ReadCodeAndAnalyse/Notes.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.data;//包声明

import android.net.Uri;//导入Android框架中的Uri类

public class Notes 
{
    public static final String AUTHORITY = "micode_notes";
    public static final String TAG = "Notes";
    public static final int TYPE_NOTE     = 0;
    public static final int TYPE_FOLDER   = 1;
    public static final int TYPE_SYSTEM   = 2;//定义了公共静态常量，用于提供一些固定的值

    /**
     * Following IDs are system folders' identifiers
     * {@link Notes#ID_ROOT_FOLDER } is default folder
     * {@link Notes#ID_TEMPARAY_FOLDER } is for notes belonging no folder
     * {@link Notes#ID_CALL_RECORD_FOLDER} is to store call records
     */
    public static final int ID_ROOT_FOLDER = 0;
    public static final int ID_TEMPARAY_FOLDER = -1;
    public static final int ID_CALL_RECORD_FOLDER = -2;
    public static final int ID_TRASH_FOLER = -3;//定义了四个public static final整型常量

    public static final String INTENT_EXTRA_ALERT_DATE = "net.micode.notes.alert_date";
    public static final String INTENT_EXTRA_BACKGROUND_ID = "net.micode.notes.background_color_id";
    public static final String INTENT_EXTRA_WIDGET_ID = "net.micode.notes.widget_id";
    public static final String INTENT_EXTRA_WIDGET_TYPE = "net.micode.notes.widget_type";
    public static final String INTENT_EXTRA_FOLDER_ID = "net.micode.notes.folder_id";
    public static final String INTENT_EXTRA_CALL_DATE = "net.micode.notes.call_date";//同样定义了四个public static final字符串常量
    //用于在Android开发中标识Intent的额外数据

    public static final int TYPE_WIDGET_INVALIDE      = -1;
    public static final int TYPE_WIDGET_2X            = 0;
    public static final int TYPE_WIDGET_4X            = 1;//定义了三个public static final整数常量，它们很可能用于标识不同类型的小部件或视图

    public static class DataConstants {
        public static final String NOTE = TextNote.CONTENT_ITEM_TYPE;
        public static final String CALL_NOTE = CallNote.CONTENT_ITEM_TYPE;
    }//定义了一个DataConstants的静态类，该类包含两个静态的、不可变的（final）字符串常量

    /**
     * Uri to query all notes and folders
     */
    public static final Uri CONTENT_NOTE_URI = Uri.parse("content://" + AUTHORITY + "/note");
//定义了一个公共的、静态的、不可变的（final）Uri对象，名为CONTENT_NOTE_URI。这个Uri对象表示一个特定的内容URI，用于Android的内容提供者来标识和访问数据
    
    /**
     * Uri to query data
     */
    public static final Uri CONTENT_DATA_URI = Uri.parse("content://" + AUTHORITY + "/data");

    public interface NoteColumns //NoteColumns这样的接口通常用于定义数据库表的列名常量
    {
        /**
         * The unique ID for a row
         * <P> Type: INTEGER (long) </P>
         */
        public static final String ID = "_id";//NoteColumns接口定义了一个公共的静态最终（public static final）字符串常量ID，其值为"_id"

        /**
         * The parent's id for note or folder
         * <P> Type: INTEGER (long) </P>
         */
        public static final String PARENT_ID = "parent_id";//NoteColumns接口定义了一个公共的静态最终（public static final）字符串常量PARENT_ID，其值为"parent_id"

        /**
         * Created data for note or folder
         * <P> Type: INTEGER (long) </P>
         */
        public static final String CREATED_DATE = "created_date";//NoteColumns接口定义了一个公共的静态最终（public static final）字符串常量CREATED_DATE，其值为"created_date"


        /**
         * Latest modified date
         * <P> Type: INTEGER (long) </P>
         */
        public static final String MODIFIED_DATE = "modified_date";//定义一个字符串常量，命名为modified_date


        /**
         * Alert date
         * <P> Type: INTEGER (long) </P>
         */
        public static final String ALERTED_DATE = "alert_date";//定义一个字符串常量，命名为alert_date

        /**
         * Folder's name or text content of note
         * <P> Type: TEXT </P>
         */
        public static final String SNIPPET = "snippet";//定义一个字符串常量，命名为snippet

        /**
         * Note's widget id
         * <P> Type: INTEGER (long) </P>
         */
        public static final String WIDGET_ID = "widget_id";//定义一个字符串常量，命名为widget_id

        /**
         * Note's widget type
         * <P> Type: INTEGER (long) </P>
         */
        public static final String WIDGET_TYPE = "widget_type";//定义一个字符串常量，命名为widget_type

        /**
         * Note's background color's id
         * <P> Type: INTEGER (long) </P>
         */
        public static final String BG_COLOR_ID = "bg_color_id";//定义一个字符串常量，命名为bg_color_id

        /**
         * For text note, it doesn't has attachment, for multi-media
         * note, it has at least one attachment
         * <P> Type: INTEGER </P>
         */
        public static final String HAS_ATTACHMENT = "has_attachment";//定义一个字符串常量，命名为has_attachment

        /**
         * Folder's count of notes
         * <P> Type: INTEGER (long) </P>
         */
        public static final String NOTES_COUNT = "notes_count";//定义一个字符串常量，命名为notes_count

        /**
         * The file type: folder or note
         * <P> Type: INTEGER </P>
         */
        public static final String TYPE = "type";//定义一个字符串常量，命名为type

