Android - SlideMenu and fragment

Question

I have followed a tutorial to create step by step a sliding menu and it works, but looking in the code I have noticed that when users touch a menu item the code will run this piece of code:

MainActivity:

....
/**
     * Slide menu item click listener
     * */
    private class SlideMenuClickListener implements
            ListView.OnItemClickListener {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position,
                long id) {
            // display view for selected nav drawer item
            displayView(position);
        }
    }
/**
     * Diplaying fragment view for selected nav drawer list item
     * */
    private void displayView(int position) {
        // update the main content by replacing fragments
        Fragment fragment = null;
        switch (position) {
            case 0:{
                fragment = new PersonaggiPrincipali();
                break;
            }
            case 1:{
                fragment = new PersonaggiSecondari();
                break;
            }
            case 2:{
                fragment = new Video();
                break;
            }
            default:
                break;
        }

        if (fragment != null) {
            FragmentManager fragmentManager = getFragmentManager();
            fragmentManager.beginTransaction()
                    .replace(R.id.frame_container, fragment).commit();

            // update selected item and title, then close the drawer
            mDrawerList.setItemChecked(position, true);
            mDrawerList.setSelection(position);
            setTitle(navMenuTitles[position]);
            mDrawerLayout.closeDrawer(mDrawerList);
        } else {
            // error in creating fragment
            Log.e("MainActivity", "Error in creating fragment");
        }
    }
....

Basically it call a new Class when the item is clicked.
The class is formed in this way:

import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class PersonaggiPrincipali extends Fragment {

    public PersonaggiPrincipali(){}

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {

        View rootView = inflater.inflate(R.layout.personaggi_principali, container, false);

        return rootView;
    }

}

So it just return the layout and the displayView function above will replace the current with the returned one, right?

if (fragment != null) {
            FragmentManager fragmentManager = getFragmentManager();
            fragmentManager.beginTransaction()
                    .replace(R.id.frame_container, fragment).commit();
....
}

My question is, in the view returned how can I manipulate it if the class is just a return of the layout?

For example, let's assume that in the returned view I have a Button and I need to set a ClickListener or just create a function that will chenge the Activity (activity that should be insert in the main view with the SlidingMenu), How can I do that?

Should I write all the code in the MainActivity to manage that?

Answer 1

Ciao Christian, when you instantiate a Fragment you don't get a view as a result but a Fragment.

The onCreateView method is just part of the lifecycle of a fragment and that's where you have to return the main view of your fragment. Also, if your fragment has a Button you can set the listener in the onCreateView method of the Fragment.

http://developer.android.com/reference/android/app/Fragment.html#onCreateView(android.view.LayoutInflater, android.view.ViewGroup, android.os.Bundle)

Example:

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{   
    View rootView = inflater.inflate(R.layout.personaggi_principali, container, false);

    Button button = (Button) rootView.findViewById(R.id.REPLACE_WITH_YOUR_BUTTON_ID);
    button.setOnClickListener(new OnClickListener()
        {   
            @Override
            public void onClick(View v)
            {
                // do you stuff here...
            }
        });

    return rootView;
}

Please notice the Button in the example is just a local variable, if you need to access it later, it's better to declare it as a class variable.

Regarding communication (Fragment to Fragment, host Activity to Fragment), I think everything you need to know is well explained in the official documentation: http://developer.android.com/training/basics/fragments/communicating.html

Answer 2

You can either do it in the same (onCreateView()) method. Additionally, you could include private references to Views inside your fragment layout in your PersonaggiPrincipali class. Also implement get() methods for these Views and you can change them from your MainActivity. For example:

public class PersonaggiPrincipali extends Fragment {
     private Button fragButton;
     public PersonaggiPrincipali(){}

     @Override
     public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
         View rootView = inflater.inflate(R.layout.personaggi_principali, container, false);
         fragButton = (Button) rootView.findViewById(R.id.fragButtonId); //replace R.id.fragButtonId with the appropriate Id from your xml layout
         return rootView;
     }
     public Button getFragButton() {
         return this.fragButton;
     }
}