Showing Popup Window In Android

public class CategoryPopUp {

    private PopupWindow popupWindowCategory;
    ArrayList<String> categories = null;
    private Context context = null;
    private SortCategoryChangeListner listner = null;

    public CategoryPopUp(ArrayList<String> categories, Context context, SortCategoryChangeListner listner) {

        this.context = context;
        this.categories = categories;
        this.listner = listner;
    }

    public void showWindow(View view) {

        popupWindowCategory = getPopupWindowCategory(categories);
        popupWindowCategory.showAsDropDown(view, -5, 0);
    }

    public PopupWindow getPopupWindowCategory(ArrayList<String> categories) {

        PopupWindow popupWindow = new PopupWindow(context);

        ListView listViewDogs = new ListView(context);

        listViewDogs.setAdapter(categoryAdapter(categories));

        listViewDogs.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
 public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {

                // add some animation when a list item was clicked
 Animation fadeInAnimation = AnimationUtils.loadAnimation(context, android.R.anim.fade_in);
                fadeInAnimation.setDuration(10);
                view.startAnimation(fadeInAnimation);

                // dismiss the pop up
 popupWindowCategory.dismiss();

                // get the text and set it as the button text
 String selectedItemText = ((TextView) view).getText().toString();
                if (!TextUtils.isEmpty(selectedItemText))
                    listner.onSortItemChanged(selectedItemText);


            }
        });

        // some other visual settings
 popupWindow.setFocusable(true);
        popupWindow.setWidth(250);
        popupWindow.setHeight(WindowManager.LayoutParams.WRAP_CONTENT);

        // set the list view as pop up window content
 popupWindow.setContentView(listViewDogs);

        return popupWindow;
    }

    private ArrayAdapter<String> categoryAdapter(ArrayList<String> categories) {


        ArrayAdapter<String> adapter = new ArrayAdapter<String>(context, android.R.layout.simple_list_item_1, categories) {

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

                // setting the ID and text for every items in the list
 String item = getItem(position);

                // visual settings for the list item
 TextView listItem = new TextView(context);

                listItem.setText(item);
                listItem.setTag(item);
                listItem.setTextSize(12);
                listItem.setPadding(10, 10, 10, 10);
                listItem.setTextColor(Color.WHITE);

                return listItem;
            }
        };

        return adapter;
    }


}

View.OnClickListener sortListner = new View.OnClickListener() {
    @Override
 public void onClick(View view) {

        ArrayList<String> categories = new ArrayList<String>();
        categories.add("all");
        categories.add("category 1");
        categories.add("category 2");
        categories.add("category 3");
        categories.add("category 4");
        categories.add("category 5");
        categories.add("category 6");

        new CategoryPopUp(categories, getActivity(), MyReferralFragment.this).showWindow(view);
    }
};