How to justify (left, right, center) each child independently? - react-native

In react native I have:
<View style={styles.navBar}>
<Text>{'<'}</Text>
<Text style={styles.navBarTitle}>
Fitness & Nutrition Tracking
</Text>
<Image source={icon} style={styles.icon}/>
</View>
with these styles:
{
navBar: {
height: 60,
flexDirection: 'row',
justifyContent: 'space-between',
alignItems: 'center',
},
navBarTitle: {
textAlign: 'center',
},
icon: {
height: 60,
resizeMode: 'contain',
},
}
This is the effect I get:
This is the effect I want:
In the first example, the spacing between items is equal.
In the second example, each item is justified differently. The first item is left-justified. The second item is center-justified. The third, right-justified.
This question is similar, but it looks like react native does not support margin: 'auto'. Furthermore, the other answers only work if you only care about left and right justification, but no one really addresses center justification without auto margin.
I am trying to make a navigation bar in react native. The vanilla ios version looks like this:
(source: apple.com)
How do I do something similar? I'm mainly concerned with centering.

One way is to use nested View (flex containers) for 3 different regions and set flex:1 to left and right region
<View style={styles.navBar}>
<View style={styles.leftContainer}>
<Text style={[styles.text, {textAlign: 'left'}]}>
{'<'}
</Text>
</View>
<Text style={styles.text}>
Fitness & Nutrition Tracking
</Text>
<View style={styles.rightContainer}>
<View style={styles.rightIcon}/>
</View>
</View>
const styles = StyleSheet.create({
navBar: {
height: 60,
flexDirection: 'row',
justifyContent: 'space-between',
alignItems: 'center',
backgroundColor: 'blue',
},
leftContainer: {
flex: 1,
flexDirection: 'row',
justifyContent: 'flex-start',
backgroundColor: 'green'
},
rightContainer: {
flex: 1,
flexDirection: 'row',
justifyContent: 'flex-end',
alignItems: 'center',
backgroundColor: 'red',
},
rightIcon: {
height: 10,
width: 10,
resizeMode: 'contain',
backgroundColor: 'white',
}
});

You could also set marginLeft: 'auto' to the middle component. It should push it to the right. Also works for React Native
Source: https://hackernoon.com/flexbox-s-best-kept-secret-bd3d892826b6

If you're using a NavigationBar from the Navigator module see my question: Changing the default style for a Navigator.NavigationBar (title)

use this
marginLeft: "auto",
marginRight: "auto"

Related

How to make a text field scrollable?

I am trying to create a calculator, but I am facing a problem when the text gets long because it turns into an ellipsis, so I used ScrollView. It can be scrolled by increasing the value of numberOfLines, but when I tried scrolling up, it bounced back, and I would like it to stay where it is scrolled.
I set adjustsFontSizeToFit to true but it gets smaller too much which is not the one I want.
You can test it from here https://snack.expo.dev/_i4anOJ8v
Here is the screenshot: https://imgur.com/a/BAYyN5e
Any help is appreciated
<View style={styles.fieldContainer}>
<ScrollView contentContainerStyle={styles.field}>
<Text
// adjustsFontSizeToFit={true}
numberOfLines={500}
style={{
fontSize: textFontSize,
}}>
{text}
</Text>
</ScrollView>
</View>;
const styles = StyleSheet.create({
fieldContainer: {
flex: 1,
justifyContent: 'flex-end',
alignItems: 'flex-end',
},
field: {
marginTop: 'auto',
justifyContent: 'flex-end',
alignItems: 'flex-end',
flexDirection: 'column',
},
});
==> you need to change your style in scrollview.
field: {
justifyContent: 'flex-end',
alignItems: 'flex-end',
flexDirection: "column",
},

