/* * 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; public class NotesProvider extends ContentProvider { // URI Matcher 用于将 URI 映射到相应的操作 private static final UriMatcher mMatcher; // 数据库帮助类实例 private NotesDatabaseHelper mHelper; // 日志标签 private static final String TAG = "NotesProvider"; // 定义常量用于 URI 匹配 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; // 静态代码块，初始化 URI Matcher static { mMatcher = new UriMatcher(UriMatcher.NO_MATCH); mMatcher.addURI(Notes.AUTHORITY, "note", URI_NOTE); // 匹配所有笔记 mMatcher.addURI(Notes.AUTHORITY, "note/#", URI_NOTE_ITEM); // 匹配单个笔记 mMatcher.addURI(Notes.AUTHORITY, "data", URI_DATA); // 匹配所有数据 mMatcher.addURI(Notes.AUTHORITY, "data/#", URI_DATA_ITEM); // 匹配单个数据 mMatcher.addURI(Notes.AUTHORITY, "search", URI_SEARCH); // 匹配搜索 mMatcher.addURI(Notes.AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY, URI_SEARCH_SUGGEST); // 匹配搜索建议 mMatcher.addURI(Notes.AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY + "/*", URI_SEARCH_SUGGEST); // 匹配搜索建议 } // 搜索结果的投影（投影是查询中返回的列的集合） 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; // 搜索的 SQL 查询 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 NotesDatabaseHelper 实例 mHelper = NotesDatabaseHelper.getInstance(getContext()); return true; } /** * 查询操作，支持不同 URI 对应不同的查询行为。 * * @param uri 查询 URI * @param projection 要查询的列 * @param selection 查询条件 * @param selectionArgs 查询条件的参数 * @param sortOrder 排序方式 * @return 查询结果的 Cursor */ @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: c = db.query(TABLE.NOTE, projection, selection, selectionArgs, null, null, sortOrder); break; case URI_NOTE_ITEM: 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: // 确保没有传递非法的参数 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); } if (c != null) { c.setNotificationUri(getContext().getContentResolver(), uri); } return c; } /** * 插入操作，支持 URI 匹配后将数据插入到相应表中。 * * @param uri 插入 URI * @param values 插入的数据 * @return 插入后的 URI */ @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: 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); } // 通知 URI 的变化 if (noteId > 0) { getContext().getContentResolver().notifyChange( ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId), null); } if (dataId > 0) { getContext().getContentResolver().notifyChange( ContentUris.withAppendedId(Notes.CONTENT_DATA_URI, dataId), null); } return ContentUris.withAppendedId(uri, insertedId); } /** * 删除操作，支持 URI 匹配后从相应表中删除数据。 * * @param uri 删除的 URI * @param selection 删除条件 * @param selectionArgs 删除条件的参数 * @return 删除的行数 */