React NativeImage # | Edit on GitHub |
A React component for displaying different types of images, including network images, static resources, temporary local images, and images from local disk, such as the camera roll.
Example usage:
renderImages: function() {
return (
<View>
<Image
style={styles.icon}
source={require('./myIcon.png')}
/>
<Image
style={styles.logo}
source={{uri: 'http://facebook.github.io/react/img/logo_og.png'}}
/>
</View>
);
},
Props #
onLayout function #
Invoked on mount and layout changes with
{nativeEvent: {layout: {x, y, width, height}}}.
onLoad function #
Invoked when load completes successfully
onLoadEnd function #
Invoked when load either succeeds or fails
onLoadStart function #
Invoked on load start
resizeMode enum('cover', 'contain', 'stretch') #
Determines how to resize the image when the frame doesn't match the raw image dimensions.
'cover': Scale the image uniformly (maintain the image's aspect ratio) so that both dimensions (width and height) of the image will be equal to or larger than the corresponding dimension of the view (minus padding).
'contain': Scale the image uniformly (maintain the image's aspect ratio) so that both dimensions (width and height) of the image will be equal to or less than the corresponding dimension of the view (minus padding).
'stretch': Scale width and height independently, This may change the aspect ratio of the src.
source {uri: string}, number #
uri is a string representing the resource identifier for the image, which
could be an http address, a local file path, or the name of a static image
resource (which should be wrapped in the require('./path/to/image.png') function).
style style #
backfaceVisibility enum('visible', 'hidden')
backgroundColor color
borderBottomLeftRadius number
borderBottomRightRadius number
borderColor color
borderRadius number
borderTopLeftRadius number
borderTopRightRadius number
borderWidth number
opacity number
overflow enum('visible', 'hidden')
resizeMode Object.keys(ImageResizeMode)
tintColor color Changes the color of all the non-transparent pixels to the tintColor.
Changes the color of all the non-transparent pixels to the tintColor.
androidoverlayColor string When the image has rounded corners, specifying an overlayColor will
cause the remaining space in the corners to be filled with a solid color.
This is useful in cases which are not supported by the Android
implementation of rounded corners:
- Certain resize modes, such as 'contain'
- Animated GIFs
A typical way to use this prop is with images displayed on a solid
background and setting the overlayColor to the same color
as the background.
For details of how this works under the hood, see
http://frescolib.org/docs/rounded-corners-and-circles.html
When the image has rounded corners, specifying an overlayColor will cause the remaining space in the corners to be filled with a solid color. This is useful in cases which are not supported by the Android implementation of rounded corners: - Certain resize modes, such as 'contain' - Animated GIFs
A typical way to use this prop is with images displayed on a solid
background and setting the overlayColor to the same color
as the background.
For details of how this works under the hood, see http://frescolib.org/docs/rounded-corners-and-circles.html
testID string #
A unique identifier for this element to be used in UI Automation testing scripts.
iosaccessibilityLabel string #
The text that's read by the screen reader when the user interacts with the image.
iosaccessible bool #
When true, indicates the image is an accessibility element.
iosblurRadius number #
blurRadius: the blur radius of the blur filter added to the image
ioscapInsets {top: number, left: number, bottom: number, right: number} #
When the image is resized, the corners of the size specified by capInsets will stay a fixed size, but the center content and borders of the image will be stretched. This is useful for creating resizable rounded buttons, shadows, and other resizable assets. More info on Apple documentation
iosdefaultSource {uri: string}, number #
A static image to display while loading the image source.
iosonError function #
Invoked on load error with {nativeEvent: {error}}
iosonProgress function #
Invoked on download progress with {nativeEvent: {loaded, total}}
Methods #
static getSize(uri: string, success: (width: number, height: number) => void, failure: (error: any) => void) #
Retrieve the width and height (in pixels) of an image prior to displaying it. This method can fail if the image cannot be found, or fails to download.
