Question

I’m new in Android development and I wanted to make application that has header, body and footer and by clicking on one of the buttons in footer some layout will be loaded into body. I used some kind of “MasterPage” as described here.
When the button is pressed neither new_exercise layout nor exercises layout is loaded. Why? Maybe instead of all of this I should use any kind of tabs? Or maybe I can’t inflate layout and should create new activity?

Here the code of the BaseActivity and NewExercise activity:

public class BaseActivity extends Activity{
    LinearLayout linBaseBody;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        super.setContentView(R.layout.base_layout);

        linBaseBody = (LinearLayout)findViewById(R.id.base_body);

        initButtons();
    }
    @Override
    public void setContentView(int id) {
        LayoutInflater inflater = (LayoutInflater)getBaseContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        inflater.inflate(id, linBaseBody);
    }

    private void initButtons()
    {
        Button btn1 = (Button) findViewById(R.id.newEx);
        btn1.setOnClickListener(new View.OnClickListener() {
              public void onClick(View view) {
                  setContentView(R.layout.new_exercise);
              }
        });
        Button btn2 = (Button) findViewById(R.id.showAllEx);   
        btn2.setOnClickListener(new View.OnClickListener() {
              public void onClick(View view) {
                  setContentView(R.layout.exercises);
              }
        });
    }

public class NewExercise extends BaseActivity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        super.setContentView(R.layout.new_exercise);
    }
}
public class Exercises extends BaseActivity {    
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);        
        setContentView(R.layout.exercises);
    }       
}

Answer 1

How your code is written, it would make more sense to use a new Activity. However, If you wanted to keep all of the view in one Activity, you could walk through all of your layouts calling mLayout.setVisible(View.VISIBLE); or you could use ViewStubs.

As to answer your question, why, what you are doing is adding the view (and their layouts) directly to your already created and inflated content view (the one you created in onCreate). You will need to clear the Activities contentView first to see the changes you are making with the button.