The check box form control doesn't have such a built in behavior but you can get something similar by using 3 check box form controls instead of just one:
Code: Select all
oxy_checkbox(edit, "#text", values, "1", uncheckedValues, "1", labels, "First")
oxy_checkbox(edit, "#text", values, "2", uncheckedValues, "2", labels, "Second")
oxy_checkbox(edit, "#text", values, "3", uncheckedValues, "3", labels, "Third");
The user will be able to select only one check box and will not be able to leave all the check boxes unchecked. What's missing is the "radio button" look (the buttons will still look like check boxes).
Another possible solution is for you to implement a custom form control that looks and behaves as required. As a starting point I can send you the JAVA source code for the built in check box form control. Modifying it for your use case should be simple enough. If you want to go on this road please let me know and I will send you the source code.