React Native: Vertically and Horizontally align image and text in same row

<View>
<Text>Hello</Text>
<Image source={require('./Vector.png')} />
</View>
I have the above View. I want to vertically and horizontally align image and text. Image should be on the right and text left in the same row. But I am not able to do align them correctly.
You can check here live dmeo here expo-snack:
Also the code is pretty ismple :
import * as React from 'react';
import { Text, View, StyleSheet,Image } from 'react-native';
export default class App extends React.Component {
render() {
return (
<View style={styles.container}>
<Text>Hey</Text>
<Image source={{uri:'https://source.unsplash.com/random'}} style={{height:50,width:50}}/>
</View>
);
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
justifyContent: 'space-between',
backgroundColor: '#ecf0f1',
padding: 8,
flexDirection:'row',
alignItems:'center'
}
});
hope it helps. feel free for doubts , and if you want the text and image to be not so distant you can have justifyContent: 'center',
For horizontal:
flexDirection: 'row',
For vertical:
flexDirection: 'column',
Use flexDirection: 'row' to make it in the same row & use justifyContent: 'center', alignItems: 'center' to align it vertically & horizontally.
<View style={{ flex: 1, flexDirection: 'row', justifyContent: 'center', alignItems: 'center' }}>
<Text>Hello</Text>
<Image style={{ width: 50, height: 50 }} source={require('./Vector.png')} />
</View>
You can simply do it by using flexDirection
Example :
<View
style={{
flex: 1,
flexDirection: "row",
alignItems: "center",
justifyContent: "center",
}}
>
<Text>Hello</Text>
<Image
style={{ width: 30, height: 30, resizeMode: "contain" }}
source={require("./Vector.png")}
/>
</View>
If you want to make the image right corner on the screen and text on the left corner try this. It can be done using position
<View
style={{
flex: 1,
flexDirection: "row"
}}
>
<Text style={{ position: "absolute", right: 0 }}>Hello</Text>
<Image
style={{
width: 30,
height: 30,
resizeMode: "contain",
position: "absolute",
left: 0
}}
source={require("./Vector.png")}
/>
</View>

Why are my buttons running off the screen?

I'm trying to have my two buttons sit in a row, equally spaced, and I want them of equal height and width. But they look like this at the moment.
I'm very new to React Native so please go gently!
Here's my code for what's returned.
return (
<View style={styles.screen}>
<View style={styles.horseProfile}>
<HorseProfile />
</View>
<View style={styles.vitalSignsGrid}>
<LargeVitalSigns />
</View>
<View style={styles.buttonContainer}>
<TouchableOpacity onPress={this._alertHandler}>
<View style={styles.buttonStyling}>
<Text style={styles.buttonText}>ECG</Text>
</View>
</TouchableOpacity>
<TouchableOpacity onPress={this._alertHandler}>
<View style={styles.buttonStyling}>
<Text style={styles.buttonText}>Resp Pattern</Text>
</View>
</TouchableOpacity>
</View>
<View>{/* timer and stop button */}</View>
</View>
)
Here are my styles.
const styles = StyleSheet.create({
screen: {
flex: 1,
justifyContent: 'center',
alignItems: 'center'
},
horsePatientProfile: {
flex: 1
},
vitalSignsGrid: {
flex: 3,
backgroundColor: '#14172B'
},
buttonContainer: {
flexDirection: 'row',
justifyContent: 'space-around',
backgroundColor: 'green',
width: '100%',
flex: 4
},
buttonStyling: {
backgroundColor: '#2B4250',
borderRadius: 30,
alignItems: 'center',
justifyContent: 'space-around',
width: '50%',
height: '35%',
flexDirection: 'row',
},
buttonText: {
color: '#84C5C6',
fontWeight: 'bold'
}
})
Can anyone help please? Thank you.
the width of your buttons styles.buttonStyling is 50% which is 50% of the parent Component, the parent is the touchableOpacity, since it doesn't have a set width itself it will stretch with the content, in other words the 50% does not mean the same thing, you should give an exact (relative size, I like react-native-size-matter) to the touchable opacity and justifyContent as space between to space evenly
For height, width try using React Native Dimensions React Native Dimentions
Import it:
import {Dimensions} from "react-native";
var {height, width} = Dimensions.get('window');
Example using in style:
buttonStyling: {
backgroundColor: '#2B4250',
borderRadius: 30,
alignItems: 'center',
justifyContent: 'space-around',
width: width/2,
height: height / 3.5,
flexDirection: 'row',
},
or use Flexbox

How to center react native headerTitle *component* (not string)

