always show keyboard again when pressing keyboard button

Mini vMac/AppDelegate.h

@@ -32,6 +32,7 @@ extern NSString *DocumentsChangedNotification;
 - (IBAction)showInsertDisk:(id)sender;
 - (IBAction)showSettings:(id)sender;
 - (IBAction)showGestureHelp:(id)sender;
+- (UIScene*)sceneWithName:(NSString*)name;
 
 @end
 

Mini vMac/AppDelegate.m

@@ -333,13 +333,12 @@ NSString *DocumentsChangedNotification = @"documentsChanged";
             return [UISceneConfiguration configurationWithName:@"Keyboard" sessionRole:UIWindowSceneSessionRoleApplication];
         }
     }
-    if (![self hasDefaultScene]) {
+    if ([self sceneWithName:@"Default"] == nil) {
         return [UISceneConfiguration configurationWithName:@"Default" sessionRole:UIWindowSceneSessionRoleApplication];
     }
     return nil;
 }
 
-
 - (void)application:(UIApplication *)application didDiscardSceneSessions:(NSSet<UISceneSession *> *)sceneSessions {
     // if only keyboard is left, show default view again
     if (![self hasDefaultScene]) {
@@ -348,13 +347,13 @@ NSString *DocumentsChangedNotification = @"documentsChanged";
     }
 }
 
-- (BOOL)hasDefaultScene {
+- (UIScene*)sceneWithName:(NSString*)name {
     for (UIScene *scene in [UIApplication sharedApplication].connectedScenes) {
-        if ([scene.session.configuration.name isEqualToString:@"Default"]) {
-            return YES;
+        if ([scene.session.configuration.name isEqualToString:name]) {
+            return scene;
         }
     }
-    return NO;
+    return nil;
 }
 
 @end

Mini vMac/KeyboardSceneDelegate.swift

@@ -20,6 +20,7 @@ class KeyboardSceneDelegate: UIResponder, UIWindowSceneDelegate {
             fatalError("No main view controller")
         }
 
+        scene.activationConditions.canActivateForTargetContentIdentifierPredicate = NSPredicate(format: "self == 'net.namedfork.keyboard'", argumentArray: nil)
         let defaultSize = mainViewController.keyboardViewController.preferredContentSize
         let minSize = defaultSize.applying(.init(scaleX: 0.75, y: 0.75))
         let maxSize = defaultSize.applying(.init(scaleX: 1.25, y: 1.25))
@@ -33,6 +34,14 @@ class KeyboardSceneDelegate: UIResponder, UIWindowSceneDelegate {
         ))
         window = UIWindow(windowScene: windowScene)
 
+        // destroy existing keyboard window
+        if let oldWindow = mainViewController.keyboardViewController?.view?.window {
+            oldWindow.rootViewController = nil
+            if let oldScene = oldWindow.windowScene?.session.scene {
+                UIApplication.shared.requestSceneSessionDestruction(oldScene.session, options: nil)
+            }
+        }
+
         if let window {
             window.rootViewController = mainViewController.keyboardViewController
             window.makeKeyAndVisible()

Mini vMac/ViewController.m

@@ -320,17 +320,24 @@ static int8_t usb_to_adb_scancode[] = {
 }
 
 - (void)setKeyboardVisible:(BOOL)visible animated:(BOOL)animated {
-    if (self.keyboardVisible == visible) {
-        return;
-    }
-    
 #if defined(TARGET_OS_VISION) && TARGET_OS_VISION == 1
     if (visible) {
         UISceneSessionActivationRequest *request = [UISceneSessionActivationRequest requestWithRole:UIWindowSceneSessionRoleApplication];
         request.userActivity = [[NSUserActivity alloc] initWithActivityType:@"net.namedfork.keyboard"];
-        [[UIApplication sharedApplication] activateSceneSessionForRequest:request errorHandler:nil];
-    } // only show, no hide
+        request.userActivity.targetContentIdentifier = @"net.namedfork.keyboard";
+        [[UIApplication sharedApplication] activateSceneSessionForRequest:request errorHandler:^(NSError * _Nonnull error) {
+            NSLog(@"Activation error: %@", error);
+        }];
+    } else {
+        UIScene *keyboardScene = [[AppDelegate sharedInstance] sceneWithName:@"Keyboard"];
+        if (keyboardScene != nil) {
+            [[UIApplication sharedApplication] requestSceneSessionDestruction:keyboardScene.session options:nil errorHandler:nil];
+        }
+    }
 #else
+    if (self.keyboardVisible == visible) {
+        return;
+    }
     if (visible) {
         [[NSUserDefaults standardUserDefaults] addObserver:self forKeyPath:@"keyboardLayout" options:0 context:NULL];
         [self loadKeyboardView];