Code review. Also, centralize calculation of final contentInset amoun…

…ts, to ensure provided insets play nicely with the keyboard.
square · Feb 26, 2020 · d42c5c1 · d42c5c1
1 parent e7caea5
commit d42c5c1
Show file tree

Hide file tree

Showing 3 changed files with 185 additions and 91 deletions.
diff --git a/BlueprintUICommonControls/Sources/Internal/KeyboardObserver.swift b/BlueprintUICommonControls/Sources/Internal/KeyboardObserver.swift
@@ -8,9 +8,13 @@
 import UIKit
 
 
-protocol KeyboardObserverDelegate : AnyObject
-{
-    func keyboardFrameWillChange(observer : KeyboardObserver)
+protocol KeyboardObserverDelegate : AnyObject {
+
+    func keyboardFrameWillChange(
+        for observer : KeyboardObserver,
+        animationDuration : Double,
+        options : UIView.AnimationOptions
+    )
 }
 
 /**
@@ -20,8 +24,8 @@ protocol KeyboardObserverDelegate : AnyObject
  iOS Docs for keyboard management:
  https://developer.apple.com/library/archive/documentation/StringsTextFonts/Conceptual/TextAndWebiPhoneOS/KeyboardManagement/KeyboardManagement.html
  */
-final class KeyboardObserver
-{
+final class KeyboardObserver {
+    
     private let center : NotificationCenter
 
     weak var delegate : KeyboardObserverDelegate?
@@ -30,8 +34,8 @@ final class KeyboardObserver
     // MARK: Initialization
     //
 
-    init(center : NotificationCenter = .default)
-    {
+    init(center : NotificationCenter = .default) {
+        
         self.center = center
 
         self.center.addObserver(self, selector: #selector(keyboardFrameChanged(_:)), name: UIWindow.keyboardWillChangeFrameNotification, object: nil)
@@ -44,14 +48,14 @@ final class KeyboardObserver
     // MARK: Handling Changes
     //
 
-    enum KeyboardFrame : Equatable
-    {
+    enum KeyboardFrame : Equatable {
+        
         case notVisible
         case visible(frame: CGRect)
     }
 
-    func currentFrame(in view : UIView) -> KeyboardFrame?
-    {
+    func currentFrame(in view : UIView) -> KeyboardFrame? {
+        
         guard view.window != nil else {
             return nil
         }
@@ -69,55 +73,45 @@ final class KeyboardObserver
         }
     }
 
-    private func animate(with info : NotificationInfo, _ animations : @escaping () -> ())
-    {
-        if info.animationDuration > 0.0 {
-            /**
-             Create an animation curve with the correct curve for showing or hiding the keyboard.
-             
-             This is unfortunately a private UIView curve. However, we can map it to the animation options' curve
-             like so: https://stackoverflow.com/questions/26939105/keyboard-animation-curve-as-int
-             */
-            let animationOptions = UIView.AnimationOptions(rawValue: info.animationCurve << 16)
-
-            UIView.animate(
-                withDuration: info.animationDuration,
-                delay: 0.0,
-                options: animationOptions,
-                animations: animations
-            )
-        } else {
-            animations()
-        }
-    }
-
     //
     // MARK: Receiving Updates
     //
 
-    private func receivedUpdatedKeyboardInfo(_ new : NotificationInfo)
-    {
+    private func receivedUpdatedKeyboardInfo(_ new : NotificationInfo) {
+        
         let old = self.latestNotification
 
         self.latestNotification = new
 
+        /// Only communicate a frame change to the delegate if the frame actually changed.
+
         if let old = old {
             guard old.endingFrame != new.endingFrame else {
                 return
             }
         }
 
-        self.animate(with: new) {
-            self.delegate?.keyboardFrameWillChange(observer: self)
-        }
+        /**
+         Create an animation curve with the correct curve for showing or hiding the keyboard.
+         
+         This is unfortunately a private UIView curve. However, we can map it to the animation options' curve
+         like so: https://stackoverflow.com/questions/26939105/keyboard-animation-curve-as-int
+         */
+        let animationOptions = UIView.AnimationOptions(rawValue: new.animationCurve << 16)
+
+        self.delegate?.keyboardFrameWillChange(
+            for: self,
+            animationDuration: new.animationDuration,
+            options: animationOptions
+        )
     }
 
     //
     // MARK: Notification Listeners
     //
 
-    @objc func keyboardFrameChanged(_ notification : Notification)
-    {
+    @objc func keyboardFrameChanged(_ notification : Notification) {
+        
         do {
             let info = try NotificationInfo(with: notification)
             self.receivedUpdatedKeyboardInfo(info)
@@ -129,15 +123,15 @@ final class KeyboardObserver
 
 extension KeyboardObserver
 {
-    struct NotificationInfo : Equatable
-    {
+    struct NotificationInfo : Equatable {
+        
         var endingFrame : CGRect = .zero
 
         var animationDuration : Double = 0.0
         var animationCurve : UInt = 0
 
-        init(with notification : Notification) throws
-        {
+        init(with notification : Notification) throws {
+            
             guard let userInfo = notification.userInfo else {
                 throw ParseError.missingUserInfo
             }
@@ -161,8 +155,8 @@ extension KeyboardObserver
             self.animationCurve = animationCurve
         }
 
-        enum ParseError : Error, Equatable
-        {
+        enum ParseError : Error, Equatable {
+            
             case missingUserInfo
             case missingEndingFrame
             case missingAnimationDuration