react-native/RNTester/js/ListViewExample.js

/**
 * 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.
 *
 * @format
 * @flow strict-local
 */

'use strict';

const React = require('react');
const ReactNative = require('react-native');
const {
  Image,
  ListView,
  TouchableHighlight,
  StyleSheet,
  Text,
  View,
} = ReactNative;
const ListViewDataSource = require('ListViewDataSource');
const RNTesterPage = require('./RNTesterPage');

import type {RNTesterProps} from 'RNTesterTypes';

type State = {|
  dataSource: ListViewDataSource,
|};

class ListViewSimpleExample extends React.Component<RNTesterProps, State> {
  static title = '<ListView>';
  static description = 'Performant, scrollable list of data.';

  state = {
    dataSource: this.getInitialDataSource(),
  };

  _pressData: {[key: number]: boolean} = {};

  getInitialDataSource() {
    const ds = new ListView.DataSource({rowHasChanged: (r1, r2) => r1 !== r2});
    return ds.cloneWithRows(this._genRows({}));
  }

  UNSAFE_componentWillMount() {
    this._pressData = {};
  }

  render() {
    return (
      <RNTesterPage
        title={this.props.navigator ? null : '<ListView>'}
        noSpacer={true}
        noScroll={true}>
        <ListView
          dataSource={this.state.dataSource}
          renderRow={this._renderRow}
          renderSeparator={this._renderSeparator}
        />
      </RNTesterPage>
    );
  }

  _renderRow = (
    rowData: string,
    sectionID: number,
    rowID: number,
    highlightRow: (sectionID: number, rowID: number) => void,
  ) => {
    var rowHash = Math.abs(hashCode(rowData));
    var imgSource = THUMB_URLS[rowHash % THUMB_URLS.length];
    return (
      <TouchableHighlight
        onPress={() => {
          this._pressRow(rowID);
          highlightRow(sectionID, rowID);
        }}>
        <View>
          <View style={styles.row}>
            <Image style={styles.thumb} source={imgSource} />
            <Text style={styles.text}>
              {rowData + ' - ' + LOREM_IPSUM.substr(0, (rowHash % 301) + 10)}
            </Text>
          </View>
        </View>
      </TouchableHighlight>
    );
  };

  _genRows(pressData: {[key: number]: boolean}): Array<string> {
    var dataBlob = [];
    for (var ii = 0; ii < 100; ii++) {
      var pressedText = pressData[ii] ? ' (pressed)' : '';
      dataBlob.push('Row ' + ii + pressedText);
    }
    return dataBlob;
  }

  _pressRow = (rowID: number) => {
    this._pressData[rowID] = !this._pressData[rowID];
    this.setState({
      dataSource: this.state.dataSource.cloneWithRows(
        this._genRows(this._pressData),
      ),
    });
  };

  _renderSeparator(
    sectionID: number,
    rowID: number,
    adjacentRowHighlighted: boolean,
  ) {
    return (
      <View
        key={`${sectionID}-${rowID}`}
        style={{
          height: adjacentRowHighlighted ? 4 : 1,
          backgroundColor: adjacentRowHighlighted ? '#3B5998' : '#CCCCCC',
        }}
      />
    );
  }
}

var THUMB_URLS = [
  require('./Thumbnails/like.png'),
  require('./Thumbnails/dislike.png'),
  require('./Thumbnails/call.png'),
  require('./Thumbnails/fist.png'),
  require('./Thumbnails/bandaged.png'),
  require('./Thumbnails/flowers.png'),
  require('./Thumbnails/heart.png'),
  require('./Thumbnails/liking.png'),
  require('./Thumbnails/party.png'),
  require('./Thumbnails/poke.png'),
  require('./Thumbnails/superlike.png'),
  require('./Thumbnails/victory.png'),
];
var LOREM_IPSUM =
  'Lorem ipsum dolor sit amet, ius ad pertinax oportere accommodare, an vix civibus corrumpit referrentur. Te nam case ludus inciderint, te mea facilisi adipiscing. Sea id integre luptatum. In tota sale consequuntur nec. Erat ocurreret mei ei. Eu paulo sapientem vulputate est, vel an accusam intellegam interesset. Nam eu stet pericula reprimique, ea vim illud modus, putant invidunt reprehendunt ne qui.';

/* eslint no-bitwise: 0 */
var hashCode = function(str) {
  var hash = 15;
  for (var ii = str.length - 1; ii >= 0; ii--) {
    hash = (hash << 5) - hash + str.charCodeAt(ii);
  }
  return hash;
};

var styles = StyleSheet.create({
  row: {
    flexDirection: 'row',
    justifyContent: 'center',
    padding: 10,
    backgroundColor: '#F6F6F6',
  },
  thumb: {
    width: 64,
    height: 64,
  },
  text: {
    flex: 1,
  },
});

module.exports = ListViewSimpleExample;