Persists customized input mappings between app launches

Cores/DeltaCore

@@ -1 +1 @@
-Subproject commit f33f8bd91a9e0b41ba55b9aa8370397dd7e7f809
+Subproject commit 7681a93515aea5c7642a56c888fe5da3aa4ea09f

Delta.xcodeproj/project.pbxproj

@@ -79,6 +79,8 @@
 		BF6BF31C1EB821A0008E83CD /* GamesDatabaseImportOption.swift in Sources */ = {isa = PBXBuildFile; fileRef = BF6BF31B1EB821A0008E83CD /* GamesDatabaseImportOption.swift */; };
 		BF6BF3211EB82362008E83CD /* GamesDatabase.storyboard in Resources */ = {isa = PBXBuildFile; fileRef = BF6BF31F1EB82362008E83CD /* GamesDatabase.storyboard */; };
 		BF6BF3271EB87EB8008E83CD /* PhotoLibraryImportOption.swift in Sources */ = {isa = PBXBuildFile; fileRef = BF6BF3261EB87EB8008E83CD /* PhotoLibraryImportOption.swift */; };
+		BF6EE5E91F7C5F860051AD6C /* _GameControllerInputMapping.swift in Sources */ = {isa = PBXBuildFile; fileRef = BF6EE5E81F7C5F860051AD6C /* _GameControllerInputMapping.swift */; };
+		BF6EE5EB1F7C5F8F0051AD6C /* GameControllerInputMapping.swift in Sources */ = {isa = PBXBuildFile; fileRef = BF6EE5EA1F7C5F8F0051AD6C /* GameControllerInputMapping.swift */; };
 		BF70798C1B6B464B0019077C /* ZipZap.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = BF70798B1B6B464B0019077C /* ZipZap.framework */; };
 		BF70798D1B6B464B0019077C /* ZipZap.framework in Embed Frameworks */ = {isa = PBXBuildFile; fileRef = BF70798B1B6B464B0019077C /* ZipZap.framework */; settings = {ATTRIBUTES = (CodeSignOnCopy, RemoveHeadersOnCopy, ); }; };
 		BF797A2D1C2D339F00F1A000 /* UILabel+FontSize.swift in Sources */ = {isa = PBXBuildFile; fileRef = BF797A2C1C2D339F00F1A000 /* UILabel+FontSize.swift */; };
@@ -109,6 +111,7 @@
 		BFEC732E1AAECC4A00650035 /* Roxas.framework in Embed Frameworks */ = {isa = PBXBuildFile; fileRef = BFEC732C1AAECC4A00650035 /* Roxas.framework */; settings = {ATTRIBUTES = (CodeSignOnCopy, RemoveHeadersOnCopy, ); }; };
 		BFF0742C1E9DC17500ACDF4A /* GBCDeltaCore.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = BFF0742B1E9DC17500ACDF4A /* GBCDeltaCore.framework */; };
 		BFF0742D1E9DC17500ACDF4A /* GBCDeltaCore.framework in Embed Frameworks */ = {isa = PBXBuildFile; fileRef = BFF0742B1E9DC17500ACDF4A /* GBCDeltaCore.framework */; settings = {ATTRIBUTES = (CodeSignOnCopy, RemoveHeadersOnCopy, ); }; };
+		BFF6452E1F7CC5060056533E /* GameControllerInputMappingTransformer.swift in Sources */ = {isa = PBXBuildFile; fileRef = BF6B82A41F7CC2A300042BFB /* GameControllerInputMappingTransformer.swift */; };
 		BFF93AA01E0FB036005EC865 /* InputStreamOutputWriter.swift in Sources */ = {isa = PBXBuildFile; fileRef = BFF93A9F1E0FB036005EC865 /* InputStreamOutputWriter.swift */; };
 		BFFA4C091E8A24D600D87934 /* GameMetadataTableViewCell.swift in Sources */ = {isa = PBXBuildFile; fileRef = BFFA4C081E8A24D600D87934 /* GameMetadataTableViewCell.swift */; };
 		BFFA71DD1AAC406100EE9DD1 /* AppDelegate.swift in Sources */ = {isa = PBXBuildFile; fileRef = BFFA71DC1AAC406100EE9DD1 /* AppDelegate.swift */; };
