NavigationComponents Transparent toolbar

Question

Is there a way to set transparent toolbar just for the main activity that holds all my fragments ?

I need to show the toolbar in other fragments but in the main host activity I want it transparent with buttons instead of colored

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        val navController = Navigation.findNavController(this, R.id.nav_host_fragment)
        setupActionBar(navController)
    }

    private fun setupActionBar(navController: NavController) {
        NavigationUI.setupActionBarWithNavController(this, navController)
    }

    override fun onSupportNavigateUp(): Boolean {
        return Navigation.findNavController(this, R.id.nav_host_fragment).navigateUp()
                || super.onSupportNavigateUp()
    }

    override fun onCreateOptionsMenu(menu: Menu?): Boolean {
        MenuInflater(this).inflate(R.menu.menu, menu)
        menu!!.findItem(R.id.eventFragment)?.isVisible = false
        return super.onCreateOptionsMenu(menu)
    }
}

From here I wonder If I can make my toolbar transparent in this activity only

I have searched but has not found nothing about Navigation Components

Answer 1

The best way to handle Action Bars/Toolbars is to use Theme.NoActionBar and then create one on you own and set the background color to transparent.

This cloud look like this:

<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".ui.settings.SettingsActivity">

<com.google.android.material.appbar.AppBarLayout
    android:id="@+id/appBarLayout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:theme="@style/AppTheme.AppBarOverlay"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent">

    <com.google.android.material.appbar.MaterialToolbar
        android:id="@+id/settingsToolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="@android:color/transparent" />

</com.google.android.material.appbar.AppBarLayout>

<fragment
    android:id="@+id/nav_host_fragment"
    android:name="androidx.navigation.fragment.NavHostFragment"
    android:layout_width="0dp"
    android:layout_height="0dp"
    android:layout_margin="10dp"
    app:defaultNavHost="true"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintHorizontal_bias="1.0"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintTop_toBottomOf="@+id/appBarLayout"
    app:navGraph="@navigation/settings_navigation" />