title: Set previously Cell Button image to its default state when another cell button is selected
body: <p>I want to change previously selected <code>Cell Button</code> image to its default state when another <code>Cell Button</code> is select.</p>
  
  <p>Default State <code>sender.selected = false</code> When Button is not selected</p>
  
  <p><a href="https://i.stack.imgur.com/Ig09J.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Ig09J.png" alt=""></a></p>
  
  <p>After Button Pressed <code>sender.selected = true</code></p>
  
  <p><a href="https://i.stack.imgur.com/psMvm.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/psMvm.png" alt="&quot;"></a></p>
  
  <pre><code>func collectionView(collectionView: UICollectionView,
                      cellForItemAtIndexPath indexPath: NSIndexPath) -&gt; UICollectionViewCell {
  
      let cell = collectionView.dequeueReusableCellWithReuseIdentifier(
                     reuseIdentifier, forIndexPath: indexPath) as! RadioCollectionViewCell
  
      cell.btnPlay.addTarget(self,
          action: Selector("audioControlButtonAction:"),
          forControlEvents: UIControlEvents.TouchUpInside)
      cell.btnPlay.tag = indexPath.row
      return cell
  }        
  
  func audioControlButtonAction(sender: UIButton) {
  
      if sender.selected == false {
          sender.selected = true 
      } else {
          sender.selected = false
      }
  }
  </code></pre>
  
  <p>Can anyone please tell me how i can do this?
  Thanks</p>