react-native/Libraries/Components/Picker/Picker.js

/**
 * Copyright (c) 2015-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 *
 * @providesModule Picker
 * @flow
 */

'use strict';

var ColorPropType = require('ColorPropType');
var PickerIOS = require('PickerIOS');
var PickerAndroid = require('PickerAndroid');
var Platform = require('Platform');
var React = require('React');
const PropTypes = require('prop-types');
var StyleSheetPropType = require('StyleSheetPropType');
var TextStylePropTypes = require('TextStylePropTypes');
var UnimplementedView = require('UnimplementedView');
const ViewPropTypes = require('ViewPropTypes');
var ViewStylePropTypes = require('ViewStylePropTypes');

var itemStylePropType = StyleSheetPropType(TextStylePropTypes);

var pickerStyleType = StyleSheetPropType({
  ...ViewStylePropTypes,
  color: ColorPropType,
});

var MODE_DIALOG = 'dialog';
var MODE_DROPDOWN = 'dropdown';

/**
 * Individual selectable item in a Picker.
 */
class PickerItem extends React.Component<{
 label: string,
 value?: any,
 color?: ColorPropType,
 testID?: string,
}> {
 static propTypes = {
   /**
    * Text to display for this item.
    */
   label: PropTypes.string.isRequired,
   /**
    * The value to be passed to picker's `onValueChange` callback when
    * this item is selected. Can be a string or an integer.
    */
   value: PropTypes.any,
   /**
    * Color of this item's text.
    * @platform android
    */
   color: ColorPropType,
   /**
    * Used to locate the item in end-to-end tests.
    */
   testID: PropTypes.string,
 };

 render() {
   // The items are not rendered directly
   throw null;
 }
}

/**
 * Renders the native picker component on iOS and Android. Example:
 *
 *     <Picker
 *       selectedValue={this.state.language}
 *       onValueChange={(itemValue, itemIndex) => this.setState({language: itemValue})}>
 *       <Picker.Item label="Java" value="java" />
 *       <Picker.Item label="JavaScript" value="js" />
 *     </Picker>
 */
class Picker extends React.Component<{
 style?: $FlowFixMe,
 selectedValue?: any,
 onValueChange?: Function,
 enabled?: boolean,
 mode?: 'dialog' | 'dropdown',
 itemStyle?: $FlowFixMe,
 prompt?: string,
 testID?: string,
}> {
 /**
  * On Android, display the options in a dialog.
  */
 static MODE_DIALOG = MODE_DIALOG;

 /**
  * On Android, display the options in a dropdown (this is the default).
  */
 static MODE_DROPDOWN = MODE_DROPDOWN;

 static Item = PickerItem;

 static defaultProps = {
   mode: MODE_DIALOG,
 };

 // $FlowFixMe(>=0.41.0)
 static propTypes = {
   ...ViewPropTypes,
   style: pickerStyleType,
   /**
    * Value matching value of one of the items. Can be a string or an integer.
    */
   selectedValue: PropTypes.any,
   /**
    * Callback for when an item is selected. This is called with the following parameters:
    *   - `itemValue`: the `value` prop of the item that was selected
    *   - `itemPosition`: the index of the selected item in this picker
    */
   onValueChange: PropTypes.func,
   /**
    * If set to false, the picker will be disabled, i.e. the user will not be able to make a
    * selection.
    * @platform android
    */
   enabled: PropTypes.bool,
   /**
    * On Android, specifies how to display the selection items when the user taps on the picker:
    *
    *   - 'dialog': Show a modal dialog. This is the default.
    *   - 'dropdown': Shows a dropdown anchored to the picker view
    *
    * @platform android
    */
   mode: PropTypes.oneOf(['dialog', 'dropdown']),
   /**
    * Style to apply to each of the item labels.
    * @platform ios
    */
   itemStyle: itemStylePropType,
   /**
    * Prompt string for this picker, used on Android in dialog mode as the title of the dialog.
    * @platform android
    */
   prompt: PropTypes.string,
   /**
    * Used to locate this view in end-to-end tests.
    */
   testID: PropTypes.string,
 };

 render() {
     if (Platform.OS === 'ios') {
       // $FlowFixMe found when converting React.createClass to ES6
       return <PickerIOS {...this.props}>{this.props.children}</PickerIOS>;
     } else if (Platform.OS === 'android') {
       // $FlowFixMe found when converting React.createClass to ES6
       return <PickerAndroid {...this.props}>{this.props.children}</PickerAndroid>;
     } else {
       return <UnimplementedView />;
     }
 }
}

module.exports = Picker;