React Native how can get view X Y positions - react-native

import { StyleSheet, Text, View , Animated} from 'react-native'
import React from 'react'
import {useState} from 'react';
const HomeScreen = () => {
const [heightBtn, setHeightBtn] = useState(false)
const [widthBtn, setWidthBtn] = useState(false)
const [XBtn, setXBtn] = useState(0)
const [YBtn, setYBtn] = useState(0)
return (
<View style={{
flex:1,
backgroundColor:'black'
}}>
<View
onLayout={({ nativeEvent }) => {
const { x, y, height, width } = nativeEvent.layout
setHeightBtn(height)
setWidthBtn(width)
setXBtn(x)
setYBtn(y)
}}
style={{
backgroundColor:'red',
height:50,
width:100,
position:'absolute',
transform: [
{
translateX: 100
},
{
translateY: 200
}
],
}}>
</View>
<View
style={{
backgroundColor:'green',
height:heightBtn,
width:widthBtn,
position:'absolute',
transform: [
{
translateX: XBtn
},
{
translateY: YBtn
}
],
}}>
</View>
</View>
)
}
export default HomeScreen
const styles = StyleSheet.create({})
I want to get Height, Width, and XY positions of element. The Height and Width works but the XY positions doesn't work in My Device in (IOS) only work when open the code in the Web View.
Here is the expo snack? Go to snack in the web view Height, Width, and XY positions work but if you open it with device only Height and Width works.

Related

Reanimated does not work with animated code? Is there a way?

