From 265eb08180612936076308a83f98160b54da7c10 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Julien=20Roze=CC=81?= <julien.roze@me.com>
Date: Tue, 18 Jul 2017 18:01:20 +0200
Subject: [PATCH 1/2] set view properties a weak property to avoid retain cycle

---
 StatefulViewController/ViewStateMachine.swift | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/StatefulViewController/ViewStateMachine.swift b/StatefulViewController/ViewStateMachine.swift
index cd1dca9..b703f39 100644
--- a/StatefulViewController/ViewStateMachine.swift
+++ b/StatefulViewController/ViewStateMachine.swift
@@ -52,7 +52,7 @@ public class ViewStateMachine {
     }()
 
     /// The view that should act as the superview for any added views
-    public let view: UIView
+    public weak var view: UIView?
     
     /// The current display state of views
     public fileprivate(set) var currentState: ViewStateMachineState = .none
@@ -163,6 +163,9 @@ public class ViewStateMachine {
     
 	fileprivate func showView(forKey state: String, animated: Bool, completion: (() -> ())? = nil) {
         // Add the container view
+        guard let view = view else {
+            return
+        }
         containerView.frame = view.bounds
         view.addSubview(containerView)
 

From d140cf7aeaf3a33782f4c12988e9ba2afa1a9e3f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Julien=20Roz=C3=A9?= <julien.roze@me.com>
Date: Wed, 2 Aug 2017 01:36:20 +0200
Subject: [PATCH 2/2] Don't use queue

---
 StatefulViewController/ViewStateMachine.swift | 35 ++++++-------------
 1 file changed, 11 insertions(+), 24 deletions(-)

diff --git a/StatefulViewController/ViewStateMachine.swift b/StatefulViewController/ViewStateMachine.swift
index b703f39..cb5f7cb 100644
--- a/StatefulViewController/ViewStateMachine.swift
+++ b/StatefulViewController/ViewStateMachine.swift
@@ -130,31 +130,18 @@ public class ViewStateMachine {
     public func transitionToState(_ state: ViewStateMachineState, animated: Bool = true, completion: (() -> ())? = nil) {
         lastState = state
         
-        queue.async { [weak self] in
-            guard let strongSelf = self else { return }
+        if state == currentState {
+            return
+        }
 
-            if state == strongSelf.currentState {
-                return
-            }
-            
-            // Suspend the queue, it will be resumed in the completion block
-            strongSelf.queue.suspend()
-            strongSelf.currentState = state
-            
-            let c: () -> () = {
-                strongSelf.queue.resume()
-                completion?()
-            }
-            
-            // Switch state and update the view
-            DispatchQueue.main.sync {
-                switch state {
-                case .none:
-                    strongSelf.hideAllViews(animated: animated, completion: c)
-                case .view(let viewKey):
-                    strongSelf.showView(forKey: viewKey, animated: animated, completion: c)
-                }
-            }
+        // Suspend the queue, it will be resumed in the completion block
+        currentState = state
+
+        switch state {
+        case .none:
+            hideAllViews(animated: animated, completion: completion)
+        case .view(let viewKey):
+            showView(forKey: viewKey, animated: animated, completion: completion)
         }
     }