Adding a DB update path to handle the QSB position change

> Renamed the id of 1st screen to 0 and making space for the QSB
by running the grid migration task.
> Added a feature flag to easily disable the QSB-in-workspace behavior

Change-Id: Ie3369f0d4433d916e9d6215d414770d4333f3e26

2 files changed, 230 insertions, 0 deletions

diff --git a/src/com/android/launcher3/provider/LauncherDbUtils.java b/src/com/android/launcher3/provider/LauncherDbUtils.java
new file mode 100644
index 000000000..faa5fad12
--- /dev/null
+++ b/src/com/android/launcher3/provider/LauncherDbUtils.java
@@ -0,0 +1,122 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * 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 com.android.launcher3.provider;
+
+import android.content.ContentValues;
+import android.database.Cursor;
+import android.database.sqlite.SQLiteDatabase;
+import android.util.Log;
+
+import com.android.launcher3.LauncherAppState;
+import com.android.launcher3.LauncherSettings.Favorites;
+import com.android.launcher3.LauncherSettings.WorkspaceScreens;
+import com.android.launcher3.logging.FileLog;
+
+import java.util.ArrayList;
+
+/**
+ * A set of utility methods for Launcher DB used for DB updates and migration.
+ */
+public class LauncherDbUtils {
+
+    private static final String TAG = "LauncherDbUtils";
+
+    /**
+     * Makes the first screen as screen 0 (if screen 0 already exists,
+     * renames it to some other number).
+     * If the first row of screen 0 is non empty, runs a 'lossy' GridMigrationTask to clear
+     * the first row. The items in the first screen are moved and resized but the carry-forward
+     * items are simply deleted.
+     */
+    public static boolean prepareScreenZeroToHostQsb(SQLiteDatabase db) {
+        db.beginTransaction();
+        try {
+            // Get the existing screens
+            ArrayList<Long> screenIds = getScreenIdsFromCursor(db.query(WorkspaceScreens.TABLE_NAME,
+                    null, null, null, null, null, WorkspaceScreens.SCREEN_RANK));
+
+            if (screenIds.isEmpty()) {
+                // No update needed
+                return true;
+            }
+            if (screenIds.get(0) != 0) {
+                // First screen is not 0, we need to rename screens
+                if (screenIds.indexOf(0L) > -1) {
+                    // There is already a screen 0. First rename it to a differen screen.
+                    long newScreenId = 1;
+                    while (screenIds.indexOf(newScreenId) > -1) newScreenId++;
+                    renameScreen(db, 0, newScreenId);
+                }
+
+                // Rename the first screen to 0.
+                renameScreen(db, screenIds.get(0), 0);
+            }
+
+            // Check if the first row is empty
+            try (Cursor c = db.query(Favorites.TABLE_NAME, null,
+                    "container = -100 and screen = 0 and cellY = 0", null, null, null, null)) {
+                if (c.getCount() == 0) {
+                    // First row is empty, no need to migrate.
+                    return true;
+                }
+            }
+
+            LauncherAppState app = LauncherAppState.getInstance();
+            new LossyScreenMigrationTask(app.getContext(), app.getInvariantDeviceProfile(), db)
+                    .migrateScreen0();
+            db.setTransactionSuccessful();
+            return true;
+        } catch (Exception e) {
+            Log.e(TAG, "Failed to update workspace size", e);
+            return false;
+        } finally {
+            db.endTransaction();
+        }
+    }
+
+    private static void renameScreen(SQLiteDatabase db, long oldScreen, long newScreen) {
+        String[] whereParams = new String[] { Long.toString(oldScreen) };
+
+        ContentValues values = new ContentValues();
+        values.put(WorkspaceScreens._ID, newScreen);
+        db.update(WorkspaceScreens.TABLE_NAME, values, "_id = ?", whereParams);
+
+        values.clear();
+        values.put(Favorites.SCREEN, newScreen);
+        db.update(Favorites.TABLE_NAME, values, "container = -100 and screen = ?", whereParams);
+    }
+
+    /**
+     * Parses the cursor containing workspace screens table and returns the list of screen IDs
