Use ViewModel instead of Callbacks for UI Updates

app/src/main/java/com/stormtales/notevault/MainActivity.java

@@ -3,6 +3,8 @@ package com.stormtales.notevault;
 import android.os.Bundle;
 import android.view.MenuItem;
 import android.view.Menu;
+import android.widget.Toast;
+import androidx.lifecycle.ViewModelProvider;
 import com.google.android.material.navigation.NavigationView;
 import androidx.navigation.NavController;
 import androidx.navigation.Navigation;
@@ -14,11 +16,13 @@ import com.stormtales.notevault.databinding.ActivityMainBinding;
 import com.stormtales.notevault.network.APICallback;
 import com.stormtales.notevault.network.auth.AuthService;
 import com.stormtales.notevault.ui.login.LoginDialog;
+import com.stormtales.notevault.ui.login.LoginViewModel;
 
 public class MainActivity extends AppCompatActivity {
 
     private AppBarConfiguration mAppBarConfiguration;
     private ActivityMainBinding binding;
+    private LoginViewModel loginViewModel;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -30,11 +34,7 @@ public class MainActivity extends AppCompatActivity {
         setSupportActionBar(binding.appBarMain.toolbar);
         binding.appBarMain.toolbar.setOnMenuItemClickListener(item -> {
             if (item.getItemId() == R.id.auth_action) {
-                if (new AuthService(getApplicationContext()).isLoggedIn()) {
+                showLoginDialog();
-                    //performLogout(); // Logout-Logik aufrufen
-                } else {
-                    showLoginDialog(); // Zeige das Login-Fenster an
-                }
                 return true;
             }
             return false;
@@ -50,6 +50,12 @@ public class MainActivity extends AppCompatActivity {
         NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment_content_main);
         NavigationUI.setupActionBarWithNavController(this, navController, mAppBarConfiguration);
         NavigationUI.setupWithNavController(navigationView, navController);
+
+        loginViewModel = new ViewModelProvider(this).get(LoginViewModel.class);
+        loginViewModel.setAuthService(new AuthService(getApplicationContext()));
+        loginViewModel.getIsLoggedIn().observe(this, isLoggedIn -> {
+            this.invalidateOptionsMenu();
+        });
     }
 
     @Override
@@ -69,7 +75,7 @@ public class MainActivity extends AppCompatActivity {
     @Override
     public boolean onPrepareOptionsMenu(Menu menu) {
         MenuItem loginItem = menu.findItem(R.id.auth_action);
-        if (new AuthService(this).isLoggedIn()) {
+        if (Boolean.TRUE.equals(loginViewModel.getIsLoggedIn().getValue())) {
             loginItem.setIcon(R.drawable.logout); // Setze das Logout-Symbol
         } else {
             loginItem.setIcon(R.drawable.login); // Setze das Login-Symbol
@@ -78,27 +84,7 @@ public class MainActivity extends AppCompatActivity {
     }
 
     public void showLoginDialog() {
-        LoginDialog loginDialog = LoginDialog.newInstance(new APICallback() {
+        LoginDialog loginDialog = new LoginDialog(loginViewModel);
-            @Override
-            public void onSuccess() {
-
-            }
-
-            @Override
-            public void onError(String error) {
-
-            }
-        }, new APICallback() {
-            @Override
-            public void onSuccess() {
-
-            }
-
-            @Override
-            public void onError(String error) {
-
-            }
-        });
         loginDialog.show(getSupportFragmentManager(), "login");
     }
 }

app/src/main/java/com/stormtales/notevault/network/auth/AuthService.java

@@ -18,7 +18,7 @@ public class AuthService {
         this.tokenManager = new TokenManager(context);
     }
 
-    public void performLogin(String email, String password, APICallback callback) {
+    public void performLogin(String email, String password, LoginCallback callback) {
         LoginRequest loginRequest = new LoginRequest(email, password);
 
         authAPI.login(loginRequest).enqueue(new Callback<LoginResponse>() {
@@ -28,7 +28,7 @@ public class AuthService {
                     String token = response.body().getToken();
                     saveToken(token);
                     // Erfolgsrückmeldung an den Callback senden
-                    callback.onSuccess();
+                    callback.onSuccess(response.body());
                 } else {
                     // Fehlermeldung an den Callback senden
                     callback.onError("Login fehlgeschlagen. Überprüfe Benutzername und Passwort.");
@@ -78,4 +78,9 @@ public class AuthService {
     public boolean isLoggedIn() {
         return !TextUtils.isEmpty(tokenManager.getToken());
     }
+
+    public interface LoginCallback {
+        void onSuccess(LoginResponse loginResponse);
+        void onError(String error);
+    }
 }

