gitProject/src/main/java/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;

public abstract class NoteWidgetProvider extends AppWidgetProvider {
    //note小部件类继承app小部件类且为抽象类待继承
    public static final String [] PROJECTION = new String [] {//设置便签挂饰数据的表头
        NoteColumns.ID,
        NoteColumns.BG_COLOR_ID,
        NoteColumns.SNIPPET//（片段，摘录）
    };

    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";//定义该类的名称

    @Override
    public void onDeleted(Context context, int[] appWidgetIds) {
        //调用AppWidgetManager中的INVALID_APPWIDGET_ID将挂件ID设置为无效，以达到删除挂件的目的
        ContentValues values = new ContentValues();
        values.put(NoteColumns.WIDGET_ID, AppWidgetManager.INVALID_APPWIDGET_ID);//将新的widget信息存入数据库
        for (int i = 0; i < appWidgetIds.length; i++) {
            //遍历并修改所有的URI值
            context.getContentResolver().update(Notes.CONTENT_NOTE_URI,
                    values,
                    NoteColumns.WIDGET_ID + "=?",
                    new String[] { String.valueOf(appWidgetIds[i])});
        }
    }

    private Cursor getNoteWidgetInfo(Context context, int widgetId) {
        //得到NoteWidget信息
        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);
    }

    protected void update(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
        //小米便签挂件appWidgetlds信息的返回与更新
        update(context, appWidgetManager, appWidgetIds, false);
    }

    private void update(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds,
            boolean privacyMode) {
        //更新widget的信息方法
        for (int i = 0; i < appWidgetIds.length; i++) {//对每一个appwidget遍历
            if (appWidgetIds[i] != AppWidgetManager.INVALID_APPWIDGET_ID) {//不是被删除的widget
                int bgId = ResourceParser.getDefaultBgId(context);
                String snippet = "";
                Intent intent = new Intent(context, NoteEditActivity.class);//创建Intent对象以用于Activity之间传递参数
                intent.setFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);
                intent.putExtra(Notes.INTENT_EXTRA_WIDGET_ID, appWidgetIds[i]);//附加组件id
                intent.putExtra(Notes.INTENT_EXTRA_WIDGET_TYPE, getWidgetType());//附加组件类型

                Cursor c = getNoteWidgetInfo(context, appWidgetIds[i]);
                if (c != null && c.moveToFirst()) {
                    if (c.getCount() > 1) {
                        //处理多个窗口同位出现的情况
                        Log.e(TAG, "Multiple message with same widget id:" + appWidgetIds[i]);
                        c.close();
                        return;
                    }
                    snippet = c.getString(COLUMN_SNIPPET);
                    bgId = c.getInt(COLUMN_BG_COLOR_ID);
                    intent.putExtra(Intent.EXTRA_UID, c.getLong(COLUMN_ID));
                    intent.setAction(Intent.ACTION_VIEW);//为intent设置一个行为
                } else {
                    ////若无关联内容则新建便签
                    snippet = context.getResources().getString(R.string.widget_havenot_content);
                    intent.setAction(Intent.ACTION_INSERT_OR_EDIT);//为intent设置一个行为
                }

                if (c != null) {
                    c.close();//关闭游标
                }
                //主要是获取对应视图
                RemoteViews rv = new RemoteViews(context.getPackageName(), getLayoutId());
                rv.setImageViewResource(R.id.widget_bg_image, getBgResourceId(bgId));
                intent.putExtra(Notes.INTENT_EXTRA_BACKGROUND_ID, bgId);
                /**
                 * Generate the pending intent to start host for the widget
                 *  为小部件生成启动主机的挂起意图
                 */
                PendingIntent pendingIntent = null;
                if (privacyMode) {
                    //判定是否是私密模式
                    rv.setTextViewText(R.id.widget_text,
                            context.getString(R.string.widget_under_visit_mode));
                    pendingIntent = PendingIntent.getActivity(context, appWidgetIds[i], new Intent(
                            context, NotesListActivity.class), PendingIntent.FLAG_UPDATE_CURRENT);
                } else {
                    //设置按钮，对点击事件进行处理
                    rv.setTextViewText(R.id.widget_text, snippet);
                    pendingIntent = PendingIntent.getActivity(context, appWidgetIds[i], intent,
                            PendingIntent.FLAG_UPDATE_CURRENT);
                }

                rv.setOnClickPendingIntent(R.id.widget_text, pendingIntent);//窗口服务部件
                appWidgetManager.updateAppWidget(appWidgetIds[i], rv);//更新widget的信息
            }
        }
    }

    protected abstract int getBgResourceId(int bgId);//从背景资源中获取当前应用ID

    protected abstract int getLayoutId();//获取布局ID

    protected abstract int getWidgetType();//获取widget类型
}