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react-native

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A framework for building native apps using React

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/** * Copyright (c) Meta Platforms, Inc. and affiliates. * * This source code is licensed under the MIT license found in the * LICENSE file in the root directory of this source tree. * * @format * @flow * @generate-docs */ 'use strict'; import * as React from 'react'; import Platform from '../Utilities/Platform'; import StyleSheet, {type ColorValue} from '../StyleSheet/StyleSheet'; import Text from '../Text/Text'; import TouchableNativeFeedback from './Touchable/TouchableNativeFeedback'; import TouchableOpacity from './Touchable/TouchableOpacity'; import View from './View/View'; import invariant from 'invariant'; import type { AccessibilityState, AccessibilityActionEvent, AccessibilityActionInfo, } from './View/ViewAccessibility'; import type {PressEvent} from '../Types/CoreEventTypes'; type ButtonProps = $ReadOnly<{| /** Text to display inside the button. On Android the given title will be converted to the uppercased form. */ title: string, /** Handler to be called when the user taps the button. The first function argument is an event in form of [PressEvent](pressevent). */ onPress: (event?: PressEvent) => mixed, /** If `true`, doesn't play system sound on touch. @platform android @default false */ touchSoundDisabled?: ?boolean, /** Color of the text (iOS), or background color of the button (Android). @default {@platform android} '#2196F3' @default {@platform ios} '#007AFF' */ color?: ?ColorValue, /** TV preferred focus. @platform tv @default false */ hasTVPreferredFocus?: ?boolean, /** Designates the next view to receive focus when the user navigates down. See the [Android documentation][android:nextFocusDown]. [android:nextFocusDown]: https://developer.android.com/reference/android/view/View.html#attr_android:nextFocusDown @platform android, tv */ nextFocusDown?: ?number, /** Designates the next view to receive focus when the user navigates forward. See the [Android documentation][android:nextFocusForward]. [android:nextFocusForward]: https://developer.android.com/reference/android/view/View.html#attr_android:nextFocusForward @platform android, tv */ nextFocusForward?: ?number, /** Designates the next view to receive focus when the user navigates left. See the [Android documentation][android:nextFocusLeft]. [android:nextFocusLeft]: https://developer.android.com/reference/android/view/View.html#attr_android:nextFocusLeft @platform android, tv */ nextFocusLeft?: ?number, /** Designates the next view to receive focus when the user navigates right. See the [Android documentation][android:nextFocusRight]. [android:nextFocusRight]: https://developer.android.com/reference/android/view/View.html#attr_android:nextFocusRight @platform android, tv */ nextFocusRight?: ?number, /** Designates the next view to receive focus when the user navigates up. See the [Android documentation][android:nextFocusUp]. [android:nextFocusUp]: https://developer.android.com/reference/android/view/View.html#attr_android:nextFocusUp @platform android, tv */ nextFocusUp?: ?number, /** Text to display for blindness accessibility features. */ accessibilityLabel?: ?string, /** If `true`, disable all interactions for this component. @default false */ disabled?: ?boolean, /** Used to locate this view in end-to-end tests. */ testID?: ?string, /** * Accessibility props. */ accessible?: ?boolean, accessibilityActions?: ?$ReadOnlyArray<AccessibilityActionInfo>, onAccessibilityAction?: ?(event: AccessibilityActionEvent) => mixed, accessibilityState?: ?AccessibilityState, accessibilityHint?: ?string, |}>; /** A basic button component that should render nicely on any platform. Supports a minimal level of customization. If this button doesn't look right for your app, you can build your own button using [TouchableOpacity](touchableopacity) or [TouchableWithoutFeedback](touchablewithoutfeedback). For inspiration, look at the [source code for this button component][button:source]. Or, take a look at the [wide variety of button components built by the community] [button:examples]. [button:source]: https://github.com/facebook/react-native/blob/HEAD/Libraries/Components/Button.js [button:examples]: https://js.coach/?menu%5Bcollections%5D=React%20Native&page=1&query=button ```jsx <Button onPress={onPressLearnMore} title="Learn