Creating a custom focus view for tvOS

CustomFocusView.swift

//
//  FocusView.swift
//  CustomNavigation
//
//  Creating a CustomFocusView
//  This code shows how to implement a custom view that can be focused in tvOS
//  Just set this class as an UIView's custom class
//

import UIKit

class CustomFocusView: UIView {

    
    //Now This View controller can get Focus
    override func canBecomeFocused() -> Bool {
        return true
    }
    
    //We Can chance the focus behavior.... Is a good idea if we evidence it
    override func didUpdateFocusInContext(context: UIFocusUpdateContext, withAnimationCoordinator coordinator: UIFocusAnimationCoordinator) {
        
        //Bahavior we will trigger when view lost focus
        if context.previouslyFocusedView === self
        {
            UIView.animateWithDuration(0.1, animations: { () -> Void in
                context.previouslyFocusedView?.transform = CGAffineTransformMakeScale(1.0, 1.0)
            })
        }
        
        //Bahavior we will trigger when view get focus
        if context.nextFocusedView === self
        {
            UIView.animateWithDuration(0.1, animations: { () -> Void in
                context.nextFocusedView?.transform = CGAffineTransformMakeScale(1.2, 1.2)
            })
        }
        
    }

}

Swift 3.x and above version,

```
import UIKit
class CustomFocusView: UIView {

  override var canBecomeFocused: Bool {
      return true
  }
  override func didUpdateFocus(in context: UIFocusUpdateContext, with coordinator: UIFocusAnimationCoordinator) {
    //Bahavior we will trigger when view lost focus
    if context.previouslyFocusedView === self
    {
      UIView.animate(withDuration: 0.1, animations: { () -> Void in
        context.previouslyFocusedView?.transform = CGAffineTransform(scaleX: 1.0, y: 1.0)
        })
    }
    
    //Bahavior we will trigger when view get focus
    if context.nextFocusedView === self
    {
      UIView.animate(withDuration: 0.1, animations: { () -> Void in
        context.nextFocusedView?.transform = CGAffineTransform(scaleX: 1.2, y: 1.2)
        })
    }
  }
}
```