Related
I tried to "change" the default refresh indicator of a Flatlist in React Native. I thought about to have something like Snapchat or Instagram or the default IOS refresh indicator instead of the ugly Android indicator. Now I tried following:
const screenHeight = Dimensions.get("screen").height;
const lockWidth = screenHeight;
const finalPosition = lockWidth;
const pan = useRef(new Animated.ValueXY({x: 0, y: 0})).current;
const translateBtn = pan.y.interpolate({
inputRange: [0, finalPosition / 0.75],
outputRange: [0, finalPosition / 2],
extrapolate: 'clamp',
});
const panResponder = useRef(
PanResponder.create({
onMoveShouldSetPanResponder: () => true,
onPanResponderGrant: () => {},
onPanResponderMove: Animated.event([null, {dy: pan.y}], {
useNativeDriver: false,
}),
onPanResponderRelease: (e, g) => {
if (g.vy > 2 || g.dy > lockWidth / 2) {
unlock();
} else {
reset();
}
},
onPanResponderTerminate: () => reset(),
}),
).current;
const reset = () => {
setGeneralState(prevState => ({...prevState, scroll: true}))
Animated.spring(pan, {
toValue: {x: 0, y: 0},
useNativeDriver: true,
bounciness: 0,
}).start();
};
const unlock = () => {
setLoading(true)
Animated.spring(pan, {
toValue: {x: 0, y: 280},
useNativeDriver: true,
bounciness: 0,
}).start();
// alert("")
setTimeout(() => {
reset();
setLoading(false)
}, 1000)
};
It works just as I expect:
Now the problem:
When the Flatlist is so big that it can be scrolled (if there are many items) I cannot pull down to refresh anymore because React Native always tries to move the flatlist when I'm scrolling.
The FlatList:
<Animated.View
style={[
styles.receiverBox,
{transform: [{translateY: translateBtn}]},
]}
{...panResponder.panHandlers}>
<View>
<FlatList
data={["user1", "user2", "user3", "user4", "user5",]}
renderItem={({item}) => {
return(
<View style={{backgroundColor: colors.background, padding: 20, marginTop: -5, width: "100%",}}>
<Text style={{fontSize: Title1, color: colors.text, textAlign: "center",}}>{item}</Text>
</View>
)
}}
/>
</View>
</Animated.View>
Figured out that this may be a problem from react native or the combination of the flatlist with the pan responder.
I'm trying to rotate a View from a starting point,
I'm tried to add prev translateX and add it again after rotating as describing here
but not works well :\ it's the same
Code snippet
const rotateAnimationStyle = useAnimatedStyle(() => {
return {
transform: [
{translateX: -1 * (120 / 2)},
// {translateY: 0},
{rotateZ: `${rotateAnimationValuew.value}deg`},
{translateX: 120 / 2},
// {translateY: 0},
],
};
});
const addAttachment = () => {
isAnimated.value = withTiming(!isAnimated.value, {duration: 4000});
rotateAnimationValuew.value = isAnimated.value
? withTiming(0, {
duration: 1500,
easing: Easing.linear,
})
: withTiming(90, {
duration: 1500,
easing: Easing.linear,
});
console.log(isAnimated.value);
};
<Animated.View
style={[styles.attachmentsElements, rotateAnimationStyle]}>
<View style={[styles.circle, {zIndex: 1}]}>
<Text>close</Text>
</View>
<View style={styles.circle}>
<Text>Camera</Text>
</View>
<View style={styles.circle}>
<Text>video</Text>
</View>
<View style={styles.circle}>
<Text>Contacts</Text>
</View>
</Animated.View>
I've been trying to build an Image carousel with a bunch of randomly selected images. I wanted to maintain their aspect ratios so I set the resizeMode to 'contain'. Somehow that step leads to the loss of any set borderRadius! What could be the reason? And if that step doesn't work at all, any other ideas on how to maintain the correct aspect ratio + get the corners rounded?
