Added comments to the data package

pull/2/head
eazzy 12 months ago
parent 8ec7da49c9
commit 1a93e734bd

@ -17,9 +17,11 @@
package net.micode.notes.data;
import android.net.Uri;
//Notes类就定义了很多常量是小米便签的数据库
public class Notes {
public static final String AUTHORITY = "micode_notes";
public static final String TAG = "Notes";
//三个type
public static final int TYPE_NOTE = 0;
public static final int TYPE_FOLDER = 1;
public static final int TYPE_SYSTEM = 2;
@ -30,6 +32,7 @@ public class Notes {
* {@link Notes#ID_TEMPARAY_FOLDER } is for notes belonging no folder
* {@link Notes#ID_CALL_RECORD_FOLDER} is to store call records
*/
//不同种类的文件夹
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;
@ -45,12 +48,12 @@ public class Notes {
public static final int TYPE_WIDGET_INVALIDE = -1;
public static final int TYPE_WIDGET_2X = 0;
public static final int TYPE_WIDGET_4X = 1;
//数据常量 包括普通note和call_note
public static class DataConstants {
public static final String NOTE = TextNote.CONTENT_ITEM_TYPE;
public static final String CALL_NOTE = CallNote.CONTENT_ITEM_TYPE;
}
//两个指针,一个找便签和文件夹,一个用来找数据
/**
* Uri to query all notes and folders
*/
@ -59,9 +62,11 @@ public class Notes {
/**
* Uri to query data
*/
public static final Uri CONTENT_DATA_URI = Uri.parse("content://" + AUTHORITY + "/data");
public static final Uri CONTENT_DATA_URI = Uri.parse("content://" + AUTHORITY + "/data");
//Notecolumns类用于创建数据库的表头
public interface NoteColumns {
//具体每一项都给了英文注释
/**
* The unique ID for a row
* <P> Type: INTEGER (long) </P>
@ -169,7 +174,7 @@ public class Notes {
public static final String PASSWORD = "password";
public static final String IMPORTANCE = "importance";
}
}//便签的各种属性
/*
* 便
*/
@ -245,7 +250,7 @@ public class Notes {
* <P> Type: TEXT </P>
*/
public static final String DATA5 = "data5";
}
}//一个便签内部各种数据类型
public static final class TextNote implements DataColumns {
/**
@ -261,7 +266,7 @@ public class Notes {
public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/text_note";
public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/text_note");
}
}//一种是文本textnote
public static final class CallNote implements DataColumns {
/**
@ -281,5 +286,5 @@ public class Notes {
public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/call_note";
public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/call_note");
}
}//另一种是通话类型的callnote
}

@ -21,17 +21,17 @@ import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
//引用了同一个包中的另一个子包Notes中一些接口
import net.micode.notes.data.Notes.DataColumns;
import net.micode.notes.data.Notes.DataConstants;
import net.micode.notes.data.Notes.NoteColumns;
//数据库操作
public class NotesDatabaseHelper extends SQLiteOpenHelper {
private static final String DB_NAME = "note.db";
private static final int DB_VERSION = 4;
//接口两部分一个Note一个DATA
public interface TABLE {
public static final String NOTE = "note";
@ -41,7 +41,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
private static final String TAG = "NotesDatabaseHelper";
private static NotesDatabaseHelper mInstance;
//基于NoteColumn创建一个NOTE_TABLE表格并附上初始数据
private static final String CREATE_NOTE_TABLE_SQL =
"CREATE TABLE " + TABLE.NOTE + "(" +
NoteColumns.ID + " INTEGER PRIMARY KEY," +
@ -62,7 +62,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
NoteColumns.GTASK_ID + " TEXT NOT NULL DEFAULT ''," +
NoteColumns.VERSION + " INTEGER NOT NULL DEFAULT 0" +
")";
//主要基于datacolumn来创建DATA_TABLE
private static final String CREATE_DATA_TABLE_SQL =
"CREATE TABLE " + TABLE.DATA + "(" +
DataColumns.ID + " INTEGER PRIMARY KEY," +
@ -77,7 +77,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
DataColumns.DATA4 + " TEXT NOT NULL DEFAULT ''," +
DataColumns.DATA5 + " TEXT NOT NULL DEFAULT ''" +
")";
//这个数据是关于INDEX编号的
private static final String CREATE_DATA_NOTE_ID_INDEX_SQL =
"CREATE INDEX IF NOT EXISTS note_id_index ON " +
