Asks user to deactivate an app when installing app without available active slot

When attempting to install a new app without any active slots available, AltStore will now present an alert asking the user to choose an app to deactivate in order to continue installation — just like when activating an app without an active slot.

AltStore/Managing Apps/AppManager.swift

@@ -230,6 +230,73 @@ extension AppManager
         
         return authenticationOperation
     }
+    
+    func deactivateApps(for app: ALTApplication, presentingViewController: UIViewController, completion: @escaping (Result<Void, Error>) -> Void)
+    {
+        guard let activeAppsLimit = UserDefaults.standard.activeAppsLimit else { return completion(.success(())) }
+        
+        DispatchQueue.main.async {
+            let activeApps = InstalledApp.fetchActiveApps(in: DatabaseManager.shared.viewContext)
+                .filter { $0.bundleIdentifier != app.bundleIdentifier } // Don't count app towards total if it matches activating app
+                .sorted { ($0.name, $0.refreshedDate) < ($1.name, $1.refreshedDate) }
+            
+            var title: String = NSLocalizedString("Cannot Activate More than 3 Apps", comment: "")
+            let message: String
+            
+            if UserDefaults.standard.activeAppLimitIncludesExtensions
+            {
+                if app.appExtensions.isEmpty
+                {
+                    message = NSLocalizedString("Non-developer Apple IDs are limited to 3 active apps and app extensions. Please choose an app to deactivate.", comment: "")
+                }
+                else
+                {
+                    title = NSLocalizedString("Cannot Activate More than 3 Apps and App Extensions", comment: "")
+                    
+                    let appExtensionText = app.appExtensions.count == 1 ? NSLocalizedString("app extension", comment: "") : NSLocalizedString("app extensions", comment: "")
+                    message = String(format: NSLocalizedString("Non-developer Apple IDs are limited to 3 active apps and app extensions, and “%@” contains %@ %@. Please choose an app to deactivate.", comment: ""), app.name, NSNumber(value: app.appExtensions.count), appExtensionText)
+                }
+            }
+            else
+            {
+                message = NSLocalizedString("Non-developer Apple IDs are limited to 3 active apps. Please choose an app to deactivate.", comment: "")
+            }
+            
+            let activeAppsCount = activeApps.map { $0.requiredActiveSlots }.reduce(0, +)
+                    
+            let availableActiveApps = max(activeAppsLimit - activeAppsCount, 0)
+            let requiredActiveSlots = UserDefaults.standard.activeAppLimitIncludesExtensions ? (1 + app.appExtensions.count) : 1
+            guard requiredActiveSlots > availableActiveApps else { return completion(.success(())) }
+            
+            let alertController = UIAlertController(title: title, message: message, preferredStyle: .alert)
+            alertController.addAction(UIAlertAction(title: UIAlertAction.cancel.title, style: UIAlertAction.cancel.style) { (action) in
+                completion(.failure(OperationError.cancelled))
+            })
+            
+            for activeApp in activeApps where activeApp.bundleIdentifier != StoreApp.altstoreAppID
+            {
+                alertController.addAction(UIAlertAction(title: activeApp.name, style: .default) { (action) in
+                    activeApp.isActive = false
+                                    
+                    self.deactivate(activeApp, presentingViewController: presentingViewController) { (result) in
+                        switch result
+                        {
+                        case .failure(let error):
+                            activeApp.managedObjectContext?.perform {
+                                activeApp.isActive = true
+                                completion(.failure(error))
+                            }
+                            
+                        case .success:
+                            self.deactivateApps(for: app, presentingViewController: presentingViewController, completion: completion)
+                        }
+                    }
+                })
+            }
+            
+            presentingViewController.present(alertController, animated: true, completion: nil)
+        }
+    }
 }
 
 extension AppManager
@@ -770,7 +837,7 @@ private extension AppManager
         return group
     }
     
-    private func _install(_ app: AppProtocol, operation: AppOperation, group: RefreshGroup, context: InstallAppOperationContext? = nil, additionalEntitlements: [ALTEntitlement: Any]? = nil, cacheApp: Bool = true, completionHandler: @escaping (Result<InstalledApp, Error>) -> Void) -> Progress
+    private func _install(_ app: AppProtocol, operation appOperation: AppOperation, group: RefreshGroup, context: InstallAppOperationContext? = nil, additionalEntitlements: [ALTEntitlement: Any]? = nil, cacheApp: Bool = true, completionHandler: @escaping (Result<InstalledApp, Error>) -> Void) -> Progress
     {
         let progress = Progress.discreteProgress(totalUnitCount: 100)
         
