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.util.Log; 25 26 import com.android.launcher3.LauncherAppState; 27 import com.android.launcher3.LauncherSettings.Favorites; 28 import com.android.launcher3.LauncherSettings.WorkspaceScreens; 29 30 import java.util.ArrayList; 31 import java.util.Collection; 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 existing screens 50 ArrayList<Long> screenIds = getScreenIdsFromCursor(db.query(WorkspaceScreens.TABLE_NAME, 51 null, null, null, null, null, WorkspaceScreens.SCREEN_RANK)); 52 53 if (screenIds.isEmpty()) { 54 // No update needed 55 t.commit(); 56 return true; 57 } 58 if (screenIds.get(0) != 0) { 59 // First screen is not 0, we need to rename screens 60 if (screenIds.indexOf(0L) > -1) { 61 // There is already a screen 0. First rename it to a different screen. 62 long newScreenId = 1; 63 while (screenIds.indexOf(newScreenId) > -1) newScreenId++; 64 renameScreen(db, 0, newScreenId); 65 } 66 67 // Rename the first screen to 0. 68 renameScreen(db, screenIds.get(0), 0); 69 } 70 71 // Check if the first row is empty 72 if (DatabaseUtils.queryNumEntries(db, Favorites.TABLE_NAME, 73 "container = -100 and screen = 0 and cellY = 0") == 0) { 74 // First row is empty, no need to migrate. 75 t.commit(); 76 return true; 77 } 78 79 new LossyScreenMigrationTask(context, LauncherAppState.getIDP(context), db) 80 .migrateScreen0(); 81 t.commit(); 82 return true; 83 } catch (Exception e) { 84 Log.e(TAG, "Failed to update workspace size", e); 85 return false; 86 } 87 } 88 renameScreen(SQLiteDatabase db, long oldScreen, long newScreen)89 private static void renameScreen(SQLiteDatabase db, long oldScreen, long newScreen) { 90 String[] whereParams = new String[] { Long.toString(oldScreen) }; 91 92 ContentValues values = new ContentValues(); 93 values.put(WorkspaceScreens._ID, newScreen); 94 db.update(WorkspaceScreens.TABLE_NAME, values, "_id = ?", whereParams); 95 96 values.clear(); 97 values.put(Favorites.SCREEN, newScreen); 98 db.update(Favorites.TABLE_NAME, values, "container = -100 and screen = ?", whereParams); 99 } 100 101 /** 102 * Parses the cursor containing workspace screens table and returns the list of screen IDs 103 */ getScreenIdsFromCursor(Cursor sc)104 public static ArrayList<Long> getScreenIdsFromCursor(Cursor sc) { 105 try { 106 return iterateCursor(sc, 107 sc.getColumnIndexOrThrow(WorkspaceScreens._ID), 108 new ArrayList<Long>()); 109 } finally { 110 sc.close(); 111 } 112 } 113 iterateCursor(Cursor c, int columnIndex, T out)114 public static <T extends Collection<Long>> T iterateCursor(Cursor c, int columnIndex, T out) { 115 while (c.moveToNext()) { 116 out.add(c.getLong(columnIndex)); 117 } 118 return out; 119 } 120 121 /** 122 * Utility class to simplify managing sqlite transactions 123 */ 124 public static class SQLiteTransaction implements AutoCloseable { 125 private final SQLiteDatabase mDb; 126 SQLiteTransaction(SQLiteDatabase db)127 public SQLiteTransaction(SQLiteDatabase db) { 128 mDb = db; 129 db.beginTransaction(); 130 } 131 commit()132 public void commit() { 133 mDb.setTransactionSuccessful(); 134 } 135 136 @Override close()137 public void close() { 138 mDb.endTransaction(); 139 } 140 } 141 } 142