title: How do I create a NSToggleButton in Interface Builder?
body: <p>I want to make an NSToggleButton because it suits my needs perfectly: show one image when toggled on, another when it's toggled off.  </p>
  
  <p>From Apple's Developer website:</p>
  
  <p>"After the first click, the button displays its alternate image or title; a second click returns the button to its normal state.
  This option is called “Toggle” in Interface Builder’s Button Inspector.
  Available in OS X v10.0 and later."
  - <a href="https://developer.apple.com/library/mac/#documentation/Cocoa/Reference/ApplicationKit/Classes/NSButtonCell_Class/Reference/Reference.html#//apple_ref/doc/c_ref/NSToggleButton" rel="nofollow">Source</a></p>
  
  <p>When looking at the Round Rect Button I created in Interface Builder, however, I can't find a "Toggle" attribute.  My google and StackOverflow searches yield only questions around attributes for the control, but I haven't found a tutorial for creating this button in particular.</p>
  
  <p>How do I create a NSToggleButton in Interface Builder?  Where is it in the Object library?</p>