let i = 0; i < visibleRest; i++) {
array.unshift(null);
array.push(null);
}
return array;
}, [options, visibleRest]);
const offsets = useMemo(() => [...Array(paddedOptions.length)].map((_, i) => i * itemHeight), [paddedOptions, itemHeight]);
const currentScrollIndex = useMemo(() => Animated.add(Animated.divide(scrollY, itemHeight), visibleRest), [visibleRest, scrollY, itemHeight]);
const handleScrollEnd = event => {
var _options$index;
const offsetY = Math.min(itemHeight * (options.length - 1), Math.max(event.nativeEvent.contentOffset.y, 0));
let index = Math.floor(offsetY / itemHeight);
const remainder = offsetY % itemHeight;
if (remainder > itemHeight / 2) {
index++;
}
const value = ((_options$index = options[index]) === null || _options$index === void 0 ? void 0 : _options$index.value) || 0;
if (index !== selectedIndex) {
onChange(value);
}
};
const handleMomentumScrollBegin = () => {
momentumStarted.current = true;
};
const handleMomentumScrollEnd = event => {
momentumStarted.current = false;
handleScrollEnd(event);
};
const handleScrollEndDrag = event => {
var _event$nativeEvent$co;
// Capture the offset value immediately
const offsetY = (_event$nativeEvent$co = event.nativeEvent.contentOffset) === null || _event$nativeEvent$co === void 0 ? void 0 : _event$nativeEvent$co.y;
// We'll start a short timer to see if momentum scroll begins
setTimeout(() => {
// If momentum scroll hasn't started within the timeout,
// then it was a slow scroll that won't trigger momentum
if (!momentumStarted.current && offsetY !== undefined) {
// Create a synthetic event with just the data we need
const syntheticEvent = {
nativeEvent: {
contentOffset: {
y: offsetY
}
}
};
handleScrollEnd(syntheticEvent);
}
}, 50);
};
const scrollEvent = useMemo(() => Animated.event([{
nativeEvent: {
contentOffset: {
y: scrollY
}
}
}], {
useNativeDriver: true
}),
// eslint-disable-next-line react-hooks/exhaustive-deps
[]);
useEffect(() => {
if (selectedIndex < 0 || selectedIndex >= options.length) {
throw new Error(`Selected index ${selectedIndex} is out of bounds [0, ${options.length - 1}]`);
}
}, [selectedIndex, options]);
/**
* If selectedIndex is changed from outside (not via onChange) we need to scroll to the specified index.
* This ensures that what the user sees as selected in the picker always corresponds to the value state.
*/
useEffect(() => {
var _flatListRef$current;
(_flatListRef$current = flatListRef.current) === null || _flatListRef$current === void 0 || _flatListRef$current.scrollToIndex({
index: selectedIndex,
animated: Platform.OS === 'ios'
});
}, [selectedIndex, itemHeight]);
return /*#__PURE__*/React.createElement(View, _extends({
style: [styles.container, {
height: containerHeight
}, theme.wheelPickerContainerStyle]
}, containerProps), /*#__PURE__*/React.createElement(View, {
style: [styles.selectedIndicator, {
transform: [{
translateY: -itemHeight / 2
}],
height: itemHeight
}, theme.wheelPickerSelectedIndicatorStyle]
}), /*#__PURE__*/React.createElement(Animated.FlatList, {
ref: flatListRef,
nestedScrollEnabled: true,
style: styles.scrollView,
showsVerticalScrollIndicator: false,
scrollEventThrottle: 16,
onScroll: scrollEvent,
snapToOffsets: offsets,
onScrollEndDrag: handleScrollEndDrag,
onMomentumScrollBegin: handleMomentumScrollBegin,
onMomentumScrollEnd: handleMomentumScrollEnd,
decelerationRate: decelerationRate,
initialScrollIndex: selectedIndex,
getItemLayout: (_, index) => ({
length: itemHeight,
offset: itemHeight * index,
index
}),
maxToRenderPerBatch: 20,
data: paddedOptions,
keyExtractor: (item, index) => item ? `${item.value}-${item.text}-${index}` : `-${index}`,
renderItem: ({
item: option,
index
}) => /*#__PURE__*/React.createElement(WheelPickerItem, {
key: `option-${index}`,
index: index,
option: option,
height: itemHeight,
currentScrollIndex: currentScrollIndex,
scaleFunction: scaleFunction,
rotationFunction: rotationFunction,
opacityFunction: opacityFunction,
visibleRest: visibleRest
})
}));
};
const styles = StyleSheet.create({
container: {
display: 'flex',
position: 'relative'
},
selectedIndicator: {
position: 'absolute',
width: '100%',
top: '50%'
},
scrollView: {
overflow: 'hidden',
flex: 1
}
});
export default /*#__PURE__*/memo(WheelPicker);
//# sourceMappingURL=wheel-picker.js.map