rebased some activities and code to make the app more smooth and faster

app/src/main/AndroidManifest.xml

@@ -25,18 +25,14 @@
             android:name=".activities.SettingsActivity"
             android:exported="false" />
         <activity
-            android:name=".activities.StartActivity"
+            android:name=".activities.MainActivity"
             android:configChanges="orientation"
             android:screenOrientation="unspecified"
             android:exported="true">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
-        </activity>
-        <activity
-            android:name=".activities.aShellActivity"
-            android:exported="false">
             <intent-filter>
                 <action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" />
             </intent-filter>

app/src/main/java/in/hridayan/ashell/activities/aShellActivity.java → app/src/main/java/in/hridayan/ashell/activities/MainActivity.java

@@ -13,10 +13,11 @@
 import com.google.android.material.dialog.MaterialAlertDialogBuilder;
 import in.hridayan.ashell.R;
 import in.hridayan.ashell.UI.KeyboardVisibilityChecker;
+import in.hridayan.ashell.fragments.StartFragment;
 import in.hridayan.ashell.fragments.aShellFragment;
 import in.hridayan.ashell.fragments.otgFragment;
 
-public class aShellActivity extends AppCompatActivity {
+public class MainActivity extends AppCompatActivity {
   private boolean isKeyboardVisible;
   public BottomNavigationView mNav;
 
@@ -77,8 +78,8 @@ private void setupNavigation() {
               return false;
           }
         });
-    // Set initial fragment
-    replaceFragment(new aShellFragment(mNav));
+
+    initialFragment();
   }
 
   private void replaceFragment(Fragment fragment) {
@@ -143,4 +144,13 @@ private void setBadge(int id, String text) {
     badge.setText(text);
     badge.setHorizontalOffset(0);
   }
+
+  private void initialFragment() {
+    if (PreferenceManager.getDefaultSharedPreferences(this).getBoolean("firstLaunch", true)) {
+      mNav.setVisibility(View.GONE);
+      replaceFragment(new StartFragment());
+    } else {
+      replaceFragment(new aShellFragment(mNav));
+    }
+  }
 }

app/src/main/java/in/hridayan/ashell/fragments/StartFragment.java

@@ -0,0 +1,51 @@
+package in.hridayan.ashell.fragments;
+
+import android.os.Bundle;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import androidx.appcompat.widget.LinearLayoutCompat;
+import androidx.fragment.app.Fragment;
+import androidx.preference.PreferenceManager;
+import com.google.android.material.bottomnavigation.BottomNavigationView;
+import com.google.android.material.button.MaterialButton;
+import com.google.android.material.textview.MaterialTextView;
+import in.hridayan.ashell.R;
+import rikka.shizuku.Shizuku;
+
+public class StartFragment extends Fragment {
+
+  public StartFragment() {}
+
+  @Override
+  public View onCreateView(
+      LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
+    View view = inflater.inflate(R.layout.fragment_start, container, false);
+    initViews(view);
+    return view;
+  }
+
+  private void initViews(View view) {
+    LinearLayoutCompat mStartLayout = view.findViewById(R.id.fragment_start);
+    MaterialButton mStartButton = view.findViewById(R.id.start_button);
+    MaterialTextView mAboutText = view.findViewById(R.id.about_text);
+
+    if (Shizuku.pingBinder()) {
+      Shizuku.requestPermission(0);
+    }
+    mStartLayout.setVisibility(View.VISIBLE);
+    mAboutText.setText(getString(R.string.app_summary));
+
+    mStartButton.setOnClickListener(
+        v -> {
+          PreferenceManager.getDefaultSharedPreferences(requireContext())
+              .edit()
+              .putBoolean("firstLaunch", false)
+              .apply();
+          getParentFragmentManager()
+              .beginTransaction()
+              .replace(R.id.fragment_container, new aShellFragment())
+              .commit();
+        });
+  }
+}

app/src/main/java/in/hridayan/ashell/fragments/aShellFragment.java

@@ -53,7 +53,7 @@
 import in.hridayan.ashell.activities.FabOnScrollDownListener;
 import in.hridayan.ashell.activities.FabOnScrollUpListener;
 import in.hridayan.ashell.activities.SettingsActivity;
-import in.hridayan.ashell.activities.aShellActivity;
+import in.hridayan.ashell.activities.MainActivity;
 import in.hridayan.ashell.adapters.CommandsAdapter;
 import in.hridayan.ashell.adapters.SettingsAdapter;
 import in.hridayan.ashell.adapters.ShellOutputAdapter;
@@ -191,6 +191,8 @@ public void onKeyboardVisibilityChanged(boolean visible) {
 
     mRecyclerViewOutput.setAdapter(mShellOutputAdapter);
 
+    mNav.setVisibility(View.VISIBLE);
+
     /*------------------------------------------------------*/
 
     mPasteButton.setOnClickListener(
@@ -1026,8 +1028,8 @@ public double getBrightness(int color) {
   /*------------------------------------------------------*/
 
   private void showBottomNav() {
-    if (getActivity() != null && getActivity() instanceof aShellActivity) {
-      ((aShellActivity) getActivity()).mNav.animate().translationY(0);
+    if (getActivity() != null && getActivity() instanceof MainActivity) {
+      ((MainActivity) getActivity()).mNav.animate().translationY(0);
     }
   }
 

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

@@ -7,7 +7,7 @@
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_height="match_parent"
     android:layout_width="match_parent"
-    tools:context=".aShellActivity">
+    tools:context=".MainActivity">
 
 
     <com.google.android.material.bottomnavigation.BottomNavigationView

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

@@ -5,7 +5,7 @@
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_height="match_parent"
     android:layout_width="match_parent"
-    tools:context=".aShellActivity">
+    tools:context=".MainActivity">
 
     <androidx.appcompat.widget.LinearLayoutCompat
         android:layout_height="match_parent"

app/src/main/res/layout/activity_start.xml → app/src/main/res/layout/fragment_start.xml

@@ -6,7 +6,7 @@
     android:layout_height="fill_parent">
 
     <androidx.appcompat.widget.LinearLayoutCompat
-        android:id="@+id/layout_main"
+        android:id="@+id/fragment_start"
         android:layout_width="fill_parent"
         android:layout_height="fill_parent"
         android:layout_gravity="center"