In order to retrieve the image dimensions, the image may first need to be loaded or downloaded, after which it will be cached. This means that in principle you could use this method to preload images, however it is not optimized for that purpose, and may in future be implemented in a way that does not fully load/download the image data. A proper, supported way to preload images will be provided as a separate API.
static prefetch(url: string) #
Prefetches a remote image for later use by downloading it to the disk cache
Examples # | Edit on GitHub |
'use strict';
var React = require('react');
var ReactNative = require('react-native');
var {
Image,
Platform,
StyleSheet,
Text,
View,
ActivityIndicatorIOS
} = ReactNative;
var base64Icon = 'data:image/png;base64,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';
var ImageCapInsetsExample = require('./ImageCapInsetsExample');
const IMAGE_PREFETCH_URL = 'http://facebook.github.io/origami/public/images/blog-hero.jpg?r=1&t=' + Date.now();
var prefetchTask = Image.prefetch(IMAGE_PREFETCH_URL);
var NetworkImageCallbackExample = React.createClass({
getInitialState: function() {
return {
events: [],
startLoadPrefetched: false,
mountTime: new Date(),
};
},
componentWillMount() {
this.setState({mountTime: new Date()});
},
render: function() {
var { mountTime } = this.state;
return (
<View>
<Image
source={this.props.source}
style={[styles.base, {overflow: 'visible'}]}
onLoadStart={() => this._loadEventFired(`✔ onLoadStart (+${new Date() - mountTime}ms)`)}
onLoad={() => this._loadEventFired(`✔ onLoad (+${new Date() - mountTime}ms)`)}
onLoadEnd={() => {
this._loadEventFired(`✔ onLoadEnd (+${new Date() - mountTime}ms)`);
this.setState({startLoadPrefetched: true}, () => {
prefetchTask.then(() => {
this._loadEventFired(`✔ Prefetch OK (+${new Date() - mountTime}ms)`);
}, error => {
this._loadEventFired(`✘ Prefetch failed (+${new Date() - mountTime}ms)`);
});
});
}}
/>
{this.state.startLoadPrefetched ?
<Image
source={this.props.prefetchedSource}
style={[styles.base, {overflow: 'visible'}]}
onLoadStart={() => this._loadEventFired(`✔ (prefetched) onLoadStart (+${new Date() - mountTime}ms)`)}
onLoad={() => this._loadEventFired(`✔ (prefetched) onLoad (+${new Date() - mountTime}ms)`)}
onLoadEnd={() => this._loadEventFired(`✔ (prefetched) onLoadEnd (+${new Date() - mountTime}ms)`)}
/>
: null}
<Text style={{marginTop: 20}}>
{this.state.events.join('\n')}
</Text>
</View>
);
},
_loadEventFired(event) {
this.setState((state) => {
return state.events = [...state.events, event];
});
}
});
var NetworkImageExample = React.createClass({
getInitialState: function() {
return {
error: false,
loading: false,
progress: 0
};
},
render: function() {
var loader = this.state.loading ?
<View style={styles.progress}>
<Text>{this.state.progress}%</Text>
<ActivityIndicatorIOS style={{marginLeft:5}}/>
</View> : null;
return this.state.error ?
<Text>{this.state.error}</Text> :
<Image
source={this.props.source}
style={[styles.base, {overflow: 'visible'}]}
onLoadStart={(e) => this.setState({loading: true})}
onError={(e) => this.setState({error: e.nativeEvent.error, loading: false})}
onProgress={(e) => this.setState({progress: Math.round(100 * e.nativeEvent.loaded / e.nativeEvent.total)})}
onLoad={() => this.setState({loading: false, error: false})}>
{loader}
</Image>;
}
});
var ImageSizeExample = React.createClass({
getInitialState: function() {
return {
width: 0,
height: 0,
};
},
componentDidMount: function() {
Image.getSize(this.props.source.uri, (width, height) => {
this.setState({width, height});
});
},
render: function() {
return (
<View style={{flexDirection: 'row'}}>
<Image
style={{
width: 60,
height: 60,
backgroundColor: 'transparent',
marginRight: 10,
}}
source={this.props.source} />
<Text>
Actual dimensions:{'\n'}
Width: {this.state.width}, Height: {this.state.height}
</Text>
</View>
);
},
});
exports.displayName = (undefined: ?string);
exports.framework = 'React';
