create-expo-cljs-app
Version:
Create a react native application with Expo and Shadow-CLJS!
381 lines (368 loc) • 11.4 kB
JavaScript
/**
* Copyright (c) Facebook, Inc. and its affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* @flow
* @format
*/
;
const React = require('react');
const {
Platform,
ScrollView,
StyleSheet,
Text,
TouchableOpacity,
View,
} = require('react-native');
const nullthrows = require('nullthrows');
import type {ViewStyleProp} from 'react-native/Libraries/StyleSheet/StyleSheet';
exports.displayName = 'ScrollViewExample';
exports.title = 'ScrollView';
exports.documentationURL = 'https://reactnative.dev/docs/scrollview';
exports.category = 'Basic';
exports.description =
'Component that enables scrolling through child components';
exports.examples = [
{
title: '<ScrollView>\n',
description:
'To make content scrollable, wrap it within a <ScrollView> component',
render: function(): React.Node {
let _scrollView: ?React.ElementRef<typeof ScrollView>;
return (
<View>
<ScrollView
ref={scrollView => {
_scrollView = scrollView;
}}
automaticallyAdjustContentInsets={false}
onScroll={() => {
console.log('onScroll!');
}}
scrollEventThrottle={200}
style={styles.scrollView}>
{ITEMS.map(createItemRow)}
</ScrollView>
<Button
label="Scroll to top"
onPress={() => {
nullthrows(_scrollView).scrollTo({y: 0});
}}
/>
<Button
label="Scroll to bottom"
onPress={() => {
nullthrows(_scrollView).scrollToEnd({animated: true});
}}
/>
<Button
label="Flash scroll indicators"
onPress={() => {
nullthrows(_scrollView).flashScrollIndicators();
}}
/>
</View>
);
},
},
{
title: '<ScrollView> (horizontal = true)\n',
description:
"You can display <ScrollView>'s child components horizontally rather than vertically",
render: function(): React.Node {
function renderScrollView(
title: string,
additionalStyles: ViewStyleProp,
) {
let _scrollView: ?React.ElementRef<typeof ScrollView>;
return (
<View style={additionalStyles}>
<Text style={styles.text}>{title}</Text>
<ScrollView
ref={scrollView => {
_scrollView = scrollView;
}}
automaticallyAdjustContentInsets={false}
horizontal={true}
style={[styles.scrollView, styles.horizontalScrollView]}>
{ITEMS.map(createItemRow)}
</ScrollView>
<Button
label="Scroll to start"
onPress={() => {
nullthrows(_scrollView).scrollTo({x: 0});
}}
/>
<Button
label="Scroll to end"
onPress={() => {
nullthrows(_scrollView).scrollToEnd({animated: true});
}}
/>
<Button
label="Flash scroll indicators"
onPress={() => {
nullthrows(_scrollView).flashScrollIndicators();
}}
/>
</View>
);
}
return (
<View>
{renderScrollView('LTR layout', {direction: 'ltr'})}
{renderScrollView('RTL layout', {direction: 'rtl'})}
</View>
);
},
},
{
title: '<ScrollView> enable & disable\n',
description: 'ScrollView scrolling behaviour can be disabled and enabled',
render: function(): React.Node {
class EnableDisableList extends React.Component<{...}, *> {
state = {
scrollEnabled: true,
};
render() {
return (
<View>
<ScrollView
automaticallyAdjustContentInsets={false}
style={styles.scrollView}
scrollEnabled={this.state.scrollEnabled}>
{ITEMS.map(createItemRow)}
</ScrollView>
<Text>
{'Scrolling enabled = ' + this.state.scrollEnabled.toString()}
</Text>
<Button
label="Disable Scrolling"
onPress={() => {
this.setState({scrollEnabled: false});
}}
/>
<Button
label="Enable Scrolling"
onPress={() => {
this.setState({scrollEnabled: true});
}}
/>
</View>
);
}
}
return <EnableDisableList />;
},
},
];
if (Platform.OS === 'ios') {
exports.examples.push({
title: '<ScrollView> smooth bi-directional content loading\n',
description:
'The `maintainVisibleContentPosition` prop allows insertions to either end of the content ' +
'without causing the visible content to jump. Re-ordering is not supported.',
render: function() {
let itemCount = 6;
class AppendingList extends React.Component<{...}, *> {
