Put document controls view in a scroll view

App/Document Controls UI/DocumentControlsView.swift

@@ -0,0 +1,29 @@
+//
+//  DocumentControlsView.swift
+//  App
+//
+//  Created by James Magahern on 4/28/21.
+//
+
+import UIKit
+
+class DocumentControlsView : UIScrollView
+{
+    public let stackView = StackView<DocumentControlItemView>(dimension: .vertical)
+    
+    convenience init() {
+        self.init(frame: .zero)
+        addSubview(stackView)
+    }
+    
+    override func layoutSubviews() {
+        super.layoutSubviews()
+        
+        let stackViewSize = stackView.sizeThatFits(CGSize(width: bounds.width, height: -1))
+        stackView.frame = CGRect(
+            origin: .zero, size: stackViewSize
+        )
+        
+        contentSize = stackViewSize
+    }
+}