I am pretty new to React Native and reanimated so please bear with me if I cant explain this as I need to.
I have a FlatList that animates a single item using animted when clicked. This works great but the problem is I am trying to use it with code that uses reanimated and I get a lot of errors for some reason? I thought it was backwards compatible?
Because I need the animation to run only on a single item I can not use the reanimated way, it seems a lot harder to keep track of everything?
The code below the working code but if I change it to reanimated, no good.
Is there a way of converting the code to run properly when using reanimated or do I just have to start the animations again using reanimated animations from scratch?
The working code :-
import React, { useState, useEffect } from 'react';
import {
Text,
View,
StyleSheet,
FlatList,
TouchableOpacity,
Animated,
} from 'react-native';
import Constants from 'expo-constants';
const dummyData = [...Array(10)].map((_, i) => ({
title: `title ${i}`,
id: i,
}));
const App = () => {
const [Data, setData] = React.useState(dummyData);
const [activeItem, setActiveItem] = React.useState(null);
const animateValue = React.useRef(new Animated.Value(0)).current;
renderItem = ({ item, index }) => {
const animate = (index) => {
setActiveItem(index);
Animated.sequence([
Animated.spring(animateValue, {
toValue: 1,
}),
Animated.spring(animateValue, {
toValue: 0,
}),
]).start(() => console.log('animation finished'));
};
animationMap = animateValue.interpolate({
inputRange: [0, 1],
outputRange: [1, 1.5],
});
return (
<TouchableOpacity onPress={(e) => animate(index)}>
{activeItem === index && (
<Animated.View
style={[styles.button, { transform: [{ scale: animationMap }] }]}>
<Text>{item.title}</Text>
</Animated.View>
)}
{activeItem !== index && (
<View style={styles.button}>
<Text>{item.title}</Text>
</View>
)}
</TouchableOpacity>
);
};
return (
<View style={styles.container}>
<FlatList
data={Data}
renderItem={renderItem}
keyExtractor={({ id }) => {
return id;
}}
extraData={activeItem}
/>
</View>
);
};
const styles = StyleSheet.create({
container: {
flex: 1,
paddingTop: Constants.statusBarHeight,
backgroundColor: '#ecf0f1',
padding: 8,
},
button: {
padding: 10,
borderWidth: 1,
alignItems: 'center',
backgroundColor: 'skyblue',
},
});
export default App;
If I change Animated from reanimated, it doesnt work?
import {
StatusBar,
Text,
View,
StyleSheet,
Image,
Dimensions,
TouchableOpacity,
Platform,
TouchableWithoutFeedback,
UIManager,
LayoutAnimation,
} from "react-native";
import { FlatList } from "react-native-gesture-handler";
import Animated, {
useAnimatedGestureHandler,
useAnimatedStyle,
useSharedValue,
SlideInDown,
BounceOut,
BounceIn,
FadeIn,
FadeOut,
Easing,
withSpring,
withRepeat,
withTiming,
} from "react-native-reanimated";
or
import {
StatusBar,
Text,
View,
StyleSheet,
Image,
Dimensions,
TouchableOpacity,
Platform,
TouchableWithoutFeedback,
UIManager,
LayoutAnimation,
Animated,
} from "react-native";
import { FlatList } from "react-native-gesture-handler";
import {
useAnimatedGestureHandler,
useAnimatedStyle,
useSharedValue,
SlideInDown,
BounceOut,
BounceIn,
FadeIn,
FadeOut,
Easing,
withSpring,
withRepeat,
withTiming,
} from "react-native-reanimated";
can you try using "useSharedValue" and set the value using
"withSequence" as below mentioned:
const App = () => {
const [Data, setData] = React.useState(dummyData);
const [activeItem, setActiveItem] = React.useState(null);
//const animateValue = React.useRef(new Animated.Value(0)).current;
const animateValue = useSharedValue(0);
renderItem = ({ item, index }) => {
const animate = (index) => {
setActiveItem(index);
animateValue.value = withSequence(withTiming(1), withTiming(0))
animationMap = animateValue.interpolate({
inputRange: [0, 1],
outputRange: [1, 1.5],
});
return (
<TouchableOpacity onPress={(e) => animate(index)}>
{activeItem === index && (
<Animated.View
style={[styles.button, { transform: [{ scale: animationMap }] }]}>
<Text>{item.title}</Text>
</Animated.View>
)}
{activeItem !== index && (
<View style={styles.button}>
<Text>{item.title}</Text>
</View>
)}
</TouchableOpacity>
);
};
return (
<View style={styles.container}>
<FlatList
data={Data}
renderItem={renderItem}
keyExtractor={({ id }) => {
return id;
}}
extraData={activeItem}
/>
</View>
);
};
const styles = StyleSheet.create({
container: {
flex: 1,
paddingTop: Constants.statusBarHeight,
backgroundColor: '#ecf0f1',
padding: 8,
},
button: {
padding: 10,
borderWidth: 1,
alignItems: 'center',
backgroundColor: 'skyblue',
},
});
export default App;