@@ -202,6 +205,7 @@
 		BF6424841F5CBDC900D6AB44 /* UIView+ParentViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "UIView+ParentViewController.swift"; sourceTree = "<group>"; };
 		BF6866161DCAC8B900BF2D06 /* ControllerSkin+Configuring.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = "ControllerSkin+Configuring.swift"; sourceTree = "<group>"; };
 		BF696B7F1D9B2B02009639E0 /* Theme.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; name = Theme.swift; path = Theming/Theme.swift; sourceTree = "<group>"; };
+		BF6B82A41F7CC2A300042BFB /* GameControllerInputMappingTransformer.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; name = GameControllerInputMappingTransformer.swift; path = Database/Model/Transformers/GameControllerInputMappingTransformer.swift; sourceTree = "<group>"; };
 		BF6BB2451BB73FE800CCF94A /* Assets.xcassets */ = {isa = PBXFileReference; lastKnownFileType = folder.assetcatalog; path = Assets.xcassets; sourceTree = "<group>"; };
 		BF6BF3121EB7E47F008E83CD /* ImportOption.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; name = ImportOption.swift; path = Importing/ImportOption.swift; sourceTree = "<group>"; };
 		BF6BF3171EB82111008E83CD /* iTunesImportOption.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; name = iTunesImportOption.swift; path = "Importing/Import Options/iTunesImportOption.swift"; sourceTree = "<group>"; };
@@ -209,6 +213,8 @@
 		BF6BF31B1EB821A0008E83CD /* GamesDatabaseImportOption.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; name = GamesDatabaseImportOption.swift; path = "Importing/Import Options/GamesDatabaseImportOption.swift"; sourceTree = "<group>"; };
 		BF6BF3201EB82362008E83CD /* Base */ = {isa = PBXFileReference; lastKnownFileType = file.storyboard; name = Base; path = Base.lproj/GamesDatabase.storyboard; sourceTree = "<group>"; };
 		BF6BF3261EB87EB8008E83CD /* PhotoLibraryImportOption.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; name = PhotoLibraryImportOption.swift; path = "Importing/Import Options/PhotoLibraryImportOption.swift"; sourceTree = "<group>"; };
+		BF6EE5E81F7C5F860051AD6C /* _GameControllerInputMapping.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; name = _GameControllerInputMapping.swift; path = Database/Model/Machine/_GameControllerInputMapping.swift; sourceTree = "<group>"; };
+		BF6EE5EA1F7C5F8F0051AD6C /* GameControllerInputMapping.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; name = GameControllerInputMapping.swift; path = Database/Model/Human/GameControllerInputMapping.swift; sourceTree = "<group>"; };
 		BF70798B1B6B464B0019077C /* ZipZap.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; path = ZipZap.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		BF797A2C1C2D339F00F1A000 /* UILabel+FontSize.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = "UILabel+FontSize.swift"; sourceTree = "<group>"; };
