gistfile1.swift

import Cocoa
import AppKit

class MyCustomSwiftAnimator: NSObject, NSViewControllerPresentationAnimator {
    
    @objc func  animatePresentationOfViewController(viewController: NSViewController, fromViewController: NSViewController) {
        
        let bottomVC = fromViewController
        let topVC = viewController
        topVC.view.wantsLayer = true
        bottomVC.view.wantsLayer = true
        topVC.view.layerContentsRedrawPolicy = .OnSetNeedsDisplay
        bottomVC.view.layerContentsRedrawPolicy = .OnSetNeedsDisplay
        topVC.view.alphaValue = 0
        bottomVC.view.addSubview(topVC.view)
        
        
        NSAnimationContext.runAnimationGroup({ (context) -> Void in
            
            context.duration = 1
            
            var frame : NSRect = topVC.view.frame
            frame.size = NSMakeSize(frame.size.width, frame.size.height)
//            frame.origin.x = frame.size.width
//            frame.origin.y = frame.size.height
//            topVC.view.frame = frame
            
            var frame2 : NSRect = bottomVC.view.frame
            frame2.size = NSMakeSize(frame2.size.width, frame2.size.height)
////            frame2.origin.x = frame2.size.width
////            frame2.origin.y = frame2.size.height
//            bottomVC.view.frame = frame2
            
//            var frame : CGRect = NSRectToCGRect(topVC.view.frame)
            
            topVC.view.animator().frame = CGRectOffset(frame, frame.size.width, 0) //Black
            bottomVC.view.animator().frame = CGRectOffset(frame2, -(frame2.size.width), 0)
            
            topVC.view.animator().alphaValue = 1
            bottomVC.view.animator().alphaValue = 1
            

        }, completionHandler: nil)
        
    }
    
    
    @objc func  animateDismissalOfViewController(viewController: NSViewController, fromViewController: NSViewController) {
        
        let bottomVC = fromViewController
        let topVC = viewController
        topVC.view.wantsLayer = true
        topVC.view.layerContentsRedrawPolicy = .OnSetNeedsDisplay

        
        NSAnimationContext.runAnimationGroup({ (context) -> Void in
            context.duration = 1.5
            
            var frame : CGRect = NSRectToCGRect(bottomVC.view.frame)
            bottomVC.view.animator().frame = CGRectOffset(frame, -100, 0)
            topVC.view.animator().frame = CGRectOffset(frame, 100, 0)
            
            topVC.view.animator().alphaValue = 0
            bottomVC.view.animator().alphaValue = 1
            
            }, completionHandler: {
                topVC.view.removeFromSuperview()
        })
        
        
    }

}