Skip to content

bugfix: wrong selected value in different fontSize/itemHeight #55

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
aliunco wants to merge 1 commit into
base: master
Choose a base branch
from
Open

bugfix: wrong selected value in different fontSize/itemHeight #55

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
43 changes: 17 additions & 26 deletions src/WheelPicker.tsx
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,15 +1,13 @@
import React, { useEffect, useMemo, useRef, useState } from 'react';
import {
Animated,
FlatList,
FlatListProps,
StyleProp,
TextStyle,
NativeSyntheticEvent,
NativeScrollEvent,
Animated,
ViewStyle,
View,
ViewProps,
FlatListProps,
FlatList,
ViewStyle,
} from 'react-native';
import styles from './WheelPicker.styles';
import WheelPickerItem from './WheelPickerItem';
Expand Down Expand Up @@ -42,16 +40,16 @@ const WheelPicker: React.FC<Props> = ({
itemTextStyle = {},
itemHeight = 40,
scaleFunction = (x: number) => 1.0 ** x,
rotationFunction = (x: number) => 1 - Math.pow(1 / 2, x),
opacityFunction = (x: number) => Math.pow(1 / 3, x),
rotationFunction = (x: number) => 1 - (1 / 2) ** x,
opacityFunction = (x: number) => (1 / 3) ** x,
visibleRest = 2,
decelerationRate = 'fast',
containerProps = {},
flatListProps = {},
}) => {
const flatListRef = useRef<FlatList>(null);
const [scrollY] = useState(new Animated.Value(0));

const calculatedSelectingIndex = React.useRef<number>(selectedIndex);
const containerHeight = (1 + visibleRest * 2) * itemHeight;
const paddedOptions = useMemo(() => {
const array: (string | null)[] = [...options];
Expand All @@ -72,23 +70,16 @@ const WheelPicker: React.FC<Props> = ({
[visibleRest, scrollY, itemHeight],
);

const handleMomentumScrollEnd = (
event: NativeSyntheticEvent<NativeScrollEvent>,
) => {
// Due to list bounciness when scrolling to the start or the end of the list
// the offset might be negative or over the last item.
// We therefore clamp the offset to the supported range.
const offsetY = Math.min(
itemHeight * (options.length - 1),
Math.max(event.nativeEvent.contentOffset.y, 0),
currentScrollIndex.addListener(({ value }) => {
calculatedSelectingIndex.current = Math.min(
Math.max(0, Math.round(value) - visibleRest),
options.length - 1,
);
});

let index = Math.floor(Math.floor(offsetY) / itemHeight);
const last = Math.floor(offsetY % itemHeight);
if (last > itemHeight / 2) index++;

if (index !== selectedIndex) {
onChange(index);
const handleMomentumScrollEnd = () => {
if (calculatedSelectingIndex.current !== selectedIndex) {
onChange(calculatedSelectingIndex.current);
}
};

Expand Down Expand Up @@ -141,13 +132,13 @@ const WheelPicker: React.FC<Props> = ({
snapToOffsets={offsets}
decelerationRate={decelerationRate}
initialScrollIndex={selectedIndex}
getItemLayout={(data, index) => ({
getItemLayout={(_, index) => ({
length: itemHeight,
offset: itemHeight * index,
index,
})}
data={paddedOptions}
keyExtractor={(item, index) => index.toString()}
keyExtractor={(_, index) => index.toString()}
renderItem={({ item: option, index }) => (
<WheelPickerItem
key={`option-${index}`}
Expand Down