 		BF7AE8041C2E858400B1B5BC /* GridMenuViewController.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; name = GridMenuViewController.swift; path = "Pause Menu/GridMenuViewController.swift"; sourceTree = "<group>"; };
@@ -378,6 +384,7 @@
 				BF5942721E09BC700051894B /* Model.xcdatamodel */,
 				BF5942741E09BC740051894B /* Human */,
 				BF5942751E09BC780051894B /* Machine */,
+				BF6B82A31F7CC29A00042BFB /* Transformers */,
 				BF5942761E09BC7C0051894B /* Misc */,
 			);
 			name = Model;
@@ -390,6 +397,7 @@
 				BF5942781E09BC830051894B /* ControllerSkin.swift */,
 				BF5942791E09BC830051894B /* Game.swift */,
 				BF59427A1E09BC830051894B /* GameCollection.swift */,
+				BF6EE5EA1F7C5F8F0051AD6C /* GameControllerInputMapping.swift */,
 				BF59427B1E09BC830051894B /* SaveState.swift */,
 			);
 			name = Human;
@@ -402,6 +410,7 @@
 				BF5942821E09BC8B0051894B /* _ControllerSkin.swift */,
 				BF5942831E09BC8B0051894B /* _Game.swift */,
 				BF5942841E09BC8B0051894B /* _GameCollection.swift */,
+				BF6EE5E81F7C5F860051AD6C /* _GameControllerInputMapping.swift */,
 				BF5942851E09BC8B0051894B /* _SaveState.swift */,
 			);
 			name = Machine;
@@ -433,6 +442,14 @@
 			name = Theming;
 			sourceTree = "<group>";
 		};
+		BF6B82A31F7CC29A00042BFB /* Transformers */ = {
+			isa = PBXGroup;
+			children = (
+				BF6B82A41F7CC2A300042BFB /* GameControllerInputMappingTransformer.swift */,
+			);
+			name = Transformers;
+			sourceTree = "<group>";
+		};
 		BF6BF3161EB820F4008E83CD /* Import Options */ = {
 			isa = PBXGroup;
 			children = (
@@ -811,6 +828,7 @@
 				BFC6F7B81F435BC500221B96 /* Input+Display.swift in Sources */,
 				BF59426A1E09BBD00051894B /* GridCollectionViewCell.swift in Sources */,
 				BF6BF3181EB82111008E83CD /* iTunesImportOption.swift in Sources */,
+				BFF6452E1F7CC5060056533E /* GameControllerInputMappingTransformer.swift in Sources */,
 				BF59427C1E09BC830051894B /* Cheat.swift in Sources */,
 				BFBAB2E31EB685A2004E0B0E /* DeltaCoreProtocol+Delta.swift in Sources */,
 				BF3540081C5DAFAD00C1184C /* PauseTransitionCoordinator.swift in Sources */,
@@ -859,9 +877,11 @@
 				BF797A2D1C2D339F00F1A000 /* UILabel+FontSize.swift in Sources */,
 				BF80E1D21F13117000847008 /* ControllerInputsViewController.swift in Sources */,
 				BF5942641E09BBB10051894B /* LoadControllerSkinImageOperation.swift in Sources */,
+				BF6EE5E91F7C5F860051AD6C /* _GameControllerInputMapping.swift in Sources */,
 				BF5942871E09BC8B0051894B /* _ControllerSkin.swift in Sources */,
 				BF95E2791E4982A10030E7AD /* GamesDatabaseBrowserViewController.swift in Sources */,
 				BFD097211D3A01B8005A44C2 /* SaveStatesViewController.swift in Sources */,
+				BF6EE5EB1F7C5F8F0051AD6C /* GameControllerInputMapping.swift in Sources */,
 				BF3540021C5DA3D500C1184C /* PauseStoryboardSegue.swift in Sources */,
 				BF107EC41BF413F000E0C32C /* GamesViewController.swift in Sources */,
 				BF59426F1E09BC5D0051894B /* DatabaseManager.swift in Sources */,

