Set default page for ViewPager in Android

I am using the following code, MAX is 2 pages. By default the position is 0 and adds a new page to the right. I inflate two layout files.

How can I show the page1 when the app starts and add a new page to the left ? Thanks.

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
	android:orientation="vertical" android:layout_width="fill_parent"
	android:layout_height="fill_parent">

	
	<android.support.v4.view.ViewPager
		android:layout_width="wrap_content" android:layout_height="wrap_content"
		android:id="@+id/pagerView" />


</LinearLayout>

Java code

public class MyPagerActivity extends Activity {
	private Context context;	
	private int pageNumber;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		context = this;

		ViewPager pagerView = (ViewPager)findViewById(R.id.pagerView);
        pagerView.setAdapter(new AwesomePagerAdapter());	
		
	}


	private class AwesomePagerAdapter extends PagerAdapter{

		@Override
		public void destroyItem(View collection, int position, Object view) {
			((ViewPager) collection).removeView((View)view);			
		}

		@Override
		public void finishUpdate(View arg0) {
			//setPageTitles(getPageNumber());
		}

		@Override
		public int getCount() {
			return 2;
		}

		@Override
		public Object instantiateItem(View collection, int position) {
			/*	TextView tv = new TextView(MyPagerActivity.this);
		tv.setText("Bonjour PAUG " + position);
		tv.setTextColor(Color.WHITE);
		tv.setTextSize(30);

		((ViewPager) collection).addView(tv,0);

		return tv;*/

			View view = getViewToShow(position);
			((ViewPager) collection).addView(view,0);
			return view;
		}

		@Override
		public boolean isViewFromObject(View view, Object object) {
			return view==((View)object);
		}

		@Override
		public void restoreState(Parcelable arg0, ClassLoader arg1) {
			// TODO Auto-generated method stub

		}

		@Override
		public Parcelable saveState() {
			// TODO Auto-generated method stub
			return null;
		}

		@Override
		public void startUpdate(View arg0) {
			// TODO Auto-generated method stub

		}

	}


	private View getViewToShow(int position){
		View view = null;
		View layout; 
		LayoutInflater mInflater =  (LayoutInflater)
		context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

		switch(position){

		case 0: 
			layout  = mInflater.inflate(R.layout.elements, null);
			view = layout;
			break;
		case 1: view = 
			layout  = mInflater.inflate(R.layout.elements2, null);
		view = layout;

		break;
		}
		return view;
	}
	
}

Have you tried using the setCurrentItem method?

The accepted solution is fine, but it's important to call this method after setting up the adapter.

    viewPager.setAdapter(adapterViewPager);
    viewPager.setCurrentItem(1);

By default, you have to set the current value 1 to show the just one default view. If you do not set setCurrentItem to 1, you can not see anything.

viewPager.setAdapter(adapterViewPager);
viewPager.setCurrentItem(1)

This solution gives the ability of setting default page without interference from outside of the Pager adapter class.

@Override
public Object instantiateItem(ViewGroup container, int position) {
	View currentPage = null;
	switch(position){
		case 0:
			currentPage = LayoutInflater.from(context).inflate(R.layout.page0, null)	
			break;
		case 1:
			currentPage = LayoutInflater.from(context).inflate(R.layout.page1, null)	
			///////////// This page will be default ////////////////////
			((ViewPager)container).setCurrentItem(position);
			////////////////////////////////////////////////////////////
			break;
		case 2:
			currentPage = LayoutInflater.from(context).inflate(R.layout.page2, null)	
			break;
    return currentPage;
}

You need to set page only during first initialisation of the fragment. Later it will restore a selected by user position from a "saved instance state". So this looks a little better:

override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
    super.onViewCreated(view, savedInstanceState)

    pager.adapter = AwesomePagerAdapter()
    if (savedInstanceState == null) {
        pager.currentItem = 1
    }
}