JJJ/src/net/micode/notes/gtask/remote/GTaskSyncService.java

/*
 * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
 *
 * Licensed 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
 *
 *        <url id="d0vutuf37oq2m9lhs9r0" type="url" status="parsed" title="Apache License, Version 2.0" wc="10467">http://www.apache.org/licenses/LICENSE-2.0</url>
 *
 * 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.
 */

package net.micode.notes.gtask.remote;

import android.app.Activity;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.os.IBinder;

public class GTaskSyncService extends Service {
    // 广播 Action 名称，用于标识同步服务的广播
    public final static String GTASK_SERVICE_BROADCAST_NAME = "net.micode.notes.gtask.remote.gtask_sync_service";

    // 广播额外数据键，用于标识是否正在同步
    public final static String GTASK_SERVICE_BROADCAST_IS_SYNCING = "isSyncing";

    // 广播额外数据键，用于同步进度消息
    public final static String GTASK_SERVICE_BROADCAST_PROGRESS_MSG = "progressMsg";

    // 操作类型常量
    public final static int ACTION_START_SYNC = 0; // 开始同步
    public final static int ACTION_CANCEL_SYNC = 1; // 取消同步
    public final static int ACTION_INVALID = 2; // 无效操作

    // 操作类型键，用于 Intent 额外数据
    public final static String ACTION_STRING_NAME = "sync_action_type";

    // 同步任务实例
    private static GTaskASyncTask mSyncTask = null;

    // 同步进度消息
    private static String mSyncProgress = "";

    // 开始同步操作
    private void startSync() {
        if (mSyncTask == null) {
            // 创建并启动同步任务
            mSyncTask = new GTaskASyncTask(this, new GTaskASyncTask.OnCompleteListener() {
                public void onComplete() {
                    mSyncTask = null; // 同步完成，清空任务引用
                    sendBroadcast(""); // 发送广播通知同步完成
                    stopSelf(); // 停止服务
                }
            });
            sendBroadcast(""); // 发送广播通知同步开始
            mSyncTask.execute(); // 执行同步任务
        }
    }

    // 取消同步操作
    private void cancelSync() {
        if (mSyncTask != null) {
            mSyncTask.cancelSync(); // 取消同步任务
        }
    }

    // 服务创建时调用
    @Override
    public void onCreate() {
        mSyncTask = null; // 初始化同步任务为 null
    }

    // 服务启动时调用
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Bundle bundle = intent.getExtras();
        if (bundle != null && bundle.containsKey(ACTION_STRING_NAME)) {
            // 根据操作类型执行相应操作
            switch (bundle.getInt(ACTION_STRING_NAME, ACTION_INVALID)) {
                case ACTION_START_SYNC:
                    startSync(); // 开始同步
                    break;
                case ACTION_CANCEL_SYNC:
                    cancelSync(); // 取消同步
                    break;
                default:
                    break;
            }
            return START_STICKY; // 返回 sticky 模式，确保服务被系统杀死后重新创建
        }
        return super.onStartCommand(intent, flags, startId);
    }

    // 内存不足时调用
    @Override
    public void onLowMemory() {
        if (mSyncTask != null) {
            mSyncTask.cancelSync(); // 取消同步任务
        }
    }

    // 绑定服务时调用
    public IBinder onBind(Intent intent) {
        return null; // 返回 null，表示不支持绑定
    }

    // 发送广播通知
    public void sendBroadcast(String msg) {
        mSyncProgress = msg; // 更新同步进度消息
        Intent intent = new Intent(GTASK_SERVICE_BROADCAST_NAME);
        intent.putExtra(GTASK_SERVICE_BROADCAST_IS_SYNCING, mSyncTask != null); // 添加是否正在同步的额外数据
        intent.putExtra(GTASK_SERVICE_BROADCAST_PROGRESS_MSG, msg); // 添加同步进度消息的额外数据
        sendBroadcast(intent); // 发送广播
    }

    // 静态方法，启动同步服务
    public static void startSync(Activity activity) {
        GTaskManager.getInstance().setActivityContext(activity); // 设置活动上下文
        Intent intent = new Intent(activity, GTaskSyncService.class); // 创建 Intent
        intent.putExtra(GTaskSyncService.ACTION_STRING_NAME, GTaskSyncService.ACTION_START_SYNC); // 添加操作类型额外数据
        activity.startService(intent); // 启动服务
    }

    // 静态方法，取消同步服务
    public static void cancelSync(Context context) {
        Intent intent = new Intent(context, GTaskSyncService.class); // 创建 Intent
        intent.putExtra(GTaskSyncService.ACTION_STRING_NAME, GTaskSyncService.ACTION_CANCEL_SYNC); // 添加操作类型额外数据
        context.startService(intent); // 启动服务
    }

    // 静态方法，检查是否正在同步
    public static boolean isSyncing() {
        return mSyncTask != null; // 返回同步任务是否为 null
    }

    // 静态方法，获取同步进度消息
    public static String getProgressString() {
        return mSyncProgress; // 返回同步进度消息
    }
}