app/src/main/java/com/stormtales/notevault/ui/login/LoginDialog.java

@@ -10,35 +10,29 @@ import android.view.View;
 import android.widget.Button;
 import android.widget.EditText;
 import android.widget.TextView;
+import android.widget.Toast;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.fragment.app.DialogFragment;
+import androidx.lifecycle.ViewModelProvider;
 import com.stormtales.notevault.R;
 import com.stormtales.notevault.network.APICallback;
 import com.stormtales.notevault.network.auth.AuthService;
 
 public class LoginDialog extends DialogFragment {
 
-    private APICallback loginCallback;
+    private LoginViewModel loginViewModel;
-    private APICallback registerCallback;
-
     private boolean isLoginMode = true;
-
     private Dialog dialog;
 
     @Override
     public void onAttach(Context context) {
         super.onAttach(context);
-        if (loginCallback == null) {
+
-            throw new IllegalStateException("LoginDialogFragment must be created using newInstance()");
-        }
     }
 
-    public static LoginDialog newInstance(APICallback loginCallback, APICallback registerCallback) {
+    public LoginDialog(LoginViewModel loginViewModel) {
-        LoginDialog fragment = new LoginDialog();
+        this.loginViewModel = loginViewModel;
-        fragment.loginCallback = loginCallback;
-        fragment.registerCallback = registerCallback;
-        return fragment;
     }
 
     @NonNull
@@ -61,15 +55,14 @@ public class LoginDialog extends DialogFragment {
                 // Handle login logic
                 String email = editTextEmail.getText().toString();
                 String password = editTextPassword.getText().toString();
-                AuthService authRepository = new AuthService(this.getContext());
+                this.loginViewModel.performLogin(email, password, this::onSuccessFullLogin);
-                authRepository.performLogin(email, password, loginCallback);
             } else {
                 // Handle registration logic
                 String email = editTextEmail.getText().toString();
                 String password = editTextPassword.getText().toString();
                 String username = editTextUsername.getText().toString();
                 AuthService authRepository = new AuthService(this.getContext());
-                authRepository.performRegistration(email, username, password, registerCallback);
+                //authRepository.performRegistration(email, username, password, registerCallback);
             }
         });
 
@@ -83,7 +76,12 @@ public class LoginDialog extends DialogFragment {
         });
 
         builder.setView(view);
-        return builder.create();
+        dialog = builder.create();
+        return dialog;
+    }
+
+    void onSuccessFullLogin() {
+        this.dialog.dismiss();
     }
 
 }

app/src/main/java/com/stormtales/notevault/ui/login/LoginViewModel.java

@@ -1,6 +1,65 @@
 package com.stormtales.notevault.ui.login;
 
+import android.util.Log;
+import android.widget.Toast;
+import androidx.lifecycle.MutableLiveData;
 import androidx.lifecycle.ViewModel;
+import com.stormtales.notevault.network.auth.AuthService;
+import com.stormtales.notevault.network.auth.LoginResponse;
 
 public class LoginViewModel extends ViewModel {
+
+    private final MutableLiveData<String> username;
+    private final MutableLiveData<Boolean> isLoggedIn;
+    private AuthService authService;
+
+    public LoginViewModel() {
+        username = new MutableLiveData<>("Not Logged In");
+        isLoggedIn = new MutableLiveData<>(false);
+    }
+
+    public void performLogin(String email, String password, SuccessFullLoginCallback successFullLoginCallback) {
+        if(authService != null) {
+            authService.performLogin(email, password, new LoginCallBackImpl(successFullLoginCallback));
+        } else {
+            throw new RuntimeException("AuthService is not provided to LoginViewModel");
+        }
+    }
+
+    public void setAuthService(AuthService authService) {
+        this.authService = authService;
+    }
+
+    public MutableLiveData<Boolean> getIsLoggedIn() {
+        return isLoggedIn;
+    }
+
+    public MutableLiveData<String> getUsername() {
+        return username;
+    }
+
+    public class LoginCallBackImpl implements AuthService.LoginCallback {
+
+        private final SuccessFullLoginCallback successFullLoginCallback;
+
+        public LoginCallBackImpl(SuccessFullLoginCallback successFullLoginCallback) {
+            this.successFullLoginCallback = successFullLoginCallback;
+        }
+
+        @Override
+        public void onSuccess(LoginResponse loginResponse) {
+            username.setValue(loginResponse.getUsername());
+            isLoggedIn.setValue(true);
+            successFullLoginCallback.onSuccess();
+        }
+
+        @Override
+        public void onError(String error) {
+            Log.d("LoginService", error);
+        }
+    }
+
+    public interface SuccessFullLoginCallback {
+        void onSuccess();
+    }
 }