Local broadcast receiver used as observer in loader

app/src/main/java/com/philliphsu/clock2/AsyncItemChangeHandler.java

@@ -5,7 +5,6 @@ import android.os.AsyncTask;
 import android.support.design.widget.Snackbar;
 import android.view.View;
 
-import com.philliphsu.clock2.alarms.AlarmsAdapter;
 import com.philliphsu.clock2.model.DatabaseManager;
 import com.philliphsu.clock2.util.AlarmUtils;
 
@@ -14,18 +13,16 @@ import com.philliphsu.clock2.util.AlarmUtils;
  *
  * TODO: Generify this class for any item.
  */
-public final class AsyncRecyclerViewItemChangeHandler {
+public final class AsyncItemChangeHandler {
 
     private final Context mContext;
-    private final AlarmsAdapter mAdapter;
     private final View mSnackbarAnchor;
 
     /**
      * @param snackbarAnchor an optional anchor for a Snackbar to anchor to
      */
-    public AsyncRecyclerViewItemChangeHandler(AlarmsAdapter adapter, View snackbarAnchor) {
+    public AsyncItemChangeHandler(Context context, View snackbarAnchor) {
-        mContext = snackbarAnchor.getContext();
+        mContext = context.getApplicationContext(); // to prevent memory leaks
-        mAdapter = adapter;
         mSnackbarAnchor = snackbarAnchor;
     }
 
@@ -39,7 +36,7 @@ public final class AsyncRecyclerViewItemChangeHandler {
             @Override
             protected void onPostExecute(Long aLong) {
                 // TODO: Snackbar/Toast here? If so, remove the code in AlarmUtils.scheduleAlarm() that does it.
-                mAdapter.addItem(alarm);
+                // Then, consider scheduling the alarm in the background.
                 AlarmUtils.scheduleAlarm(mContext, alarm, true);
             }
         }.execute();
@@ -49,8 +46,6 @@ public final class AsyncRecyclerViewItemChangeHandler {
         new AsyncTask<Void, Void, Integer>() {
             @Override
             protected Integer doInBackground(Void... params) {
-                mAdapter.updateItem(oldAlarm, newAlarm);
-                // Save the item to the db
                 return DatabaseManager.getInstance(mContext).updateAlarm(oldAlarm.id(), newAlarm);
             }
 
@@ -65,14 +60,11 @@ public final class AsyncRecyclerViewItemChangeHandler {
         new AsyncTask<Void, Void, Integer>() {
             @Override
             protected Integer doInBackground(Void... params) {
-                mAdapter.removeItem(alarm);
-                // Save the item to the db
                 return DatabaseManager.getInstance(mContext).deleteAlarm(alarm);
             }
 
             @Override
             protected void onPostExecute(Integer integer) {
-                // TODO: Snackbar
                 if (mSnackbarAnchor != null) {
                     String message = mContext.getString(R.string.snackbar_item_deleted,
                             mContext.getString(R.string.alarm));

app/src/main/java/com/philliphsu/clock2/alarms/AlarmsFragment.java

@@ -3,8 +3,8 @@ package com.philliphsu.clock2.alarms;
 import android.app.Activity;
 import android.content.Context;
 import android.content.Intent;
+import android.database.Cursor;
 import android.os.Bundle;
-import android.os.Handler;
 import android.support.design.widget.Snackbar;
 import android.support.v4.app.Fragment;
 import android.support.v4.app.LoaderManager.LoaderCallbacks;
@@ -17,30 +17,25 @@ import android.view.View;
 import android.view.ViewGroup;
 
 import com.philliphsu.clock2.Alarm;
-import com.philliphsu.clock2.AsyncRecyclerViewItemChangeHandler;
 import com.philliphsu.clock2.OnListItemInteractionListener;
 import com.philliphsu.clock2.R;
 import com.philliphsu.clock2.editalarm.EditAlarmActivity;
-import com.philliphsu.clock2.model.AlarmListLoader;
+import com.philliphsu.clock2.model.AlarmsListCursorLoader;
 import com.philliphsu.clock2.model.DatabaseManager;
 import com.philliphsu.clock2.util.AlarmUtils;
 
-import java.util.Collections;
-import java.util.List;
-
 import butterknife.Bind;
 import butterknife.ButterKnife;
 