        /**
         * The last sync id
         * <P> Type: INTEGER (long) </P>
         */
        public static final String SYNC_ID = "sync_id";//定义一个字符串常量，命名为sync_id

        /**
         * Sign to indicate local modified or not
         * <P> Type: INTEGER </P>
         */
        public static final String LOCAL_MODIFIED = "local_modified";//定义一个字符串常量，命名为local_modified

        /**
         * Original parent id before moving into temporary folder
         * <P> Type : INTEGER </P>
         */
        public static final String ORIGIN_PARENT_ID = "origin_parent_id";//定义一个字符串常量，命名为origin_parent_id

        /**
         * The gtask id
         * <P> Type : TEXT </P>
         */
        public static final String GTASK_ID = "gtask_id";//定义一个字符串常量，命名为gtask_id

        /**
         * The version code
         * <P> Type : INTEGER (long) </P>
         */
        public static final String VERSION = "version";//定义一个字符串常量，命名为version
    }
    //其实质上就是对之前出现过的变量与常量进行初始化与处理，

    public interface DataColumns //同样是一个定义数据库列名常量的地方
    {
        /**
         * The unique ID for a row
         * <P> Type: INTEGER (long) </P>
         */
        public static final String ID = "_id";//定义了一个名为 ID 的常量，其值为字符串 _id

        /**
         * The MIME type of the item represented by this row.
         * <P> Type: Text </P>
         */
        public static final String MIME_TYPE = "mime_type";//定义了一个名为MIME_TYPE的常量，其值为字符串 mime_type

        /**
         * The reference id to note that this data belongs to
         * <P> Type: INTEGER (long) </P>
         */
        public static final String NOTE_ID = "note_id";//对其NOTE_ID进行定义与初始化

        /**
         * Created data for note or folder
         * <P> Type: INTEGER (long) </P>
         */
        public static final String CREATED_DATE = "created_date";//对其CREATED_DATE进行定义与初始化

        /**
         * Latest modified date
         * <P> Type: INTEGER (long) </P>
         */
        public static final String MODIFIED_DATE = "modified_date";//对其MODIFIED_DATE进行定义与初始化

        /**
         * Data's content
         * <P> Type: TEXT </P>
         */
        public static final String CONTENT = "content";//对其CONTENT进行定义与初始化


        /**
         * Generic data column, the meaning is {@link #MIMETYPE} specific, used for
         * integer data type
         * <P> Type: INTEGER </P>
         */
        public static final String DATA1 = "data1";//对其DATA1进行定义与初始化

        /**
         * Generic data column, the meaning is {@link #MIMETYPE} specific, used for
         * integer data type
         * <P> Type: INTEGER </P>
         */
        public static final String DATA2 = "data2";//对其DATA2 进行定义与初始化

        /**
         * Generic data column, the meaning is {@link #MIMETYPE} specific, used for
         * TEXT data type
         * <P> Type: TEXT </P>
         */
        public static final String DATA3 = "data3";//对其DATA3进行定义与初始化

        /**
         * Generic data column, the meaning is {@link #MIMETYPE} specific, used for
         * TEXT data type
         * <P> Type: TEXT </P>
         */
        public static final String DATA4 = "data4";//对其 DATA4 进行定义与初始化

        /**
         * Generic data column, the meaning is {@link #MIMETYPE} specific, used for
         * TEXT data type
         * <P> Type: TEXT </P>
         */
        public static final String DATA5 = "data5";//对其DATA5进行定义与初始化
    }

    public static final class TextNote implements DataColumns //TextNote 是一个公共的静态最终类（public static final class），它实现了 DataColumns 接口。
    //这意味着 TextNote 类将继承 DataColumns 接口中定义的所有公共和受保护的常量和方法
    {
        /**
         * Mode to indicate the text in check list mode or not
         * <P> Type: Integer 1:check list mode 0: normal mode </P>
         */
        public static final String MODE = DATA1;//定义了一个名为 MODE 的公共静态最终字符串常量

        public static final int MODE_CHECK_LIST = 1;//定义了一个名为 MODE_CHECK_LIST 的公共静态最终整数常量，并赋值为 1

        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/text_note";//这行代码定义了一个名为 CONTENT_TYPE 的公共静态最终字符串常量，用来表示文本笔记内容类型的MIME类型

        public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/text_note";//这行代码定义了一个名为 CONTENT_ITEM_TYPE 的公共静态最终字符串常量，

        public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/text_note");//定义了一个公共的、静态的、最终的 Uri 对象
    }

    public static final class CallNote implements DataColumns //定义了一个名为CallNote的静态内部类，并且这个类实现了DataColumns接口
    {
        /**
         * Call date for this record
         * <P> Type: INTEGER (long) </P>
         */
        public static final String CALL_DATE = DATA1;//CALL_DATE是一个公共的、静态的、最终的字符串常量，它的值被设置为DATA1

        /**
         * Phone number for this record
         * <P> Type: TEXT </P>
         */
        public static final String PHONE_NUMBER = DATA3;//同样地，PHONE_NUMBER是一个公共的、静态的、最终的字符串常量，它的值被设置为DATA3

        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/call_note";//CONTENT_TYPE是一个表示MIME类型的常量，用于描述CallNote类型的数据集是一个目录（dir）

        public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/call_note";//CONTENT_ITEM_TYPE是一个表示MIME类型的常量，用于描述CallNote类型的数据项是一个单个项目

        public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/call_note");//定义了一个公共的、静态的、最终的Uri对象，名为CONTENT_URI。
    }
}