kristopherjohnson · October 6, 2023 14:45 · Apr 25, 2015 · Apr 25, 2015 · Dec 31, 2014 · Dec 31, 2014
diff --git a/KeyboardNotification.swift b/KeyboardNotification.swift
@@ -2,7 +2,7 @@ import UIKit
 
 /// Wrapper for the NSNotification userInfo values associated with a keyboard notification.
 ///
-/// It provides properties retrieve userInfo dictionary values with these keys:
+/// It provides properties that retrieve userInfo dictionary values with these keys:
 /// 
 /// - UIKeyboardFrameBeginUserInfoKey
 /// - UIKeyboardFrameEndUserInfoKey

diff --git a/KeyboardNotification.swift b/KeyboardNotification.swift
@@ -77,7 +77,7 @@ public struct KeyboardNotification {
         return view.convertRect(screenFrameBegin, fromView: view.window)
     }
 
-    /// Start frame of the keyboard in coordinates of specified view
+    /// End frame of the keyboard in coordinates of specified view
     ///
     /// :param: view UIView to whose coordinate system the frame will be converted
     /// :returns: frame rectangle in view's coordinate system

diff --git a/ViewController.swift b/ViewController.swift
@@ -38,7 +38,7 @@ final class ViewController: UIViewController {
         UIView.animateWithDuration(animationDuration,
             delay: 0,
             options: UIViewAnimationOptions(rawValue: UInt(animationCurve << 16)),
-            animations: { () -> Void in
+            animations: {
                 self.bottomLayoutConstraint.constant = newBottomOffset
                 self.view.layoutIfNeeded()
             },

diff --git a/ViewController.swift b/ViewController.swift
@@ -34,11 +34,13 @@ final class ViewController: UIViewController {
         let viewFrame = self.view.frame
         let newBottomOffset = viewFrame.maxY - keyboardFrame.minY
 
+        self.view.layoutIfNeeded()
         UIView.animateWithDuration(animationDuration,
             delay: 0,
             options: UIViewAnimationOptions(rawValue: UInt(animationCurve << 16)),
             animations: { () -> Void in
                 self.bottomLayoutConstraint.constant = newBottomOffset
+                self.view.layoutIfNeeded()
             },
             completion: nil
         )

diff --git a/ViewController.swift b/ViewController.swift
@@ -9,7 +9,7 @@ final class ViewController: UIViewController {
     // 
     // This constraint will be updated when the keyboard appears, disappears,
     // or changes size.
-    @IBOutlet weak var inputTextFieldBottomLayoutConstraint: NSLayoutConstraint!
+    @IBOutlet weak var bottomLayoutConstraint: NSLayoutConstraint!
 
     override func viewWillAppear(animated: Bool) {
         super.viewWillAppear(animated)
@@ -38,7 +38,7 @@ final class ViewController: UIViewController {
             delay: 0,
             options: UIViewAnimationOptions(rawValue: UInt(animationCurve << 16)),
             animations: { () -> Void in
-                self.inputTextFieldBottomLayoutConstraint.constant = newBottomOffset
+                self.bottomLayoutConstraint.constant = newBottomOffset
             },
             completion: nil
         )

diff --git a/ViewController.swift b/ViewController.swift
@@ -40,7 +40,8 @@ final class ViewController: UIViewController {
             animations: { () -> Void in
                 self.inputTextFieldBottomLayoutConstraint.constant = newBottomOffset
             },
-            completion: nil)
+            completion: nil
+        )
     }
 }
 
diff --git a/ViewController.swift b/ViewController.swift
@@ -0,0 +1,46 @@
+// Example of using KeyboardNotification to update an NSLayoutConstraint
+
+import UIKit
+
+final class ViewController: UIViewController {
+
+    // Outlet for a layout constraint that specifies distance from bottom of
+    // a subview to the bottom of the view.
+    // 
+    // This constraint will be updated when the keyboard appears, disappears,
+    // or changes size.
+    @IBOutlet weak var inputTextFieldBottomLayoutConstraint: NSLayoutConstraint!
+
+    override func viewWillAppear(animated: Bool) {
+        super.viewWillAppear(animated)
+
+        NSNotificationCenter.defaultCenter().addObserver(self,
+            selector: "keyboardWillChangeFrameNotification:",
+            name: UIKeyboardWillChangeFrameNotification,
+            object: nil)
+    }
+
+    override func viewDidDisappear(animated: Bool) {
+        NSNotificationCenter.defaultCenter().removeObserver(self)
+        super.viewDidDisappear(animated)
+    }
+
+    func keyboardWillChangeFrameNotification(notification: NSNotification) {
+        let n = KeyboardNotification(notification)
+        let keyboardFrame = n.frameEndForView(self.view)
+        let animationDuration = n.animationDuration
+        let animationCurve = n.animationCurve
+
+        let viewFrame = self.view.frame
+        let newBottomOffset = viewFrame.maxY - keyboardFrame.minY
+
+        UIView.animateWithDuration(animationDuration,
+            delay: 0,
+            options: UIViewAnimationOptions(rawValue: UInt(animationCurve << 16)),
+            animations: { () -> Void in
+                self.inputTextFieldBottomLayoutConstraint.constant = newBottomOffset
+            },
+            completion: nil)
+    }
+}
+
diff --git a/KeyboardNotification.swift b/KeyboardNotification.swift
@@ -17,7 +17,7 @@ public struct KeyboardNotification {
     /// Initializer
     ///
     /// :param: notification Keyboard-related notification
-    public init(notification: NSNotification) {
+    public init(_ notification: NSNotification) {
         self.notification = notification
         if let userInfo = notification.userInfo {
             self.userInfo = userInfo