Delta/Database/Model/Human/GameControllerInputMapping.swift

@@ -0,0 +1,77 @@
+//
+//  GameControllerInputMapping.swift
+//  Delta
+//
+//  Created by Riley Testut on 8/30/16.
+//  Copyright (c) 2016 Riley Testut. All rights reserved.
+//
+
+import Foundation
+
+import DeltaCore
+
+@objc(GameControllerInputMapping)
+public class GameControllerInputMapping: _GameControllerInputMapping
+{
+    fileprivate var inputMapping: DeltaCore.GameControllerInputMapping {
+        get { return self.deltaCoreInputMapping as! DeltaCore.GameControllerInputMapping }
+        set { self.deltaCoreInputMapping = newValue }
+    }
+    
+    public convenience init(inputMapping: DeltaCore.GameControllerInputMapping, context: NSManagedObjectContext)
+    {
+        self.init(entity: GameControllerInputMapping.entity(), insertInto: context)
+        
+        self.inputMapping = inputMapping
+    }
+}
+
+extension GameControllerInputMapping
+{
+    class func inputMapping(for gameController: GameController, gameType: GameType, in managedObjectContext: NSManagedObjectContext) -> GameControllerInputMapping?
+    {
+        guard let playerIndex = gameController.playerIndex else {
+            return nil
+        }
+                
+        let fetchRequest: NSFetchRequest<GameControllerInputMapping> = GameControllerInputMapping.fetchRequest()
+        fetchRequest.returnsObjectsAsFaults = false
+        fetchRequest.predicate = NSPredicate(format: "%K == %@ AND %K == %@ AND %K == %d", #keyPath(GameControllerInputMapping.gameControllerInputType), gameController.inputType.rawValue, #keyPath(GameControllerInputMapping.gameType), gameType.rawValue, #keyPath(GameControllerInputMapping.playerIndex), playerIndex)
+        
+        do
+        {
+            let inputMappings = try managedObjectContext.fetch(fetchRequest)
+            
+            let inputMapping = inputMappings.first
+            return inputMapping
+        }
+        catch
+        {
+            print(error)
+            
+            return nil
+        }        
+    }
+}
+
+extension GameControllerInputMapping: GameControllerInputMappingProtocol
+{
+    var name: String? {
+        get { return self.inputMapping.name }
+        set { self.inputMapping.name = newValue }
+    }
+    
+    var supportedControllerInputs: [Input] {
+        return self.inputMapping.supportedControllerInputs
+    }
+    
+    public func input(forControllerInput controllerInput: Input) -> Input?
+    {
+        return self.inputMapping.input(forControllerInput: controllerInput)
+    }
+    
+    func set(_ input: Input?, forControllerInput controllerInput: Input)
+    {
+        self.inputMapping.set(input, forControllerInput: controllerInput)
+    }
+}

Delta/Database/Model/Machine/_GameControllerInputMapping.swift

@@ -0,0 +1,28 @@
+// DO NOT EDIT. This file is machine-generated and constantly overwritten.
+// Make changes to GameControllerInputMapping.swift instead.
+
+import Foundation
+import CoreData
+
+import DeltaCore
+
+public class _GameControllerInputMapping: NSManagedObject 
+{   
+    @nonobjc public class func fetchRequest() -> NSFetchRequest<GameControllerInputMapping> {
+        return NSFetchRequest<GameControllerInputMapping>(entityName: "GameControllerInputMapping")
+    }
+
+    // MARK: - Properties
+
+    @NSManaged public var deltaCoreInputMapping: Any
+
+    @NSManaged public var gameControllerInputType: GameControllerInputType
+
+    @NSManaged public var gameType: GameType
+
+    @NSManaged public var playerIndex: Int16
+
+    // MARK: - Relationships
+
+}
+

Delta/Database/Model/Model.xcdatamodel/contents

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
-<model type="com.apple.IDECoreDataModeler.DataModel" documentVersion="1.0" lastSavedToolsVersion="11759" systemVersion="16C68" minimumToolsVersion="Xcode 7.0" sourceLanguage="Objective-C" userDefinedModelVersionIdentifier="1.0">
+<model type="com.apple.IDECoreDataModeler.DataModel" documentVersion="1.0" lastSavedToolsVersion="13240" systemVersion="16G29" minimumToolsVersion="Xcode 7.0" sourceLanguage="Objective-C" userDefinedModelVersionIdentifier="1.0">
     <entity name="Cheat" representedClassName="Cheat" syncable="YES">
         <attribute name="code" attributeType="String" syncable="YES"/>
         <attribute name="creationDate" attributeType="Date" usesScalarValueType="NO" syncable="YES"/>
@@ -79,6 +79,31 @@
             </uniquenessConstraint>
         </uniquenessConstraints>
     </entity>
+    <entity name="GameControllerInputMapping" representedClassName="GameControllerInputMapping" syncable="YES">
+        <attribute name="deltaCoreInputMapping" attributeType="Transformable" valueTransformerName="GameControllerInputMappingTransformer" syncable="YES">
+            <userInfo>
+                <entry key="attributeValueClassName" value="Any"/>
+            </userInfo>
+        </attribute>
+        <attribute name="gameControllerInputType" attributeType="Transformable" valueTransformerName="" syncable="YES">
+            <userInfo>
+                <entry key="attributeValueClassName" value="GameControllerInputType"/>
+            </userInfo>
+        </attribute>
+        <attribute name="gameType" attributeType="Transformable" syncable="YES">
+            <userInfo>
+                <entry key="attributeValueClassName" value="GameType"/>
+            </userInfo>
+        </attribute>
+        <attribute name="playerIndex" attributeType="Integer 16" defaultValueString="0" usesScalarValueType="NO" syncable="YES"/>
+        <uniquenessConstraints>
+            <uniquenessConstraint>
+                <constraint value="gameControllerInputType"/>
+                <constraint value="gameType"/>
+                <constraint value="playerIndex"/>
+            </uniquenessConstraint>
+        </uniquenessConstraints>
+    </entity>
     <entity name="SaveState" representedClassName="SaveState" syncable="YES">
         <attribute name="creationDate" attributeType="Date" usesScalarValueType="NO" syncable="YES"/>
         <attribute name="filename" attributeType="String" syncable="YES">
@@ -107,6 +132,7 @@
         <element name="ControllerSkin" positionX="-387" positionY="90" width="128" height="135"/>
         <element name="Game" positionX="-378" positionY="-54" width="128" height="180"/>
         <element name="GameCollection" positionX="-585" positionY="-27" width="128" height="90"/>
+        <element name="GameControllerInputMapping" positionX="-387" positionY="90" width="128" height="105"/>
         <element name="SaveState" positionX="-198" positionY="113" width="128" height="165"/>
     </elements>
 </model>

