a multichoice dialog class

MultiChoiceListDialog.java

import android.app.*;
import android.content.*;
import android.os.*;
import java.util.*;

public class MultiChoiceListDialog extends DialogFragment {
 private String title;
 private String[] choices;
 private ArrayList<String> selectedItems;
 private OnDismissListener listener;
 private FragmentManager fragmentManager;

 public MultiChoiceListDialog(FragmentManager fragmentManager, String title, String[] choices) {
	this.title = title;
	this.fragmentManager = fragmentManager;
	this.choices = choices;
	listener = null;
 }

 @Override
 public Dialog onCreateDialog(Bundle savedInstanceState) {
	// TODO: Implement this method
	selectedItems = new ArrayList<>();
	AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
	builder.setTitle(title)
	 .setMultiChoiceItems(choices, null, new DialogInterface.OnMultiChoiceClickListener(){

		@Override
		public void onClick(DialogInterface p1, int p2, boolean p3) {
		 // TODO: Implement this method
		 if(p3){
			selectedItems.add(choices[p2]);
		 }else if(selectedItems.contains(choices[p2])){
			selectedItems.remove(choices[p2]);
		 }
		}

		
	 })
	.setPositiveButton("Ok", new DialogInterface.OnClickListener(){

		@Override
		public void onClick(DialogInterface p1, int p2) {
		 // TODO: Implement this method
		 listener.onDismiss(selectedItems);
		}
	 })
	 .setNeutralButton("Cancel", new DialogInterface.OnClickListener(){

		@Override
		public void onClick(DialogInterface p1, int p2) {
		 // TODO: Implement this method
		 listener.onDismiss(null);
		}
	 });
	return builder.create();
 }

 public void show() {
	show(fragmentManager, "");
 }

 public void setOnDismissListener(MultiChoiceListDialog.OnDismissListener listener) {
	this.listener = listener;
 }

 // listener interface
 public interface OnDismissListener {
	public void onDismiss(ArrayList<String> choice);
 }

}