Trying basic MVVM implementation based on https://github.com/mitchtabian/MVVMExample1

app/src/main/java/it/danieleverducci/nextcloudmaps/activity/main/GeofavoriteAdapter.java

@@ -82,17 +82,6 @@ public class GeofavoriteAdapter extends RecyclerView.Adapter<GeofavoriteAdapter.
         return geofavoriteListFiltered.get(position);
     }
 
-    public void removeById(int id) {
-        for (Geofavorite g : geofavoriteList) {
-            if (g.getId() == id) {
-                geofavoriteList.remove(g);
-                geofavoriteListFiltered.remove(g);
-                break;
-            }
-        }
-        notifyDataSetChanged();
-    }
-
     public int getSortRule() {
         return sortRule;
     }

app/src/main/java/it/danieleverducci/nextcloudmaps/activity/main/MainActivity.java

@@ -25,6 +25,7 @@ import android.text.TextUtils;
 import android.util.Log;
 import android.widget.Toast;
 
+import androidx.annotation.Nullable;
 import androidx.appcompat.app.AlertDialog;
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.appcompat.widget.AppCompatImageButton;
@@ -35,6 +36,7 @@ import androidx.core.view.GravityCompat;
 import androidx.drawerlayout.widget.DrawerLayout;
 import androidx.fragment.app.FragmentManager;
 import androidx.fragment.app.FragmentTransaction;
+import androidx.lifecycle.ViewModelProvider;
 import androidx.preference.PreferenceManager;
 import androidx.recyclerview.widget.RecyclerView;
 import androidx.recyclerview.widget.StaggeredGridLayoutManager;
@@ -61,8 +63,9 @@ import static android.view.View.VISIBLE;
 import static it.danieleverducci.nextcloudmaps.activity.main.GeofavoriteAdapter.*;
 import static it.danieleverducci.nextcloudmaps.activity.main.GeofavoriteAdapter.SORT_BY_CREATED;
 import static it.danieleverducci.nextcloudmaps.activity.main.GeofavoriteAdapter.SORT_BY_TITLE;
+import androidx.lifecycle.Observer;
 
-public class MainActivity extends AppCompatActivity implements MainView, OnSortingOrderListener {
+public class MainActivity extends AppCompatActivity implements OnSortingOrderListener {
 
     private static final int INTENT_ADD = 100;
     private static final int INTENT_EDIT = 200;
@@ -84,9 +87,9 @@ public class MainActivity extends AppCompatActivity implements MainView, OnSorti
     private StaggeredGridLayoutManager layoutManager;
     private FloatingActionButton fab;
 
-    private MainPresenter presenter;
     private GeofavoriteAdapter geofavoriteAdapter;
     private ItemClickListener rvItemClickListener;
+    private MainActivityViewModel mMainActivityViewModel;
 
     NavigationAdapter navigationCommonAdapter;
 
@@ -95,6 +98,8 @@ public class MainActivity extends AppCompatActivity implements MainView, OnSorti
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
 
+        mMainActivityViewModel = new ViewModelProvider(this).get(MainActivityViewModel.class);
+        mMainActivityViewModel.init();
         preferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
 
         int sortRule = preferences.getInt(getString(R.string.setting_sort_by), SORT_BY_CREATED);
@@ -104,8 +109,6 @@ public class MainActivity extends AppCompatActivity implements MainView, OnSorti
         layoutManager = new StaggeredGridLayoutManager(gridViewEnabled ? 2 : 1, StaggeredGridLayoutManager.VERTICAL);
         recyclerView.setLayoutManager(layoutManager);
 
-        presenter = new MainPresenter(this);
-
         rvItemClickListener = new ItemClickListener() {
             @Override
             public void onItemClick(Geofavorite item) {
@@ -133,7 +136,7 @@ public class MainActivity extends AppCompatActivity implements MainView, OnSorti
         geofavoriteAdapter.setSortRule(sortRule);
 
         swipeRefresh = findViewById(R.id.swipe_refresh);
-        swipeRefresh.setOnRefreshListener(() -> presenter.getGeofavorites());
+        swipeRefresh.setOnRefreshListener(() -> updateGeofavorites());
 
         fab = findViewById(R.id.add);
         fab.setOnClickListener(view -> addGeofavorite());
@@ -190,7 +193,7 @@ public class MainActivity extends AppCompatActivity implements MainView, OnSorti
         super.onStart();
 
         // Update list
-        presenter.getGeofavorites();
+        mMainActivityViewModel.getGeofavorites().observe(this, this);
     }
 
     private void setupNavigationMenu() {
@@ -239,9 +242,9 @@ public class MainActivity extends AppCompatActivity implements MainView, OnSorti
     public void onActivityResult(int requestCode, int resultCode, Intent data) {
         super.onActivityResult(requestCode, resultCode, data);
         if (requestCode == INTENT_ADD && resultCode == RESULT_OK) {
-            presenter.getGeofavorites();
+            mMainActivityViewModel.getGeofavorites().observe(this, this);
         } else if (requestCode == INTENT_EDIT && resultCode == RESULT_OK) {
-            presenter.getGeofavorites();
+            mMainActivityViewModel.getGeofavorites().observe(this, this);
         }
     }
 