TABLE.DATA + "(" + DataColumns.NOTE_ID + ");";
@ -93,7 +93,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
" SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + " + 1" +
" WHERE " + NoteColumns.ID + "=new." + NoteColumns.PARENT_ID + ";" +
" END";
//移入note时触发修改一系列数据从哪来之类的
/**
* Decrease folder's note count when move note from folder
*/
@ -106,7 +106,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
" WHERE " + NoteColumns.ID + "=old." + NoteColumns.PARENT_ID +
" AND " + NoteColumns.NOTES_COUNT + ">0" + ";" +
" END";
//移除Note时触发与上面移入对应
/**
* Increase folder's note count when insert new note to the folder
*/
@ -118,7 +118,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
" SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + " + 1" +
" WHERE " + NoteColumns.ID + "=new." + NoteColumns.PARENT_ID + ";" +
" END";
//插入Note
/**
* Decrease folder's note count when delete note from the folder
*/
@ -131,7 +131,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
" WHERE " + NoteColumns.ID + "=old." + NoteColumns.PARENT_ID +
" AND " + NoteColumns.NOTES_COUNT + ">0;" +
" END";
//删除note
/**
* Update note's content when insert data with type {@link DataConstants#NOTE}
*/
@ -144,7 +144,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
" SET " + NoteColumns.SNIPPET + "=new." + DataColumns.CONTENT +
" WHERE " + NoteColumns.ID + "=new." + DataColumns.NOTE_ID + ";" +
" END";
//当给note插入新数据时触发
/**
* Update note's content when data with {@link DataConstants#NOTE} type has changed
*/
@ -156,7 +156,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
" UPDATE " + TABLE.NOTE +
" SET " + NoteColumns.SNIPPET + "=new." + DataColumns.CONTENT +
" WHERE " + NoteColumns.ID + "=new." + DataColumns.NOTE_ID + ";" +
" END";
" END";//note数据被修改update
/**
* Update note's content when data with {@link DataConstants#NOTE} type has deleted
@ -169,7 +169,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
" UPDATE " + TABLE.NOTE +
" SET " + NoteColumns.SNIPPET + "=''" +
" WHERE " + NoteColumns.ID + "=old." + DataColumns.NOTE_ID + ";" +
" END";
" END";//更新已经删除的便签的数据
/**
* Delete datas belong to note which has been deleted
@ -180,7 +180,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
" BEGIN" +
" DELETE FROM " + TABLE.DATA +
" WHERE " + DataColumns.NOTE_ID + "=old." + NoteColumns.ID + ";" +
" END";
" END";//删除 已经被删除的便签的数据
/**
* Delete notes belong to folder which has been deleted
@ -191,7 +191,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
" BEGIN" +
" DELETE FROM " + TABLE.NOTE +
" WHERE " + NoteColumns.PARENT_ID + "=old." + NoteColumns.ID + ";" +
" END";
" END";//删除 已删除folder文件夹 中的便签要修改的数据
/**
* Move notes belong to folder which has been moved to trash folder
@ -204,12 +204,12 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
" UPDATE " + TABLE.NOTE +
" SET " + NoteColumns.PARENT_ID + "=" + Notes.ID_TRASH_FOLER +
" WHERE " + NoteColumns.PARENT_ID + "=old." + NoteColumns.ID + ";" +
" END";
" END";//移动trash_folder中的便签
public NotesDatabaseHelper(Context context) {
super(context, DB_NAME, null, DB_VERSION);
}
//构造函数
public void createNoteTable(SQLiteDatabase db) {
db.execSQL(CREATE_NOTE_TABLE_SQL);
reCreateNoteTableTriggers(db);
@ -233,7 +233,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
db.execSQL(NOTE_INCREASE_FOLDER_COUNT_ON_INSERT_TRIGGER);
db.execSQL(FOLDER_DELETE_NOTES_ON_DELETE_TRIGGER);
db.execSQL(FOLDER_MOVE_NOTES_ON_TRASH_TRIGGER);
}
}//数据库操作的API重新创建
private void createSystemFolder(SQLiteDatabase db) {
ContentValues values = new ContentValues();
@ -268,14 +268,14 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
values.put(NoteColumns.ID, Notes.ID_TRASH_FOLER);
values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
db.insert(TABLE.NOTE, null, values);
}
}//创建系统文件夹
public void createDataTable(SQLiteDatabase db) {
db.execSQL(CREATE_DATA_TABLE_SQL);