Thanks a lot for your help!
here's the code:
import React, { useCallback, memo, useRef, useState } from "react";
import {
FlatList,
View,
Dimensions,
Text,
StyleSheet,
Image,
} from "react-native";
const images = [
Image1,
Image2,
Image3,
Image4,
Image5,
Image6,
Image7,
Image8,
Image9,
Image10,
Image11,
Image12,
Image13,
Image14,
Image15,
Image16,
Image17,
Image18,
Image19,
Image20,
Image21,
Image22,
Image23,
Image24,
Image25,
Image26,
Image27,
Image28,
Image29,
Image30,
Image31,
Image32,
Image33,
Image34,
Image35,
Image36,
Image37,
Image38,
Image39,
Image40,
Image41,
]
const { width: windowWidth, height: windowHeight } = Dimensions.get("window");
const randomImage = () =>
images[Math.floor(Math.random() * images.length)];
const styles = StyleSheet.create({
slide: {
height: windowHeight,
width: windowWidth,
//justifyContent: "center",
alignItems: "center",
},
slideImage: {
height: '70%',
width: '90%',
borderRadius: 20,
marginTop: 20,
},
slideTitle: {
fontSize: 24,
marginTop: 0,
},
slideSubtitle: {
fontSize: 18,
marginTop: 10,
},
pagination: {
position: "absolute",
bottom: 8,
justifyContent: "center",
flexDirection: "row",
marginBottom: 12
},
paginationDot: {
width: 8,
height: 8,
borderRadius: 4,
marginHorizontal: 2,
},
paginationDotActive: { backgroundColor: "lightblue" },
paginationDotInactive: { backgroundColor: "gray" },
carousel: {},
});
const slideList = Array.from({ length: 999 }).map((_, i) => {
return {
id: i,
image: randomImage,
title: `This is the title ${i + 1}!`,
subtitle: `This is the subtitle ${i + 1}!`,
};
});
const Slide = memo(function Slide({ data }) {
return (
<View style={styles.slide}>
<Image resizeMode = 'contain' source = {randomImage()} style={styles.slideImage}></Image>
<Text style={styles.slideTitle}>{data.title}</Text>
<Text style={styles.slideSubtitle}>{data.subtitle}</Text>
</View>
);
});
function Pagination({ index }) {
return (
<View style={styles.pagination} pointerEvents="none">
{slideList.map((_, i) => {
return (
<View
key={i}
style={[
styles.paginationDot,
index === i
? styles.paginationDotActive
: styles.paginationDotInactive,
]}
/>
);
})}
</View>
);
}
export default function Carousel() {
const [index, setIndex] = useState(0);
const indexRef = useRef(index);
indexRef.current = index;
const onScroll = useCallback((event) => {
const slideSize = event.nativeEvent.layoutMeasurement.width;
const index = event.nativeEvent.contentOffset.x / slideSize;
const roundIndex = Math.round(index);
const distance = Math.abs(roundIndex - index);
// Prevent one pixel triggering setIndex in the middle
// of the transition. With this we have to scroll a bit
// more to trigger the index change.
const isNoMansLand = 0.4 < distance;
if (roundIndex !== indexRef.current && !isNoMansLand) {
setIndex(roundIndex);
}
}, []);
const flatListOptimizationProps = {
initialNumToRender: 0,
maxToRenderPerBatch: 1,
removeClippedSubviews: true,
scrollEventThrottle: 16,
windowSize: 2,
keyExtractor: useCallback(s => String(s.id), []),
getItemLayout: useCallback(
(_, index) => ({
index,
length: windowWidth,
offset: index * windowWidth,
}),
[]
),
};
const renderItem = useCallback(function renderItem({ item }) {
return <Slide data={item} />;
}, []);
return (
<>
<FlatList
data={slideList}
style={styles.carousel}
renderItem={renderItem}
pagingEnabled
horizontal
showsHorizontalScrollIndicator={false}
bounces={false}
onScroll={onScroll}
{...flatListOptimizationProps}
/>
<Pagination index={index}></Pagination>
</>
);
}
``
Actually borderRadius works but you can't see it because of an incorrect ratio.