diff --git a/KeyboardNotification.swift b/KeyboardNotification.swift
@@ -66,7 +66,7 @@ public struct KeyboardNotification {
         if let number = userInfo[UIKeyboardAnimationCurveUserInfoKey] as? NSNumber {
             return number.integerValue
         }
-        return UIViewAnimationCurve.EaseInOut.toRaw()
+        return UIViewAnimationCurve.EaseInOut.rawValue
     }
 
     /// Start frame of the keyboard in coordinates of specified view

diff --git a/KeyboardNotification.swift b/KeyboardNotification.swift
@@ -1,3 +1,5 @@
+import UIKit
+
 /// Wrapper for the NSNotification userInfo values associated with a keyboard notification.
 ///
 /// It provides properties retrieve userInfo dictionary values with these keys:

diff --git a/KeyboardNotification.swift b/KeyboardNotification.swift
@@ -1,4 +1,12 @@
-/// Wrapper for the userInfo values associated with a UIKeyboard notification
+/// Wrapper for the NSNotification userInfo values associated with a keyboard notification.
+///
+/// It provides properties retrieve userInfo dictionary values with these keys:
+/// 
+/// - UIKeyboardFrameBeginUserInfoKey
+/// - UIKeyboardFrameEndUserInfoKey
+/// - UIKeyboardAnimationDurationUserInfoKey
+/// - UIKeyboardAnimationCurveUserInfoKey
+
 public struct KeyboardNotification {
 
     let notification: NSNotification

diff --git a/KeyboardNotification.swift b/KeyboardNotification.swift
@@ -50,7 +50,8 @@ public struct KeyboardNotification {
     /// Keyboard animation curve
     ///
     /// Note that the value returned by this method may not correspond to a
-    /// UIViewAnimationCurve enum value.
+    /// UIViewAnimationCurve enum value.  For example, in iOS 7 and iOS 8,
+    /// this returns the value 7.
     public var animationCurve: Int {
         if let number = userInfo[UIKeyboardAnimationCurveUserInfoKey] as? NSNumber {
             return number.integerValue

diff --git a/KeyboardNotification.swift b/KeyboardNotification.swift
@@ -0,0 +1,76 @@
+/// Wrapper for the userInfo values associated with a UIKeyboard notification
+public struct KeyboardNotification {
+
+    let notification: NSNotification
+    let userInfo: NSDictionary
+
+    /// Initializer
+    ///
+    /// :param: notification Keyboard-related notification
+    public init(notification: NSNotification) {
+        self.notification = notification
+        if let userInfo = notification.userInfo {
+            self.userInfo = userInfo
+        }
+        else {
+            self.userInfo = NSDictionary()
+        }
+    }
+
+    /// Start frame of the keyboard in screen coordinates
+    public var screenFrameBegin: CGRect {
+        if let value = userInfo[UIKeyboardFrameBeginUserInfoKey] as? NSValue {
+            return value.CGRectValue()
+        }
+        else {
+            return CGRectZero
+        }
+    }
+
+    /// End frame of the keyboard in screen coordinates
+    public var screenFrameEnd: CGRect {
+        if let value = userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue {
+            return value.CGRectValue()
+        }
+        else {
+            return CGRectZero
+        }
+    }
+
+    /// Keyboard animation duration
+    public var animationDuration: Double {
+        if let number = userInfo[UIKeyboardAnimationDurationUserInfoKey] as? NSNumber {
+            return number.doubleValue
+        }
+        else {
+            return 0.25
+        }
+    }
+
+    /// Keyboard animation curve
+    ///
+    /// Note that the value returned by this method may not correspond to a
+    /// UIViewAnimationCurve enum value.
+    public var animationCurve: Int {
+        if let number = userInfo[UIKeyboardAnimationCurveUserInfoKey] as? NSNumber {
+            return number.integerValue
+        }
+        return UIViewAnimationCurve.EaseInOut.toRaw()
+    }
+
+    /// Start frame of the keyboard in coordinates of specified view
+    ///
+    /// :param: view UIView to whose coordinate system the frame will be converted
+    /// :returns: frame rectangle in view's coordinate system
+    public func frameBeginForView(view: UIView) -> CGRect {
+        return view.convertRect(screenFrameBegin, fromView: view.window)
+    }
+
+    /// Start frame of the keyboard in coordinates of specified view
+    ///
+    /// :param: view UIView to whose coordinate system the frame will be converted
+    /// :returns: frame rectangle in view's coordinate system
+    public func frameEndForView(view: UIView) -> CGRect {
+        return view.convertRect(screenFrameEnd, fromView: view.window)
+    }
+}