More" color="#841584" accessibilityLabel="Learn more about this purple button" /> ``` ```SnackPlayer name=Button%20Example import React from 'react'; import { StyleSheet, Button, View, SafeAreaView, Text, Alert } from 'react-native'; const Separator = () => ( <View style={styles.separator} /> ); const App = () => ( <SafeAreaView style={styles.container}> <View> <Text style={styles.title}> The title and onPress handler are required. It is recommended to set accessibilityLabel to help make your app usable by everyone. </Text> <Button title="Press me" onPress={() => Alert.alert('Simple Button pressed')} /> </View> <Separator /> <View> <Text style={styles.title}> Adjust the color in a way that looks standard on each platform. On iOS, the color prop controls the color of the text. On Android, the color adjusts the background color of the button. </Text> <Button title="Press me" color="#f194ff" onPress={() => Alert.alert('Button with adjusted color pressed')} /> </View> <Separator /> <View> <Text style={styles.title}> All interaction for the component are disabled. </Text> <Button title="Press me" disabled onPress={() => Alert.alert('Cannot press this one')} /> </View> <Separator /> <View> <Text style={styles.title}> This layout strategy lets the title define the width of the button. </Text> <View style={styles.fixToText}> <Button title="Left button" onPress={() => Alert.alert('Left button pressed')} /> <Button title="Right button" onPress={() => Alert.alert('Right button pressed')} /> </View> </View> </SafeAreaView> ); const styles = StyleSheet.create({ container: { flex: 1, justifyContent: 'center', marginHorizontal: 16, }, title: { textAlign: 'center', marginVertical: 8, }, fixToText: { flexDirection: 'row', justifyContent: 'space-between', }, separator: { marginVertical: 8, borderBottomColor: '#737373', borderBottomWidth: StyleSheet.hairlineWidth, }, }); export default App; ``` */ class Button extends React.Component<ButtonProps> { render(): React.Node { const { accessibilityLabel, color, onPress, touchSoundDisabled, title, hasTVPreferredFocus, nextFocusDown, nextFocusForward, nextFocusLeft, nextFocusRight, nextFocusUp, testID, accessible, accessibilityActions, accessibilityHint, onAccessibilityAction, } = this.props; const buttonStyles = [styles.button]; const textStyles = [styles.text]; if (color) { if (Platform.OS === 'ios') { textStyles.push({color: color}); } else { buttonStyles.push({backgroundColor: color}); } } const disabled = this.props.disabled != null ? this.props.disabled : this.props.accessibilityState?.disabled; const accessibilityState = disabled !== this.props.accessibilityState?.disabled ? {...this.props.accessibilityState, disabled} : this.props.accessibilityState; if (disabled) { buttonStyles.push(styles.buttonDisabled); textStyles.push(styles.textDisabled); } invariant( typeof title === 'string', 'The title prop of a Button must be a string', ); const formattedTitle = Platform.OS === 'android' ? title.toUpperCase() : title; const Touchable = Platform.OS === 'android' ? TouchableNativeFeedback : TouchableOpacity; return ( <Touchable accessible={accessible} accessibilityActions={accessibilityActions} onAccessibilityAction={onAccessibilityAction} accessibilityLabel={accessibilityLabel} accessibilityHint={accessibilityHint} accessibilityRole="button" accessibilityState={accessibilityState} hasTVPreferredFocus={hasTVPreferredFocus} nextFocusDown={nextFocusDown} nextFocusForward={nextFocusForward} nextFocusLeft={nextFocusLeft} nextFocusRight={nextFocusRight} nextFocusUp={nextFocusUp} testID={testID} disabled={disabled} onPress={onPress} touchSoundDisabled={touchSoundDisabled}> <View style={buttonStyles}> <Text style={textStyles} disabled={disabled}> {formattedTitle} </Text> </View> </Touchable> ); } } const styles = StyleSheet.create({ button: Platform.select({ ios: {}, android: { elevation: 4, // Material design blue from https://material.google.com/style/color.html#color-color-palette backgroundColor: '#2196F3', borderRadius: 2, }, }), text: { textAlign: 'center', margin: 8, ...Platform.select({ ios: { // iOS blue from https://developer.apple.com/ios/human-interface-guidelines/visual-design/color/ color: '#007AFF', fontSize: 18, }, android: { color: 'white', fontWeight: '500', }, }), }, buttonDisabled: Platform.select({ ios: {}, android: { elevation: 0, backgroundColor: '#dfdfdf', }, }), textDisabled: Platform.select({ ios: { color: '#cdcdcd', }, android: { color: '#a1a1a1', }, }), }); module.exports = Button;