Delta/Database/Model/Transformers/GameControllerInputMappingTransformer.swift

@@ -0,0 +1,61 @@
+//
+//  GameControllerInputMappingTransformer.swift
+//  Delta
+//
+//  Created by Riley Testut on 9/27/17.
+//  Copyright © 2017 Riley Testut. All rights reserved.
+//
+
+import Foundation
+
+import DeltaCore
+
+@objc(GameControllerInputMappingTransformer)
+class GameControllerInputMappingTransformer: ValueTransformer
+{
+    override class func transformedValueClass() -> AnyClass {
+        return NSData.self
+    }
+    
+    override class func allowsReverseTransformation() -> Bool {
+        return true
+    }
+    
+    override func transformedValue(_ value: Any?) -> Any?
+    {
+        guard let inputMapping = value as? DeltaCore.GameControllerInputMapping else { return nil }
+        
+        let plistEncoder = PropertyListEncoder()
+        
+        do
+        {
+            let data = try plistEncoder.encode(inputMapping)
+            return data
+        }
+        catch
+        {
+            print(error)
+            
+            return nil
+        }
+    }
+    
+    override func reverseTransformedValue(_ value: Any?) -> Any?
+    {
+        guard let inputMappingData = value as? Data else { return nil }
+        
+        let plistDecoder = PropertyListDecoder()
+        
+        do
+        {
+            let inputMapping = try plistDecoder.decode(DeltaCore.GameControllerInputMapping.self, from: inputMappingData)
+            return inputMapping
+        }
+        catch
+        {
+            print(error)
+            
+            return nil
+        }
+    }
+}

Delta/Emulation/GameViewController.swift

@@ -32,12 +32,15 @@ private extension GameViewController
     
     struct SustainInputsMapping: GameControllerInputMappingProtocol
     {
-        let gameControllerInputType: GameControllerInputType
+        let gameController: GameController
-        let previousInputMapping: GameControllerInputMappingProtocol?
+        
+        var gameControllerInputType: GameControllerInputType {
+            return self.gameController.inputType
+        }
         
         func input(forControllerInput controllerInput: Input) -> Input?
         {
-            if let mappedInput = self.previousInputMapping?.input(forControllerInput: controllerInput), mappedInput == StandardGameControllerInput.menu
+            if let mappedInput = self.gameController.defaultInputMapping?.input(forControllerInput: controllerInput), mappedInput == StandardGameControllerInput.menu
             {
                 return mappedInput
             }
@@ -355,6 +358,8 @@ private extension GameViewController
 {
     @objc func updateControllers()
     {
+        guard let emulatorCore = self.emulatorCore, let game = self.game else { return }
+        
         let controllers = [self.controllerView as GameController] + ExternalGameControllerManager.shared.connectedControllers
         
         if let index = Settings.localControllerPlayerIndex
@@ -368,28 +373,25 @@ private extension GameViewController
             self.controllerView.isHidden = true
         }
         
