Hide the album play button when scrolling starts

Persephone/Controllers/AlbumViewController.swift

@@ -19,6 +19,8 @@ class AlbumViewController: NSViewController,
   override func viewDidLoad() {
     super.viewDidLoad()
 
+    albumScrollView.postsBoundsChangedNotifications = true
+
     NotificationCenter.default.addObserver(
       self,
       selector: #selector(updateAlbums(_:)),
@@ -73,5 +75,6 @@ class AlbumViewController: NSViewController,
     return NSSize(width: itemWidth, height: itemHeight)
   }
 
+  @IBOutlet var albumScrollView: NSScrollView!
   @IBOutlet var albumCollectionView: NSCollectionView!
 }

Persephone/Views/AlbumItemView.swift

@@ -31,15 +31,38 @@ class AlbumItemView: NSView {
     addTrackingArea(trackingArea)
   }
 
+  required init?(coder decoder: NSCoder) {
+    super.init(coder: decoder)
+
+    NotificationCenter.default.addObserver(
+      self,
+      selector: #selector(viewWillScroll(_:)),
+      name: NSScrollView.willStartLiveScrollNotification,
+      object: nil
+    )
+  }
+
+  @objc func viewWillScroll(_ notification: Notification) {
+    hidePlayButton()
+  }
+
   override func resize(withOldSuperviewSize oldSize: NSSize) {
-    playButton.isHidden = true
+    hidePlayButton()
   }
 
   override func mouseEntered(with event: NSEvent) {
-    playButton.isHidden = false
+    showPlayButton()
   }
 
   override func mouseExited(with event: NSEvent) {
+    hidePlayButton()
+  }
+
+  func showPlayButton() {
+    playButton.isHidden = false
+  }
+
+  func hidePlayButton() {
     playButton.isHidden = true
   }