text123/NoteWidgetProvider.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
 *
 *        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.
 */

package net.micode.notes.widget;

import android.app.PendingIntent;
import android.appwidget.AppWidgetManager;
import android.appwidget.AppWidgetProvider;
import android.content.ContentValues;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.util.Log;
import android.widget.RemoteViews;

import net.micode.notes.R;
import net.micode.notes.data.Notes;
import net.micode.notes.data.Notes.NoteColumns;
import net.micode.notes.tool.ResourceParser;
import net.micode.notes.ui.NoteEditActivity;
import net.micode.notes.ui.NotesListActivity;

public abstract class NoteWidgetProvider extends AppWidgetProvider {
    
    // 定义查询列的数组，用于获取小部件相关的笔记信息
    public static final String[] PROJECTION = new String[] {
        NoteColumns.ID,
        NoteColumns.BG_COLOR_ID,
        NoteColumns.SNIPPET
    };

    // 每一列在查询结果中的索引
    public static final int COLUMN_ID           = 0;
    public static final int COLUMN_BG_COLOR_ID  = 1;
    public static final int COLUMN_SNIPPET      = 2;

    private static final String TAG = "NoteWidgetProvider";

    // 小部件删除时调用，清理小部件ID与笔记的关联
    @Override
    public void onDeleted(Context context, int[] appWidgetIds) {
        ContentValues values = new ContentValues();
        values.put(NoteColumns.WIDGET_ID, AppWidgetManager.INVALID_APPWIDGET_ID); // 设置无效小部件ID
        for (int i = 0; i < appWidgetIds.length; i++) {
            context.getContentResolver().update(Notes.CONTENT_NOTE_URI, // 更新数据库中与该小部件ID关联的笔记
                    values,
                    NoteColumns.WIDGET_ID + "=?",
                    new String[] { String.valueOf(appWidgetIds[i]) });
        }
    }

    // 获取特定小部件ID的笔记信息，过滤掉“回收站”中的笔记
    private Cursor getNoteWidgetInfo(Context context, int widgetId) {
        return context.getContentResolver().query(Notes.CONTENT_NOTE_URI,
                PROJECTION,
                NoteColumns.WIDGET_ID + "=? AND " + NoteColumns.PARENT_ID + "<>?", // 排除回收站
                new String[] { String.valueOf(widgetId), String.valueOf(Notes.ID_TRASH_FOLER) },
                null);
    }

    // 更新小部件内容，默认调用该方法，privacyMode为false
    protected void update(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
        update(context, appWidgetManager, appWidgetIds, false);
    }

    // 更新小部件的具体实现
    private void update(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds,
            boolean privacyMode) {
        for (int i = 0; i < appWidgetIds.length; i++) {
            if (appWidgetIds[i] != AppWidgetManager.INVALID_APPWIDGET_ID) { // 确保小部件ID有效
                int bgId = ResourceParser.getDefaultBgId(context); // 获取默认背景ID
                String snippet = ""; // 初始化笔记内容
                Intent intent = new Intent(context, NoteEditActivity.class); // 打开笔记编辑页面
                intent.setFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP); // 设置Activity启动模式
                intent.putExtra(Notes.INTENT_EXTRA_WIDGET_ID, appWidgetIds[i]); // 传递小部件ID
                intent.putExtra(Notes.INTENT_EXTRA_WIDGET_TYPE, getWidgetType()); // 传递小部件类型

                // 查询与该小部件ID关联的笔记信息
                Cursor c = getNoteWidgetInfo(context, appWidgetIds[i]);
                if (c != null && c.moveToFirst()) { // 如果查询到笔记
                    if (c.getCount() > 1) { // 如果查询到多条数据，打印日志并返回
                        Log.e(TAG, "Multiple message with same widget id:" + appWidgetIds[i]);
                        c.close();
                        return;
                    }
                    snippet = c.getString(COLUMN_SNIPPET); // 获取笔记摘要
                    bgId = c.getInt(COLUMN_BG_COLOR_ID); // 获取背景ID
                    intent.putExtra(Intent.EXTRA_UID, c.getLong(COLUMN_ID)); // 传递笔记ID
                    intent.setAction(Intent.ACTION_VIEW); // 设置查看笔记的动作
                } else { // 如果没有找到笔记
                    snippet = context.getResources().getString(R.string.widget_havenot_content); // 设置默认提示文字
                    intent.setAction(Intent.ACTION_INSERT_OR_EDIT); // 设置插入或编辑动作
                }

                if (c != null) {
                    c.close(); // 关闭Cursor
                 }

                // 创建RemoteViews，设置小部件布局
                RemoteViews rv = new RemoteViews(context.getPackageName(), getLayoutId());
                rv.setImageViewResource(R.id.widget_bg_image, getBgResourceId(bgId)); // 设置背景图
                intent.putExtra(Notes.INTENT_EXTRA_BACKGROUND_ID, bgId); // 传递背景ID

                // 生成PendingIntent，处理点击事件
                PendingIntent pendingIntent = null;
                if (privacyMode) { // 如果处于隐私模式
                    rv.setTextViewText(R.id.widget_text,
                            context.getString(R.string.widget_under_visit_mode)); // 设置隐私模式提示
                    pendingIntent = PendingIntent.getActivity(context, appWidgetIds[i], new Intent(
                            context, NotesListActivity.class), PendingIntent.FLAG_UPDATE_CURRENT);
                } else { // 正常模式
                    rv.setTextViewText(R.id.widget_text, snippet); // 设置笔记摘要
                    pendingIntent = PendingIntent.getActivity(context, appWidgetIds[i], intent,
                            PendingIntent.FLAG_UPDATE_CURRENT);
                }

                rv.setOnClickPendingIntent(R.id.widget_text, pendingIntent); // 设置点击事件
                appWidgetManager.updateAppWidget(appWidgetIds[i], rv); // 更新小部件
            }
        }
 }

    // 抽象方法：获取背景资源ID
    protected abstract int getBgResourceId(int bgId);

    // 抽象方法：获取小部件的布局ID
    protected abstract int getLayoutId();

    // 抽象方法：获取小部件的类型
    protected abstract int getWidgetType();
}