add SafeAreaInputAccessoryViewWrapperView class

Author: jeffaburt

Example/Pods/Pods.xcodeproj/project.pbxproj

@@ -0,0 +1,78 @@
+//
+//  SafeAreaInputAccessoryViewWrapperView.swift
+//  StockX
+//
+//  Created by Jeff Burt on 10/5/17.
+//  Copyright © 2017 StockX. All rights reserved.
+//
+
+import UIKit
+
+/**
+ SafeAreaInputAccessoryViewWrapperView is useful for wrapping a view to be used
+ as an inputAccessoryView. Without this, setting the view as an
+ inputAccessoryView will ignore safe area layouts. For example, the Home screen
+ indicator on iPhone X will battle for the same spot. This class ensures that
+ the view respects safe area layouts and does not cover up system UI elements
+ such as the Home screen indicator on iPhone X.
+ */
+public class SafeAreaInputAccessoryViewWrapperView: UIView {
+    private var addedConstraints = [NSLayoutConstraint]() {
+        didSet {
+            NSLayoutConstraint.deactivate(oldValue)
+            NSLayoutConstraint.activate(addedConstraints)
+        }
+    }
+    
+    deinit {
+        addedConstraints = []
+    }
+    
+    public init(for view: UIView) {
+        super.init(frame: .zero)
+        
+        addSubview(view)
+        
+        // Allow 'self' to be sized based on autolayout constraints. Without
+        // this, the frame would have to be set manually.
+        autoresizingMask = .flexibleHeight
+        
+        view.translatesAutoresizingMaskIntoConstraints = false
+        
+        defer {
+            let leadingAnchor: NSLayoutXAxisAnchor
+            let trailingAnchor: NSLayoutXAxisAnchor
+            let topAnchor: NSLayoutYAxisAnchor
+            let bottomAnchor: NSLayoutYAxisAnchor
+            
+            if #available(iOS 11, *) {
+                leadingAnchor = safeAreaLayoutGuide.leadingAnchor
+                trailingAnchor = safeAreaLayoutGuide.trailingAnchor
+                topAnchor = safeAreaLayoutGuide.topAnchor
+                bottomAnchor = safeAreaLayoutGuide.bottomAnchor
+            }
+            else {
+                leadingAnchor = self.leadingAnchor
+                trailingAnchor = self.trailingAnchor
+                topAnchor = self.topAnchor
+                bottomAnchor = self.bottomAnchor
+            }
+            
+            addedConstraints =
+                [view.leadingAnchor.constraint(equalTo: leadingAnchor),
+                 view.trailingAnchor.constraint(equalTo: trailingAnchor),
+                 view.topAnchor.constraint(equalTo: topAnchor),
+                 view.bottomAnchor.constraint(equalTo: bottomAnchor)]
+        }
+    }
+    
+    public required init?(coder aDecoder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+    
+    public override var intrinsicContentSize: CGSize {
+        // Allow 'self' to be sized based on autolayout constraints. Without
+        // this, the frame would have to be set manually.
+        return .zero
+    }
+}