 // TODO: Use native fragments since we're targeting API >=19?
 // TODO: Use native LoaderCallbacks.
-public class AlarmsFragment extends Fragment implements LoaderCallbacks<List<Alarm>>,
+public class AlarmsFragment extends Fragment implements LoaderCallbacks<Cursor>,
         OnListItemInteractionListener<Alarm> {
     private static final int REQUEST_EDIT_ALARM = 0;
     public static final int REQUEST_CREATE_ALARM = 1;
     private static final String TAG = "AlarmsFragment";
 
-    private AsyncRecyclerViewItemChangeHandler mAsyncRecyclerViewItemChangeHandler;
+    private AlarmsCursorAdapter mAdapter;
-    private AlarmsAdapter mAdapter;
 
     @Bind(R.id.list) RecyclerView mList;
 
@@ -80,11 +75,8 @@ public class AlarmsFragment extends Fragment implements LoaderCallbacks<List<Ala
         // Set the adapter
         Context context = view.getContext();
         mList.setLayoutManager(new LinearLayoutManager(context));
-        mAdapter = new AlarmsAdapter(Collections.<Alarm>emptyList(), this);
+        mAdapter = new AlarmsCursorAdapter(this);
         mList.setAdapter(mAdapter);
-
-        mAsyncRecyclerViewItemChangeHandler = new AsyncRecyclerViewItemChangeHandler(
-                mAdapter, getActivity().findViewById(R.id.main_content));
         return view;
     }
 
@@ -107,20 +99,18 @@ public class AlarmsFragment extends Fragment implements LoaderCallbacks<List<Ala
     }
 
     @Override
-    public Loader<List<Alarm>> onCreateLoader(int id, Bundle args) {
+    public Loader<Cursor> onCreateLoader(int id, Bundle args) {
-        return new AlarmListLoader(getActivity());
+        return new AlarmsListCursorLoader(getActivity());
     }
 
     @Override
-    public void onLoadFinished(Loader<List<Alarm>> loader, List<Alarm> data) {
+    public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
-        mAdapter.replaceData(data);
+        mAdapter.swapCursor(data);
     }
 
     @Override
-    public void onLoaderReset(Loader<List<Alarm>> loader) {
+    public void onLoaderReset(Loader<Cursor> loader) {
-        // Can't pass in null, because replaceData() will try to add all the elements
+        mAdapter.swapCursor(null);
-        // from the given collection, so we would run into an NPE.
-        mAdapter.replaceData(Collections.<Alarm>emptyList());
     }
 
     @Override
@@ -132,14 +122,9 @@ public class AlarmsFragment extends Fragment implements LoaderCallbacks<List<Ala
 
         switch (requestCode) {
             case REQUEST_CREATE_ALARM:
-                Log.d(TAG, "Async add alarm");
+                // TODO: Should we still do the async add here?
-                final Alarm createdAlarm = data.getParcelableExtra(EditAlarmActivity.EXTRA_MODIFIED_ALARM);
+                // We must if we want the async handler to post the toast/snackbar
-                new Handler().postDelayed(new Runnable() {
+                // for us.
-                    @Override
-                    public void run() {
-                        mAsyncRecyclerViewItemChangeHandler.asyncAddAlarm(createdAlarm);
-                    }
-                }, 1000);
                 break;
             case REQUEST_EDIT_ALARM:
                 Alarm deletedAlarm;

app/src/main/java/com/philliphsu/clock2/editalarm/EditAlarmActivity.java

@@ -26,6 +26,7 @@ import android.widget.Toast;
 import android.widget.ToggleButton;
 
 import com.philliphsu.clock2.Alarm;
+import com.philliphsu.clock2.AsyncItemChangeHandler;
 import com.philliphsu.clock2.BaseActivity;
 import com.philliphsu.clock2.DaysOfWeek;
 import com.philliphsu.clock2.R;
@@ -68,6 +69,7 @@ public class EditAlarmActivity extends BaseActivity implements AlarmNumpad.KeyLi
     private Uri mSelectedRingtoneUri;
     private Alarm mOldAlarm;
     private DatabaseManager mDatabaseManager;
+    private AsyncItemChangeHandler mAsyncItemChangeHandler;
 
