Android - How to enable a button if a radio button is checked?

Question

I want to know/learn how to enable a button when/if a radio button is checked

Steps done

I created a fragment and inside a radio group with 3 radio buttons inside

Goal

My main goal is to enable the button when a radio button is checked, and disable it when the radio button is unchecked

Code

So far I have this code

public class Operations extends Fragment
{
    RadioButton surfArea, rad, diam;
    RadioGroup radG;
    Button openSelect;

    public Operations()
    {
        // Required empty public constructor
    }

    public static Operations newInstance()
    {
        return new Operations();
    }

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

    @Override
    public View onCreateView(LayoutInflater inflater,
                             ViewGroup container,
                             Bundle savedInstanceState)
    {
        View rootView = inflater.inflate(R.layout.fragment_operations_sphere, container, false);

        surfArea = (RadioButton) rootView.findViewById(R.id.RB_surfArea);
        rad = (RadioButton) rootView.findViewById(R.id.RB_Rad);
        diam = (RadioButton) rootView.findViewById(R.id.RB_Diam);
        openSelect = (Button) rootView.findViewById(R.id.btn_open_select);

        radG = (RadioGroup) rootView.findViewById(R.id.RG_group);

        openSelect.setEnabled(false);

        openSelect.setOnClickListener(new View.OnClickListener()
        { //This piece of code is for testing purposes
            @Override
            public void onClick(View v)
            {
                if (surfArea.isChecked())
                {
                    openSelect.setEnabled(true); //I detected my mistake here, so I would like to know a better way to achieve this
                    Intent sa = new Intent(getContext(), OperSphere.class);
                    startActivity(sa);
                }
            }
        });

        return rootView;
    }

    @Override
    public void onResume()
    { //Here the radio button unchecks
        radG.clearCheck();
        super.onResume();
    }
}

Question

How to enable a button when a radio button is checked?

Some examples would be great

Thanks in advance

Answer 1

Sorry my bad, here try this solution;

Since you are using RadioGroup, set the listener on this to disable or enable button accordingly.

RadioGroup radG = (RadioGroup) findViewById(R.id.yourRadioGroup);        
radG.setOnCheckedChangeListener(new OnCheckedChangeListener() 
{
    @Override
    public void onCheckedChanged(RadioGroup group, int checkedId) {
        // checkedId is the RadioButton selected
        switch(checkedId) 
        {
        case R.id.surfArea:     
        //enable or disable button
        break;

        case R.id.rad: 
        //enable or disable button        
        break;

        case R.id.diam:  
        //enable or disable button       
        break;
        }
    }
});