If your image has a 16:9 ratio, for example, 1600x900 dimensions, then you need to set width and height with the same ratio.
<Image
source={ 1600x900 }
resizeMode="contain"
style={{
width: 300,
height: 300,
borderRadius: 15,
backgroundColor: 'red'
}} />
The result will be:
Because the image has width and height 300, ie 1:1 ratio. If you modify width and height like 320 and 180, ie 16:9, then the image fills all the space and borders will be visible.
Another workaround is to wrap your image with view that hides the overflow
<View
style={{
width: 300,
height: 300,
borderRadius: 150,
overflow: 'hidden',
}}
>
<Image
source={item.image}
style={{
width: 300,
height: 300,
}}
resizeMode='contain'
/>
</View>
Description
I am working on a react-native project using expo SDK36.
I want to do a swipe left/right list view. I use react-native-swipe-list-view to achieve it.
So far everything worked perfectly, the default example uses a fixed height: 50 per row, while I want to set the height of each row dynamically.
Every attempt where a failure, note that I already use <SwipeListView recalculateHiddenLayout={true} />
This is bad for the UX, since the default line is having a small height: 50, it is nearly impossible to drag the line on iOS and android properly.
Reproduction
Snack: https://snack.expo.io/#kopax/react-native-swipe-list-view-408
import React from 'react';
import { Dimensions, Text, View, StyleSheet } from 'react-native';
import Constants from 'expo-constants';
// You can import from local files
import SwipeListView from './components/SwipeListView';
// or any pure javascript modules available in npm
import { Card } from 'react-native-paper';
export default class App extends React.Component {
render() {
return (
<View style={styles.container}>
<Text style={styles.paragraph}>
Change code in the editor and watch it change on your phone! Save to get a shareable url.
</Text>
<Card>
<SwipeListView
dimensions={Dimensions.get('window')}
listViewData={Array(20).fill('').map((d, i) => ({
...d,
title: `Item ${i}`,
description: `This is a very long description for item number #${i},
it should be so long that you cannot see all the content,
the issue is about fixing the dynamic height for each row`
}))
}
minHeight={200}
/>
</Card>
</View>
);
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: 'center',
paddingTop: Constants.statusBarHeight,
backgroundColor: '#ecf0f1',
padding: 8,
},
paragraph: {
margin: 24,
fontSize: 18,
fontWeight: 'bold',
textAlign: 'center',
},
});
This is my components/SwipeListView.js
import React, { Component } from 'react';
import {
Animated,
Image,
StyleSheet,
TouchableOpacity,
TouchableHighlight,
View,
} from 'react-native';
import {
Avatar,
Button,
Text,
Title,
Subheading,
TouchableRipple,
withTheme,
} from 'react-native-paper';
import { SwipeListView as SwipeListViewDefault } from 'react-native-swipe-list-view';
/* eslint-disable react/prop-types, react/destructuring-assignment, react/no-access-state-in-setstate */
class SwipeListView extends Component {
leftBtnRatio = 0.25;
rightBtnRatio = 0.75;
constructor(props) {
super(props);
this.state = {
listType: 'FlatList',
listViewData: props.listViewData
.map((data, i) => ({ key: `${i}`, ...data })),
};
this.rowTranslateAnimatedValues = {};
props.listViewData
.forEach((data, i) => {
this.rowTranslateAnimatedValues[`${i}`] = new Animated.Value(1);
});
}
getStyles() {
const { minHeight, theme } = this.props;
const { colors } = theme;
return StyleSheet.create({
rowFrontContainer: {
overflow: 'hidden',
},
rowFront: {
alignItems: 'center',
