Cleaned Up KeyboardLayoutConstraint

Spring/KeyboardLayoutConstraint.swift

@@ -23,88 +23,67 @@
 import UIKit
 
 #if !os(tvOS)
-@available(tvOS, unavailable)
 public class KeyboardLayoutConstraint: NSLayoutConstraint {
+    private var offset: CGFloat = 0
 
-    private var offset : CGFloat = 0
-    private var keyboardVisibleHeight : CGFloat = 0
+    private var visibleKeyboardHeight: CGFloat = 0 {
+        didSet {
+            constant = offset + visibleKeyboardHeight
+        }
+    }
 
-    @available(tvOS, unavailable)
     override public func awakeFromNib() {
         super.awakeFromNib()
 
         offset = constant
 
-        NotificationCenter.default.addObserver(self, selector: #selector(KeyboardLayoutConstraint.keyboardWillShowNotification(_:)), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
-        NotificationCenter.default.addObserver(self, selector: #selector(KeyboardLayoutConstraint.keyboardWillHideNotification(_:)), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
+        NotificationCenter.default.addObserver(
+            self,
+            selector: #selector(keyboardWillShowNotification),
+            name: .UIKeyboardWillShow,
+            object: nil
+        )
+        NotificationCenter.default.addObserver(
+            self,
+            selector: #selector(keyboardWillHideNotification),
+            name: .UIKeyboardWillHide,
+            object: nil
+        )
     }
 
     deinit {
         NotificationCenter.default.removeObserver(self)
     }
 
-    // MARK: Notification
-
     @objc func keyboardWillShowNotification(_ notification: Notification) {
-        if let userInfo = notification.userInfo {
-            if let frameValue = userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue {
-                let frame = frameValue.cgRectValue
-                keyboardVisibleHeight = frame.size.height
-            }
-
-            self.updateConstant()
-            switch (userInfo[UIKeyboardAnimationDurationUserInfoKey] as? NSNumber, userInfo[UIKeyboardAnimationCurveUserInfoKey] as? NSNumber) {
-            case let (.some(duration), .some(curve)):
-
-                let options = UIViewAnimationOptions(rawValue: curve.uintValue)
-
-                UIView.animate(
-                    withDuration: TimeInterval(duration.doubleValue),
-                    delay: 0,
-                    options: options,
-                    animations: {
-                        UIApplication.shared.keyWindow?.layoutIfNeeded()
-                        return
-                    }, completion: { finished in
-                })
-            default:
-
-                break
-            }
-
-        }
+        guard let userInfo = notification.userInfo else { return }
+
+        guard let frame = userInfo[UIKeyboardFrameEndUserInfoKey] as? CGRect else { return }
+        visibleKeyboardHeight = frame.size.height
 
+        animateChanges(accordingTo: userInfo)
     }
 
     @objc func keyboardWillHideNotification(_ notification: NSNotification) {
-        keyboardVisibleHeight = 0
-        self.updateConstant()
+        guard let userInfo = notification.userInfo else { return }
 
-        if let userInfo = notification.userInfo {
-
-            switch (userInfo[UIKeyboardAnimationDurationUserInfoKey] as? NSNumber, userInfo[UIKeyboardAnimationCurveUserInfoKey] as? NSNumber) {
-            case let (.some(duration), .some(curve)):
-
-                let options = UIViewAnimationOptions(rawValue: curve.uintValue)
-
-                UIView.animate(
-                    withDuration: TimeInterval(duration.doubleValue),
-                    delay: 0,
-                    options: options,
-                    animations: {
-                        UIApplication.shared.keyWindow?.layoutIfNeeded()
-                        return
-                    }, completion: { finished in
-                })
-            default:
-                break
-            }
-        }
+        visibleKeyboardHeight = 0
+
+        animateChanges(accordingTo: userInfo)
     }
 
-    func updateConstant() {
-        self.constant = offset + keyboardVisibleHeight
+    private func animateChanges(accordingTo userInfo: [AnyHashable: Any]) {
+        guard
+            let duration = userInfo[UIKeyboardAnimationDurationUserInfoKey] as? TimeInterval,
+            let options = userInfo[UIKeyboardAnimationCurveUserInfoKey] as? UInt
+            else { return }
+
+        UIView.animate(
+            withDuration: duration,
+            delay: 0,
+            options: UIViewAnimationOptions(rawValue: options),
+            animations: UIApplication.shared.keyWindow!.layoutIfNeeded
+        )
     }
-
 }
 #endif