     @Bind(R.id.save) Button mSave;
     @Bind(R.id.delete) Button mDelete;
@@ -98,6 +100,8 @@ public class EditAlarmActivity extends BaseActivity implements AlarmNumpad.KeyLi
             showDetails();
         }
         setTimeTextHint(); // TODO: private access
+
+        mAsyncItemChangeHandler = new AsyncItemChangeHandler(this, null);
     }
 
     @Override
@@ -246,13 +250,15 @@ public class EditAlarmActivity extends BaseActivity implements AlarmNumpad.KeyLi
             mDatabaseManager.updateAlarm(mOldAlarm.id(), alarm);
         } else {
             //mDatabaseManager.insertAlarm(alarm);
-            intent.putExtra(EXTRA_MODIFIED_ALARM, alarm);
+            mAsyncItemChangeHandler.asyncAddAlarm(alarm);
+            //intent.putExtra(EXTRA_MODIFIED_ALARM, alarm);
         }
 
         if (alarm.isEnabled()) {
             //scheduleAlarm(alarm);
         }
 
+        // TODO: Remove intent
         setResult(RESULT_OK, intent);
         showEditorClosed();
     }

app/src/main/java/com/philliphsu/clock2/model/AlarmDatabaseHelper.java

@@ -9,6 +9,7 @@ import android.database.sqlite.SQLiteOpenHelper;
 import android.util.Log;
 
 import com.philliphsu.clock2.Alarm;
+import com.philliphsu.clock2.util.LocalBroadcastHelper;
 
 import static com.philliphsu.clock2.DaysOfWeek.FRIDAY;
 import static com.philliphsu.clock2.DaysOfWeek.MONDAY;
@@ -65,8 +66,13 @@ public class AlarmDatabaseHelper extends SQLiteOpenHelper {
     private static final String SORT_ORDER =
             COLUMN_RING_TIME_MILLIS + " ASC, " + COLUMN_ID + " ASC";
 
+    private final Context mAppContext;
+
     public AlarmDatabaseHelper(Context context) {
         super(context, DB_NAME, null, VERSION_1);
+        // Since DatabaseManager calls this with the application
+        // context, we can safely hold onto this context.
+        mAppContext = context;
     }
 
     @Override
@@ -105,6 +111,7 @@ public class AlarmDatabaseHelper extends SQLiteOpenHelper {
         long id = getWritableDatabase().insert(TABLE_ALARMS,
                 null, toContentValues(alarm));
         alarm.setId(id);
+        notifyContentChanged();
         return id;
     }
 
@@ -115,26 +122,32 @@ public class AlarmDatabaseHelper extends SQLiteOpenHelper {
     public int updateAlarm(Alarm oldAlarm, Alarm newAlarm) {
         newAlarm.setId(oldAlarm.id());
         SQLiteDatabase db = getWritableDatabase();
-        return db.update(TABLE_ALARMS,
+        int rowsUpdated = db.update(TABLE_ALARMS,
                 toContentValues(newAlarm),
                 COLUMN_ID + " = " + newAlarm.id(),
                 null);
+        notifyContentChanged();
+        return rowsUpdated;
     }
 
     public int updateAlarm(long id, Alarm newAlarm) {
         newAlarm.setId(id);
         SQLiteDatabase db = getWritableDatabase();
-        return db.update(TABLE_ALARMS,
+        int rowsUpdated = db.update(TABLE_ALARMS,
                 toContentValues(newAlarm),
                 COLUMN_ID + " = " + id,
                 null);
+        notifyContentChanged();
+        return rowsUpdated;
     }
 
     public int deleteAlarm(Alarm alarm) {
         SQLiteDatabase db = getWritableDatabase();
-        return db.delete(TABLE_ALARMS,
+        int rowsDeleted = db.delete(TABLE_ALARMS,
                 COLUMN_ID + " = " + alarm.id(),
                 null);
+        notifyContentChanged();
+        return rowsDeleted;
     }
 
     public AlarmCursor queryAlarm(long id) {
@@ -184,6 +197,12 @@ public class AlarmDatabaseHelper extends SQLiteOpenHelper {
         return values;
     }
 
