feat: improve main screen accessibility and UX

app/src/main/java/com/d4rk/androidtutorials/java/ui/components/navigation/BaseActivity.java

@@ -0,0 +1,34 @@
+package com.d4rk.androidtutorials.java.ui.components.navigation;
+
+import android.os.Bundle;
+import android.view.View;
+
+import androidx.annotation.Nullable;
+import androidx.appcompat.app.ActionBar;
+import androidx.appcompat.app.AppCompatActivity;
+
+import com.d4rk.androidtutorials.java.R;
+import com.d4rk.androidtutorials.java.utils.EdgeToEdgeDelegate;
+
+public abstract class BaseActivity extends AppCompatActivity {
+
+    @Override
+    protected void onPostCreate(@Nullable Bundle savedInstanceState) {
+        super.onPostCreate(savedInstanceState);
+        View container = findViewById(R.id.container);
+        if (container != null) {
+            EdgeToEdgeDelegate edgeToEdgeDelegate = new EdgeToEdgeDelegate(this);
+            edgeToEdgeDelegate.applyEdgeToEdge(container);
+        }
+        ActionBar actionBar = getSupportActionBar();
+        if (actionBar != null) {
+            actionBar.setDisplayHomeAsUpEnabled(true);
+        }
+    }
+
+    @Override
+    public boolean onSupportNavigateUp() {
+        finish();
+        return true;
+    }
+}

app/src/main/java/com/d4rk/androidtutorials/java/ui/screens/help/HelpActivity.java

@@ -9,9 +9,8 @@
 import android.view.MenuItem;
 
 import androidx.annotation.NonNull;
-import androidx.appcompat.app.ActionBar;
 import androidx.appcompat.app.AlertDialog;
-import com.d4rk.androidtutorials.java.ui.components.navigation.UpNavigationActivity;
+import com.d4rk.androidtutorials.java.ui.components.navigation.BaseActivity;
 import androidx.lifecycle.ViewModelProvider;
 import androidx.preference.Preference;
 import androidx.preference.PreferenceFragmentCompat;
@@ -21,7 +20,6 @@
 import com.d4rk.androidtutorials.java.databinding.ActivityHelpBinding;
 import com.d4rk.androidtutorials.java.databinding.DialogVersionInfoBinding;
 import com.d4rk.androidtutorials.java.ui.screens.help.repository.HelpRepository;
-import com.d4rk.androidtutorials.java.utils.EdgeToEdgeDelegate;
 import com.d4rk.androidtutorials.java.utils.OpenSourceLicensesUtils;
 import com.google.android.material.snackbar.Snackbar;
 import com.google.android.play.core.review.ReviewInfo;
@@ -30,7 +28,7 @@
 import dagger.hilt.android.AndroidEntryPoint;
 
 @AndroidEntryPoint
-public class HelpActivity extends UpNavigationActivity {
+public class HelpActivity extends BaseActivity {
 
     private HelpViewModel helpViewModel;
 
@@ -40,16 +38,8 @@ protected void onCreate(Bundle savedInstanceState) {
         ActivityHelpBinding binding = ActivityHelpBinding.inflate(getLayoutInflater());
         setContentView(binding.getRoot());
 
-        EdgeToEdgeDelegate edgeToEdgeDelegate = new EdgeToEdgeDelegate(this);
-        edgeToEdgeDelegate.applyEdgeToEdge(binding.container);
-
         helpViewModel = new ViewModelProvider(this).get(HelpViewModel.class);
 
-        ActionBar actionBar = getSupportActionBar();
-        if (actionBar != null) {
-            actionBar.setDisplayHomeAsUpEnabled(true);
-        }
-
         getSupportFragmentManager().beginTransaction()
                 .replace(R.id.frame_layout_faq, new FaqFragment())
                 .commit();
@@ -73,7 +63,10 @@ public boolean onCreateOptionsMenu(Menu menu) {
     public boolean onOptionsItemSelected(@NonNull MenuItem item) {
         int itemId = item.getItemId();
 
-        if (itemId == R.id.view_in_google_play) {
+        if (itemId == android.R.id.home) {
+            finish();
+            return true;
+        } else if (itemId == R.id.view_in_google_play) {
             openGooglePlayListing();
             return true;
         } else if (itemId == R.id.version_info) {

app/src/main/java/com/d4rk/androidtutorials/java/ui/screens/main/MainActivity.java