@@ -778,7 +845,7 @@ private extension AppManager
         assert(context.authenticatedContext === group.context)
         
         context.beginInstallationHandler = { (installedApp) in
-            switch operation
+            switch appOperation
             {
             case .update where installedApp.bundleIdentifier == StoreApp.altstoreAppID:
                 // AltStore will quit before installation finishes,
@@ -843,6 +910,43 @@ private extension AppManager
         verifyOperation.addDependency(downloadOperation)
         
         
+        /* Deactivate Apps (if necessary) */
+        let deactivateAppsOperation = RSTAsyncBlockOperation { [weak self] (operation) in
+            do
+            {
+                // Only attempt to deactivate apps if we're installing a new app.
+                // We handle deactivating apps separately when activating an app.
+                guard case .install = appOperation else {
+                    operation.finish()
+                    return
+                }
+                
+                if let error = context.error
+                {
+                    throw error
+                }
+                                
+                guard let app = context.app, let presentingViewController = context.authenticatedContext.presentingViewController else { throw OperationError.invalidParameters }
+                
+                self?.deactivateApps(for: app, presentingViewController: presentingViewController) { result in
+                    switch result
+                    {
+                    case .failure(let error): group.context.error = error
+                    case .success: break
+                    }
+                    
+                    operation.finish()
+                }
+            }
+            catch
+            {
+                group.context.error = error
+                operation.finish()
+            }
+        }
+        deactivateAppsOperation.addDependency(verifyOperation)
+        
+        
         /* Refresh Anisette Data */
         let refreshAnisetteDataOperation = FetchAnisetteDataOperation(context: group.context)
         refreshAnisetteDataOperation.resultHandler = { (result) in
@@ -852,7 +956,7 @@ private extension AppManager
             case .success(let anisetteData): group.context.session?.anisetteData = anisetteData
             }
         }
-        refreshAnisetteDataOperation.addDependency(verifyOperation)
+        refreshAnisetteDataOperation.addDependency(deactivateAppsOperation)
         
         
         /* Fetch Provisioning Profiles */
@@ -921,7 +1025,7 @@ private extension AppManager
         progress.addChild(installOperation.progress, withPendingUnitCount: 30)
         installOperation.addDependency(sendAppOperation)
         
-        let operations = [downloadOperation, verifyOperation, refreshAnisetteDataOperation, fetchProvisioningProfilesOperation, resignAppOperation, sendAppOperation, installOperation]
+        let operations = [downloadOperation, verifyOperation, deactivateAppsOperation, refreshAnisetteDataOperation, fetchProvisioningProfilesOperation, resignAppOperation, sendAppOperation, installOperation]
         group.add(operations)
         self.run(operations, context: group.context)
         

AltStore/My Apps/MyAppsViewController.swift

@@ -9,6 +9,7 @@
 import UIKit
 import MobileCoreServices
 import Intents
+import Combine
 
 import AltStoreCore
 import AltSign
@@ -1038,46 +1039,76 @@ private extension MyAppsViewController
     
     func activate(_ installedApp: InstalledApp)
     {
-        func activate()
+        func finish(_ result: Result<InstalledApp, Error>)
         {
-            installedApp.isActive = true
-            
-            AppManager.shared.activate(installedApp, presentingViewController: self) { (result) in
-                do
-                {
-                    let app = try result.get()
+            do
+            {
+                let app = try result.get()
+                app.managedObjectContext?.perform {
                     try? app.managedObjectContext?.save()
                 }
-                catch
-                {
-                    print("Failed to activate app:", error)
+            }
+            catch OperationError.cancelled
+            {
+                // Ignore
+            }
+            catch
+            {
+                print("Failed to activate app:", error)
+                
+                DispatchQueue.main.async {
+                    installedApp.isActive = false
                     