-        // Removing all game controllers from EmulatorCore will reset each controller's playerIndex to nil
+        for gameController in controllers
-        // We temporarily cache their playerIndexes, and then we reset them after removing all controllers
-        var controllerIndexes = [ObjectIdentifier: Int?]()
-        controllers.forEach { controllerIndexes[ObjectIdentifier($0)] = $0.playerIndex }
-        
-        self.emulatorCore?.removeAllGameControllers()
-        
-        // Reset each controller's playerIndex to what it was before removing all controllers from EmulatorCore
-        controllers.forEach { $0.playerIndex = controllerIndexes[ObjectIdentifier($0)] ?? nil }
-        
-        for controller in controllers
         {
-            if let index = controller.playerIndex
+            if gameController.playerIndex != nil
             {
-                // We need to place the underscore here to silence erroneous unused result warning despite annotating function with @discardableResult
+                if let inputMapping = GameControllerInputMapping.inputMapping(for: gameController, gameType: game.type, in: DatabaseManager.shared.viewContext)
-                // Hopefully this bug won't be around for too long...
+                {
-                _ = self.emulatorCore?.setGameController(controller, at: index)
+                    gameController.addReceiver(self, inputMapping: inputMapping)
-                controller.addReceiver(self)
+                    gameController.addReceiver(emulatorCore, inputMapping: inputMapping)
                 }
                 else
                 {
-                controller.removeReceiver(self)
+                    gameController.addReceiver(self)
+                    gameController.addReceiver(emulatorCore)
+                }
+            }
+            else
+            {
+                gameController.removeReceiver(self)
+                gameController.removeReceiver(emulatorCore)
             }
         }
         
@@ -623,8 +625,8 @@ private extension GameViewController
         
         self.isSelectingSustainedButtons = true
         
-        self.sustainInputsMapping = SustainInputsMapping(gameControllerInputType: gameController.inputType, previousInputMapping: gameController.inputMapping)
+        let sustainInputsMapping = SustainInputsMapping(gameController: gameController)
-        gameController.inputMapping = self.sustainInputsMapping
+        gameController.addReceiver(self, inputMapping: sustainInputsMapping)
         
         let blurEffect = self.sustainButtonsBlurView.effect
         self.sustainButtonsBlurView.effect = nil
@@ -643,7 +645,7 @@ private extension GameViewController
         
         self.isSelectingSustainedButtons = false
         
-        gameController.inputMapping = self.sustainInputsMapping?.previousInputMapping
+        self.updateControllers()
         self.sustainInputsMapping = nil
         
         // Reactivate all sustained inputs, since they will now be mapped to game inputs.

Delta/Settings/Controllers/ControllerInputsViewController.swift

@@ -17,7 +17,7 @@ class ControllerInputsViewController: UIViewController
 {
     var gameController: GameController! {
         didSet {
-            self.prepareGameController()
+            self.gameController.addReceiver(self, inputMapping: nil)
         }
     }
     
@@ -28,8 +28,8 @@ class ControllerInputsViewController: UIViewController
         }
     }
     
-    fileprivate var inputMapping: GameControllerInputMapping!
+    fileprivate lazy var managedObjectContext: NSManagedObjectContext = DatabaseManager.shared.newBackgroundContext()
-    fileprivate var previousInputMapping: GameControllerInputMappingProtocol?
+    fileprivate var inputMappings = [System: GameControllerInputMapping]()
     
     fileprivate let supportedActionInputs: [ActionInput] = [.saveState, .loadState, .fastForward]
     
@@ -91,8 +91,11 @@ extension ControllerInputsViewController
             self.actionsMenuViewController = segue.destination as! GridMenuViewController
             self.prepareActionsMenuViewController()
             
-        case "cancelControllerControls": self.gameController.inputMapping = self.previousInputMapping
+        case "cancelControllerInputs": break
-        case "saveControllerControls": self.gameController.inputMapping = self.inputMapping
+        case "saveControllerInputs":
+            self.managedObjectContext.performAndWait {
+                self.managedObjectContext.saveWithErrorLogging()
+            }
             
         default: break
         }
@@ -105,6 +108,7 @@ private extension ControllerInputsViewController
     {
         guard self.isViewLoaded else { return }
         