Changed from react native class to function and it doesnt work 100%

I am trying to change a class into a function. This is mainly because if I can get it working, I want to use it for learning different animations, I have had some success but not 100%. Originally it displayed an icon that when clicked it spun it one way and then when clicked again it spun the other way. What I have tried to do it get rid of the icon and replace it with an image. It works when clicked once but then does nothing.
I am struggling with toggled aspect of it and setting the state I think because I cant seem to set it up properly in a function.
I have tried several things but this is the best I can get. If I show the original code and then what I have managed to change, maybe someone can point me in the right direction as to what I am doing wrong.
All I want is the image to display and then when clicked spins right and then if clicked again it spins left.
I am doing this so I can mess around with the settings and hopefully learn animation a bit better.
Any help would be greatly appreciated.
The original code :
import React from 'react';
import { View, StyleSheet, Animated, Image, TouchableOpacity } from 'react-native';
import { Ionicons } from '#expo/vector-icons';
const TabIcon = ({
onPress,
menuToggled
}) => {
const logoStyles = [styles.logoStyle];
if (menuToggled !== null) {
const animation = new Animated.Value(menuToggled ? 0 : 1);
Animated.timing(animation, {
toValue: menuToggled ? 1 : 0,
duration: 500,
useNativeDriver: true
}).start();
const rotateInterpolate = animation.interpolate({
inputRange: [0, 1],
outputRange: ['0deg', '360deg']
});
const animatedStyles = { transform: [{ rotate: rotateInterpolate }] };
logoStyles.push(animatedStyles);
}
return (
<TouchableOpacity
style={styles.tabStyle}
onPress={onPress}
>
<Animated.View style={logoStyles}>
<Animated.Image
style={styles.tinyLogo}
source={{
uri: 'https://reactnative.dev/img/tiny_logo.png',
}}
/></Animated.View>
</TouchableOpacity>
);
};
export default class App extends React.Component {
state = {
menuToggled: null
}
toggleMenu = () => {
this.setState(prevState => {
return { menuToggled: !prevState.menuToggled };
});
}
render () {
return (
<View style={styles.container}>
<TabIcon
onPress={this.toggleMenu}
menuToggled={this.state.menuToggled}
/>
</View>
);
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: 'center',
alignItems: 'center',
backgroundColor: 'white'
},
tinyLogo: {
width: 150,
height: 150,
borderRadius: 100,
margin: 8,
},
});
and what I have changed so far :
import React, { useRef, useState } from "react";
import { View, StyleSheet, Animated, Image, TouchableOpacity, Easing } from 'react-native';
import Constants from 'expo-constants';
const App = () => {
const spinValue = useRef(new Animated.Value(0)).current;
const [menuToggled, setMenuToggled] = useState([null]);
toggleMenu = () => {
setMenuToggled(menuToggled === "null" ? "menuToggled" : "null");
}
const Spinner = ({
onPress,
menuToggled
}) => {
const logoStyles = [styles.logoStyle];
const animation = new Animated.Value(0);
const go = () => {
Animated.timing(animation, {
toValue: 1,
duration: 1500,
easing: Easing.elastic(1),
useNativeDriver: true
}).start();
}
const rotateInterpolate = animation.interpolate({
inputRange: [0, 1],
outputRange: ['0deg', '360deg']
});
const animatedStyles = { transform: [{ rotate: rotateInterpolate }] };
logoStyles.push(animatedStyles);
return (
<TouchableOpacity
onPress={go}
>
<Animated.View style={logoStyles}>
<Animated.Image
style={styles.tinyLogo}
source={{
uri: 'https://reactnative.dev/img/tiny_logo.png',
}}
/></Animated.View>
</TouchableOpacity>
);
};
return (
<View style={styles.container}>
<Spinner
onPress={toggleMenu}
menuToggled={menuToggled}
/>
</View>
);
}
const styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: 'center',
alignItems: 'center',
backgroundColor: 'white'
},
tinyLogo: {
width: 150,
height: 150,
borderRadius: 100,
margin: 8,
},
});
export default App;
There are a few issues. You first had menuToggled initialized to [null] when it should have been null. You also had forgotten to use onPress in TabIcon. The most noteworthy thing was wrapping TabIcon in a useCallback to prevent it from being recreated all the time. Expo snack:
import React, { useRef, useState, useCallback } from 'react';
import {
View,
StyleSheet,
Animated,
Image,
TouchableOpacity,
} from 'react-native';
import Constants from 'expo-constants';
const App = () => {
const spinValue = useRef(new Animated.Value(0)).current;
const [menuToggled, setMenuToggled] = useState(null);
const TabIcon = useCallback(({ onPress, menuToggled }) => {
const logoStyles = [styles.logoStyle];
// initialized base on menuToggled
// if not done then it will take an additional button press to trigger
// the animation
const animation = useRef(new Animated.Value(menuToggled ? 0 : 1)).current;
const startAnimation = () => {
Animated.timing(animation, {
toValue: menuToggled ? 1 :0,
duration: 500,
useNativeDriver: true,
}).start();
};
const rotateInterpolate = animation.interpolate({
inputRange: [0, 1],
outputRange: ['0deg', '360deg'],
});
const animatedStyles = { transform: [{ rotate: rotateInterpolate }] };
logoStyles.push(animatedStyles);
return (
<TouchableOpacity
onPress={() => {
startAnimation();
onPress?.();
}}>
<Animated.View style={logoStyles}>
<Animated.Image
style={styles.tinyLogo}
source={{
uri: 'https://reactnative.dev/img/tiny_logo.png',
}}
/>
</Animated.View>
</TouchableOpacity>
);
},[]);
return (
<View style={styles.container}>
<TabIcon
onPress={() => setMenuToggled((prev) => !prev)}
menuToggled={menuToggled}
/>
</View>
);
};
const styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: 'center',
alignItems: 'center',
backgroundColor: 'white',
},
tinyLogo: {
width: 150,
height: 150,
borderRadius: 100,
margin: 8,
},
});
export default App;

