I have a View with few form elements and a button (TouchableHighlight). On clicking the button, an Activity Indicator should be shown as an overlay to the existing view. The Activity Indicator should be centered within the page and the existing view should be slightly blurred to indicate overlay. I tried different options but could not get it to work.
render() {
const { username, password } = this.state;
return (
<View style={styles.container}>
<View style={styles.group}>
<Text style={styles.text}>Username:</Text>
<TextInput
style={styles.input}
onChangeText={this.handleUserNameChange.bind(this)}
value={username}
underlineColorAndroid="transparent"
/>
</View>
<View style={styles.group}>
<Text style={styles.text}>Password:</Text>
<TextInput
style={styles.input}
secureTextEntry={true}
onChangeText={this.handlePasswordChange.bind(this)}
value={password}
underlineColorAndroid="transparent"
/>
</View>
<TouchableHighlight
style={styles.button}
onPress={this.handleLogin.bind(this)}>
<Text style={styles.buttonText}>Logon</Text>
</TouchableHighlight>
</View>
);
}
Existing styles:
const styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: 'flex-start',
alignItems: 'center',
backgroundColor: '#F5FCFF',
marginTop: 60
},
group: {
alignItems: 'flex-start',
padding: 10
},
input: {
width: 150,
padding: 2,
paddingLeft: 5,
borderColor: 'gray',
borderWidth: 1
},
text: {
padding: 0
},
button: {
width: 150,
backgroundColor: '#2299F2',
padding: 15,
marginTop: 20,
borderRadius: 5
},
buttonText: {
textAlign: 'center',
color: '#fff',
fontSize: 24
},
});
I need to an ActivityIndicator to the above View, overlay the view, and center the ActivityIndicator.
For this to work, you'd need to absolute position it, and render it after the elements that should be underneath the overlay:
loading: {
position: 'absolute',
left: 0,
right: 0,
top: 0,
bottom: 0,
alignItems: 'center',
justifyContent: 'center'
}Then simply compose it into the render method conditionally, based on a loading state. I am going to assume this.handleLogin sets some sort of loading state already.
Make sure it's rendered last so it takes precedence.
...
{this.state.loading &&
<View style={styles.loading}>
<ActivityIndicator size='large' />
</View>
}Here is a complete example using create react native app.
import React from 'react';
import {StyleSheet, ActivityIndicator, View} from "react-native";
export default class Example extends React.Component {
constructor(props) {
super(props);
this.state = {}
render() {
return (
<View
style={{flex: 1}}
>
//Add other content here
{this.state.loading &&
<View style={styles.loading}>
<ActivityIndicator/>
</View>
}
</View>
);
}
}
showLoading() {
this.setState({loading: true})
}
hideLoading() {
this.setState({loading: false})
}
const styles = StyleSheet.create({
loading: {
position: 'absolute',
left: 0,
right: 0,
top: 0,
bottom: 0,
opacity: 0.5,
backgroundColor: 'black',
justifyContent: 'center',
alignItems: 'center'
}
})
You can use StyleSheet.absoluteFill to shorten code.
Add this to your render:
<View style={styles.container}>
//... other code here
{this.state.loading && <View
style={{
...StyleSheet.absoluteFill,
justifyContent: 'center',
alignItems: 'center',
}}>
<ActivityIndicator />
</View>}
</View>Improvement:
You can also create a Loading component:
Loading.js
import React from 'react';
import {View, ActivityIndicator, StyleSheet} from 'react-native';
export const Loading = ({theme = 'white', size = 'large'}) => {
const color = theme === 'white' ? '#00bdcd' : '#fff';
return (
<View
style={{
...StyleSheet.absoluteFill,
justifyContent: 'center',
alignItems: 'center',
}}>
<ActivityIndicator size={size} color={color} />
</View>
);
};Then use it anywhere you want
<View style={styles.container}>
//... other code here
// remember to import Loading component
{this.state.loading && <Loading />}
</View>