Fun little Android class

package appisode.gepro;

/**
 * @author Tobias
 */

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.ViewFlipper;

public abstract class SplashActivity extends Activity {
    private ViewFlipper flipper = null;
    private Button prev = null;
    private Button next = null;

    private int currentPos = 0;
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(null);

        setContentView(R.layout.general_splash);

        viewHolder = new ArrayList<View[]>(getCount());

        flipper = (ViewFlipper) findViewById(R.id.splashFlipper);
        prev = (Button) findViewById(R.id.prev);
        next = (Button) findViewById(R.id.next);

        for(int i = 0; i < getCount(); i++) {
            View v = getLayoutInflater().inflate(getLayout(i), null);
            flipper.addView(v);
            viewHolder.add(create(i, (ViewGroup) v));

            if(savedInstanceState != null) {
                Bundle b = savedInstanceState.getBundle("screen"+i);
                if(b != null) {
                    restore(i, viewHolder.get(i), b);
                }
            }
        }

        flipper.setDisplayedChild(0);

        prev.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                if(currentPos > 0) {
                    if(move(currentPos, currentPos-1)) {
                        return;
                    }
                    prev.setText(R.string.back);
                    next.setText(R.string.fwd);
                    next.setVisibility(View.VISIBLE);
                    currentPos--;
                    if(currentPos == 0) {
                        prev.setVisibility(View.INVISIBLE);
                    }
                    flipper.setDisplayedChild(currentPos);
                    moved(currentPos);
                }
            }
        });

        next.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                if(currentPos < getCount()-1) {
                    if(move(currentPos, currentPos+1)) {
                        return;
                    }
                    prev.setVisibility(View.VISIBLE);
                    currentPos++;
                    if(currentPos == getCount()-1) {
                        next.setText(R.string.finish);
                    }
                    flipper.setDisplayedChild(currentPos);
                    moved(currentPos);
                }
                else if(currentPos == getCount()-1) {
                    onFinish();
                }
            }
        });
    }

    public void onSaveInstanceState(Bundle out) {
        for(int i = 0; i < getCount(); i++) {
            out.putBundle("screen"+i, save(i, viewHolder.get(i)));
        }
    }

    public ViewGroup getItem(int pos) {
        return (ViewGroup)  flipper.getChildAt(pos);
    }

    private List<View[]> viewHolder = null;

    public abstract int getCount();
    public abstract int getLayout(int pos);
    public abstract View[] create(int pos, ViewGroup v);
    public abstract Bundle save(int pos, View[] holder);
    public abstract void restore(int pos, View[] holder, Bundle restore);
    public abstract void reset(int pos, ViewGroup v, View[] holder);
    public abstract boolean move(int current, int to);
    public abstract void moved(int pos);
    public abstract void onFinish();
}