@@ -260,35 +263,12 @@ public class MainActivity extends AppCompatActivity implements MainView, OnSorti
         startActivity(intent);
     }
 
-    @Override
-    public void showLoading() {
-        swipeRefresh.setRefreshing(true);
-    }
 
-    @Override
+//    @Override
-    public void hideLoading() {
+//    public void onErrorLoading(String message) {
-        swipeRefresh.setRefreshing(false);
+//        Toast.makeText(MainActivity.this, R.string.list_geofavorite_connection_error, Toast.LENGTH_LONG).show();
-    }
+//        Log.e(TAG, "Unable to obtain geofavorites list: " + message);
-
+//    }
-    @Override
-    public void onGetResult(List<Geofavorite> geofavorite_list) {
-        geofavoriteAdapter.setGeofavoriteList(geofavorite_list);
-    }
-
-    @Override
-    public void onGeofavoriteDeleted(int id) {
-        // Update list
-        runOnUiThread(() -> {
-            geofavoriteAdapter.removeById(id);
-            Toast.makeText(MainActivity.this, R.string.list_geofavorite_deleted, Toast.LENGTH_LONG).show();
-        });
-    }
-
-    @Override
-    public void onErrorLoading(String message) {
-        Toast.makeText(MainActivity.this, R.string.list_geofavorite_connection_error, Toast.LENGTH_LONG).show();
-        Log.e(TAG, "Unable to obtain geofavorites list: " + message);
-    }
 
     @Override
     public void onSortingOrderChosen(int sortSelection) {
@@ -328,7 +308,7 @@ public class MainActivity extends AppCompatActivity implements MainView, OnSorti
                 .setTitle(R.string.dialog_delete_title)
                 .setPositiveButton(R.string.dialog_delete_delete, new DialogInterface.OnClickListener() {
                     public void onClick(DialogInterface dialog, int id) {
-                        presenter.deleteGeofavorite(item.getId());
+                        // TODO presenter.deleteGeofavorite(item.getId());
                         dialog.dismiss();
                         // Callback is onGeofavoriteDeleted
                     }
@@ -348,4 +328,26 @@ public class MainActivity extends AppCompatActivity implements MainView, OnSorti
         startActivity(i);
     }
 
+    private void updateGeofavorites() {
+        mMainActivityViewModel.getGeofavorites().observe(this, new Observer<List<Geofavorite>>() {
+            @Override
+            public void onChanged(List<Geofavorite> geofavorites) {
+                geofavoriteAdapter.setGeofavoriteList(geofavorites);
+            }
+        });
+
+        // TODO: è possibile registrare un solo listener?
+        mMainActivityViewModel.getIsUpdating().observe(this, new Observer<Boolean>() {
+            @Override
+            public void onChanged(@Nullable Boolean aBoolean) {
+                if(aBoolean){
+                    swipeRefresh.setRefreshing(true);
+                }
+                else{
+                    swipeRefresh.setRefreshing(false);
+                }
+            }
+        });
+    }
+
 }

app/src/main/java/it/danieleverducci/nextcloudmaps/activity/main/MainActivityViewModel.java

@@ -0,0 +1,33 @@
+package it.danieleverducci.nextcloudmaps.activity.main;
+
+import androidx.lifecycle.LiveData;
+import androidx.lifecycle.MutableLiveData;
+import androidx.lifecycle.ViewModel;
+
+import java.util.List;
+
+import it.danieleverducci.nextcloudmaps.model.Geofavorite;
+import it.danieleverducci.nextcloudmaps.repository.GeofavoriteRepository;
+
+public class MainActivityViewModel extends ViewModel {
+
+    private MutableLiveData<List<Geofavorite>> mGeofavorites;
+    private GeofavoriteRepository mRepo;
+    private MutableLiveData<Boolean> mIsUpdating = new MutableLiveData<>();
+
+    public void init() {
+        if (mGeofavorites != null)
+            return;
+
+        mRepo = GeofavoriteRepository.getInstance();
+        mGeofavorites = mRepo.getGeofavorites();
+    }
+
+    public LiveData<List<Geofavorite>> getGeofavorites(){
+        return mGeofavorites;
+    }
+
+    public LiveData<Boolean> getIsUpdating(){
+        return mIsUpdating;
+    }
+}

app/src/main/java/it/danieleverducci/nextcloudmaps/activity/main/MainPresenter.java

