MainActivity.java

package net.learn2develop.gallery;

import android.app.Activity;
import android.content.Context;
import android.content.res.TypedArray;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.ImageView;
import android.widget.Toast;

@SuppressWarnings("deprecation")
public class MainActivity extends Activity {
    //---the images to display---
    Integer[] imageIDs = {
            R.drawable.pic1,
            R.drawable.pic2,
            R.drawable.pic3,
            R.drawable.pic4,
            R.drawable.pic5,
            R.drawable.pic6,
            R.drawable.pic7
    };
    
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        Gallery gallery = (Gallery) findViewById(R.id.gallery1); 
        gallery.setAdapter(new ImageAdapter(this)); 
        gallery.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();

                //---display the images selected---
                ImageView imageView = (ImageView) findViewById(R.id.image1); 
                imageView.setImageResource(imageIDs[position]);
            } 
        });

    }

    public class ImageAdapter extends BaseAdapter {
        private Context context;
        private int itemBackground;
        public ImageAdapter(Context c)
        {
            context = c;

            //---sets a grey background; wraps around the images
            TypedArray a =
                obtainStyledAttributes(R.styleable.MyGallery); 
            itemBackground = a.getResourceId(
                R.styleable.MyGallery_android_galleryItemBackground, 0);
            a.recycle();
        }

        //---returns the number of images---
        public int getCount() {
            return imageIDs.length;
        }

        //---returns the ID of an item---
        public Object getItem(int position) {
            return position;
        }

        //---returns the ID of an item---
        public long getItemId(int position) {
            return position;
        }

        //---returns an ImageView view---
        public View getView(int position, View convertView, ViewGroup parent) {
            ImageView imageView = new ImageView(context);
            imageView.setImageResource(imageIDs[position]); 
            imageView.setScaleType(ImageView.ScaleType.FIT_XY); 
            imageView.setLayoutParams(new Gallery.LayoutParams(150, 120)); 
            imageView.setBackgroundResource(itemBackground); 
            return imageView;
        } 
    }

    
}