React native flatlist inverted onscrollbegin runs every time I scrol

I want to use onScrollBegin on my flatlist. But everytime I make scroll the function runs. I only want to run this function when I am at the top, not everytime I scroll.
import * as React from 'react';
import { StyleSheet, Text, View, Pressable, Image, Dimensions, Platform, FlatList, TextInput } from 'react-native';
import { messages } from '../utils/mockChat';
import { useDispatch, useSelector } from 'react-redux';
import moment from 'moment';
import Modal from 'react-native-modalbox';
import { openModalImage } from '../redux/slice/chat/chatSlice';
const { width, height } = Dimensions.get('screen');
function propsEqual(prevProp, nextProp) {
if(prevProp.id === nextProp.id) {
return true;
}
}
const Item = React.memo(({ global_user_id, id, type, render, allDates, name, user_id, reciever, text, images, video, sending, pending, read, date }) => {
const dateNum = moment(date).format('DD-MM-YYYY');
return (
<View style={s.item}>
<View style={s.itemContainer}>
<View style={global_user_id === user_id ? s.ownerText : s.reciever_text}>
<Text style={s.text}>{ text }</Text>
</View>
</View>
</View>
)
}, propsEqual);
const userState = state => state.user.userID;
const modalState = state => state.chatSlice.modalImage;
const Chat = ({ route, navigation }) => {
const { image } = route.params;
const dispatch = useDispatch();
const modalSec = useSelector(modalState);
const userID = useSelector(userState);
const [message, setMessage] = React.useState(generateItems(messages));
const modalR = React.useRef(null);
const timerCloseModal = React.useRef(null);
React.useEffect(() => {
modalSec && modalR.current.open();
}, [modalSec]);
const dates = new Set();
function renderDate(date) {
dates.add(moment(date).format('DD-MM-YYYY'));
return (
<Text style={{color: '#333', fontSize: 12}}>{moment(date).format('DD-MM-YYYY')}</Text>
)
}
const showFooter = () => {
return (
<View style={s.footerContainer}>
<TextInput style={{height: 50, width: '100%', padding: 20}} />
</View>
)
};
const rowRenderer = ({ item }) => {
return (
<Item
item={item}
id={item.id}
allDates={dates}
render={(date) => renderDate(date)}
global_user_id={userID}
name={item.name}
user_id={item.user_id}
reciever={item.reciever}
text={item.text}
images={item.images}
video={item.video}
sending={item.sending}
pending={item.pending}
read={item.read}
type={item.type}
date={item.date} />
)
};
const closeModalImage = React.useCallback(() => {
dispatch(openModalImage());
}, [dispatch, modalR]);
return (
<View style={s.container}>
<FlatList
data={message}
keyExtractor={i => i.id.toString()}
renderItem={rowRenderer}
initialNumToRender={10}
onScrollBeginDrag={() => {
console.log('s');
// setMessage(items);
}}
extraData={message}
ListHeaderComponent={showFooter}
inverted
/>
</View>
)
};
const s = StyleSheet.create({
container: {
flex: 1
},
modal: {
justifyContent: 'center',
alignItems: 'center',
width: 300,
height: 300,
borderRadius: 200,
backgroundColor: 'transparent',
maxHeight: 500,
},
item: {
backgroundColor: 'red',
height: 250,
width: width * 0.8,
marginVertical: 12
},
ownerText: {
alignSelf: 'flex-end',
backgroundColor: 'blue'
},
reciever_text: {
alignSelf: 'flex-start'
}
});
export default Chat;
How can I fix it, that I can only scroll if I am on the top? I use inverted so its hard for me, to know where is the top position. I am very thankful for your help
Make use of the onEndReached prop.
The onEndReached function calls every time you reach the end of a list.
official doc

