how to create smooth navigation drawer

Question

I am using this example for navigation drawer. When clicking on of item of left drawer listview it shows some images but drawerLayout closes not smoothly.

What should I

Answer 1

Please review my MainActivity to make smooth DrawerLayout (open/close) with a custom topBar layout.

public class MainActivity extends BaseActivity
    implements NavigationView.OnNavigationItemSelectedListener {

Fragment fragment = null;
Class fragmentClass = null;
FrameLayout frameLayout;
TextView topTilte;
DrawerLayout drawer;
NavigationView navigationView;
private boolean isDrawerOpen = false;

@Override
protected void onCreateFinished() {
    setContentView(R.layout.activity_main);

    drawer = findViewById(R.id.drawer_layout);
    navigationView = findViewById(R.id.nav_view);

    topTilte = findViewById(R.id.toolbar_title);
    fragmentClass = HomeFragment.class;
    topTilte.setText(R.string.menu_home);
    setFragment();

    drawer.addDrawerListener(new DrawerLayout.DrawerListener() {
        @Override
        public void onDrawerSlide(@NonNull View view, float slideOffset) {
            if(slideOffset > .55 && !isDrawerOpen){
                onDrawerOpened(view);
                isDrawerOpen = true;
            } else if(slideOffset < .45 && isDrawerOpen) {
                onDrawerClosed(view);
                isDrawerOpen = false;
            }
        }

        @Override
        public void onDrawerOpened(@NonNull View view) {

        }

        @Override
        public void onDrawerClosed(@NonNull View view) {

        }

        @Override
        public void onDrawerStateChanged(int i) {

        }
    });

    navigationView.setNavigationItemSelectedListener(this);
}

@Override
protected void afterInjection() {

}

public void openMenu(View v) {
    drawer.openDrawer(Gravity.LEFT);
}

@Override
public void onBackPressed() {
    DrawerLayout drawer = findViewById(R.id.drawer_layout);
    if (drawer.isDrawerOpen(GravityCompat.START)) {
        drawer.closeDrawer(GravityCompat.START);
    } else {
        super.onBackPressed();
    }
}

@SuppressWarnings("StatementWithEmptyBody")
@Override
public boolean onNavigationItemSelected(MenuItem item) {
    // Handle navigation view item clicks here.
    int id = item.getItemId();
    if (id == R.id.nav_home) {
        topTilte.setText(R.string.menu_home);
        fragmentClass = HomeFragment.class;
        setFragment();

    } else if (id == R.id.nav_profile) {

    } 

    return true;
}

private void setFragment() {


    final Handler handler = new Handler();
    handler.postDelayed(new Runnable() {
        @Override
        public void run() {
            try {
                fragment = (Fragment) fragmentClass.newInstance();
            } catch (Exception e) {
                e.printStackTrace();
            }

            FragmentManager fragmentManager = getSupportFragmentManager();
            fragmentManager.beginTransaction().replace(R.id.container, fragment).commit();

            drawer.closeDrawer(GravityCompat.START);
        }
    }, 200);
}
}