UI Android

package app.test;
import android.app.Activity;
import android.os.Bundle;
import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.Toast;
public class Test extends Activity {
    Integer[] imageIDs = {
            R.drawable.icon,
            R.drawable.icon,
            R.drawable.icon,
            R.drawable.icon,
            R.drawable.icon,
            R.drawable.icon,
            R.drawable.icon
    };
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        GridView gridView = (GridView) findViewById(R.id.gridview);
        gridView.setAdapter(new ImageAdapter(this));
 
        gridView.setOnItemClickListener(new OnItemClickListener() 
        {
            public void onItemClick(AdapterView parent, 
            View v, int position, long id) 
            {                
                Toast.makeText(getBaseContext(), 
                        "pic" + (position + 1) + " selected", 
                        Toast.LENGTH_SHORT).show();
            }
        });        
    }
    
    public class ImageAdapter extends BaseAdapter 
    {
        private Context context;
 
        public ImageAdapter(Context c) 
        {
            context = c;
        }
 
        //---returns the number of images---
        public int getCount() {
            return imageIDs.length;
        }
 
        //---returns the ID of an item--- 
        public Object getItem(int position) {
            return position;
        }
 
        public long getItemId(int position) {
            return position;
        }
 
        //---returns an ImageView view---
        public View getView(int position, View convertView, ViewGroup parent) 
        {
            ImageView imageView;
            if (convertView == null) {
                imageView = new ImageView(context);
                imageView.setLayoutParams(new GridView.LayoutParams(185, 185));
                imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
                imageView.setPadding(5, 5, 5, 5);
            } else {
                imageView = (ImageView) convertView;
            }
            imageView.setImageResource(imageIDs[position]);
            return imageView;
        }
    }    
}
//main.xml

    android:id="@+id/gridview"
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent"
    android:numColumns="auto_fit"
    android:verticalSpacing="10dp"
    android:horizontalSpacing="10dp"
    android:columnWidth="90dp"
    android:stretchMode="columnWidth"
    android:gravity="center"
/>