+     */
+    public static ArrayList<Long> getScreenIdsFromCursor(Cursor sc) {
+        ArrayList<Long> screenIds = new ArrayList<Long>();
+        try {
+            final int idIndex = sc.getColumnIndexOrThrow(WorkspaceScreens._ID);
+            while (sc.moveToNext()) {
+                try {
+                    screenIds.add(sc.getLong(idIndex));
+                } catch (Exception e) {
+                    FileLog.d(TAG, "Invalid screen id", e);
+                }
+            }
+        } finally {
+            sc.close();
+        }
+        return screenIds;
+    }
+}
diff --git a/src/com/android/launcher3/provider/LossyScreenMigrationTask.java b/src/com/android/launcher3/provider/LossyScreenMigrationTask.java
new file mode 100644
index 000000000..bb6ed0de9
--- /dev/null
+++ b/src/com/android/launcher3/provider/LossyScreenMigrationTask.java
@@ -0,0 +1,108 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * 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 com.android.launcher3.provider;
+
+import android.content.ContentValues;
+import android.content.Context;
+import android.database.Cursor;
+import android.database.sqlite.SQLiteDatabase;
+import android.graphics.Point;
+import android.util.Log;
+
+import com.android.launcher3.InvariantDeviceProfile;
+import com.android.launcher3.LauncherSettings.Favorites;
+import com.android.launcher3.Utilities;
+import com.android.launcher3.Workspace;
+import com.android.launcher3.model.GridSizeMigrationTask;
+import com.android.launcher3.util.LongArrayMap;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+
+/**
+ * An extension of {@link GridSizeMigrationTask} which migrates only one screen and
+ * deletes all carry-forward items.
+ */
+public class LossyScreenMigrationTask extends GridSizeMigrationTask {
+
+    private final SQLiteDatabase mDb;
+
+    private final LongArrayMap<DbEntry> mOriginalItems;
+    private final LongArrayMap<DbEntry> mUpdates;
+
+    protected LossyScreenMigrationTask(
+            Context context, InvariantDeviceProfile idp, SQLiteDatabase db) {
+        // Decrease the rows count by 1
+        super(context, idp, getValidPackages(context), new HashMap<String, Point>(),
+                new Point(idp.numColumns, idp.numRows + 1), new Point(idp.numColumns, idp.numRows));
+
+        mDb = db;
+        mOriginalItems = new LongArrayMap<>();
+        mUpdates = new LongArrayMap<>();
+    }
+
+    @Override
+    protected Cursor queryWorkspace(String[] columns, String where) {
+        return mDb.query(Favorites.TABLE_NAME, columns, where, null, null, null, null);
+    }
+
+    @Override
+    protected void update(DbEntry item) {
+        mUpdates.put(item.id, item.copy());
+    }
+
+    @Override
+    protected ArrayList<DbEntry> loadWorkspaceEntries(long screen) {
+        ArrayList<DbEntry> result = super.loadWorkspaceEntries(screen);
+        for (DbEntry entry : result) {
+            mOriginalItems.put(entry.id, entry.copy());
+
+            // Shift all items by 1 in y direction and mark them for update.
+            entry.cellY++;
+            mUpdates.put(entry.id, entry.copy());
+        }
+
+        return result;
+    }
+
+    public void migrateScreen0() {
+        migrateScreen(Workspace.FIRST_SCREEN_ID);
+
+        ContentValues tempValues = new ContentValues();
+        for (DbEntry update : mUpdates) {
+            DbEntry org = mOriginalItems.get(update.id);
+
+            if (org.cellX != update.cellX || org.cellY != update.cellY
+                    || org.spanX != update.spanX || org.spanY != update.spanY) {
+                tempValues.clear();
+                update.addToContentValues(tempValues);
+                mDb.update(Favorites.TABLE_NAME, tempValues, "_id = ?",
+                        new String[] {Long.toString(update.id)});
+            }
+        }
+
+        // Delete any carry over items as we are only migration a single screen.
+        for (DbEntry entry : mCarryOver) {
+            mEntryToRemove.add(entry.id);
+        }
+
+        if (!mEntryToRemove.isEmpty()) {
+            mDb.delete(Favorites.TABLE_NAME,
+                    Utilities.createDbSelectionQuery(Favorites._ID, mEntryToRemove), null);
+        }
+    }
+}