@@ -8,6 +8,7 @@
 import android.util.Log;
 import android.util.SparseIntArray;
 import android.view.View;
+import android.widget.Toast;
 
 import androidx.activity.OnBackPressedCallback;
 import androidx.activity.result.ActivityResultLauncher;
@@ -42,7 +43,6 @@
 import com.d4rk.androidtutorials.java.utils.EdgeToEdgeDelegate;
 import com.google.android.gms.ads.AdRequest;
 import com.google.android.gms.ads.MobileAds;
-import com.google.android.material.dialog.MaterialAlertDialogBuilder;
 import com.google.android.material.navigation.NavigationBarView;
 import com.google.android.material.navigationrail.NavigationRailView;
 import com.google.android.material.snackbar.Snackbar;
@@ -80,6 +80,8 @@ public class MainActivity extends AppCompatActivity {
     private AppUpdateNotificationsManager appUpdateNotificationsManager;
     private AppUpdateManager appUpdateManager;
     private InstallStateUpdatedListener installStateUpdatedListener;
+    private long backPressedTime;
+    private static final long BACK_PRESS_INTERVAL = 2000;
     private final DefaultLifecycleObserver lifecycleObserver = new DefaultLifecycleObserver() {
         @Override
         public void onResume(@NonNull LifecycleOwner owner) {
@@ -88,11 +90,13 @@ public void onResume(@NonNull LifecycleOwner owner) {
                 if (ConsentUtils.canShowAds(MainActivity.this)) {
                     if (mBinding.adView.getVisibility() != View.VISIBLE) {
                         MobileAds.initialize(MainActivity.this);
+                        mBinding.adPlaceholder.setVisibility(View.GONE);
                         mBinding.adView.setVisibility(View.VISIBLE);
                         mBinding.adView.loadAd(new AdRequest.Builder().build());
                     }
                 } else {
                     mBinding.adView.setVisibility(View.GONE);
+                    mBinding.adPlaceholder.setVisibility(View.VISIBLE);
                 }
             }
         }
@@ -149,15 +153,15 @@ protected void onCreate(Bundle savedInstanceState) {
         getOnBackPressedDispatcher().addCallback(this, new OnBackPressedCallback(true) {
             @Override
             public void handleOnBackPressed() {
-                new MaterialAlertDialogBuilder(MainActivity.this)
-                        .setTitle(R.string.alert_dialog_close)
-                        .setMessage(R.string.summary_alert_dialog_close)
-                        .setPositiveButton(android.R.string.yes, (dialog, which) -> {
-                            finish();
-                            moveTaskToBack(true);
-                        })
-                        .setNegativeButton(android.R.string.no, null)
-                        .show();            }
+                long currentTime = System.currentTimeMillis();
+                if (currentTime - backPressedTime < BACK_PRESS_INTERVAL) {
+                    finish();
+                    moveTaskToBack(true);
+                } else {
+                    backPressedTime = currentTime;
+                    Toast.makeText(MainActivity.this, R.string.press_back_again_to_exit, Toast.LENGTH_SHORT).show();
+                }
+            }
         });
     }
 
@@ -214,10 +218,12 @@ private void observeViewModel() {
                 if (mBinding.adView != null) {
                     if (ConsentUtils.canShowAds(this)) {
                         MobileAds.initialize(this);
+                        mBinding.adPlaceholder.setVisibility(View.GONE);
                         mBinding.adView.setVisibility(View.VISIBLE);
                         mBinding.adView.loadAd(new AdRequest.Builder().build());
                     } else {
                         mBinding.adView.setVisibility(View.GONE);
+                        mBinding.adPlaceholder.setVisibility(View.VISIBLE);
                     }
                 }
             }
@@ -287,6 +293,9 @@ private void observeViewModel() {
                 recreate();
             }
         });
+
+        mainViewModel.getLoadingState().observe(this, isLoading ->
+                mBinding.progressBar.setVisibility(Boolean.TRUE.equals(isLoading) ? View.VISIBLE : View.GONE));
     }
 
     private void setupUpdateNotifications() {

app/src/main/java/com/d4rk/androidtutorials/java/ui/screens/main/MainViewModel.java

@@ -39,6 +39,7 @@ public class MainViewModel extends ViewModel {
     private final BuildShortcutIntentUseCase buildShortcutIntentUseCase;
     private final GetAppUpdateManagerUseCase getAppUpdateManagerUseCase;
     private final MutableLiveData<MainUiState> uiState = new MutableLiveData<>();
+    private final MutableLiveData<Boolean> isLoading = new MutableLiveData<>(false);
 
     @Inject
     public MainViewModel(ApplyThemeSettingsUseCase applyThemeSettingsUseCase,
@@ -80,6 +81,7 @@ public MainViewModel(ApplyThemeSettingsUseCase applyThemeSettingsUseCase,
     public void applySettings(String[] themeValues,
                               String[] bottomNavBarLabelsValues,
                               String[] defaultTabValues) {
+        isLoading.setValue(true);
         boolean changedTheme = applyThemeSettingsUseCase.invoke(themeValues);
 
