1 /* 2 * Copyright (C) 2016 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.launcher3.provider; 18 19 import android.content.ContentValues; 20 import android.content.Context; 21 import android.database.Cursor; 22 import android.database.DatabaseUtils; 23 import android.database.sqlite.SQLiteDatabase; 24 import android.os.Binder; 25 import android.util.Log; 26 27 import com.android.launcher3.LauncherAppState; 28 import com.android.launcher3.LauncherSettings.Favorites; 29 import com.android.launcher3.util.IntArray; 30 31 import java.util.Locale; 32 33 /** 34 * A set of utility methods for Launcher DB used for DB updates and migration. 35 */ 36 public class LauncherDbUtils { 37 38 private static final String TAG = "LauncherDbUtils"; 39 40 /** 41 * Makes the first screen as screen 0 (if screen 0 already exists, 42 * renames it to some other number). 43 * If the first row of screen 0 is non empty, runs a 'lossy' GridMigrationTask to clear 44 * the first row. The items in the first screen are moved and resized but the carry-forward 45 * items are simply deleted. 46 */ prepareScreenZeroToHostQsb(Context context, SQLiteDatabase db)47 public static boolean prepareScreenZeroToHostQsb(Context context, SQLiteDatabase db) { 48 try (SQLiteTransaction t = new SQLiteTransaction(db)) { 49 // Get the first screen 50 final int firstScreenId; 51 try (Cursor c = db.rawQuery(String.format(Locale.ENGLISH, 52 "SELECT MIN(%1$s) from %2$s where %3$s = %4$d", 53 Favorites.SCREEN, Favorites.TABLE_NAME, Favorites.CONTAINER, 54 Favorites.CONTAINER_DESKTOP), null)) { 55 56 if (!c.moveToNext()) { 57 // No update needed 58 t.commit(); 59 return true; 60 } 61 62 firstScreenId = c.getInt(0); 63 } 64 65 if (firstScreenId != 0) { 66 // Rename the first screen to 0. 67 renameScreen(db, firstScreenId, 0); 68 } 69 70 // Check if the first row is empty 71 if (DatabaseUtils.queryNumEntries(db, Favorites.TABLE_NAME, 72 "container = -100 and screen = 0 and cellY = 0") == 0) { 73 // First row is empty, no need to migrate. 74 t.commit(); 75 return true; 76 } 77 78 new LossyScreenMigrationTask(context, LauncherAppState.getIDP(context), db) 79 .migrateScreen0(); 80 t.commit(); 81 return true; 82 } catch (Exception e) { 83 Log.e(TAG, "Failed to update workspace size", e); 84 return false; 85 } 86 } 87 renameScreen(SQLiteDatabase db, int oldScreen, int newScreen)88 private static void renameScreen(SQLiteDatabase db, int oldScreen, int newScreen) { 89 String[] whereParams = new String[] { Integer.toString(oldScreen) }; 90 ContentValues values = new ContentValues(); 91 values.put(Favorites.SCREEN, newScreen); 92 db.update(Favorites.TABLE_NAME, values, "container = -100 and screen = ?", whereParams); 93 } 94 queryIntArray(SQLiteDatabase db, String tableName, String columnName, String selection, String groupBy, String orderBy)95 public static IntArray queryIntArray(SQLiteDatabase db, String tableName, String columnName, 96 String selection, String groupBy, String orderBy) { 97 IntArray out = new IntArray(); 98 try (Cursor c = db.query(tableName, new String[] { columnName }, selection, null, 99 groupBy, null, orderBy)) { 100 while (c.moveToNext()) { 101 out.add(c.getInt(0)); 102 } 103 } 104 return out; 105 } 106 tableExists(SQLiteDatabase db, String tableName)107 public static boolean tableExists(SQLiteDatabase db, String tableName) { 108 try (Cursor c = db.query(true, "sqlite_master", new String[] {"tbl_name"}, 109 "tbl_name = ?", new String[] {tableName}, 110 null, null, null, null, null)) { 111 return c.getCount() > 0; 112 } 113 } 114 dropTable(SQLiteDatabase db, String tableName)115 public static void dropTable(SQLiteDatabase db, String tableName) { 116 db.execSQL("DROP TABLE IF EXISTS " + tableName); 117 } 118 119 /** 120 * Utility class to simplify managing sqlite transactions 121 */ 122 public static class SQLiteTransaction extends Binder implements AutoCloseable { 123 private final SQLiteDatabase mDb; 124 SQLiteTransaction(SQLiteDatabase db)125 public SQLiteTransaction(SQLiteDatabase db) { 126 mDb = db; 127 db.beginTransaction(); 128 } 129 commit()130 public void commit() { 131 mDb.setTransactionSuccessful(); 132 } 133 134 @Override close()135 public void close() { 136 mDb.endTransaction(); 137 } 138 getDb()139 public SQLiteDatabase getDb() { 140 return mDb; 141 } 142 } 143 } 144