Keep the configure sheet alive between reads

Sources/ConfigureSheetController.swift

@@ -18,7 +18,7 @@ final class ConfigureSheetController: NSObject {
 
     let window: NSWindow
 
-    private var settings = MacstifySettings.load()
+    private var settings = MacstifySettings.standard
     private let onDismiss: (_ saved: Bool) -> Void
     private var rows: [Row] = []
 
@@ -32,7 +32,18 @@ final class ConfigureSheetController: NSObject {
         )
         super.init()
         window.title = "Macstify"
+        // ARC owns this window through `window`; leaving the default on would
+        // let a host that closes the sheet release it a second time.
+        window.isReleasedWhenClosed = false
         buildInterface()
+        reload()
+    }
+
+    /// Re-reads the saved settings into the controls. The same sheet is handed
+    /// to the host every time it asks, so this is what makes the second opening
+    /// show what is stored rather than where the first one was left.
+    func reload() {
+        settings = .load()
         refresh()
     }
 

Sources/MacstifyView.swift

@@ -8,8 +8,9 @@ import ScreenSaver
 @objc(MacstifyView)
 final class MacstifyView: ScreenSaverView {
     private let engine: MacstifyEngine
-    /// Held strongly: the host releases its reference once the sheet is up,
-    /// and a deallocated controller takes the sheet's targets with it.
+    /// Built once and kept: the host releases its reference once the sheet is
+    /// up, and a deallocated controller takes the sheet's window and targets
+    /// with it.
     private var sheetController: ConfigureSheetController?
 
     override init?(frame: NSRect, isPreview: Bool) {
@@ -54,18 +55,25 @@ final class MacstifyView: ScreenSaverView {
         true
     }
 
+    /// Hosts read this more than once, and can replace the view between reading
+    /// it and presenting it. Building a controller per read would hand back a
+    /// window whose only owner was dropped by the very next read — and the sheet
+    /// then simply never appears. One controller, kept, re-reading the settings
+    /// each time it is handed over.
     override var configureSheet: NSWindow? {
-        let controller = ConfigureSheetController { [weak self] saved in
-            guard let self else { return }
-            if saved {
-                engine.apply(Self.settings(isPreview: isPreview))
-            }
-            sheetController = nil
-        }
+        let controller = sheetController ?? makeSheetController()
         sheetController = controller
+        controller.reload()
         return controller.window
     }
 
+    private func makeSheetController() -> ConfigureSheetController {
+        ConfigureSheetController { [weak self] saved in
+            guard let self, saved else { return }
+            engine.apply(Self.settings(isPreview: isPreview))
+        }
+    }
+
     private static func settings(isPreview: Bool) -> MacstifySettings {
         let settings = MacstifySettings.load()
         return isPreview ? settings.previewAdjusted : settings