         String labelVisibilityStr = getBottomNavLabelVisibilityUseCase.invoke();
@@ -99,6 +101,7 @@ public void applySettings(String[] themeValues,
 
         uiState.setValue(new MainUiState(visibilityMode, startFragmentId, changedTheme));
         applyLanguageSettingsUseCase.invoke();
+        isLoading.setValue(false);
     }
 
     /**
@@ -136,6 +139,13 @@ public LiveData<MainUiState> getUiState() {
         return uiState;
     }
 
+    /**
+     * Expose loading state to toggle progress indicators.
+     */
+    public LiveData<Boolean> getLoadingState() {
+        return isLoading;
+    }
+
     /**
      * Expose the AppUpdateManager if the Activity wants to directly check for in-app updates.
      */

app/src/main/java/com/d4rk/androidtutorials/java/ui/screens/support/SupportActivity.java

@@ -3,25 +3,20 @@
 import android.content.Intent;
 import android.net.Uri;
 import android.os.Bundle;
-import android.view.MenuItem;
-
-import androidx.annotation.NonNull;
-import androidx.appcompat.app.ActionBar;
-import androidx.appcompat.app.AppCompatActivity;
+import com.d4rk.androidtutorials.java.ui.components.navigation.BaseActivity;
 import androidx.lifecycle.ViewModelProvider;
 
 import com.android.billingclient.api.ProductDetails;
 import com.d4rk.androidtutorials.java.data.repository.SupportRepository;
 import com.d4rk.androidtutorials.java.databinding.ActivitySupportBinding;
-import com.d4rk.androidtutorials.java.utils.EdgeToEdgeDelegate;
 import com.google.android.gms.ads.AdRequest;
 
 import java.util.List;
 
 import dagger.hilt.android.AndroidEntryPoint;
 
 @AndroidEntryPoint
-public class SupportActivity extends AppCompatActivity {
+public class SupportActivity extends BaseActivity {
 
     private ActivitySupportBinding binding;
     private SupportViewModel supportViewModel;
@@ -32,15 +27,6 @@ protected void onCreate(Bundle savedInstanceState) {
         binding = ActivitySupportBinding.inflate(getLayoutInflater());
         setContentView(binding.getRoot());
 
-
-        EdgeToEdgeDelegate edgeToEdgeDelegate = new EdgeToEdgeDelegate(this);
-        edgeToEdgeDelegate.applyEdgeToEdge(binding.container);
-
-        ActionBar actionBar = getSupportActionBar();
-        if (actionBar != null) {
-            actionBar.setDisplayHomeAsUpEnabled(true);
-        }
-
         supportViewModel = new ViewModelProvider(this).get(SupportViewModel.class);
 
         AdRequest adRequest = supportViewModel.initMobileAds();
@@ -81,12 +67,5 @@ private void initiatePurchase(String productId) {
         }
     }
 
-    @Override
-    public boolean onOptionsItemSelected(@NonNull MenuItem item) {
-        if (item.getItemId() == android.R.id.home) {
-            finish();
-            return true;
-        }
-        return super.onOptionsItemSelected(item);
-    }
+    // Up navigation handled by BaseActivity
 }

app/src/main/res/layout/activity_main.xml

@@ -15,6 +15,7 @@
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             app:navigationIcon="@drawable/ic_menu"
+            app:navigationContentDescription="@string/menu"
             app:shapeAppearanceOverlay="@style/ShapeTokens.Clover"
             app:title="@string/app_name" />
     </com.google.android.material.appbar.AppBarLayout>
@@ -26,7 +27,7 @@
         android:visibility="gone"
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toBottomOf="@id/app_bar_layout"
-        app:layout_constraintBottom_toTopOf="@+id/ad_view"
+        app:layout_constraintBottom_toTopOf="@+id/ad_container"
         app:menu="@menu/bottom_nav_menu" />
 
     <androidx.fragment.app.FragmentContainerView
@@ -37,17 +38,30 @@
         app:defaultNavHost="true"
         app:layout_constraintStart_toEndOf="@id/nav_rail"
         app:layout_constraintEnd_toEndOf="parent"
-        app:layout_constraintBottom_toTopOf="@+id/ad_view"
+        app:layout_constraintBottom_toTopOf="@+id/ad_container"
         app:layout_constraintTop_toBottomOf="@id/app_bar_layout"
         app:navGraph="@navigation/mobile_navigation" />
 
-    <com.google.android.gms.ads.AdView
-        android:id="@+id/ad_view"
+    <FrameLayout
+        android:id="@+id/ad_container"
         android:layout_width="match_parent"
-        android:layout_height="wrap_content"
-        app:adSize="FULL_BANNER"
-        app:adUnitId="@string/ad_banner_unit_id"
-        app:layout_constraintBottom_toTopOf="@+id/nav_view" />
+        android:layout_height="50dp"
+        app:layout_constraintBottom_toTopOf="@+id/nav_view">
+
+        <View
+            android:id="@+id/ad_placeholder"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:background="@android:color/darker_gray" />
+
+        <com.google.android.gms.ads.AdView
+            android:id="@+id/ad_view"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:visibility="gone"
+            app:adSize="FULL_BANNER"
+            app:adUnitId="@string/ad_banner_unit_id" />
+    </FrameLayout>
 
