Android : drag-sort-listview Drag is not working Android

i am using drag-sort-listview https://github.com/bauerca/drag-sort-list-view to sort rows of my list-view, and i have created a demo using this library, but it is not working, when i try to drag rows it is not working.

public class MainActivity extends Activity implements OnItemClickListener {

    public static final String[] titles = new String[] { "Strawberry",
            "Banana", "Orange", "Mixed" };

    public static final String[] descriptions = new String[] {
            "It is an aggregate accessory fruit",
            "It is the largest herbaceous flowering plant", "Citrus Fruit",
            "Mixed Fruits" };

    public static final Integer[] images = { R.drawable.drag,
            R.drawable.drag, R.drawable.drag, R.drawable.drag };

    //ListView listView;
    DragSortListView listView;
    List<RowItem> rowItems;
    CustomListViewAdapter adapter;
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        rowItems = new ArrayList<RowItem>();
        for (int i = 0; i < titles.length; i++) {
            RowItem item = new RowItem(images[i], titles[i], descriptions[i]);
            rowItems.add(item);
        }
        listView = (DragSortListView) findViewById(R.id.listview);
        //listView = (ListView) findViewById(R.id.list);
        final CustomListViewAdapter adapter = new CustomListViewAdapter(this,
                R.layout.list_item, rowItems);
        listView.setAdapter(adapter);
        listView.setOnItemClickListener(this);
        listView.setDropListener(new DropListener() {

             @Override
                public void drop(int from, int to) {
                    if (from != to) {
                        //DragSortListView list = getListView();
                        RowItem item = adapter.getItem(from);
                        adapter.remove(item);
                        adapter.insert(item, to);
                        listView.moveCheckState(from, to);

                        //Log.d("DSLV", "Selected item is " + listView.getCheckedItemPosition());
                    }
                }
        });
    }

    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position,
            long id) {
        Toast toast = Toast.makeText(getApplicationContext(), "Item "
                + (position + 1) + ": " + rowItems.get(position),
                Toast.LENGTH_SHORT);
        toast.setGravity(Gravity.BOTTOM | Gravity.CENTER_HORIZONTAL, 0, 0);
        toast.show();
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:dslv="http://schemas.android.com/apk/res/com.example.testingui"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <com.mobeta.android.dslv.DragSortListView
        android:id="@+id/listview"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:dividerHeight="5dp"
        dslv:collapsed_height="2dp"
        dslv:drag_enabled="true"
        dslv:drag_handle_id="@drawable/drag"
        dslv:drag_scroll_start="0.33"
        dslv:drag_start_mode="onMove"
        dslv:float_alpha="0.6"
        dslv:max_drag_scroll_speed="0.5"
        dslv:remove_enabled="true"
        dslv:remove_mode="flingRemove"
        dslv:slide_shuffle_speed="0.3"
        dslv:sort_enabled="true"
        dslv:track_drag_sort="true"
        dslv:use_default_controller="true" />

</RelativeLayout>

CustomListViewAdapter.java

public class CustomListViewAdapter extends ArrayAdapter<RowItem> {

    Context context;

    public CustomListViewAdapter(Context context, int resourceId,
            List<RowItem> items) {
        super(context, resourceId, items);
        this.context = context;
    }

    /*private view holder class*/
    private class ViewHolder {
        ImageView imageView;
        TextView txtTitle;
        TextView txtDesc;
    }

    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder = null;
        RowItem rowItem = getItem(position);

        LayoutInflater mInflater = (LayoutInflater) context .getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
        if (convertView == null) {
            convertView = mInflater.inflate(R.layout.list_item, null);
            holder = new ViewHolder();
            holder.txtDesc = (TextView) convertView.findViewById(R.id.descs);
            holder.txtTitle = (TextView) convertView.findViewById(R.id.titles);
            holder.imageView = (ImageView) convertView.findViewById(R.id.icons);
            convertView.setTag(holder);
        } else
            holder = (ViewHolder) convertView.getTag();

        holder.txtDesc.setText(rowItem.getDesc());
        holder.txtTitle.setText(rowItem.getTitle());
        holder.imageView.setImageResource(rowItem.getImageId());

        return convertView;
    }
}

list_item.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >
    <ImageView
        android:id="@+id/icons"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:paddingLeft="10dp"
        android:paddingRight="10dp" />

    <TextView
        android:id="@+id/titles"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_toRightOf="@+id/icons"
        android:paddingBottom="10dp"
        android:textColor="#CC0033"
        android:textSize="16dp" />

    <TextView
        android:id="@+id/descs"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/titles"
        android:layout_toRightOf="@+id/icons"
        android:paddingLeft="10dp"
        android:textColor="#3399FF"
        android:textSize="14dp" />
</RelativeLayout>

RowItem.java

public class RowItem {
    private int imageId;
    private String title;
    private String desc;

    public RowItem(int imageId, String title, String desc) {
        this.imageId = imageId;
        this.title = title;
        this.desc = desc;
    }
    public int getImageId() {
        return imageId;
    }
    public void setImageId(int imageId) {
        this.imageId = imageId;
    }
    public String getDesc() {
        return desc;
    }
    public void setDesc(String desc) {
        this.desc = desc;
    }
    public String getTitle() {
        return title;
    }
    public void setTitle(String title) {
        this.title = title;
    }
    @Override
    public String toString() {
        return title + "\n" + desc;
    }   
}