What is the best way to add a back button to custom toolbars?

Question

So i know how to add a backwards navigation button to my custom toolbar, however there must be a more efficient way to add the functionality to multiple activities than copying and pasting this code in each one...

        Toolbar toolbar = findViewById(R.id.tlbar);
        setSupportActionBar(toolbar);
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        toolbar.setNavigationOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                finish();
            }
        });

I've tried making a common class were i create a function that could be called in each activity however you need to findViewById which can only be done in the activity. Any suggestions around this?

Answer 1

First Create a base class like this

public class BaseActivity extends AppCompatActivity{


    public  void setToolbar(@IdRes int toolbarID){
        try {
            Toolbar toolbar = findViewById(toolbarID);
            setSupportActionBar(toolbar);
            getSupportActionBar().setDisplayHomeAsUpEnabled(true);
            toolbar.setNavigationOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    finish();
                }
            });
        }catch (Exception e){
            e.printStackTrace();

        }

    }

}

After extends all Activity class with BaseActivity class

public class LoginNewActivity extends BaseActivity{

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setToolbar(R.id.toolbar); //You can call your method like this
    }
}

If you want to know more about this do search for Inheritance and polymorphism in JAVA