reCreateDataTableTriggers(db);
db.execSQL(CREATE_DATA_NOTE_ID_INDEX_SQL);
Log.d(TAG, "data table has been created");
}
}//创建数据表格
private void reCreateDataTableTriggers(SQLiteDatabase db) {
db.execSQL("DROP TRIGGER IF EXISTS update_note_content_on_insert");
@ -285,20 +285,20 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
db.execSQL(DATA_UPDATE_NOTE_CONTENT_ON_INSERT_TRIGGER);
db.execSQL(DATA_UPDATE_NOTE_CONTENT_ON_UPDATE_TRIGGER);
db.execSQL(DATA_UPDATE_NOTE_CONTENT_ON_DELETE_TRIGGER);
}
}//类似于recreatenotetable重新创建触发器
static synchronized NotesDatabaseHelper getInstance(Context context) {
if (mInstance == null) {
mInstance = new NotesDatabaseHelper(context);
}
return mInstance;
}
}//sync同步同一时刻只有一个线程执行
@Override
public void onCreate(SQLiteDatabase db) {
createNoteTable(db);
createDataTable(db);
}
}//创建Note Data两个表格
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
@ -331,14 +331,14 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
throw new IllegalStateException("Upgrade notes database to version " + newVersion
+ "fails");
}
}
}//数据库版本更新
private void upgradeToV2(SQLiteDatabase db) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE.NOTE);
db.execSQL("DROP TABLE IF EXISTS " + TABLE.DATA);
createNoteTable(db);
createDataTable(db);
}
}//更新到V2
private void upgradeToV3(SQLiteDatabase db) {
// drop unused triggers
@ -353,10 +353,10 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
values.put(NoteColumns.ID, Notes.ID_TRASH_FOLER);
values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
db.insert(TABLE.NOTE, null, values);
}
}//更新到V3
private void upgradeToV4(SQLiteDatabase db) {
db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.VERSION
+ " INTEGER NOT NULL DEFAULT 0");
}
}//更新到V4
}

@ -1,22 +1,5 @@
/*
* 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;
import android.app.SearchManager;
import android.content.ContentProvider;
import android.content.ContentUris;
@ -33,9 +16,15 @@ import net.micode.notes.R;
import net.micode.notes.data.Notes.DataColumns;
import net.micode.notes.data.Notes.NoteColumns;
import net.micode.notes.data.NotesDatabaseHelper.TABLE;
//为存储和获取数据提供接口。可以在不同的应用程序之间共享数据
//ContentProvider提供的方法
//query查询
//insert插入
//update更新
//delete删除
//getType得到数据类型
public class NotesProvider extends ContentProvider {
// UriMatcher用于匹配Uri
private static final UriMatcher mMatcher;
private NotesDatabaseHelper mHelper;
@ -51,7 +40,9 @@ public class NotesProvider extends ContentProvider {
private static final int URI_SEARCH_SUGGEST = 6;
static {
// 创建UriMatcher时调用UriMatcher(UriMatcher.NO_MATCH)表示不匹配任何路径的返回码
mMatcher = new UriMatcher(UriMatcher.NO_MATCH);
// 把需要匹配Uri路径全部给注册上
mMatcher.addURI(Notes.AUTHORITY, "note", URI_NOTE);
mMatcher.addURI(Notes.AUTHORITY, "note/#", URI_NOTE_ITEM);
mMatcher.addURI(Notes.AUTHORITY, "data", URI_DATA);
@ -65,6 +56,7 @@ public class NotesProvider extends ContentProvider {
* x'0A' represents the '\n' character in sqlite. For title and content in the search result,
* we will trim '\n' and white space in order to show more information.
*/
// 声明 NOTES_SEARCH_PROJECTION
private static final String NOTES_SEARCH_PROJECTION = NoteColumns.ID + ","
+ NoteColumns.ID + " AS " + SearchManager.SUGGEST_COLUMN_INTENT_EXTRA_DATA + ","
+ "TRIM(REPLACE(" + NoteColumns.SNIPPET + ", x'0A','')) AS " + SearchManager.SUGGEST_COLUMN_TEXT_1 + ","
@ -72,7 +64,7 @@ public class NotesProvider extends ContentProvider {
+ R.drawable.search_result + " AS " + SearchManager.SUGGEST_COLUMN_ICON_1 + ","
+ "'" + Intent.ACTION_VIEW + "' AS " + SearchManager.SUGGEST_COLUMN_INTENT_ACTION + ","
+ "'" + Notes.TextNote.CONTENT_TYPE + "' AS " + SearchManager.SUGGEST_COLUMN_INTENT_DATA;
// 声明NOTES_SNIPPET_SEARCH_QUERY
private static String NOTES_SNIPPET_SEARCH_QUERY = "SELECT " + NOTES_SEARCH_PROJECTION
+ " FROM " + TABLE.NOTE
+ " WHERE " + NoteColumns.SNIPPET + " LIKE ?"
