MINotes/src/net/micode/notes/widget/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;

/**
 * 基础类：NoteWidgetProvider，用于管理便签小部件的生命周期和更新逻辑。
 */
public abstract class NoteWidgetProvider extends AppWidgetProvider {

    // 数据库查询所需字段
    public static final String[] PROJECTION = new String[]{
            NoteColumns.ID,
            NoteColumns.BG_COLOR_ID,
            NoteColumns.SNIPPET
    };

    // PROJECTION 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";

    /**
     * 当某个小部件被删除时调用。
     * 删除小部件对应的数据库信息，将 WIDGET_ID 设置为无效值。
     */
    @Override
    public void onDeleted(Context context, int[] appWidgetIds) {
        ContentValues values = new ContentValues();
        values.put(NoteColumns.WIDGET_ID, AppWidgetManager.INVALID_APPWIDGET_ID);

        // 遍历所有被删除的小部件 ID，更新数据库
        for (int i = 0; i < appWidgetIds.length; i++) {
            context.getContentResolver().update(
                    Notes.CONTENT_NOTE_URI,
                    values,
                    NoteColumns.WIDGET_ID + "=?",
                    new String[]{String.valueOf(appWidgetIds[i])});
        }
    }

    /**
     * 从数据库中获取指定小部件 ID 的便签信息。
     */
    private Cursor getNoteWidgetInfo(Context context, int widgetId) {
        return context.getContentResolver().query(
                Notes.CONTENT_NOTE_URI,
                PROJECTION,
                NoteColumns.WIDGET_ID + "=? AND " + NoteColumns.PARENT_ID + "<>?",
                new String[]{String.valueOf(widgetId), String.valueOf(Notes.ID_TRASH_FOLER)},
                null);
    }

    /**
     * 更新指定小部件的显示内容（调用重载方法）。
     */
    protected void update(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
        update(context, appWidgetManager, appWidgetIds, false); // 默认非隐私模式
    }

    /**
     * 更新小部件内容。
     *
     * @param privacyMode 是否为隐私模式
     */
    private void update(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds,
                        boolean privacyMode) {
        for (int i = 0; i < appWidgetIds.length; i++) {
            // 忽略无效小部件 ID
            if (appWidgetIds[i] != AppWidgetManager.INVALID_APPWIDGET_ID) {
                int bgId = ResourceParser.getDefaultBgId(context); // 默认背景颜色 ID
                String snippet = ""; // 便签内容

                // 创建启动 NoteEditActivity 的 Intent
                Intent intent = new Intent(context, NoteEditActivity.class);
                intent.setFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);
                intent.putExtra(Notes.INTENT_EXTRA_WIDGET_ID, appWidgetIds[i]);
                intent.putExtra(Notes.INTENT_EXTRA_WIDGET_TYPE, getWidgetType());

                // 查询小部件对应的便签信息
                Cursor c = getNoteWidgetInfo(context, appWidgetIds[i]);
                if (c != null && c.moveToFirst()) {
                    if (c.getCount() > 1) {
                        Log.e(TAG, "Multiple message with same widget id:" + appWidgetIds[i]);
                        c.close();
                        return; // 如果有多个便签对应同一小部件 ID，返回错误
                    }
                    snippet = c.getString(COLUMN_SNIPPET); // 获取便签内容
                    bgId = c.getInt(COLUMN_BG_COLOR_ID); // 获取便签背景 ID
                    intent.putExtra(Intent.EXTRA_UID, c.getLong(COLUMN_ID)); // 传递便签 ID
                    intent.setAction(Intent.ACTION_VIEW); // 设置动作为查看
                } else {
                    snippet = context.getResources().getString(R.string.widget_havenot_content); // 无便签内容时的占位文本
                    intent.setAction(Intent.ACTION_INSERT_OR_EDIT); // 设置动作为插入或编辑
                }

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

                // 设置小部件的显示内容
                RemoteViews rv = new RemoteViews(context.getPackageName(), getLayoutId());
                rv.setImageViewResource(R.id.widget_bg_image, getBgResourceId(bgId)); // 设置背景图像
                intent.putExtra(Notes.INTENT_EXTRA_BACKGROUND_ID, bgId);

                // 根据隐私模式设置小部件显示和点击动作
                PendingIntent pendingIntent = null;
                if (privacyMode) {
                    rv.setTextViewText(R.id.widget_text, context.getString(R.string.widget_under_visit_mode)); // 隐私模式文本
                    pendingIntent = PendingIntent.getActivity(
                            context,
                            appWidgetIds[i],
                            new Intent(context, NotesListActivity.class),
                            PendingIntent.FLAG_UPDATE_CURRENT);
                } else {
                    rv.setTextViewText(R.id.widget_text, snippet); // 显示便签内容
                    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
            }
        }
    }

    /**
     * 获取背景资源 ID（由子类实现）。
     */
    protected abstract int getBgResourceId(int bgId);

    /**
     * 获取布局 ID（由子类实现）。
     */
    protected abstract int getLayoutId();

    /**
     * 获取小部件类型（由子类实现）。
     */
    protected abstract int getWidgetType();
}