backgroundColor: colors.surface,
borderBottomColor: colors.accent,
borderBottomWidth: 1,
justifyContent: 'center',
minHeight: '100%',
flex: 1,
},
rowBack: {
alignItems: 'center',
backgroundColor: colors.surface,
flexDirection: 'row',
justifyContent: 'space-between',
paddingLeft: 15,
minHeight: '100%',
},
backBtn: {
alignItems: 'center',
bottom: 0,
justifyContent: 'center',
position: 'absolute',
top: 0,
},
backLeftBtn: {
backgroundColor: colors.primary,
left: 0,
width: `${this.leftBtnRatio * 100}%`,
},
backRightBtn: {
backgroundColor: colors.accent,
right: 0,
width: `${this.rightBtnRatio * 100}%`,
},
});
}
onRowDidOpen = (rowKey) => {
console.log('This row opened', rowKey);
};
onSwipeValueChange = swipeData => {
const { dimensions } = this.props;
const { key, value } = swipeData;
if (value < -dimensions.width * this.rightBtnRatio && !this.animationIsRunning) {
this.animationIsRunning = true;
Animated.timing(this.rowTranslateAnimatedValues[key], {
toValue: 0,
duration: 200,
}).start(() => {
const newData = [...this.state.listViewData];
const prevIndex = this.state.listViewData.findIndex(item => item.key === key);
newData.splice(prevIndex, 1);
this.setState({listViewData: newData});
this.animationIsRunning = false;
});
}
};
closeRow(rowMap, rowKey) {
if (rowMap[rowKey]) {
rowMap[rowKey].closeRow();
}
}
deleteRow(rowMap, rowKey) {
this.closeRow(rowMap, rowKey);
const newData = [...this.state.listViewData];
const prevIndex = this.state.listViewData.findIndex(
(item) => item.key === rowKey,
);
newData.splice(prevIndex, 1);
this.setState({ listViewData: newData });
}
render() {
const { minHeight, dimensions, theme } = this.props;
const { colors } = theme;
const styles = this.getStyles();
return (
<SwipeListViewDefault
data={this.state.listViewData}
renderItem={data => (
<Animated.View
style={[styles.rowFrontContainer, {
height: this.rowTranslateAnimatedValues[data.item.key].interpolate({
inputRange: [0, 1],
outputRange: [0, minHeight],
})}]}
>
<TouchableRipple
onPress={() => console.log('You touched me')}
style={styles.rowFront}
underlayColor={colors.background}
>
<View>
<Title>{data.item.title}</Title>
<Text>
{data.item.description}
</Text>
</View>
</TouchableRipple>
</Animated.View>
)}
renderHiddenItem={(data, rowMap) => (
<View style={styles.rowBack}>
<TouchableOpacity
style={[
styles.backLeftBtn,
styles.backBtn,
]}
onPress={() => this.closeRow(rowMap, data.item.key)}
>
<Text>Tap pour annuler</Text>
</TouchableOpacity>
<TouchableOpacity
style={[
styles.backRightBtn,
styles.backBtn,
]}
onPress={() => this.deleteRow(rowMap, data.item.key)}
>
<Animated.View
style={[
styles.trash,
{
transform: [
{
scale: this.rowTranslateAnimatedValues[
data.item.key
].interpolate({
inputRange: [
45,
90,
],
outputRange: [0, 1],
extrapolate:
'clamp',
}),
},
],
},
]}
>
<Text>Swipe left to delete</Text>
</Animated.View>
</TouchableOpacity>
</View>
)}
leftOpenValue={dimensions.width * this.leftBtnRatio}
rightOpenValue={-dimensions.width * this.rightBtnRatio}
previewRowKey={'0'}
previewOpenValue={-40}
previewOpenDelay={3000}
onRowDidOpen={this.onRowDidOpen}
onSwipeValueChange={this.onSwipeValueChange}
recalculateHiddenLayout={true}
/>
);
}
}
export default withTheme(SwipeListView);
Expect
I expect when using recalculateHiddenLayout={true}, to get the hidden row height calculated dynamically
Result Screenshots
On the web, I am able to set the height:
but I when using iOS and Android, the height is forced.
Environment
OS: ios/android/web
RN Version: expo SDK36
How can I set the height of each row dynamically?
