Question

For this app I’m trying to write, the idea is that I’m going to host some pictures online and save the individual urls into a sqlite database. Then I will extract each url from the database and download the picture to be shown in a gallery widget. I read about Lazy List (kudos for the great work!) but I’m having problems implementing it. I have tried to modify the coding from Lazy List but it doesnt seem to work. I’m not sure if there is an error in my app or have I modified the Lazy List wrongly. Any help is greatly appreciated and thank you in advance! =)

Code for my app:

public class ResultDetails extends ListActivity {

    protected int foodId;
    protected String pic1, pic2, pic3, pic4, pic5;
    LazyAdapter adapter1;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.result_details);
        foodId = getIntent().getIntExtra("FOOD_ID", 0);
        SQLiteDatabase db = (new DatabaseHelper(this)).getWritableDatabase();
        Cursor cursor = db.rawQuery("SELECT _id, pic1, pic2, pic3, pic4, pic5 FROM database WHERE _id = ?", new String[]{""+foodId});
    pic1 = cursor.getString(cursor.getColumnIndex("pic1"));
    pic2 = cursor.getString(cursor.getColumnIndex("pic2"));
    pic3 = cursor.getString(cursor.getColumnIndex("pic3"));
    pic4 = cursor.getString(cursor.getColumnIndex("pic4"));
    pic5 = cursor.getString(cursor.getColumnIndex("pic5"));
    String[] mStrings={
            pic1,
            pic2,
            pic3, 
            pic4, 
            pic5};
    Gallery g = (Gallery) findViewById(R.id.photobar);
    adapter1=new LazyAdapter(this, mStrings);
    g.setAdapter(adapter1);
}

I have modified the LazyAdapter as such:

public class LazyAdapter extends BaseAdapter {
   int mGalleryItemBackground;
   private Context mContext;

    private Activity activity;
    private String[] data;
    private static LayoutInflater inflater=null;
    public ImageLoader imageLoader; 

    public LazyAdapter(Activity a, String[] d) {
        activity = a;
        data=d;
        inflater = (LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        imageLoader=new ImageLoader(activity.getApplicationContext());
    }
    public LazyAdapter(Context c) {
       mContext = c;
       TypedArray b = c.obtainStyledAttributes(R.styleable.Theme);
       mGalleryItemBackground = b.getResourceId(
         R.styleable.Theme_android_galleryItemBackground,
                   0);
       b.recycle();
   }


    public int getCount() {
        return data.length;
    }

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

    public long getItemId(int position) {
        return position;
    }

    public View getView(int position, View convertView, ViewGroup parent) {

        ImageView vi = new ImageView(mContext);
        imageLoader.DisplayImage(data[position], vi);
        vi.setLayoutParams(new Gallery.LayoutParams(150, 100));
    vi.setScaleType(ImageView.ScaleType.FIT_XY);
        return vi;
    }
}

Answer 1

With the help of Fedor, I figured out what was wrong with the implementation. Whether for list or gallery, there is no need to change the LazyAdapter! Just use the adapter as it is and use the following code in your app to load the pictures:

 g = (Gallery) findViewById(R.id.photobar);
 adapter1=new LazyAdapter(this, mStrings);
 g.setAdapter(adapter1);}

I noticed that there are a lot of examples on using LazyList for lists and not galleries. To help those who want to use it for galleries, here is an example of the implementation:

public class ResultDetails extends ListActivity {

protected int foodId;
protected String pic1, pic2, pic3, pic4, pic5;
LazyAdapter adapter1;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.result_details);
    foodId = getIntent().getIntExtra("FOOD_ID", 0);
    SQLiteDatabase db = (new DatabaseHelper(this)).getWritableDatabase();
    Cursor cursor = db.rawQuery("SELECT _id, pic1, pic2, pic3, pic4, pic5 FROM database WHERE _id = ?", new String[]{""+foodId});
    pic1 = cursor.getString(cursor.getColumnIndex("pic1"));
    pic2 = cursor.getString(cursor.getColumnIndex("pic2"));
    pic3 = cursor.getString(cursor.getColumnIndex("pic3"));
    pic4 = cursor.getString(cursor.getColumnIndex("pic4"));
    pic5 = cursor.getString(cursor.getColumnIndex("pic5"));
    String[] mStrings={pic1, pic2, pic3, pic4, pic5};
    g = (Gallery) findViewById(R.id.photobar);
    adapter1=new LazyAdapter(this, mStrings);
    g.setAdapter(adapter1);}