Use a dummy animation object to deal with the completion callback, fi…

…xing tomvanzummeren#70 (Completion closure never called when animating showing/hiding) and tomvanzummeren#50 (Setting TZStackView to hidden inside animateAlongsideCoordinator's animation block causes strange behavior)

TZStackView/TZStackView.swift

@@ -8,15 +8,6 @@
 
 import UIKit
 
-struct TZAnimationDidStopQueueEntry: Equatable {
-    let view: UIView
-    let hidden: Bool
-}
-
-func ==(lhs: TZAnimationDidStopQueueEntry, rhs: TZAnimationDidStopQueueEntry) -> Bool {
-    return lhs.view === rhs.view
-}
-
 public class TZStackView: UIView {
 
     public var distribution: TZStackViewDistribution = .Fill {
@@ -51,8 +42,6 @@ public class TZStackView: UIView {
 
     private var spacerViews = [UIView]()
 
-    private var animationDidStopQueueEntries = [TZAnimationDidStopQueueEntry]()
-
     private var registeredKvoSubviews = [UIView]()
 
     private var animatingToHiddenViews = [UIView]()
@@ -112,37 +101,30 @@ public class TZStackView: UIView {
 
             removeHiddenListener(view)
             view.hidden = false
-
-            if let _ = view.layer.animationKeys() {
-                UIView.setAnimationDelegate(self)
-                animationDidStopQueueEntries.insert(TZAnimationDidStopQueueEntry(view: view, hidden: hidden), atIndex: 0)
-                UIView.setAnimationDidStopSelector("hiddenAnimationStopped")
-            } else {
-                didFinishSettingHiddenValue(view, hidden: hidden)
-            }
-        }
-    }
-
-    private func didFinishSettingHiddenValue(arrangedSubview: UIView, hidden: Bool) {
-        arrangedSubview.hidden = hidden
-        if let index = animatingToHiddenViews.indexOf(arrangedSubview) {
-            animatingToHiddenViews.removeAtIndex(index)
-        }
-        addHiddenListener(arrangedSubview)
-    }
-
-    func hiddenAnimationStopped() {
-        var queueEntriesToRemove = [TZAnimationDidStopQueueEntry]()
-        for entry in animationDidStopQueueEntries {
-            let view = entry.view
-            if view.layer.animationKeys() == nil {
-                didFinishSettingHiddenValue(view, hidden: entry.hidden)
-                queueEntriesToRemove.append(entry)
+
+            let hidingAnimation = view.layer.animationForKey("bounds.size")
+
+            let animationFinishFunc = { [weak self, weak view] () in
+                view?.layer.hidden = hidden
+                if let selv = self, strongView = view {
+                    if let index = selv.animatingToHiddenViews.indexOf(strongView) {
+                        selv.animatingToHiddenViews.removeAtIndex(index)
+                    }
+                    selv.addHiddenListener(strongView)
+                }
             }
-        }
-        for entry in queueEntriesToRemove {
-            if let index = animationDidStopQueueEntries.indexOf(entry) {
-                animationDidStopQueueEntries.removeAtIndex(index)
+
+            if let hidingAnimation = hidingAnimation {
+                let group = CAAnimationGroup()
+                group.animations = []
+                group.delegate = TZFuncAnimationDelegate { _ in
+                    animationFinishFunc()
+                }
+                group.tz_copyTiming(hidingAnimation)
+
+                view.layer.addAnimation(group, forKey: "TZSV-hidden-callback")
+            } else {
+                animationFinishFunc()
             }
         }
     }