Important edit
The problem is the fixed value here in the animation:
height: this.rowTranslateAnimatedValues[data.item.key].interpolate({
inputRange: [0, 1],
outputRange: [0, 200], // <--- here
})}]}
I have replaced it in the example with props.minHeight:
height: this.rowTranslateAnimatedValues[data.item.key].interpolate({
inputRange: [0, 1],
outputRange: [0, this.props.minHeight],
})}]}
It doesn't permit dynamic height, how can I get the row height dynamically?
I am using Animation.view to change the height and the background of the header.
I set my height and the background settings like this:
const HeaderHeight = this.state.scrollY.interpolate({
inputRange:[0, Header_Max_Height - Header_Min_Height],
outputRange:[Header_Max_Height, Header_Min_Height],
extrapolate:'clamp'
})
const AnimateHeaderBackgroundColor = this.state.scrollY.interpolate({
inputRange: [ 0, ( Header_Max_Height - Header_Min_Height ) ],
outputRange: [ '#009688', '#00BCD4' ],
extrapolate: 'clamp'
})
This is my animated.view.
<Animated.View style={{width:'100%', height: HeaderHeight, backgroundColor:AnimateHeaderBackgroundColor}}></Animated.View>
Everything works well.
My question is there a way I could change the view like the height and the backgroundcolor?
For example, say I have two views:
//view1
<View style={{width:'100%',height:100, backgroundColor:'red'}}>
<Text>View1</Text>
</View>
//view2
<View style={{width:'100%',height:100, backgroundColor:'blue'}}>
<Text>View2</Text>
</View>
I want the view1 to show by default and show view2 as I scroll to the top of the screen. Placing the View in the outputRange would make this possible?
I guess there's no direct way in RN if you want to animated a change of view, however, in your case I can think of a little trick using the mix of opacity, position: absolute and interpolate(), here is a minimal example which you can directly copy and paste to test it:
import React, { Component } from 'react';
import { StyleSheet, Animated, View, ScrollView } from 'react-native';
class AnimationExample extends Component {
constructor(props) {
super(props)
this.state = {
showBlueView: false,
animatedOpacityValue: new Animated.Value(0),
}
}
handleScroll = (event) => {
const { animatedOpacityValue, showBlueView } = this.state;
const scrollPosition = event.nativeEvent.contentOffset.y;
if (scrollPosition > 100 && !showBlueView) {
Animated.timing(animatedOpacityValue, {
toValue: 1,
}).start(() => this.setState({ showBlueView: true }))
}
if (scrollPosition < 100 && showBlueView) {
Animated.timing(animatedOpacityValue, {
toValue: 0,
}).start(() => this.setState({ showBlueView: false }))
}
}
render() {
const { animatedOpacityValue } = this.state;
return (
<ScrollView
style={styles.scrollView}
onScroll={this.handleScroll}
scrollEventThrottle={16}
>
<View style={styles.green} />
<View style={styles.animatedViewsPositioner}>
<Animated.View
style={{
...styles.red,
opacity: animatedOpacityValue.interpolate({
inputRange: [0, 1],
outputRange: [1, 0],
}),
}}
/>
<Animated.View
style={{
...styles.blue,
opacity: animatedOpacityValue.interpolate({
inputRange: [0, 1],
outputRange: [0, 1],
}),
}}
/>
</View>
</ScrollView>
)
}
}
const styles = StyleSheet.create({
scrollView: {
flex: 1,
},
green: {
height: 600,
width: '100%',
backgroundColor: 'green',
},
red: {
height: 300,
width: '100%',
backgroundColor: 'red',
},
blue: {
position: 'absolute',
height: 300,
width: '100%',
backgroundColor: 'blue',
},
animatedViewsPositioner: {
position: 'relative',
},
})
In the example above, I first access the scroll position by applying a handleScroll function to the scrollView. Make sure you have scrollEventThrottle set to 16 to ensure the function is triggered every second, but beware of possible performance issue caused by that (if you care, you might take a look at this for more info).