Why does my image not show when wrapped in an Animated.View?

I am new to programming and my task is to animate the height of my image on scroll. i.e. decrease height on scroll down and increase height to original when scrolling up. However, following the React Native documentation on Animated, I replaced Text component with my Image and I'm unable to get the image showing. It shows when I don't wrap it in <Animated.View>, can anyone explain why and tell me how to fix? Thank you.
This is my current code just trying to do the sample fade animation before I try to animate height and running into issues getting the TopImage component showing:
import React, { useRef } from 'react';
import {
Animated,
View,
ScrollView,
StyleSheet,
} from 'react-native';
import { useHeaderHeight } from '#react-navigation/stack';
import TopImage from '../components/TopImage';
import GroceryList from '../components/GroceryList';
const App = () => {
const { theme } = useContext(ThemeContext);
const styles = createStyleSheet();
const fadeAnim = useRef(new Animated.Value(0)).current;
const fadeIn = () => {
Animated.timing(fadeAnim, {
toValue: 1,
duration: 5000,
useNativeDriver: true,
}).start();
};
const fadeOut = () => {
Animated.timing(fadeAnim, {
toValue: 0,
duration: 3000,
useNativeDriver: true,
}).start();
};
return (
<View style={styles.container}>
<Animated.View
style={
{
// Bind opacity to animated value
opacity: fadeAnim,
},
}>
<TopImage />
</Animated.View>
<ScrollView
style={styles.scrollContainer}
onScrollBeginDrag={() => fadeIn()}>
<GroceryList />
</ScrollView>
</View>
);
};
const createStyleSheet = () => {
const headerHeight = useHeaderHeight();
return StyleSheet.create({
container: { flex: 1 },
scrollContainer: { paddingTop: headerHeight + 100 },
});
};
export default App;
and this is the code for my TopImage component:
import React from 'react';
import { Image, StyleSheet } from 'react-native';
const topImage = require('../images/top.png');
const TopImage = () => {
const styles = createStyleSheet();
return <Image source={topImage} style={styles.image} />;
};
const createStyleSheet = () => {
return StyleSheet.create({
image: {
position: 'absolute',
width: '100%',
height: '50%',
},
});
};
export default TopImage;
The reason it's not showing is because your image is 'absolute' positioned and as such, the outer container (Animated.View) has no height.
If you apply a height to the Animated.View like below. You'll see that the opacity is actually working, you just couldn't see it before because the Animated.View was 0 pixels tall.
<Animated.View
style={
{
// Bind opacity to animated value
opacity: fadeAnim,
height: 300,
},
}>
<TopImage />
</Animated.View>
Alternatively you could make the image position relative, height 0 and animate it to the correct size.

