/* * 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; import android.content.ContentValues; import android.content.Intent; import android.content.UriMatcher; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.net.Uri; import android.text.TextUtils; import android.util.Log; 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; // 该类继承自 ContentProvider，用于管理便签数据的访问 // 提供对便签数据的增删改查操作，通过 ContentResolver 供其他组件调用 public class NotesProvider extends ContentProvider { // 定义 UriMatcher，用于匹配不同的 URI 模式 private static final UriMatcher mMatcher; private NotesDatabaseHelper mHelper; private static final String TAG = "NotesProvider"; private static final int URI_NOTE = 1; private static final int URI_NOTE_ITEM = 2; private static final int URI_DATA = 3; private static final int URI_DATA_ITEM = 4; private static final int URI_SEARCH = 5; private static final int URI_SEARCH_SUGGEST = 6; static { mMatcher = new UriMatcher(UriMatcher.NO_MATCH); mMatcher.addURI(Notes.AUTHORITY, "note", URI_NOTE); mMatcher.addURI(Notes.AUTHORITY, "note/#", URI_NOTE_ITEM); mMatcher.addURI(Notes.AUTHORITY, "data", URI_DATA); mMatcher.addURI(Notes.AUTHORITY, "data/#", URI_DATA_ITEM); mMatcher.addURI(Notes.AUTHORITY, "search", URI_SEARCH); mMatcher.addURI(Notes.AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY, URI_SEARCH_SUGGEST); mMatcher.addURI(Notes.AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY + "/*", URI_SEARCH_SUGGEST); } /** * 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. */ 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 + "," + "TRIM(REPLACE(" + NoteColumns.SNIPPET + ", x'0A','')) AS " + SearchManager.SUGGEST_COLUMN_TEXT_2 + "," + 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; private static String NOTES_SNIPPET_SEARCH_QUERY = "SELECT " + NOTES_SEARCH_PROJECTION + " FROM " + TABLE.NOTE + " WHERE " + NoteColumns.SNIPPET + " LIKE ?" + " AND " + NoteColumns.PARENT_ID + "<>" + Notes.ID_TRASH_FOLER + " AND " + NoteColumns.TYPE + "=" + Notes.TYPE_NOTE; @Override public boolean onCreate() { // 初始化数据库帮助类 mHelper = NotesDatabaseHelper.getInstance(getContext()); return true; } @Override public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) { Cursor c = null; SQLiteDatabase db = mHelper.getReadableDatabase(); String id = null; switch (mMatcher.match(uri)) { case URI_NOTE: //查询所有便签 c = db.query(TABLE.NOTE, projection, selection, selectionArgs, null, null, sortOrder); break; case URI_NOTE_ITEM: //查询单个便签 id = uri.getPathSegments().get(1); c = db.query(TABLE.NOTE, projection, NoteColumns.ID + "=" + id + parseSelection(selection), selectionArgs, null, null, sortOrder); break; case URI_DATA: c = db.query(TABLE.DATA, projection, selection, selectionArgs, null, null, sortOrder); break; case URI_DATA_ITEM: id = uri.getPathSegments().get(1); c = db.query(TABLE.DATA, projection, DataColumns.ID + "=" + id + parseSelection(selection), selectionArgs, null, null, sortOrder); break; case URI_SEARCH: case URI_SEARCH_SUGGEST: if (sortOrder != null || projection != null) { throw new IllegalArgumentException( "do not specify sortOrder, selection, selectionArgs, or projection" + "with this query"); } String searchString = null; if (mMatcher.match(uri) == URI_SEARCH_SUGGEST) { if (uri.getPathSegments().size() > 1) { searchString = uri.getPathSegments().get(1); } } else { searchString = uri.getQueryParameter("pattern"); } if (TextUtils.isEmpty(searchString)) { return null; } try { searchString = String.format("%%%s%%", searchString); c = db.rawQuery(NOTES_SNIPPET_SEARCH_QUERY, new String[] { searchString }); } catch (IllegalStateException ex) { Log.e(TAG, "got exception: " + ex.toString()); } break; default: throw new IllegalArgumentException("Unknown URI " + uri); } // 设置通知 URI，当数据变化时通知观察者 if (c != null) { c.setNotificationUri(getContext().getContentResolver(), uri); } return c; } @Override public Uri insert(Uri uri, ContentValues values) { SQLiteDatabase db = mHelper.getWritableDatabase(); long dataId = 0, noteId = 0, insertedId = 0; switch (mMatcher.match(uri)) { case URI_NOTE: //插入便签数据 insertedId = noteId = db.insert(TABLE.NOTE, null, values); break; case URI_DATA: if (values.containsKey(DataColumns.NOTE_ID)) { noteId = values.getAsLong(DataColumns.NOTE_ID); } else { Log.d(TAG, "Wrong data format without note id:" + values.toString()); } insertedId = dataId = db.insert(TABLE.DATA, null, values); break; default: throw new IllegalArgumentException("Unknown URI " + uri); } // Notify the note uri if (noteId > 0) { // 插入成功，返回新便签的 URI getContext().getContentResolver().notifyChange( ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId), null); } // Notify the data uri if (dataId > 0) { getContext().getContentResolver().notifyChange( ContentUris.withAppendedId(Notes.CONTENT_DATA_URI, dataId), null); } return ContentUris.withAppendedId(uri, insertedId); } @Override public int delete(Uri uri, String selection, String[] selectionArgs) { int count = 0;// 用于记录删除的数据条数 String id = null;// 用于存储从Uri中解析出的ID SQLiteDatabase db = mHelper.getWritableDatabase(); // 获取可写的数据库对象 boolean deleteData = false;// 标记是否需要删除数据表中的记录 switch (mMatcher.match(uri)) { // 根据Uri匹配对应的处理逻辑 case URI_NOTE: // 更新所有匹配条件的便签 selection = "(" + selection + ") AND " + NoteColumns.ID + ">0 "; count = db.delete(TABLE.NOTE, selection, selectionArgs); // 执行删除操作 break; case URI_NOTE_ITEM: // 更新单个便签 id = uri.getPathSegments().get(1); /** * ID that smaller than 0 is system folder which is not allowed to * trash */ long noteId = Long.valueOf(id); if (noteId <= 0) { break; } count = db.delete(TABLE.NOTE, NoteColumns.ID + "=" + id + parseSelection(selection), selectionArgs); // 删除便签表中的记录 break; case URI_DATA: count = db.delete(TABLE.DATA, selection, selectionArgs); deleteData = true;// 标记需要删除数据表中的记录 break; case URI_DATA_ITEM: id = uri.getPathSegments().get(1); count = db.delete(TABLE.DATA, DataColumns.ID + "=" + id + parseSelection(selection), selectionArgs); // 删除数据表中的记录 deleteData = true; // 标记需要删除数据表中的记录 break; default: throw new IllegalArgumentException("Unknown URI " + uri); } //通知数据变化 if (count > 0) { if (deleteData) {// 如果删除了数据表中的记录 getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null); } getContext().getContentResolver().notifyChange(uri, null); } return count;// 返回删除的记录数 } @Override public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) { int count = 0; String id = null; SQLiteDatabase db = mHelper.getWritableDatabase(); boolean updateData = false; switch (mMatcher.match(uri)) { case URI_NOTE: // 删除所有匹配条件的便签 increaseNoteVersion(-1, selection, selectionArgs); count = db.update(TABLE.NOTE, values, selection, selectionArgs); break; case URI_NOTE_ITEM: //删除单个便签 id = uri.getPathSegments().get(1); increaseNoteVersion(Long.valueOf(id), selection, selectionArgs); count = db.update(TABLE.NOTE, values, NoteColumns.ID + "=" + id + parseSelection(selection), selectionArgs); break; case URI_DATA: count = db.update(TABLE.DATA, values, selection, selectionArgs); updateData = true; break; case URI_DATA_ITEM: id = uri.getPathSegments().get(1); count = db.update(TABLE.DATA, values, DataColumns.ID + "=" + id + parseSelection(selection), selectionArgs); updateData = true; break; default: throw new IllegalArgumentException("Unknown URI " + uri); } // 通知数据变化 if (count > 0) { if (updateData) { getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null); } getContext().getContentResolver().notifyChange(uri, null); } return count; } private String parseSelection(String selection) { return (!TextUtils.isEmpty(selection) ? " AND (" + selection + ')' : ""); } private void increaseNoteVersion(long id, String selection, String[] selectionArgs) { StringBuilder sql = new StringBuilder(120); sql.append("UPDATE "); sql.append(TABLE.NOTE); sql.append(" SET "); sql.append(NoteColumns.VERSION); sql.append("=" + NoteColumns.VERSION + "+1 "); if (id > 0 || !TextUtils.isEmpty(selection)) { sql.append(" WHERE "); } if (id > 0) { sql.append(NoteColumns.ID + "=" + String.valueOf(id)); } if (!TextUtils.isEmpty(selection)) { String selectString = id > 0 ? parseSelection(selection) : selection; for (String args : selectionArgs) { selectString = selectString.replaceFirst("\\?", args); } sql.append(selectString); } mHelper.getWritableDatabase().execSQL(sql.toString()); } @Override public String getType(Uri uri) { // TODO Auto-generated method stub return null; } }