exports.title = '<Image>';
exports.description = 'Base component for displaying different types of images.';
exports.examples = [
{
title: 'Plain Network Image',
description: 'If the `source` prop `uri` property is prefixed with ' +
'"http", then it will be downloaded from the network.',
render: function() {
return (
<Image
source={{uri: 'http://facebook.github.io/react/img/logo_og.png'}}
style={styles.base}
/>
);
},
},
{
title: 'Plain Static Image',
description: 'Static assets should be placed in the source code tree, and ' +
'required in the same way as JavaScript modules.',
render: function() {
return (
<View style={styles.horizontal}>
<Image source={require('./uie_thumb_normal.png')} style={styles.icon} />
<Image source={require('./uie_thumb_selected.png')} style={styles.icon} />
<Image source={require('./uie_comment_normal.png')} style={styles.icon} />
<Image source={require('./uie_comment_highlighted.png')} style={styles.icon} />
</View>
);
},
},
{
title: 'Image Loading Events',
render: function() {
return (
<NetworkImageCallbackExample source={{uri: 'http://facebook.github.io/origami/public/images/blog-hero.jpg?r=1&t=' + Date.now()}}
prefetchedSource={{uri: IMAGE_PREFETCH_URL}}/>
);
},
},
{
title: 'Error Handler',
render: function() {
return (
<NetworkImageExample source={{uri: 'http://TYPO_ERROR_facebook.github.io/react/img/logo_og.png'}} />
);
},
platform: 'ios',
},
{
title: 'Image Download Progress',
render: function() {
return (
<NetworkImageExample source={{uri: 'http://facebook.github.io/origami/public/images/blog-hero.jpg?r=1'}}/>
);
},
platform: 'ios',
},
{
title: 'defaultSource',
description: 'Show a placeholder image when a network image is loading',
render: function() {
return (
<Image
defaultSource={require('./bunny.png')}
source={{uri: 'http://facebook.github.io/origami/public/images/birds.jpg'}}
style={styles.base}
/>
);
},
platform: 'ios',
},
{
title: 'Border Color',
render: function() {
return (
<View style={styles.horizontal}>
<Image
source={smallImage}
style={[
styles.base,
styles.background,
{borderWidth: 3, borderColor: '#f099f0'}
]}
/>
</View>
);
},
},
{
title: 'Border Width',
render: function() {
return (
<View style={styles.horizontal}>
<Image
source={smallImage}
style={[
styles.base,
styles.background,
{borderWidth: 5, borderColor: '#f099f0'}
]}
/>
</View>
);
},
},
{
title: 'Border Radius',
render: function() {
return (
<View style={styles.horizontal}>
<Image
style={[styles.base, {borderRadius: 5}]}
source={fullImage}
/>
<Image
style={[styles.base, styles.leftMargin, {borderRadius: 19}]}
source={fullImage}
/>
</View>
);
},
},
{
title: 'Background Color',
render: function() {
return (
<View style={styles.horizontal}>
<Image source={smallImage} style={styles.base} />
<Image
style={[
styles.base,
styles.leftMargin,
{backgroundColor: 'rgba(0, 0, 100, 0.25)'}
]}
source={smallImage}
/>
<Image
style={[styles.base, styles.leftMargin, {backgroundColor: 'red'}]}
source={smallImage}
/>
<Image
style={[styles.base, styles.leftMargin, {backgroundColor: 'black'}]}
source={smallImage}
/>
</View>
);
},
},
{
title: 'Opacity',
render: function() {
return (
<View style={styles.horizontal}>
<Image
style={[styles.base, {opacity: 1}]}
source={fullImage}
/>
<Image
style={[styles.base, styles.leftMargin, {opacity: 0.8}]}
source={fullImage}
/>
<Image
style={[styles.base, styles.leftMargin, {opacity: 0.6}]}
source={fullImage}
/>
<Image
style={[styles.base, styles.leftMargin, {opacity: 0.4}]}
source={fullImage}
/>
<Image
style={[styles.base, styles.leftMargin, {opacity: 0.2}]}
source={fullImage}
/>
<Image
style={[styles.base, styles.leftMargin, {opacity: 0}]}
source={fullImage}
/>
</View>
);
},
},
{
title: 'Nesting',
render: function() {
return (
<Image
style={{width: 60, height: 60, backgroundColor: 'transparent'}}
source={fullImage}>
<Text style={styles.nestedText}>
React
</Text>
</Image>
);
},
},
{
title: 'Tint Color',
description: 'The `tintColor` style prop changes all the non-alpha ' +