@ -80,18 +72,24 @@ public class NotesProvider extends ContentProvider {
+ " AND " + NoteColumns.TYPE + "=" + Notes.TYPE_NOTE;
@Override
// Context只有在onCreate()中才被初始化
// 对mHelper进行实例化
public boolean onCreate() {
mHelper = NotesDatabaseHelper.getInstance(getContext());
return true;
}
@Override
// 查询uri在数据库中对应的位置
public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
String sortOrder) {
Cursor c = null;
// 获取可读数据库
SQLiteDatabase db = mHelper.getReadableDatabase();
String id = null;
// 匹配查找uri
switch (mMatcher.match(uri)) {
// 对于不同的匹配值,在数据库中查找相应的条目
case URI_NOTE:
c = db.query(TABLE.NOTE, projection, selection, selectionArgs, null, null,
sortOrder);
@ -113,6 +111,7 @@ public class NotesProvider extends ContentProvider {
case URI_SEARCH:
case URI_SEARCH_SUGGEST:
if (sortOrder != null || projection != null) {
// 不合法的参数异常
throw new IllegalArgumentException(
"do not specify sortOrder, selection, selectionArgs, or projection" + "with this query");
}
@ -120,6 +119,8 @@ public class NotesProvider extends ContentProvider {
String searchString = null;
if (mMatcher.match(uri) == URI_SEARCH_SUGGEST) {
if (uri.getPathSegments().size() > 1) {
// getPathSegments()方法得到一个String的List
// 在uri.getPathSegments().get(1)为第2个元素
searchString = uri.getPathSegments().get(1);
}
} else {
@ -139,6 +140,7 @@ public class NotesProvider extends ContentProvider {
}
break;
default:
// 抛出异常
throw new IllegalArgumentException("Unknown URI " + uri);
}
if (c != null) {
@ -148,13 +150,17 @@ public class NotesProvider extends ContentProvider {
}
@Override
// 插入一个uri
public Uri insert(Uri uri, ContentValues values) {
// 获得可写的数据库
SQLiteDatabase db = mHelper.getWritableDatabase();
long dataId = 0, noteId = 0, insertedId = 0;
switch (mMatcher.match(uri)) {
// 新增一个条目
case URI_NOTE:
insertedId = noteId = db.insert(TABLE.NOTE, null, values);
break;
// 如果存在查找NOTE_ID
case URI_DATA:
if (values.containsKey(DataColumns.NOTE_ID)) {
noteId = values.getAsLong(DataColumns.NOTE_ID);
@ -167,6 +173,7 @@ public class NotesProvider extends ContentProvider {
throw new IllegalArgumentException("Unknown URI " + uri);
}
// Notify the note uri
// notifyChange获得一个ContextResolver对象并且更新里面的内容
if (noteId > 0) {
getContext().getContentResolver().notifyChange(
ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId), null);
@ -178,13 +185,17 @@ public class NotesProvider extends ContentProvider {
ContentUris.withAppendedId(Notes.CONTENT_DATA_URI, dataId), null);
}
// 返回插入的uri的路径
return ContentUris.withAppendedId(uri, insertedId);
}
@Override
// 删除一个uri
public int delete(Uri uri, String selection, String[] selectionArgs) {
//Uri代表要操作的数据Android上可用的每种资源 -包括 图像、视频片段、音频资源等都可以用Uri来表示。
int count = 0;
String id = null;
// 获得可写的数据库
SQLiteDatabase db = mHelper.getWritableDatabase();
boolean deleteData = false;
switch (mMatcher.match(uri)) {
@ -228,6 +239,7 @@ public class NotesProvider extends ContentProvider {
}
@Override
// 更新一个uri
public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
int count = 0;
String id = null;
@ -267,10 +279,12 @@ public class NotesProvider extends ContentProvider {
return count;
}
// 将字符串解析成规定格式
private String parseSelection(String selection) {
return (!TextUtils.isEmpty(selection) ? " AND (" + selection + ')' : "");
}
//增加一个noteVersion
private void increaseNoteVersion(long id, String selection, String[] selectionArgs) {
StringBuilder sql = new StringBuilder(120);
sql.append("UPDATE ");
@ -293,6 +307,7 @@ public class NotesProvider extends ContentProvider {
sql.append(selectString);
}
// execSQL()方法可以执行insert、delete、update和CREATE TABLE之类有更改行为的SQL语句
mHelper.getWritableDatabase().execSQL(sql.toString());
}

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