1 files changed, 50 insertions, 13 deletions

diff --git a/src/com/android/launcher3/LauncherProvider.java b/src/com/android/launcher3/LauncherProvider.java
index 71ddb1ab1..3ebc30737 100644
--- a/src/com/android/launcher3/LauncherProvider.java
+++ b/src/com/android/launcher3/LauncherProvider.java
@@ -62,6 +62,7 @@ import java.net.URISyntaxException;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashSet;
+import java.util.List;
 
 public class LauncherProvider extends ContentProvider {
     private static final String TAG = "Launcher.LauncherProvider";
@@ -99,6 +100,7 @@ public class LauncherProvider extends ContentProvider {
 
     public void setLauncherProviderChangeListener(LauncherProviderChangeListener listener) {
         mListener = listener;
+        mOpenHelper.mListener = mListener;
     }
 
     @Override
@@ -262,6 +264,42 @@ public class LauncherProvider extends ContentProvider {
         return null;
     }
 
+    /**
+     * Deletes any empty folder from the DB.
+     * @return Ids of deleted folders.
+     */
+    public List<Long> deleteEmptyFolders() {
+        ArrayList<Long> folderIds = new ArrayList<Long>();
+        SQLiteDatabase db = mOpenHelper.getWritableDatabase();
+        db.beginTransaction();
+        try {
+            // Select folders whose id do not match any container value.
+            String selection = LauncherSettings.Favorites.ITEM_TYPE + " = "
+                    + LauncherSettings.Favorites.ITEM_TYPE_FOLDER + " AND "
+                    + LauncherSettings.Favorites._ID +  " NOT IN (SELECT " +
+                            LauncherSettings.Favorites.CONTAINER + " FROM "
+                                + TABLE_FAVORITES + ")";
+            Cursor c = db.query(TABLE_FAVORITES,
+                    new String[] {LauncherSettings.Favorites._ID},
+                    selection, null, null, null, null);
+            while (c.moveToNext()) {
+                folderIds.add(c.getLong(0));
+            }
+            c.close();
+            if (folderIds.size() > 0) {
+                db.delete(TABLE_FAVORITES, Utilities.createDbSelectionQuery(
+                        LauncherSettings.Favorites._ID, folderIds), null);
+            }
+            db.setTransactionSuccessful();
+        } catch (SQLException ex) {
+            Log.e(TAG, ex.getMessage(), ex);
+            folderIds.clear();
+        } finally {
+            db.endTransaction();
+        }
+        return folderIds;
+    }
+
     private void notifyListeners() {
         // always notify the backup agent
         LauncherBackupAgentHelper.dataChanged(getContext());
@@ -270,18 +308,6 @@ public class LauncherProvider extends ContentProvider {
         }
     }
 
-    @Thunk void notifyAppWidgetHostReset() {
-        new MainThreadExecutor().execute(new Runnable() {
-
-            @Override
-            public void run() {
-                if (mListener != null) {
-                    mListener.onAppWidgetHostReset();
-                }
-            }
-        });
-    }
-
     @Thunk static void addModifiedTime(ContentValues values) {
         values.put(LauncherSettings.ChangeLogColumns.MODIFIED, System.currentTimeMillis());
     }
@@ -429,6 +455,7 @@ public class LauncherProvider extends ContentProvider {
             SQLiteDatabase.deleteDatabase(dbFile);
         }
         mOpenHelper = new DatabaseHelper(getContext());
+        mOpenHelper.mListener = mListener;
     }
 
     private static class DatabaseHelper extends SQLiteOpenHelper implements LayoutParserCallback {
@@ -439,6 +466,8 @@ public class LauncherProvider extends ContentProvider {
 
         private boolean mNewDbCreated = false;
 
+        @Thunk LauncherProviderChangeListener mListener;
+
         DatabaseHelper(Context context) {
             super(context, LauncherFiles.LAUNCHER_DB, null, DATABASE_VERSION);
             mContext = context;
@@ -508,7 +537,15 @@ public class LauncherProvider extends ContentProvider {
                  * want to re-call {@link AppWidgetHost#startListening()} to ensure
                  * callbacks are correctly set.
                  */
-                LauncherAppState.getLauncherProvider().notifyAppWidgetHostReset();
+                new MainThreadExecutor().execute(new Runnable() {
+
+                    @Override
+                    public void run() {
+                        if (mListener != null) {
+                            mListener.onAppWidgetHostReset();
+                        }
+                    }
+                });
             }
 
             // Fresh and clean launcher DB.