For the life of me, I can't center the headerTitle component. Ideas?
class GroupSelectionScreen extends React.Component{
static navigationOptions = ({navigation}) => {
return {
headerLeft: <View>
<Image source={logoImg} style={{width:72, height:33, marginLeft:5}}/>
</View>,
headerStyle: {
backgroundColor: theme.colors.darkBlue,
height: 75,
},
headerTitle: <View style={{
alignItems: "center",
flexDirection: 'row',
}}>
<View style={{backgroundColor: statusColor, width: 15, height: 15, borderRadius: 8}}></View>
<Text style={{color: 'white', fontSize: 25}}>{username}</Text>
</View>,
headerRight: <SetStatusButton onPress={navigation.getParam('toggleSetStatus')}/>,
};
};
Because you are using flexDirection:'row' you will probably want to add the property justifyContent:'center' to center the content of the view horizontally
This is due to the fact that justifyContent works on the primary axis and alignItems work on the secondary axis. Setting the flexDirection as row changes the primary axis to be row.
Adding flexDirection to a component's style determines the primary axis of its layout.
Adding justifyContent to a component's style determines the distribution of children along the primary axis.
You can see more in the docs
https://facebook.github.io/react-native/docs/flexbox
Here is a snack https://snack.expo.io/#andypandy/flexdirection
Each of the three views have flexDirection: 'row'
The first view has justifyContent: 'center' and the text is centred horizontally.
The second view has alignItems: 'center' and the text is centred vertically.
The third view has both justifyContent: 'center' and alignItems: 'center' and the text is centred horizontally and vertically
Here is an image of what it looks like
And here is the code
<View>
<View style={{flexDirection: 'row', justifyContent: 'center', backgroundColor: 'yellow', height: 100, width: 100, margin: 10}} >
<Text>Hello</Text>
</View>
<View style={{flexDirection: 'row', alignItems: 'center', backgroundColor: 'cyan', height: 100, width: 100, margin: 10}} >
<Text>Hello</Text>
</View>
<View style={{flexDirection: 'row', justifyContent: 'center', alignItems:'center', backgroundColor: 'forestgreen', height: 100, width: 100, margin: 10}} >
<Text>Hello</Text>
</View>
</View>
Update
In react-navigation there appears to be a difference between how headerTitle given by the question poster is handled in Android and iOS.
In iOS the headerTitle centres vertically and horizontally, however in Android it centres only vertically and is aligned left. Obviously this is not ideal.
There is a way to make it work in both iOS and Android, simply
Wrap the original header in a View with flex:1
Make sure the original header's View has a style with justifyContent: 'center' and alignItems: 'center'
Here is the code for the new headerTitle
<View style={{flex: 1}}>
<View style={{flexDirection: 'row', justifyContent: 'center', alignItems: 'center'}}>
<View style={{backgroundColor: 'green', width: 15, height: 15, borderRadius: 8}}/>
<Text>Spencer</Text>
</View>
</View>
Here is a snack showing it working https://snack.expo.io/#andypandy/navigation-header

react native,child's width by percentage

Here is my code. I want the product view to take up 90% width of its parent. However, the settings below are not working.
...any idea how to achieve it without using dimensions?
return (
<LazyloadScrollView
style={styles.container}
contentContainerStyle={styles.content}
name="scrollImage" >
{list.map((product, i) => <View key={i} style={styles.product}>
<LazyloadImage
host="scrollImage"
style={styles.image}
source={image}
animation={false}>
<View style={styles.id}>
<Text style={styles.idText}>{product.id}</Text>
</View>
</LazyloadImage>
</View>)
}
</LazyloadScrollView>
);
}
}
const styles = StyleSheet.create({
container: {
flex: 1,
backgroundColor: '#ffffff'
},
content: {
paddingTop: 20,
justifyContent: 'center',
alignItems: 'center',
backgroundColor: '#eee'
},
product: {
flex: 0.9,
marginTop: 5,
flexDirection: 'row',
alignItems: 'center',
backgroundColor: '#FFFFFF'
},
Why not use Dimensions? It will enable your app to be responsive.
If you don't want to use dimensions, try some style settings in the container and it's children, for example, make it full width with padding
container: {
backgroundColor: '#ffffff',
alignSelf: 'stretch',
padding: 30
}
I don't know if it works because you would have to post the rest of the code to test it but keep playing with the style and flex properties until you make it work, shouldn't take long.
Btw, always good to revisit the official layout props docs from react native
And css tricks guide to flexbox