'pixels to the tint color.',
render: function() {
return (
<View>
<View style={styles.horizontal}>
<Image
source={require('./uie_thumb_normal.png')}
style={[styles.icon, {borderRadius: 5, tintColor: '#5ac8fa' }]}
/>
<Image
source={require('./uie_thumb_normal.png')}
style={[styles.icon, styles.leftMargin, {borderRadius: 5, tintColor: '#4cd964' }]}
/>
<Image
source={require('./uie_thumb_normal.png')}
style={[styles.icon, styles.leftMargin, {borderRadius: 5, tintColor: '#ff2d55' }]}
/>
<Image
source={require('./uie_thumb_normal.png')}
style={[styles.icon, styles.leftMargin, {borderRadius: 5, tintColor: '#8e8e93' }]}
/>
</View>
<Text style={styles.sectionText}>
It also works with downloaded images:
</Text>
<View style={styles.horizontal}>
<Image
source={smallImage}
style={[styles.base, {borderRadius: 5, tintColor: '#5ac8fa' }]}
/>
<Image
source={smallImage}
style={[styles.base, styles.leftMargin, {borderRadius: 5, tintColor: '#4cd964' }]}
/>
<Image
source={smallImage}
style={[styles.base, styles.leftMargin, {borderRadius: 5, tintColor: '#ff2d55' }]}
/>
<Image
source={smallImage}
style={[styles.base, styles.leftMargin, {borderRadius: 5, tintColor: '#8e8e93' }]}
/>
</View>
</View>
);
},
},
{
title: 'Resize Mode',
description: 'The `resizeMode` style prop controls how the image is ' +
'rendered within the frame.',
render: function() {
return (
<View>
{[smallImage, fullImage].map((image, index) => {
return (
<View key={index}>
<View style={styles.horizontal}>
<View>
<Text style={[styles.resizeModeText]}>
Contain
</Text>
<Image
style={styles.resizeMode}
resizeMode={Image.resizeMode.contain}
source={image}
/>
</View>
<View style={styles.leftMargin}>
<Text style={[styles.resizeModeText]}>
Cover
</Text>
<Image
style={styles.resizeMode}
resizeMode={Image.resizeMode.cover}
source={image}
/>
</View>
</View>
<View style={styles.horizontal}>
<View>
<Text style={[styles.resizeModeText]}>
Stretch
</Text>
<Image
style={styles.resizeMode}
resizeMode={Image.resizeMode.stretch}
source={image}
/>
</View>
{ Platform.OS === 'android' ?
<View style={styles.leftMargin}>
<Text style={[styles.resizeModeText]}>
Center
</Text>
<Image
style={styles.resizeMode}
resizeMode={Image.resizeMode.center}
source={image}
/>
</View>
: null }
</View>
</View>
);
})}
</View>
);
},
},
{
title: 'Animated GIF',
render: function() {
return (
<Image
style={styles.gif}
source={{uri: 'http://38.media.tumblr.com/9e9bd08c6e2d10561dd1fb4197df4c4e/tumblr_mfqekpMktw1rn90umo1_500.gif'}}
/>
);
},
platform: 'ios',
},
{
title: 'Base64 image',
render: function() {
return (
<Image
style={styles.base64}
source={{uri: base64Icon, scale: 3}}
/>
);
},
platform: 'ios',
},
{
title: 'Cap Insets',
description:
'When the image is resized, the corners of the size specified ' +
'by capInsets will stay a fixed size, but the center content and ' +
'borders of the image will be stretched. This is useful for creating ' +
'resizable rounded buttons, shadows, and other resizable assets.',
render: function() {
return <ImageCapInsetsExample />;
},
platform: 'ios',
},
{
title: 'Image Size',
render: function() {
return <ImageSizeExample source={fullImage} />;
},
platform: 'ios',
},
];
var fullImage = {uri: 'http://facebook.github.io/react/img/logo_og.png'};
var smallImage = {uri: 'http://facebook.github.io/react/img/logo_small_2x.png'};
var styles = StyleSheet.create({
base: {
width: 38,
height: 38,
},
progress: {
flex: 1,
alignItems: 'center',
flexDirection: 'row',
width: 100
},
leftMargin: {
marginLeft: 10,
},
background: {
backgroundColor: '#222222'
},
sectionText: {
marginVertical: 6,
},
nestedText: {
marginLeft: 12,
marginTop: 20,
backgroundColor: 'transparent',
color: 'white'
},
resizeMode: {
width: 90,
height: 60,
borderWidth: 0.5,
borderColor: 'black'
},
resizeModeText: {
fontSize: 11,
marginBottom: 3,
},
icon: {
width: 15,
height: 15,
},
horizontal: {
flexDirection: 'row',
},
gif: {
flex: 1,
height: 200,
},
base64: {
flex: 1,
height: 50,
resizeMode: 'contain',
},
});
