title: How to implement a button whose functionality is a cross between radiobutton and checkbutton?
body: <p>I want to dynamically disable or enable <code>checkbutton</code>s based on the options the user selects. What I would like is a cross between <code>radiobutton</code> and <code>checkbutton</code>.</p>
  
  <pre class="lang-tcl prettyprint-override"><code>checkbutton .c1 -text "C1" -variable c1
  checkbutton .c2 -text "C2" -variable c2
  checkbutton .c3 -text "C3" -variable c3
  checkbutton .c4 -text "C4" -variable c4
  
  grid .c1 -sticky w
  grid .c2 -sticky w
  grid .c3 -sticky w
  grid .c4 -sticky w
  </code></pre>
  
  <p>In the above example, if I check <code>C1</code>, then the options <code>C2</code> and <code>C4</code> should be grayed out. 
  Similarly, if I check <code>C3</code> then <code>C4</code> should be grayed out. </p>
  
  <p>It would be great if there is an elegant method which implements this cross between <code>radiobutton</code> and <code>checkbutton</code> which also scales well as the number of options increases?</p>