Put the configure sheet back, and document why Options dies

README.md

@@ -64,6 +64,30 @@ killall legacyScreenSaver
 
 then reopen System Settings.
 
+### Known issue: the Options button does nothing
+
+On macOS 26 the Options button stops responding, reliably if you switch the screen
+saver away and back. Nothing appears, and nothing is logged.
+
+This is a bug in the host, not in the saver. System Settings spawns duplicate
+`legacyScreenSaver` instances and loses track of them, so the configure sheet is
+handed over, attached and ordered in — against a remote view window that is no
+longer on screen. Traced from inside the bundle, the sheet reports
+`isVisible == true` with a live `sheetParent`, while `occlusionState` never gains
+`.visible`: attached to a ghost, and never drawn.
+
+Apple has it as FB19201567, along with FB19204084 for the `ScreenSaverView`
+instances that pile up alongside; neither is fixed as of 26.1b3. See
+[macOS 26 Tahoe Screen Saver issues](https://developer.apple.com/forums/thread/787444).
+
+Until it is fixed, restart the host:
+
+```sh
+killall legacyScreenSaver
+```
+
+then quit System Settings and open it again.
+
 ## Development
 
 `make preview` builds and runs `NecoSaverPreview`, a small host app that puts the

Sources/ConfigureSheetController.swift

@@ -21,7 +21,7 @@ final class ConfigureSheetController: NSObject {
 
     let window: NSWindow
 
-    private var settings = NecoSaverSettings.standard
+    private var settings = NecoSaverSettings.load()
     private let onDismiss: (_ saved: Bool) -> Void
     private var rows: [Row] = []
     private let pictureCheckbox = NSButton(checkboxWithTitle: "Picture:", target: nil, action: nil)
@@ -39,28 +39,13 @@ final class ConfigureSheetController: NSObject {
         super.init()
         window.title = "NecoSaver"
         // ARC owns this window through `window`; leaving the default on would let a
-        // host that closes the sheet release it a second time.
+        // host that closes the sheet rather than ordering it out release it a
+        // second time.
         window.isReleasedWhenClosed = false
         buildInterface()
-        reload()
-    }
-
-    /// Re-reads the stored 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 = Self.stored()
         refresh()
     }
 
-    /// The saved settings, with the picture seeded the same way the saver seeds it,
-    /// so the field shows the path the cats are actually walking on.
-    private static func stored() -> NecoSaverSettings {
-        var settings = NecoSaverSettings.load()
-        settings.seedPicturePath(with: Wallpaper.desktopPicturePath(for: nil) ?? "")
-        return settings
-    }
-
     // MARK: - Interface
 
     private func buildInterface() {

Sources/NecoSaverView.swift

@@ -8,8 +8,8 @@ import ScreenSaver
 @objc(NecoSaverView)
 final class NecoSaverView: ScreenSaverView {
     private let engine: NecoSaverEngine
-    /// 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.
+    /// Held strongly: the host releases its reference once the sheet is up, and a
+    /// deallocated controller takes the sheet's targets with it.
     private var sheetController: ConfigureSheetController?
 
     override init?(frame: NSRect, isPreview: Bool) {
@@ -62,26 +62,19 @@ final class NecoSaverView: 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 = sheetController ?? makeSheetController()
+        let controller = ConfigureSheetController { [weak self] saved in
+            guard let self else { return }
+            if saved {
+                engine.apply(settings())
+                loadWallpaper()
+            }
+            sheetController = nil
+        }
         sheetController = controller
-        controller.reload()
         return controller.window
     }
 
-    private func makeSheetController() -> ConfigureSheetController {
-        ConfigureSheetController { [weak self] saved in
-            guard let self, saved else { return }
-            engine.apply(settings())
-            loadWallpaper()
-        }
-    }
-
     /// Reads a picture only when one is going to be drawn — decoding one costs
     /// several megabytes that a grey backdrop has no use for.
     private func loadWallpaper() {