First Fragment Remains In The Background After Transition

I am currently trying to create an app having a splash screen, a login screen and a register screen. The only way to achieve exactly what I need is through fragments. Though when I

Solution 1:

The problem is that you cannot replace fragments added via the <fragment> tag.

Instead, you should either:

1) Switch to FragmentContainerView, which was added in Fragment 1.2.0. It does not suffer from the same issue as the <fragment> tag and lets you do replace operations without issues:

<?xml version="1.0" encoding="utf-8"?><RelativeLayoutxmlns: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=".StartActivity"android:background="@mipmap/background"><androidx.fragment.app.FragmentContainerViewandroid:layout_width="match_parent"android:layout_height="match_parent"android:id="@+id/viewpagerstart"android:layout_centerInParent="true"android:name="com.example.distributedsystemsui.SplashFragment"></androidx.fragment.app.FragmentContainerView></RelativeLayout>

2) Use a FrameLayout in your layout and manually add the SplashFragment in your activity (this is essentially what FragmentContainerView does for you):

<?xml version="1.0" encoding="utf-8"?><RelativeLayoutxmlns: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=".StartActivity"android:background="@mipmap/background"><FrameLayoutandroid:layout_width="match_parent"android:layout_height="match_parent"android:id="@+id/viewpagerstart"android:layout_centerInParent="true"></FrameLayout></RelativeLayout>

which means you need to add the SplashFragment manually:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_start);
    if (savedInstanceState == null) {
        getSupportFragmentManager().beginTransaction()
            .add(R.id.viewpagerstart, new SplashFragment())
            .commit()
    }
}

Solution 2:

I think it is better to do the fragment transactions from your activity instead of doing it from your fragment. You might consider having functions in your MainActivity as follows.

publicclassStartActivityextendsAppCompatActivity {

    @OverrideprotectedvoidonCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_start);
    }

    publicvoidgoToLoginFragment() {
        FragmentTransactionft= getFragmentManager().beginTransaction();
        ft.setCustomAnimations(R.anim.slide_enter_left, R.anim.slide_exit_left,
                R.anim.slide_enter_right, R.anim.slide_exit_right);
        LoginFragmentloginFragment= LoginFragment.newInstance();
        ft.replace(R.id.viewpagerstart, loginFragment);
        ft.commit();
    }

    publicvoidgoToRegisterFragment() {
        FragmentTransactionft= getFragmentManager().beginTransaction();
        ft.setCustomAnimations(R.anim.slide_enter_left, R.anim.slide_exit_left,
                R.anim.slide_enter_right, R.anim.slide_exit_right);
        LoginFragmentregisterFragment= RegisterFragment.newInstance();
        ft.replace(R.id.viewpagerstart, registerFragment);
        ft.commit();
    }

    @OverridepublicvoidonBackPressed(){
        Toast.makeText(getApplicationContext(), "Back button is disabled", Toast.LENGTH_SHORT).show();
    }
}

And then from your SplashFragment call the function that is defined in your activity.

Handler handler = new Handler();
handler.postDelayed(new Runnable() {
    publicvoidrun() {
        ((MainActivity) getActivity()).goToLoginFragment();
    }
}, 3000);

I hope that solves the problem.