Adds back/forward buttons to page menu

App/Document Controls UI/NavigationControlsView.swift

@@ -0,0 +1,37 @@
+//
+//  NavigationControlsView.swift
+//  App
+//
+//  Created by James Magahern on 2/11/21.
+//
+
+import UIKit
+
+class NavigationControlsView: DocumentControlView
+{
+    let backButton = UIButton(frame: .zero)
+    let forwardButton = UIButton(frame: .zero)
+    
+    let stack = StackView(dimension: .horizontal, layoutType: .equalSize)
+    
+    override init() {
+        super.init()
+        
+        backButton.setImage(UIImage(systemName: "chevron.left"), for: .normal)
+        stack.addArrangedSubview(backButton)
+        
+        forwardButton.setImage(UIImage(systemName: "chevron.right"), for: .normal)
+        stack.addArrangedSubview(forwardButton)
+        
+        addSubview(stack)
+    }
+    
+    required init?(coder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+    
+    override func layoutSubviews() {
+        super.layoutSubviews()
+        stack.frame = bounds
+    }
+}