state = {
/* $FlowFixMe(>=0.85.0 site=react_native_fb) This comment suppresses
* an error found when Flow v0.85 was deployed. To see the error,
* delete this comment and run Flow. */
items: [...Array(itemCount)].map((_, ii) => (
<Item msg={`Item ${ii}`} />
)),
};
render() {
return (
<View>
<ScrollView
automaticallyAdjustContentInsets={false}
maintainVisibleContentPosition={{
minIndexForVisible: 1,
autoscrollToTopThreshold: 10,
}}
style={styles.scrollView}>
{this.state.items.map(item =>
React.cloneElement(item, {key: item.props.msg}),
)}
</ScrollView>
<ScrollView
horizontal={true}
automaticallyAdjustContentInsets={false}
maintainVisibleContentPosition={{
minIndexForVisible: 1,
autoscrollToTopThreshold: 10,
}}
style={[styles.scrollView, styles.horizontalScrollView]}>
{this.state.items.map(item =>
React.cloneElement(item, {key: item.props.msg, style: null}),
)}
</ScrollView>
<View style={styles.row}>
<Button
label="Add to top"
onPress={() => {
this.setState(state => {
const idx = itemCount++;
return {
items: [
<Item
style={{paddingTop: idx * 5}}
msg={`Item ${idx}`}
/>,
].concat(state.items),
};
});
}}
/>
<Button
label="Remove top"
onPress={() => {
this.setState(state => ({
items: state.items.slice(1),
}));
}}
/>
<Button
label="Change height top"
onPress={() => {
this.setState(state => ({
items: [
React.cloneElement(state.items[0], {
style: {paddingBottom: Math.random() * 40},
}),
].concat(state.items.slice(1)),
}));
}}
/>
</View>
<View style={styles.row}>
<Button
label="Add to end"
onPress={() => {
this.setState(state => ({
items: state.items.concat(
<Item msg={`Item ${itemCount++}`} />,
),
}));
}}
/>
<Button
label="Remove end"
onPress={() => {
this.setState(state => ({
items: state.items.slice(0, -1),
}));
}}
/>
<Button
label="Change height end"
onPress={() => {
this.setState(state => ({
items: state.items.slice(0, -1).concat(
React.cloneElement(
state.items[state.items.length - 1],
{
style: {paddingBottom: Math.random() * 40},
},
),
),
}));
}}
/>
</View>
</View>
);
}
}
return <AppendingList />;
},
});
exports.examples.push({
title: '<ScrollView> (centerContent = true)\n',
description:
'ScrollView puts its content in the center if the content is smaller than scroll view',
render: function(): React.Node {
function CenterContentList(): React.Node {
return (
<ScrollView style={styles.scrollView} centerContent={true}>
<Text>This should be in center.</Text>
</ScrollView>
);
}
return <CenterContentList />;
},
});
exports.examples.push({
title: '<ScrollView> (contentOffset = {x: 100, y: 0})\n',
description: 'Initial contentOffset can be set on ScrollView.',
render: function(): React.Node {
function CenterContentList(): React.Node {
return (
<ScrollView
style={[styles.scrollView, {height: 100}]}
horizontal={true}
contentOffset={{x: 100, y: 0}}>
{ITEMS.map(createItemRow)}
</ScrollView>
);
}
return <CenterContentList />;
},
});
}
class Item extends React.PureComponent<{|
msg?: string,
style?: ViewStyleProp,
|}> {
render() {
return (
<View style={[styles.item, this.props.style]}>
<Text>{this.props.msg}</Text>
</View>
);
}
}
let ITEMS = [...Array(12)].map((_, i) => `Item ${i}`);
const createItemRow = (msg, index) => <Item key={index} msg={msg} />;
const Button = ({label, onPress}) => (
<TouchableOpacity style={styles.button} onPress={onPress}>
<Text>{label}</Text>
</TouchableOpacity>
);
const styles = StyleSheet.create({
scrollView: {
backgroundColor: '#eeeeee',
height: 300,
},
horizontalScrollView: {
height: 106,
},
text: {
fontSize: 16,
fontWeight: 'bold',
margin: 5,
},
button: {
margin: 5,
padding: 5,
alignItems: 'center',
backgroundColor: '#cccccc',
borderRadius: 3,
},
row: {
flexDirection: 'row',
justifyContent: 'space-around',
},
item: {
margin: 5,
padding: 5,
backgroundColor: '#cccccc',
borderRadius: 3,
minWidth: 96,
},
});