NavigationDrawer main page and styling

Question

this is the first application I am creating using a NavigationDrawer. I have a pretty simple question. How do I make the first page in the NavigationDrawer the main one? Also I'm not too familiar with formatting since this is my first time using the drawer so I would appreciate it if someone more familiar could tell me if I am doing it correctly. Right now each page just displays text but eventually it will do more. And one of my questions is how do I make it so that clicking a page in the drawer can open up a new page using a RelativeLayout for example. From my understanding Adapters are only for Views, would I create a completely new activity and call startActivity() in my iteration for the drawerclick? If so, is that efficient? Meaning will it take a long time for the page to load? My main activity is:

public class MainActivity extends Activity {
private String[] mPages;
private DrawerLayout mDrawerLayout;
private ListView mDrawerList;
private ActionBarDrawerToggle mDrawerToggle;
private CharSequence mDrawerTitle;
private CharSequence mTitle;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.drawer_layout);

    mPages = getResources().getStringArray(R.array.page_titles);
    mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
    mDrawerList = (ListView) findViewById(R.id.left_drawer);
    mDrawerList.setAdapter(new ArrayAdapter<String>(this,
            R.layout.drawer_list_item, mPages));
    mTitle = mDrawerTitle = getTitle();
    mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
    mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout,
            R.drawable.ic_drawer, R.string.drawer_open,
            R.string.drawer_close) {

        /** Called when a drawer has settled in a completely closed state. */
        public void onDrawerClosed(View view) {
            getActionBar().setTitle(mTitle);
        }

        /** Called when a drawer has settled in a completely open state. */
        public void onDrawerOpened(View drawerView) {
            getActionBar().setTitle(mDrawerTitle);
        }
    };

    // Set the drawer toggle as the DrawerListener
    mDrawerLayout.setDrawerListener(mDrawerToggle);
    mDrawerList.setOnItemClickListener(new DrawerItemClickListener());

    getActionBar().setDisplayHomeAsUpEnabled(true);
    getActionBar().setHomeButtonEnabled(true);
}

@Override
protected void onPostCreate(Bundle savedInstanceState) {
    super.onPostCreate(savedInstanceState);
    // Sync the toggle state after onRestoreInstanceState has occurred.
    mDrawerToggle.syncState();
}

@Override
public void onConfigurationChanged(Configuration newConfig) {
    super.onConfigurationChanged(newConfig);
    mDrawerToggle.onConfigurationChanged(newConfig);
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Pass the event to ActionBarDrawerToggle, if it returns
    // true, then it has handled the app icon touch event
    if (mDrawerToggle.onOptionsItemSelected(item)) {
        return true;
    }
    // Handle your other action bar items...

    return super.onOptionsItemSelected(item);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

private class DrawerItemClickListener implements ListView.OnItemClickListener {
    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        selectItem(position);
    }
}

/** Swaps fragments in the main content view */
private void selectItem(int position) {
    // Create a new fragment and specify the planet to show based on position
    Fragment fragment;
    if(position == 0){
        fragment = new OneFragment();

        // Insert the fragment by replacing any existing fragment
        android.app.FragmentManager fragmentManager = getFragmentManager();
        fragmentManager.beginTransaction()
                       .replace(R.id.content_frame, fragment)
                       .commit();
    }
    else if(position == 1){
        fragment = new TwoFragment();

        // Insert the fragment by replacing any existing fragment
        android.app.FragmentManager fragmentManager = getFragmentManager();
        fragmentManager.beginTransaction()
                       .replace(R.id.content_frame, fragment)
                       .commit();
    }
    else if(position == 2){
        fragment = new ThreeFragment();

        // Insert the fragment by replacing any existing fragment
        android.app.FragmentManager fragmentManager = getFragmentManager();
        fragmentManager.beginTransaction()
                       .replace(R.id.content_frame, fragment)
                       .commit();
    }
    else if(position == 3){
        fragment = new FourFragment();

        // Insert the fragment by replacing any existing fragment
        android.app.FragmentManager fragmentManager = getFragmentManager();
        fragmentManager.beginTransaction()
                       .replace(R.id.content_frame, fragment)
                       .commit();
    }

    // Highlight the selected item, update the title, and close the drawer
    mDrawerList.setItemChecked(position, true);
    setTitle(mPages[position]);
    mDrawerLayout.closeDrawer(mDrawerList);
}

@Override
public void setTitle(CharSequence title) {
    mTitle = title;
    getActionBar().setTitle(mTitle);
}

public static class OneFragment extends Fragment{

    public OneFragment(){

    }
    View rootView;
    TextView text;
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup contatiner,
            Bundle savedInstanceState){
        rootView = inflater.inflate(R.layout.drawer_layout,
                contatiner, false);
        text = (TextView)rootView.findViewById(R.id.text_view1);
        text.setText("One");
        return rootView;
    }

}

public static class TwoFragment extends Fragment{

    public TwoFragment(){

    }
    View rootView;
    TextView text;
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup contatiner,
            Bundle savedInstanceState){
        rootView = inflater.inflate(R.layout.drawer_layout,
                contatiner, false);
        text = (TextView)rootView.findViewById(R.id.text_view1);
        text.setText("Two");
        return rootView;
    }

}

public static class ThreeFragment extends Fragment{

    public ThreeFragment(){

    }
    View rootView;
    TextView text;
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup contatiner,
            Bundle savedInstanceState){
        rootView = inflater.inflate(R.layout.drawer_layout,
                contatiner, false);
        text = (TextView)rootView.findViewById(R.id.text_view1);
        text.setText("Three");
        return rootView;
    }

}

public static class FourFragment extends Fragment{

    public FourFragment(){

    }
    View rootView;
    TextView text;
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup contatiner,
            Bundle savedInstanceState){
        rootView = inflater.inflate(R.layout.drawer_layout,
                contatiner, false);
        text = (TextView)rootView.findViewById(R.id.text_view1);
        text.setText("Four");
        return rootView;
    }

}
}

I apologize for the lengthy question, but the developer site wasn't helping out too much and I want to make sure I do this correctly the first time so I don't have to go back too much

Answer 1

Whatever you want to show needs to be within the child of the DrawerLayout. In your case, I think you would do a fragment transaction in onCreate() to put whatever fragment you want visible first inside of the content area.

if (savedInstanceState == null) {
    fragment = new OneFragment();

    // Insert the fragment by replacing any existing fragment
    getFragmentManager().beginTransaction()
            .replace(R.id.content_frame, fragment).commit();

}

You can hold references to these fragments so you don't create a new instance of them each time the user makes a selection. You probably also want to make sure the new selection isn't the same as the current one, or else you will have extra transactions you don't need.

For opening a "new page", you want to use startActivity() and show another activity with it's own layout. Generally speaking, don't be concerned about how long it takes an Activity to load unless you are specifically doing some meaningful work (like loading a bunch of data out of a database).

Lastly, Adapters are specifically for AdapterViews (like ListView) and are an entirely different matter. They are used in conjunction with specific UI components to generate child views for representing potentially large data sets and which can be recycled for efficiency reasons. I suggest you watch The World of ListView if you want more information/clarity about that.