Problems with automatic image carousel when data is dynamic from an api using react native

I am implementing an image carousel which has an automatic rotation. When I implement it with static data (for example: creating a constant with an array) it works just the way I want it to.
However when I am getting the data from an api using axios, the carrosuel has a wrong behavior. The wrong behavior is as follows:
Swipe to the second image on the carousel and before moving on to the third image, go back to the first image and then go to the third image, then go to the fourth image, go back to the first image, and then go to the first image. fourth, this behavior is repeated x times.
So I think the problem is when I use axios. I attach the code of the classes that intervene in the problem that I am currently presenting.
I am using react native 0.62 with hooks and axios
HomeScreen.js
import React, { useEffect, useState } from "react";
import { View } from "react-native";
import CategoriesScreen from "./Categories/CategoriesScreen";
import { ScrollView } from "react-native-gesture-handler";
import Carousel from "./Banner/BannerOficial";
import { axiosClient } from "../../config/axios";
export default function HomeScreen({ navigation }) {
const [banners, setBanners] = useState([]);
useEffect(() => {
getBannersAPI();
}, []);
function getBannersAPI(){
axiosClient
.get("/service/banner_available")
.then(async function (response) {
setBanners(response.data);
})
.catch(function (error) {
console.log("Error cargando los banners: ", error);
});
}
return (
<View style={{ flex: 1 }}>
<ScrollView>
<Carousel data={banners} />
<CategoriesScreen navigation={navigation} />
</ScrollView>
</View>
);
}
Carousel.js
import React, { useState, useEffect } from 'react'
import { View, Text, StyleSheet, Dimensions, FlatList, Animated } from 'react-native'
import CarouselItem from './BannerItem'
const { width, heigth } = Dimensions.get('window')
let flatList
function infiniteScroll(dataList){
const numberOfData = dataList.length
let scrollValue = 0, scrolled = 0
setInterval(function() {
scrolled ++
if(scrolled < numberOfData)
scrollValue = scrollValue + width
else{
scrollValue = 0
scrolled = 0
}
this.flatList.scrollToOffset({ animated: true, offset: scrollValue})
}, 3000)
}
const Carousel = ({ data }) => {
const scrollX = new Animated.Value(0)
let position = Animated.divide(scrollX, width)
const [dataList, setDataList] = useState(data)
useEffect(()=> {
setDataList(data)
infiniteScroll(dataList)
})
if (data && data.length) {
return (
<View>
<FlatList data={data}
ref = {(flatList) => {this.flatList = flatList}}
keyExtractor={(item, index) => 'key' + index}
horizontal
pagingEnabled
scrollEnabled
snapToAlignment="center"
scrollEventThrottle={16}
decelerationRate={"fast"}
showsHorizontalScrollIndicator={false}
renderItem={({ item }) => {
return <CarouselItem item={item} />
}}
onScroll={Animated.event(
[{ nativeEvent: { contentOffset: { x: scrollX } } }]
)}
/>
<View style={styles.dotView}>
{data.map((_, i) => {
let opacity = position.interpolate({
inputRange: [i - 1, i, i + 1],
outputRange: [0.3, 1, 0.3],
extrapolate: 'clamp'
})
return (
<Animated.View
key={i}
style={{ opacity, height: 10, width: 10, backgroundColor: '#595959', margin: 8, borderRadius: 5 }}
/>
)
})}
</View>
</View>
)
}
console.log('Please provide Images')
return null
}
const styles = StyleSheet.create({
dotView: { flexDirection: 'row', justifyContent: 'center'}
})
export default Carousel
CarouselItem.js
import React from "react";
import { View, StyleSheet, Text, Image, Dimensions} from 'react-native';
const { width, height} = Dimensions.get('window')
const CarouselItem = ({item}) => {
return(
<View style={styles.cardView}>
<Image style={styles.image} source = {{ uri: item.imagePath}}/>
</View>
)
}
const styles = StyleSheet.create({
cardView:{
flex:1,
width: width -20,
height: height / 7,
backgroundColor: "white",
margin: 10,
borderRadius: 10,
shadowColor: "#000",
shadowOffset: {width: 0.5, height: 0.5},
shadowOpacity: 0.5,
shadowRadius: 3,
elevation: 5,
},
image: {
width: width-20,
height: height / 3,
borderRadius: 10
}
})
export default CarouselItem