+        // Update popoverMenuButton to display correctly on iOS 10.
         if let popoverMenuButton = self.navigationItem.popoverMenuController?.popoverMenuButton
         {
             popoverMenuButton.title = self.system.localizedShortName
@@ -113,8 +117,31 @@ private extension ControllerInputsViewController
             self.navigationController?.navigationBar.layoutIfNeeded()
         }
         
+        // Update controller view's controller skin.
         self.gameViewController.controllerView.controllerSkin = DeltaCore.ControllerSkin.standardControllerSkin(for: self.system.gameType)
         
+        // Fetch input mapping if it hasn't already been fetched.
+        if let gameController = self.gameController, let playerIndex = gameController.playerIndex, self.inputMappings[self.system] == nil
+        {
+            self.managedObjectContext.performAndWait {
+                let inputMapping = GameControllerInputMapping.inputMapping(for: gameController, gameType: self.system.gameType, in: self.managedObjectContext) ?? {
+                    let deltaCoreInputMapping = gameController.defaultInputMapping as? DeltaCore.GameControllerInputMapping ?? DeltaCore.GameControllerInputMapping(gameControllerInputType: gameController.inputType)
+                    
+                    let inputMapping = GameControllerInputMapping(inputMapping: deltaCoreInputMapping, context: self.managedObjectContext)
+                    inputMapping.gameControllerInputType = gameController.inputType
+                    inputMapping.gameType = self.system.gameType
+                    inputMapping.playerIndex = Int16(playerIndex)
+                    
+                    return inputMapping
+                }()
+                
+                inputMapping.name = String.localizedStringWithFormat("Custom %@", gameController.name)
+                
+                self.inputMappings[self.system] = inputMapping
+            }
+        }
+        
+        // Update callouts, if view is already on screen.
         if self.view.window != nil
         {
             self.calloutViews.forEach { $1.dismissCallout(animated: true) }
@@ -126,18 +153,6 @@ private extension ControllerInputsViewController
         }
     }
     
-    func prepareGameController()
-    {
-        self.gameController.addReceiver(self)
-        
-        self.previousInputMapping = self.gameController.inputMapping
-        
-        self.inputMapping = self.gameController.inputMapping as? GameControllerInputMapping ?? GameControllerInputMapping(gameControllerInputType: self.gameController.inputType)
-        self.inputMapping.name = String.localizedStringWithFormat("Custom %@", self.gameController.name)
-        
-        self.gameController.inputMapping = nil
-    }
-    
     func preparePopoverMenuController()
     {
         let listMenuViewController = ListMenuViewController()
@@ -186,7 +201,7 @@ private extension ControllerInputsViewController
                 text = NSLocalizedString("Fast Forward", comment: "")
             }
             
-            let item = MenuItem(text: text, image: image) { (item) in
+            let item = MenuItem(text: text, image: image) { [unowned self] (item) in
                 guard let calloutView = self.calloutViews[AnyInput(input)] else { return }
                 self.toggle(calloutView)
             }
@@ -204,7 +219,8 @@ private extension ControllerInputsViewController
             let controllerView = self.gameViewController.controllerView,
             let traits = controllerView.controllerSkinTraits,
             let items = controllerView.controllerSkin?.items(for: traits),
-            let controllerViewInputMapping = controllerView.inputMapping
+            let controllerViewInputMapping = controllerView.defaultInputMapping,
+            let inputMapping = self.inputMappings[self.system]
         else { return }
         
         // Implicit assumption that all skins used for controller input mapping don't have multiple items with same input.
@@ -218,8 +234,9 @@ private extension ControllerInputsViewController
             self.calloutViews[AnyInput(input)] = calloutView
         }
         
+        self.managedObjectContext.performAndWait {
             // Update callout views with controller inputs that map to callout views' associated controller skin inputs.
-        for input in self.inputMapping.supportedControllerInputs
+            for input in inputMapping.supportedControllerInputs
             {
                 let mappedInput = self.mappedInput(for: input)
                 