+    private void notifyContentChanged() {
+        Log.d(TAG, "notifyContentChanged()");
+        LocalBroadcastHelper.sendBroadcast(mAppContext,
+                SQLiteCursorLoader.ACTION_CHANGE_CONTENT);
+    }
+
     // An alternative method to creating an Alarm from a cursor is to
     // make an Alarm constructor that takes an Cursor param. However,
     // this method has the advantage of keeping all the constants

app/src/main/java/com/philliphsu/clock2/model/SQLiteCursorLoader.java

@@ -1,8 +1,13 @@
 package com.philliphsu.clock2.model;
 
+import android.content.BroadcastReceiver;
 import android.content.Context;
+import android.content.Intent;
 import android.database.Cursor;
 import android.support.v4.content.AsyncTaskLoader;
+import android.util.Log;
+
+import com.philliphsu.clock2.util.LocalBroadcastHelper;
 
 /**
  * Created by Phillip Hsu on 6/28/2016.
@@ -12,7 +17,10 @@ import android.support.v4.content.AsyncTaskLoader;
 public abstract class SQLiteCursorLoader extends AsyncTaskLoader<Cursor> {
     private static final String TAG = "SQLiteCursorLoader";
 
+    public static final String ACTION_CHANGE_CONTENT = "com.philliphsu.clock2.model.action.CHANGE_CONTENT";
+
     private Cursor mCursor;
+    private OnContentChangeReceiver mOnContentChangeReceiver;
 
     public SQLiteCursorLoader(Context context) {
         super(context);
@@ -66,30 +74,54 @@ public abstract class SQLiteCursorLoader extends AsyncTaskLoader<Cursor> {
         if (mCursor != null) {
             deliverResult(mCursor);
         }
+
+        if (mOnContentChangeReceiver == null) {
+            mOnContentChangeReceiver = new OnContentChangeReceiver();
+            LocalBroadcastHelper.registerReceiver(getContext(),
+                    mOnContentChangeReceiver, ACTION_CHANGE_CONTENT);
+        }
+
         if (takeContentChanged() || mCursor == null) {
             forceLoad();
         }
     }
+
     @Override
     protected void onStopLoading() {
         // Attempt to cancel the current load task if possible.
         cancelLoad();
     }
+
     @Override
     public void onCanceled(Cursor cursor) {
         if (cursor != null && !cursor.isClosed()) {
             cursor.close();
         }
     }
+
     @Override
     protected void onReset() {
         super.onReset();
         // Ensure the loader is stopped
         onStopLoading();
+
         if (mCursor != null && !mCursor.isClosed()) {
             mCursor.close();
         }
         mCursor = null;
+
+        if (mOnContentChangeReceiver != null) {
+            LocalBroadcastHelper.unregisterReceiver(getContext(),
+                    mOnContentChangeReceiver);
+            mOnContentChangeReceiver = null;
+        }
     }
 
+    private final class OnContentChangeReceiver extends BroadcastReceiver {
+        @Override
+        public void onReceive(Context context, Intent intent) {
+            Log.d(TAG, "Received content change event");
+            onContentChanged();
+        }
+    }
 }

app/src/main/java/com/philliphsu/clock2/util/LocalBroadcastHelper.java

@@ -1,7 +1,9 @@
 package com.philliphsu.clock2.util;
 
+import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
+import android.content.IntentFilter;
 import android.support.v4.content.LocalBroadcastManager;
 
 /**
@@ -14,5 +16,16 @@ public final class LocalBroadcastHelper {
         LocalBroadcastManager.getInstance(context).sendBroadcast(new Intent(action));
     }
 
+    /** Registers a BroadcastReceiver that filters intents by the action specified */
+    // TODO: Refactor any local registrations to use this utility method.
+    public static void registerReceiver(Context context, BroadcastReceiver receiver, String action) {
+        LocalBroadcastManager.getInstance(context).registerReceiver(receiver, new IntentFilter(action));
+    }
+
+    // TODO: Refactor any local unregistrations to use this utility method.
+    public static void unregisterReceiver(Context context, BroadcastReceiver receiver) {
+        LocalBroadcastManager.getInstance(context).unregisterReceiver(receiver);
+    }
+
     private LocalBroadcastHelper() {}
 }