     <com.google.android.material.bottomnavigation.BottomNavigationView
         android:id="@+id/nav_view"
@@ -56,4 +70,14 @@
         app:labelVisibilityMode="labeled"
         app:layout_constraintBottom_toBottomOf="parent"
         app:menu="@menu/bottom_nav_menu" />
+
+    <ProgressBar
+        android:id="@+id/progress_bar"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:visibility="gone"
+        app:layout_constraintTop_toTopOf="parent"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintEnd_toEndOf="parent" />
 </androidx.constraintlayout.widget.ConstraintLayout>

app/src/main/res/values-ar-rEG/strings.xml

@@ -5,6 +5,8 @@
     <string name="summary_notification_update">إصدار جديد من التطبيق متاح. اضغط للتحديث.</string>
     <string name="notification_last_time_used_title">بقالك فترة مدخلتش.</string>
     <string name="summary_notification_last_time_used">It\'s been a while—learn something new about Android.</string>
+    <string name="menu">القائمة</string>
+    <string name="press_back_again_to_exit">اضغط مرة أخرى للخروج</string>
     <string name="welcome">أهلاً بك</string>
     <string name="summary_browse_terms_of_service_and_privacy_policy">Read and agree to the Terms of Service and Privacy Policy to continue</string>
     <string name="agree">موافق</string>

app/src/main/res/values-bg-rBG/strings.xml

@@ -5,6 +5,8 @@
     <string name="summary_notification_update">Налична е нова версия на приложението. Кликнете, за да актуализирате.</string>
     <string name="notification_last_time_used_title">Отдавна не сме се виждали.</string>
     <string name="summary_notification_last_time_used">It\'s been a while—learn something new about Android.</string>
+    <string name="menu">Меню</string>
+    <string name="press_back_again_to_exit">Натиснете отново назад, за да излезете</string>
     <string name="welcome">Добре дошли</string>
     <string name="summary_browse_terms_of_service_and_privacy_policy">Read and agree to the Terms of Service and Privacy Policy to continue</string>
     <string name="agree">Съгласен съм</string>

app/src/main/res/values-bn-rBD/strings.xml

@@ -5,6 +5,8 @@
     <string name="summary_notification_update">অ্যাপটির একটি নতুন সংস্করণ উপলব্ধ। আপডেট করতে ক্লিক করুন.</string>
     <string name="notification_last_time_used_title">অনেক দিন হয়ে গেছে.</string>
     <string name="summary_notification_last_time_used">It\'s been a while—learn something new about Android.</string>
+    <string name="menu">মেনু</string>
+    <string name="press_back_again_to_exit">প্রস্থান করতে আবার ফিরে টিপুন</string>
     <string name="welcome">স্বাগতম</string>
     <string name="summary_browse_terms_of_service_and_privacy_policy">Read and agree to the Terms of Service and Privacy Policy to continue</string>
     <string name="agree">সম্মত</string>

app/src/main/res/values-de-rDE/strings.xml

@@ -5,6 +5,8 @@
     <string name="summary_notification_update">Eine neue Version der App ist verfügbar. Zum Aktualisieren klicken.</string>
     <string name="notification_last_time_used_title">Schon eine Weile her.</string>
     <string name="summary_notification_last_time_used">It\'s been a while—learn something new about Android.</string>
+    <string name="menu">Menü</string>
+    <string name="press_back_again_to_exit">Drücken Sie erneut zurück, um zu verlassen</string>
     <string name="welcome">Willkommen</string>
     <string name="summary_browse_terms_of_service_and_privacy_policy">Read and agree to the Terms of Service and Privacy Policy to continue</string>
     <string name="agree">Zustimmen</string>

app/src/main/res/values-es-rGQ/strings.xml

@@ -5,6 +5,8 @@
     <string name="summary_notification_update">Hay una nueva versión de la aplicación disponible. Haz clic para actualizar.</string>
     <string name="notification_last_time_used_title">Ha pasado un tiempo.</string>
     <string name="summary_notification_last_time_used">It\'s been a while—learn something new about Android.</string>
+    <string name="menu">Menú</string>
+    <string name="press_back_again_to_exit">Presione de nuevo para salir</string>
     <string name="welcome">Bienvenido</string>
     <string name="summary_browse_terms_of_service_and_privacy_policy">Read and agree to the Terms of Service and Privacy Policy to continue</string>
     <string name="agree">Aceptar</string>