@@ -236,6 +253,7 @@ private extension ControllerInputsViewController
                     }
                 }
             }
+        }
         
         // Present only callout views that are associated with a controller input.
         for calloutView in self.calloutViews.values
@@ -252,6 +270,8 @@ private extension ControllerInputsViewController
 {
     func updateActiveCalloutView(with controllerInput: Input?)
     {
+        guard let inputMapping = self.inputMappings[self.system] else { return }
+        
         guard let activeCalloutView = self.activeCalloutView else { return }
         
         guard let input = self.calloutViews.first(where: { $0.value == activeCalloutView })?.key else { return }
@@ -271,20 +291,22 @@ private extension ControllerInputsViewController
             }
         }
         
-        for supportedInput in self.inputMapping.supportedControllerInputs
+        self.managedObjectContext.performAndWait {
+            for supportedInput in inputMapping.supportedControllerInputs
             {
                 let mappedInput = self.mappedInput(for: supportedInput)
                 
                 if mappedInput == input
                 {
                     // Set all existing controller inputs that currently map to "input" to instead map to nil.
-                self.inputMapping.set(nil, forControllerInput: supportedInput)
+                    inputMapping.set(nil, forControllerInput: supportedInput)
                 }
             }
             
             if let controllerInput = controllerInput
             {
-            self.inputMapping.set(input, forControllerInput: controllerInput)
+                inputMapping.set(input, forControllerInput: controllerInput)
+            }
         }
         
         activeCalloutView.input = controllerInput
@@ -352,7 +374,11 @@ private extension ControllerInputsViewController
 {
     func mappedInput(for input: Input) -> AnyInput
     {
-        guard let mappedInput = self.inputMapping.input(forControllerInput: input) else {
+        guard let inputMapping = self.inputMappings[self.system] else {
+            fatalError("Input mapping for current system does not exist.")
+        }
+        
+        guard let mappedInput = inputMapping.input(forControllerInput: input) else {
             fatalError("Mapped input for provided input does not exist.")
         }
         
@@ -450,6 +476,8 @@ extension ControllerInputsViewController: GameControllerReceiver
 {
     func gameController(_ gameController: GameController, didActivate controllerInput: DeltaCore.Input)
     {
+        guard self.isViewLoaded else { return }
+        
         switch gameController
         {
         case self.gameViewController.controllerView:

Delta/Settings/Controllers/ControllersSettingsViewController.swift

@@ -36,7 +36,7 @@ private class LocalDeviceController: NSObject, GameController
     
     let inputType: GameControllerInputType = .standard
     
-    var inputMapping: GameControllerInputMappingProtocol?
+    var defaultInputMapping: GameControllerInputMappingProtocol?
 }
 
 class ControllersSettingsViewController: UITableViewController

Delta/Settings/Settings.storyboard

@@ -286,12 +286,12 @@
                     <navigationItem key="navigationItem" id="UeP-Yr-9jA">
                         <barButtonItem key="leftBarButtonItem" systemItem="cancel" id="QfC-sf-WbP">
                             <connections>
-                                <segue destination="8l5-7I-Z7e" kind="unwind" identifier="cancelControllerControls" unwindAction="unwindFromControllerControlsViewController:" id="AkD-Lu-h5b"/>
+                                <segue destination="8l5-7I-Z7e" kind="unwind" identifier="cancelControllerInputs" unwindAction="unwindFromControllerControlsViewController:" id="AkD-Lu-h5b"/>
                             </connections>
                         </barButtonItem>
                         <barButtonItem key="rightBarButtonItem" style="done" systemItem="save" id="WHh-7W-jpl">
                             <connections>
-                                <segue destination="8l5-7I-Z7e" kind="unwind" identifier="saveControllerControls" unwindAction="unwindFromControllerControlsViewController:" id="4xr-OB-4dx"/>
+                                <segue destination="8l5-7I-Z7e" kind="unwind" identifier="saveControllerInputs" unwindAction="unwindFromControllerControlsViewController:" id="4xr-OB-4dx"/>
                             </connections>
                         </barButtonItem>
                     </navigationItem>