react-native-arenakit/sources/support/Arena.js

为编写arena app中react native应用提供基础的ui及原生能力api支撑

import {NativeModules, Platform, DeviceEventEmitter, Dimensions} from 'react-native';

import AndroidApiMap from './android-api-map';

let RNMeasureText = NativeModules.RNMeasureText;

//提供arena容器通讯能力
const Arena = {

    /**
        params:
          text: 文本
          fontSize: 字体大小
          fontFamily?: 字体族
          width: 限制宽度

      callback(result):
        result:
          width: 宽度
          height: 高度
          lineCount: 行数量
          lastLineWidth：最后一行宽度
    */
    measureText: (params) => {
      var fontSize = params && params.fontSize

      if (typeof fontSize !== 'number') {
        return Promise.reject(new Error('missing required \'fontSize\' property'));
      }

      var fontScale = Dimensions.get('window').fontScale || 1;

      if (fontScale !== 1) {
        params = Object.assign(
          {},
          params,
          { fontSize: fontSize * fontScale }
        );
      }
      return RNMeasureText.measure(params);
    },
    
    /**
     * 添加原生事件
     * @param name
     * @param callback
     */
    addEventListener: (name, callback) => {
        if (Platform.OS === 'android') {
            DeviceEventEmitter.addListener(name, callback);
        } else {
            const { ArenaNotification } = NativeModules;
            if (ArenaNotification) {
                ArenaNotification.startReceiveNotification();//在原生中注册通知
                const arenaNotificationEmitter = new NativeEventEmitter(ArenaNotification);
                arenaNotificationEmitter.addListener(
                    name,
                    callback
                );
            }
        }
    }
};

module.exports = Arena;