-                    DispatchQueue.main.async {
-                        installedApp.isActive = false
-                        
-                        let toastView = ToastView(error: error)
-                        toastView.show(in: self)
-                    }
+                    let toastView = ToastView(error: error)
+                    toastView.show(in: self)
                 }
             }
         }
-        
-        if UserDefaults.standard.activeAppsLimit != nil
+                
+        if UserDefaults.standard.activeAppsLimit != nil, #available(iOS 13, *)
         {
-            self.deactivateApps(for: installedApp) { (shouldContinue) in
-                if shouldContinue
-                {
-                    activate()
+            // UserDefaults.standard.activeAppsLimit is only non-nil on iOS 13.3.1 or later, so the #available check is just so we can use Combine.
+            
+            guard let app = ALTApplication(fileURL: installedApp.fileURL) else { return finish(.failure(OperationError.invalidApp)) }
+            
+            var cancellable: AnyCancellable?
+            cancellable = DatabaseManager.shared.viewContext.registeredObjects.publisher
+                .compactMap { $0 as? InstalledApp }
+                .filter(\.isActive)
+                .map { $0.publisher(for: \.isActive) }
+                .collect()
+                .flatMap { publishers in
+                    Publishers.MergeMany(publishers)
                 }
-                else
-                {
-                    installedApp.isActive = false
+                .first { isActive in !isActive }
+                .sink { _ in
+                    // A previously active app is now inactive,
+                    // which means there are now enough slots to activate the app,
+                    // so pre-emptively mark it as active to provide visual feedback sooner.
+                    installedApp.isActive = true
+                    cancellable?.cancel()
+                }
+            
+            AppManager.shared.deactivateApps(for: app, presentingViewController: self) { result in
+                cancellable?.cancel()
+                installedApp.managedObjectContext?.perform {
+                    switch result
+                    {
+                    case .failure(let error):
+                        installedApp.isActive = false
+                        finish(.failure(error))
+                        
+                    case .success:
+                        installedApp.isActive = true
+                        AppManager.shared.activate(installedApp, presentingViewController: self, completionHandler: finish(_:))
+                    }
                 }
             }
         }
         else
         {
-            activate()
+            installedApp.isActive = true
+            AppManager.shared.activate(installedApp, presentingViewController: self, completionHandler: finish(_:))
         }
     }
     
@@ -1110,75 +1141,6 @@ private extension MyAppsViewController
         }
     }
     
-    func deactivateApps(for installedApp: InstalledApp, completion: @escaping (Bool) -> Void)
-    {
-        guard let activeAppsLimit = UserDefaults.standard.activeAppsLimit else { return completion(true) }
-        
-        let activeApps = InstalledApp.fetchActiveApps(in: DatabaseManager.shared.viewContext)
-            .filter { $0.bundleIdentifier != installedApp.bundleIdentifier } // Don't count app towards total if it matches activating app
-        
-        var title: String = NSLocalizedString("Cannot Activate More than 3 Apps", comment: "")
-        let message: String
-        
-        if UserDefaults.standard.activeAppLimitIncludesExtensions
-        {
-            if installedApp.appExtensions.isEmpty
-            {
-                message = NSLocalizedString("Free developer accounts are limited to 3 active apps and app extensions. Please choose an app to deactivate.", comment: "")
-            }
-            else
-            {
-                title = NSLocalizedString("Cannot Activate More than 3 Apps and App Extensions", comment: "")
-                
-                let appExtensionText = installedApp.appExtensions.count == 1 ? NSLocalizedString("app extension", comment: "") : NSLocalizedString("app extensions", comment: "")
-                message = String(format: NSLocalizedString("Free developer accounts are limited to 3 active apps and app extensions, and “%@” contains %@ %@. Please choose an app to deactivate.", comment: ""), installedApp.name, NSNumber(value: installedApp.appExtensions.count), appExtensionText)
-            }
-        }
-        else
-        {
-            message = NSLocalizedString("Free developer accounts are limited to 3 active apps. Please choose an app to deactivate.", comment: "")
-        }
-        
-        let activeAppsCount = activeApps.map { $0.requiredActiveSlots }.reduce(0, +)
-                
-        let availableActiveApps = max(activeAppsLimit - activeAppsCount, 0)
-        guard installedApp.requiredActiveSlots > availableActiveApps else { return completion(true) }
-        
-        let alertController = UIAlertController(title: title, message: message, preferredStyle: .alert)
-        alertController.addAction(UIAlertAction(title: UIAlertAction.cancel.title, style: UIAlertAction.cancel.style) { (action) in
-            completion(false)
-        })
-        
-        for app in activeApps where app.bundleIdentifier != StoreApp.altstoreAppID
-        {
-            alertController.addAction(UIAlertAction(title: app.name, style: .default) { (action) in
-                let availableActiveApps = availableActiveApps + app.requiredActiveSlots
-                if availableActiveApps >= installedApp.requiredActiveSlots
-                {
-                    // There are enough slots now to activate the app, so pre-emptively
-                    // mark it as active to provide visual feedback sooner.
-                    installedApp.isActive = true
-                }
-                                
-                self.deactivate(app) { (result) in
-                    installedApp.managedObjectContext?.perform {
-                        switch result
-                        {
-                        case .failure:
-                            installedApp.isActive = false
-                            completion(false)
-                            
-                        case .success:
-                            self.deactivateApps(for: installedApp, completion: completion)
-                        }
-                    }
-                }
-            })
-        }
-        
-        self.present(alertController, animated: true, completion: nil)
-    }
-    
     func remove(_ installedApp: InstalledApp)
     {
         let title = String(format: NSLocalizedString("Remove “%@” from AltStore?", comment: ""), installedApp.name)