Android – How to stop scrolling in a Gallery Widget

androidandroid-widgetgalleryscroll

I loaded some images into a gallery. Now I'm able to scroll but once started scrolling the scrolling won't stop. I would like the gallery to just scroll to the next image and then stop until the user does the scroll gesture again.

this is my code

import android.widget.ImageView;
import android.widget.Toast;
 import android.widget.AdapterView.OnItemClickListener;

public class GalleryExample extends Activity {

private Gallery gallery;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

     gallery = (Gallery) findViewById(R.id.examplegallery);
     gallery.setAdapter(new AddImgAdp(this));

     gallery.setOnItemClickListener(new OnItemClickListener() {
        public void onItemClick(AdapterView parent, View v, int position, long id) {

            Toast.makeText(GalleryExample.this, "Position=" + position, Toast.LENGTH_SHORT).show();
        }
    });

}

public class AddImgAdp extends BaseAdapter {
    int GalItemBg;
    private Context cont;


    private Integer[] Imgid = {
            R.drawable.a_1, R.drawable.a_2, R.drawable.a_3, R.drawable.a_4, R.drawable.a_5, R.drawable.a_6, R.drawable.a_7
    };

    public AddImgAdp(Context c) {
        cont = c;
        TypedArray typArray = obtainStyledAttributes(R.styleable.GalleryTheme);
        GalItemBg = typArray.getResourceId(R.styleable.GalleryTheme_android_galleryItemBackground, 0);
        typArray.recycle();
    }

    public int getCount() {
        return Imgid.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 imgView = new ImageView(cont);

        imgView.setImageResource(Imgid[position]);

        i.setScaleType(ImageView.ScaleType.FIT_CENTER);
        imgView.setBackgroundResource(GalItemBg);

        return imgView;
    }
}

}

and the xmlLayout file

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:id="@+id/LinearLayout01"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android" >
<Gallery xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/examplegallery"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" />
</LinearLayout>

Best Solution

I think I found a way to achieve both only scrolling 1 view at a time in the gallery and be able to have a minimal swipe length to trigger animation.

Override the onFling method of the gallery widget and instead of calling super.onFling, check to see whether or not the swipe was from left to right or right to left and call the appropriate dpad event as shown below:

private boolean isScrollingLeft(MotionEvent e1, MotionEvent e2){
  return e2.getX() > e1.getX();
}

@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY){
  int kEvent;
  if(isScrollingLeft(e1, e2)){ //Check if scrolling left
    kEvent = KeyEvent.KEYCODE_DPAD_LEFT;
  }
  else{ //Otherwise scrolling right
    kEvent = KeyEvent.KEYCODE_DPAD_RIGHT;
  }
  onKeyDown(kEvent, null);
  return true;  
}