Android: Programmatically animate between images in Gallery widget

Question

I'd like to programmatically move between images in the Gallery widget, with animation.

I can change the currently displaying image using the setSelection(int position) method, however that does not animate. Then there's setSelection(int position, bool animate) but the extra boolean on the end there doesn't appear to do anything.

In the source of Gallery it appears that it can handle DPAD key-presses, so a work-around I thought of was to fake the key-presses. Eg.

dispatchKeyEvent(new KeyEvent(KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_DPAD_LEFT))

However I can't get this working for some reason. Anyone tried this?

I notice three of the widget's methods I'd love to use moveNext(), movePrevious() and scrollToChild() are all private and unusable.

Does anyone know how I might be able to do this?

Answer 1

Use gallery.setSelected(int); Here is a simple example.

public class Splash extends Activity {

    ArrayList objects = new ArrayList();
    Gallery g;
    int i = 0;
    @Override
    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        setContentView(R.layout.photos);
        g = (Gallery) findViewById(R.id.gallery);
        objects.add(getResources().getDrawable(R.drawable.icon));
        objects.add(getResources().getDrawable(R.drawable.icon));
        objects.add(getResources().getDrawable(R.drawable.icon));
        objects.add(getResources().getDrawable(R.drawable.icon));
        objects.add(getResources().getDrawable(R.drawable.icon));
        objects.add(getResources().getDrawable(R.drawable.icon));
        g.setAdapter(new CustomAdapter(this, objects));
        g.setOnItemSelectedListener(new OnItemSelectedListener() {

            @Override
            public void onItemSelected(AdapterView arg0, View arg1,
                    int arg2, long arg3) {
                Log.i("", "selected " + arg2);
            }

            @Override
            public void onNothingSelected(AdapterView arg0) {}
        });
    }

    @Override
    public void onBackPressed() {
            g.setSelection(i++);
    }

        private class CustomAdapter extends BaseAdapter {

        private Context mCtx;
        private List objects;

        public int getCount() {
            return this.objects.size();
        }

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

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

        public CustomAdapter(Context context, ArrayList objects) {
            super();
            mCtx = context;
            this.objects = objects;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            ImageView row = (ImageView) convertView;
            if (row == null) {
                row = new ImageView(mCtx);
                row.setBackgroundDrawable(objects.get(position));
            }
            return row;
        }
    }
}

Answer 2

In the end I wrote my own version of the Gallery widget with the help of the code at this site.

I then wrote my own method which uses mFlingRunnable.startUsingDistance(distance);

Now I can programmatically animate the gallery between images.

Answer 3

I am facing same problem. Now its working but alpha is not working for unseleted child. Please give me some idea to resolve this.

Advance thanks Ramesh

Answer 4

Just call the key press handler for the gallery directly:

public boolean onKeyDown(int keyCode, KeyEvent event)

i.e

Gallery gallery = ((Gallery) findViewById(R.id.gallery));

gallery.onKeyDown(KeyEvent.KEYCODE_DPAD_LEFT, new KeyEvent(0, 0));

Answer 5

Hi.. Can any one post a sample quote to animate gallery between images

i have tried with onKeydown..of not luck..:(

Thanks