Demo: Add support for reloading contents

Author: Vadim Shpakovski

Demo/Demo/EmptyViewController.swift

@@ -42,7 +42,8 @@ extension EmptyViewController {
     stackView.orientation = .vertical
     stackView.distribution = .fill
     stackView.addView(scrollableEditor, in: .center)
-    stackView.addView(NSButton(title: "Replace Sidebar Contents", target: self, action: #selector(replaceSidebarContents(_:))), in: .center)
+    stackView.addView(NSButton(title: "Fill Sidebar", target: self, action: #selector(fillSidebar(_:))), in: .center)
+    stackView.addView(NSButton(title: "Reload Sidebar", target: nil, action: #selector(MasterViewController.reloadSidebar(_:))), in: .center)
     stackView.addView(NSButton(title: "Expand All Items", target: nil, action: #selector(MasterViewController.expandAllItems(_:))), in: .center)
     stackView.addView(NSButton(title: "Collapse All Items", target: nil, action: #selector(MasterViewController.collapseAllItems(_:))), in: .center)
     stackView.setHuggingPriority(.fittingSizeCompression, for: .horizontal)
@@ -71,7 +72,7 @@ extension EmptyViewController {
 private extension EmptyViewController {
 
   /// Replaces the whole tree with the given contents.
-  @IBAction func replaceSidebarContents(_ sender: Any?) {
+  @IBAction func fillSidebar(_ sender: Any?) {
     guard let textView = scrollableEditor.documentView as? NSTextView else { return }
     var snapshot: DiffableDataSourceSnapshot<MasterItem> = .init()
     let lines = textView.string.components(separatedBy: .newlines)

Demo/Demo/MasterViewController.swift

@@ -98,14 +98,25 @@ extension MasterViewController {
 
 extension MasterViewController {
 
+  /// Reloads data from the data source to check consistency.
+  @IBAction func reloadSidebar(_ sender: Any?) {
+    scrollableOutlineView.outlineView.reloadData()
+  }
+
   /// Expands all outline view items.
   @IBAction func expandAllItems(_ sender: Any?) {
-    scrollableOutlineView.outlineView.expandItem(nil, expandChildren: true)
+    NSAnimationContext.runAnimationGroup { context in
+      if shouldAnimate == false { context.duration = 0 }
+      scrollableOutlineView.outlineView.animator().expandItem(nil, expandChildren: true)
+    }
   }
 
   /// Collapses all outline view items.
   @IBAction func collapseAllItems(_ sender: Any?) {
-    scrollableOutlineView.outlineView.collapseItem(nil, collapseChildren: true)
+    NSAnimationContext.runAnimationGroup { context in
+      if shouldAnimate == false { context.duration = 0 }
+      scrollableOutlineView.outlineView.animator().collapseItem(nil, collapseChildren: true)
+    }
   }
 }