Java [Android] Listener, welches beim Loslassen ein Ereignis auslöst, gesucht

@Override
protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		ImageView g = (ImageView) findViewById(R.id.imageView1);
		g.setOnTouchListener(new OnTouchListener() {
			float maxDistance = 0f;
			float startX, startY;

			@Override
			public boolean onTouch(View v, MotionEvent event) {
                                if (event.getAction() == MotionEvent.ACTION_DOWN) {
	 				startX = event.getX();
					startY = event.getY();
					maxDistance = 0f;
				}
				if (event.getAction() == MotionEvent.ACTION_MOVE) {
					float distance = distance(startX, startY, event.getX(),
							event.getY());
					if (distance > maxDistance) {
						maxDistance = distance;
						System.out.println("New maxDistance: " + maxDistance);
					}
				}				
				if (event.getAction() == MotionEvent.ACTION_UP) {
					System.out.println("maxDistance: "+maxDistance);
					if(maxDistance > 50f) {
						System.out.println("nervous?");
					}
				}
				return true;
			}
		});
}

private float distance(float startX, float startY, float endX, float endY) {
		return (float) Math.sqrt((startX - endX) * (startX - endX)
				+ (startY - endY) * (startY - endY));
}

import android.os.Bundle;
import android.app.Activity;
import android.widget.Gallery;

public class MainActivity extends Activity{

	private Gallery _gallery = null;
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		
		_gallery = new Gallery(this);
		_gallery.setAdapter(new SimplerAdapter(this));
		_gallery.setSpacing(0);
		
		setContentView(_gallery);
						
	}

}

import android.content.Context;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.TextView;

public class SimplerAdapter extends BaseAdapter implements OnTouchListener{

	private final Context _Context;
	
	public SimplerAdapter(Context _context) {

		this._Context = _context;		
		
	}
	
	@Override
	public int getCount() {
		return 50;
	}

	@Override
	public Object getItem(int position) {
		return position;
	}

	@Override
	public long getItemId(int position) {
		return 0;
	}
	
	@Override
	public View getView(int position, View convertView, ViewGroup parent) {
		
		View _View = convertView;

		if (_View == null) {
			
			Gallery.LayoutParams eglp = new Gallery.LayoutParams
				(Gallery.LayoutParams.MATCH_PARENT, Gallery.LayoutParams.MATCH_PARENT);
			
			_View = new TextView(_Context);
			((TextView)_View).setTextSize(20 * _Context.getResources().getDisplayMetrics().density);
			_View.setLayoutParams(eglp);
			_View.setOnTouchListener(this);
			
		}
		
		((TextView )_View).setText("" + position);
				
		return _View;
		
	}

	@Override
	public boolean onTouch(View v, MotionEvent event) {
		
		if(v instanceof TextView){
			
			((TextView) v).setText("wurde berührt");
			
		}
		
		return false;
		
	}
	
}