@@ -1,89 +0,0 @@
-/*
- * Nextcloud Maps Geofavorites for Android
- *
- * @copyright Copyright (c) 2020 John Doe <john@doe.com>
- * @author John Doe <john@doe.com>
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-package it.danieleverducci.nextcloudmaps.activity.main;
-
-import android.util.Log;
-
-import androidx.annotation.NonNull;
-import androidx.appcompat.app.AppCompatActivity;
-
-import java.util.List;
-
-import it.danieleverducci.nextcloudmaps.api.ApiProvider;
-import it.danieleverducci.nextcloudmaps.model.Geofavorite;
-import retrofit2.Call;
-import retrofit2.Callback;
-import retrofit2.Response;
-
-public class MainPresenter {
-    private MainView view;
-
-    public MainPresenter(MainView view) {
-        this.view = view;
-    }
-
-    public void getGeofavorites() {
-        view.showLoading();
-        Call<List<Geofavorite>> call = ApiProvider.getAPI().getGeofavorites();
-        call.enqueue(new Callback<List<Geofavorite>>() {
-            @Override
-            public void onResponse(@NonNull Call<List<Geofavorite>> call, @NonNull Response<List<Geofavorite>> response) {
-                ((AppCompatActivity) view).runOnUiThread(() -> {
-                    view.hideLoading();
-                    if (response.isSuccessful() && response.body() != null) {
-                        view.onGetResult(response.body());
-                    } else {
-                        ((AppCompatActivity) view).runOnUiThread(() -> {
-                            view.hideLoading();
-                            view.onErrorLoading(response.raw().message());
-                        });
-                    }
-                });
-            }
-
-            @Override
-            public void onFailure(@NonNull Call<List<Geofavorite>> call, @NonNull Throwable t) {
-                ((AppCompatActivity) view).runOnUiThread(() -> {
-                    view.hideLoading();
-                    view.onErrorLoading(t.getLocalizedMessage());
-                });
-            }
-        });
-    }
-
-    public void deleteGeofavorite(int id) {
-        view.showLoading();
-        Call<Geofavorite> call = ApiProvider.getAPI().deleteGeofavorite(id);
-        call.enqueue(new Callback<Geofavorite>() {
-            @Override
-            public void onResponse(Call<Geofavorite> call, Response<Geofavorite> response) {
-                view.hideLoading();
-                view.onGeofavoriteDeleted(id);
-            }
-
-            @Override
-            public void onFailure(Call<Geofavorite> call, Throwable t) {
-                view.hideLoading();
-                view.onErrorLoading(t.getLocalizedMessage());
-            }
-        });
-    }
-}

app/src/main/java/it/danieleverducci/nextcloudmaps/activity/main/MainView.java

@@ -1,33 +0,0 @@
-/*
- * Nextcloud Maps Geofavorites for Android
- *
- * @copyright Copyright (c) 2020 John Doe <john@doe.com>
- * @author John Doe <john@doe.com>
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-package it.danieleverducci.nextcloudmaps.activity.main;
-
-import java.util.List;
-
-import it.danieleverducci.nextcloudmaps.model.Geofavorite;
-
-public interface MainView {
-    void showLoading();
-    void hideLoading();
-    void onGetResult(List<Geofavorite> geofavorites);
-    void onGeofavoriteDeleted(int id);
-    void onErrorLoading(String message);
-}

app/src/main/java/it/danieleverducci/nextcloudmaps/repository/GeofavoriteRepository.java

@@ -0,0 +1,56 @@
+package it.danieleverducci.nextcloudmaps.repository;
+
+import androidx.annotation.NonNull;
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.lifecycle.MutableLiveData;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import it.danieleverducci.nextcloudmaps.api.ApiProvider;
+import it.danieleverducci.nextcloudmaps.model.Geofavorite;
+import retrofit2.Call;
+import retrofit2.Callback;
+import retrofit2.Response;
+
+/**
+ * Singleton pattern
+ */
+public class GeofavoriteRepository {
+
+    private static GeofavoriteRepository instance;
+    private ArrayList<Geofavorite> dataSet = new ArrayList<>();
+
+    public static GeofavoriteRepository getInstance() {
+        if(instance == null){
+            instance = new GeofavoriteRepository();
+        }
+        return instance;
+    }
+
+    public MutableLiveData<List<Geofavorite>> getGeofavorites(){
+        // Obtain geofavorites
+        Call<List<Geofavorite>> call = ApiProvider.getAPI().getGeofavorites();
+        call.enqueue(new Callback<List<Geofavorite>>() {
+            @Override
+            public void onResponse(@NonNull Call<List<Geofavorite>> call, @NonNull Response<List<Geofavorite>> response) {
+                if (response.isSuccessful() && response.body() != null) {
+                    dataSet.addAll(response.body());
+                } else {
+                    onFailure(call, new Throwable("Dataset is empty"));
+                }
+            }
+
+            @Override
+            public void onFailure(@NonNull Call<List<Geofavorite>> call, @NonNull Throwable t) {
+                // TODO
+            }
+        });
+
+        MutableLiveData<List<Geofavorite>> data = new MutableLiveData<>();
+        data.setValue(dataSet);
+        return data;
+    }
+
+
+}