public class PersActivity extends Activity {

    Button start, calcaverage1;

    private SubjectAdapter adapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.subject_list_view);

        setupListViewAdapter();

        setupAddMarkButton();

        // Accept button
                Button acceptbn= (Button)findViewById(R.id.start1);
                acceptbn.setOnClickListener(new OnClickListener()
                {   public void onClick(View v)
                    {
                        Intent intent = new Intent(PersActivity.this, MainActivity.class);
                            startActivity(intent);
                            finish();
                    }
                });
    }

    public void addNumberFromText()
    {
        int total=0;
        for(int i=0;i<ListView.getChildCount();i++)
        {
            View wantedView = ListView.getChildAt(i);
            EditText edtText=View.findViewById(R.id.subjectmark);
            //not checking wheter integer valid or not, Please do so
            int value=Integer.parseInt(edtText.toString());
            total+=value;
        }
        Log.d(TAG,"total sum is "+total);
    }

    public void removeClick(View v) {
        Mark itemToRemove = (Mark)v.getTag();
        adapter.remove(itemToRemove);
    }

    private void setupListViewAdapter() {
        adapter = new SubjectAdapter(PersActivity.this, R.layout.subject_list_item, new ArrayList<Mark>());
        ListView atomPaysListView = (ListView)findViewById(R.id.subject_list_item);
        atomPaysListView.setAdapter(adapter);
    }

    private void setupAddMarkButton() {
        findViewById(R.id.addsubject).setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                adapter.insert(new Mark("", 0), 0);
            }
        });
    }
}