java - How to set the button property and action in another class and use them in my Activity class in android

Question

Please help me to implment the Button Action in below the Class

   public class DoneButtonMain extends MainActivity implements OnClickListener{

        private Activity activity;
        private Context context;


        public DoneButtonMain(Activity activity) {
            this.activity=activity;
            // TODO Auto-generated constructor stub
        }


        public View prepareControl(){

            Button btn=new Button(activity);
            btn.setText("Done");
            btn.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
            btn.setBackgroundColor(Color.parseColor("#05a5a6"));
            btn.setTypeface(Typeface.DEFAULT_BOLD);
            btn.setPadding(7,7, 7, 7);

            btn.setTextColor(Color.parseColor("#ffffff"));

        return btn;


        }

    public LayoutParams prepareLayoutParam() {
        RelativeLayout.LayoutParams param = new RelativeLayout.LayoutParams(
                android.view.ViewGroup.LayoutParams.WRAP_CONTENT,
                android.view.ViewGroup.LayoutParams.WRAP_CONTENT);
        param.addRule(RelativeLayout.ALIGN_PARENT_RIGHT,RelativeLayout.TRUE);
        param.addRule(RelativeLayout.CENTER_VERTICAL,RelativeLayout.TRUE);
        param.rightMargin=20;
        param.bottomMargin=20;
        param.topMargin=20;
        return param;


    }
}

And MainActivity looks as below

public class MainActivity extends Activity {


        @Override
    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);


    LinearLayout parentlinLayout = new LinearLayout(this);
        parentlinLayout.setOrientation(LinearLayout.VERTICAL);
        LayoutParams linLayoutParam = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT); 


    RelativeLayout raltivelayout1=new RelativeLayout(this);
        raltivelayout1.setBackgroundColor(Color.parseColor("#1B4F91"));

      //Button Added to the relativeLayaout
        DoneButtonMain object=new DoneButtonMain(this);

        raltivelayout1.addView(object.prepareControl(),object.prepareLayoutParam());
        //Relative layout is added to the Linear View
        parentlinLayout.addView(raltivelayout1);
}

i have tried to button.setOnClickListener but i am getting a null pointer exception

Answer 1

Thanks all, i got the sloution. as i have implemented the OnClickListener in class DoneButtonMain the prepareControl through activity object.

private void handleBtnClick() {
        btn.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {

//required code
});
    }