title: NSButton in Swift, handle click and release events
body: <p>i'm trying to manage different state of a simple push button on an OS X application : When the user click on it, and when the user release the click.</p>
  
  <p>Currently i set my button type by <strong>NSMomentaryLightButton</strong></p>
  
  <blockquote>
    <p>NSMomentaryLightButton When the button is clicked (on state), it
    appears illuminated. If the button has borders, it may also appear
    recessed. When the button is released, it returns to its normal (off)
    state.</p>
    
    <p>This type of button is best for simply triggering actions because it
    doesn’t show its state; it always displays its normal image or title.
    This option is called Momentary Light in Interface Builder’s Button
    inspector</p>
  </blockquote>
  
  <p>I thought it was the good way, but when i print my button status, it's like a toggle button than the push button that i set. As you can see on <a href="http://i.stack.imgur.com/DwDHz.gif" rel="nofollow">exemple gif </a></p>
  
  <p>To sum up, <strong>How can i have a real push button behaviour ?</strong> Call function when the user click on it, and when the user release the click.</p>
  
  <p>Thank,</p>