cordova-android/cordova-js-src/platform.js

/*
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 *
*/

// The last resume event that was received that had the result of a plugin call.
var lastResumeEvent = null;

module.exports = {
    id: 'android',
    bootstrap: function() {
        var channel = require('cordova/channel'),
            cordova = require('cordova'),
            exec = require('cordova/exec'),
            modulemapper = require('cordova/modulemapper');

        // Get the shared secret needed to use the bridge.
        exec.init();

        // TODO: Extract this as a proper plugin.
        modulemapper.clobbers('cordova/plugin/android/app', 'navigator.app');

        var APP_PLUGIN_NAME = Number(cordova.platformVersion.split('.')[0]) >= 4 ? 'CoreAndroid' : 'App';

        // Inject a listener for the backbutton on the document.
        var backButtonChannel = cordova.addDocumentEventHandler('backbutton');
        backButtonChannel.onHasSubscribersChange = function() {
            // If we just attached the first handler or detached the last handler,
            // let native know we need to override the back button.
            exec(null, null, APP_PLUGIN_NAME, "overrideBackbutton", [this.numHandlers == 1]);
        };

        // Add hardware MENU and SEARCH button handlers
        cordova.addDocumentEventHandler('menubutton');
        cordova.addDocumentEventHandler('searchbutton');

        function bindButtonChannel(buttonName) {
            // generic button bind used for volumeup/volumedown buttons
            var volumeButtonChannel = cordova.addDocumentEventHandler(buttonName + 'button');
            volumeButtonChannel.onHasSubscribersChange = function() {
                exec(null, null, APP_PLUGIN_NAME, "overrideButton", [buttonName, this.numHandlers == 1]);
            };
        }
        // Inject a listener for the volume buttons on the document.
        bindButtonChannel('volumeup');
        bindButtonChannel('volumedown');

        // The resume event is not "sticky", but it is possible that the event
        // will contain the result of a plugin call. We need to ensure that the
        // plugin result is delivered even after the event is fired (CB-10498)
        var cordovaAddEventListener = document.addEventListener;

        document.addEventListener = function(evt, handler, capture) {
            cordovaAddEventListener(evt, handler, capture);

            if (evt === 'resume' && lastResumeEvent) {
                handler(lastResumeEvent);
            }
        };

        // Let native code know we are all done on the JS side.
        // Native code will then un-hide the WebView.
        channel.onCordovaReady.subscribe(function() {
            exec(onMessageFromNative, null, APP_PLUGIN_NAME, 'messageChannel', []);
            exec(null, null, APP_PLUGIN_NAME, "show", []);
        });
    }
};

function onMessageFromNative(msg) {
    var cordova = require('cordova');
    var action = msg.action;

    switch (action)
    {
        // Button events
        case 'backbutton':
        case 'menubutton':
        case 'searchbutton':
        // App life cycle events
        case 'pause':
        // Volume events
        case 'volumedownbutton':
        case 'volumeupbutton':
            cordova.fireDocumentEvent(action);
            break;
        case 'resume':
            if(arguments.length > 1 && msg.pendingResult) {
                if(arguments.length === 2) {
                    msg.pendingResult.result = arguments[1];
                } else {
                    // The plugin returned a multipart message
                    var res = [];
                    for(var i = 1; i < arguments.length; i++) {
                        res.push(arguments[i]);
                    }
                    msg.pendingResult.result = res;
                }

                // Save the plugin result so that it can be delivered to the js
                // even if they miss the initial firing of the event
                lastResumeEvent = msg;
            }
            cordova.fireDocumentEvent(action, msg);
            break;
        default:
            throw new Error('Unknown event action ' + action);
    }
}