Can we use Bottom Navigation View with activities? In the FOSSASIA Phimpme Project we integrated two big projects such as Open Camera and Leafpic. Both are activity based projects and not developed over fragment. The bottom navigation we use will work with fragment.

In Leafpic as well as in Open Camera, there are a lot of Multi level inheritance which runs the app components. The problem faced to continue to work on activities. For theme management using base activity is necessary. The base activity extend to AppcompatActivity. The leafpic code hierarchy is very complex and depend on various activities. Better way is to shift to activities for using Bottom navigation view and  work with activity similar like fragments.

Image source: https://storage.googleapis.com/material-design/

Solution:

This is possible if we copy the bottom navigation item in each of the activity and setting the clicked state of it as per the menu item ID.

Steps to Implement (How I did in Phimpme)

• Add a Base Activity which takes care of two thing
  

  • Taking the layout element and setting in the activity.
  • Set up the correct navigation menu item clicked

Function selectBottomNavigationBarItem(int itemId) will take care of what item is currently active. Called this function in onStart(), getNavigationMenuItemId() function will return the menu id and selectBottomNavigagionBarItem update the bottom navigation view.

public abstract class BaseActivity extends AppCompatActivity implements BottomNavigationView.OnNavigationItemSelectedListener

private void updateNavigationBarState() {
   int actionId = getNavigationMenuItemId();
   selectBottomNavigationBarItem(actionId);
}

void selectBottomNavigationBarItem(int itemId) {
   Menu menu = navigationView.getMenu();
   for (int i = 0, size = menu.size(); i < size; i++) {
       MenuItem item = menu.getItem(i);
       boolean shouldBeChecked = item.getItemId() == itemId;
       if (shouldBeChecked) {
           item.setChecked(true);
           break;
       }
   }
}

• Add two abstract functions in the BaseActivity for above task

public abstract int getContentViewId();

public abstract int getNavigationMenuItemId();

• Extend every activity to the Base Activity

For example I created a blank Activity: AccountsActivity and extend to BaseActivity

public class AccountsActivity extends BaseActivity

• Implement the abstract function in the every activity and set the correct layout and menu item id.

@Override
public int getContentViewId() {
 return R.layout.content_accounts;
}

@Override
public int getNavigationMenuItemId() {
   return R.id.navigation_accounts;
}

• Remove the setContentView(R.layout.activity_main);

• Add the onNavigationItemSelected in BaseActivity

@Override
public boolean onNavigationItemSelected(@NonNull final MenuItem item) {
   switch (item.getItemId()) {
       case R.id.navigation_home:
    startActivity(new Intent(this, LFMainActivity.class));
           Break;
       case R.id.navigation_camera:
           startActivity(new Intent(this, CameraActivity.class));
           Break;
       case R.id.navigation_accounts:
           startActivity(new Intent(this, AccountsActivity.class));
           Break;
   }
   finish();
   return true;
}

Output:

The transition is as smooth as we use bottom navigation views with Fragment. The bottom navigation also appear on above of the activity.

Source: https://stackoverflow.com/a/42811144/2902518

Resources:

• BottomNavigation View Guidelines : https://material.io/guidelines/components/bottom-navigation.html#
• Bottom navigation view Documentation : https://developer.android.com/reference/android/support/design/widget/BottomNavigationView.html