To achieve a view change triggered when user scroll to certain position (which is actually not, but it looks like that), I use a view to wrap both red and blue views, the red one is default with opacity: 1, while the blue one with default opacity: 0, sitting on top of the red one.
I hide the red view and show the blue one by animating their opacity using interpolate(). With the help of that, both opacity values are controlled by one animatedValue animatedOpacityValue put in the state. I added a state showBlueView to optimise the performance by avoid constantly setting states triggered by onScroll.
Here's an update to add touchableOpacities on both views, simply achieve by hiding the blue view when it's unused.
First, add a log function:
log = (stringToPrint) => () => {
console.log(stringToPrint)
}
Next, change the scrollView like this by adding two touchableOpacity
<ScrollView
style={styles.scrollView}
onScroll={this.handleScroll}
scrollEventThrottle={16}
>
<View style={styles.green} />
<View style={styles.animatedViewsPositioner}>
<Animated.View
style={{
...styles.red,
opacity: animatedOpacityValue.interpolate({
inputRange: [0, 1],
outputRange: [1, 0],
}),
}}
>
<TouchableOpacity
style={{ backgroundColor: 'black', width: 80, height: 30 }}
onPress={this.log('click on red')}
/>
</Animated.View>
{showBlueView && (
<Animated.View
style={{
...styles.blue,
opacity: animatedOpacityValue.interpolate({
inputRange: [0, 1],
outputRange: [0, 1],
}),
}}
>
<TouchableOpacity
style={{ backgroundColor: 'black', width: 80, height: 30 }}
onPress={this.log('click on blue')}
/>
</Animated.View>
)}
</View>
</ScrollView>
Note that I added showBlueView && to hide the blue view when its opacity is 0, so that it will not block any click event applied to the red view (even though the blue view is hidden, it is actually on top of the red view with opacity: 0).
#Andus 's ans with Animated.event
The idea is to get the latest scrollY then wrap it to view's opacity. The example input range of blue target is 0-50 and got opacity 1 to 0. That means it would fade out when scrolling down the first 50 px.
The red one is the reverse one with input range 0-200 and out to opacity 0 to 1.(fade in)
import React, { Component } from 'react';
import { StyleSheet, Animated, View, ScrollView, SafeAreaView } from 'react-native';
export default class AnimationExample extends Component {
constructor(props) {
super(props)
this.state = {
scrollY: new Animated.Value(0)
}
}
render() {
const {scrollY} = this.state;
return (
<SafeAreaView style={{flex: 1}}>
<ScrollView
style={styles.scrollView}
onScroll={Animated.event(
[{nativeEvent: {contentOffset: {y: this.state.scrollY}}}]
)}
scrollEventThrottle={16}
>
<View style={styles.animatedViewsPositioner}>
<Animated.View
style={[styles.box, styles.target, {
opacity: scrollY.interpolate({
inputRange: [0, 50],
outputRange: [1, 0],
}),
}]}
/>
<Animated.View
style={[styles.box, styles.origin, {
opacity: scrollY.interpolate({
inputRange: [0, 200],
outputRange: [0, 1],
}),
}]}
/>
</View>
</ScrollView>
</SafeAreaView>
)
}
}
const styles = StyleSheet.create({
scrollView: {
flex: 1,
},
box: {
height: 1000,
width: '100%',
position: 'absolute'
},
origin: {
backgroundColor: 'red',
zIndex: 1
},
target: {
backgroundColor: 'blue',
zIndex: 2
},
animatedViewsPositioner: {
position: 'relative',
backgroundColor: 'pink',
height: 10000
},
})
If you are using ScrollView in displaying the View, I believe you can use the onScroll callback to get the position of your screen inside the ScrollView and change the height and color dynamically when your user scroll to the top.
<ScrollView onScroll={this.handleScroll} />
And getting the position,
handleScroll: function(event: Object) {
console.log(event.nativeEvent.contentOffset.y);
},
Reference: Get current scroll position of ScrollView in React Native