IOS7: Implement Apple GCVirtualController

Apple introduced the GCVirtualController in iOS 15 which is a
software emulation of a real controller. The virtual controllers
can be configurable with different inputs. See more info at:
https://developer.apple.com/documentation/gamecontroller/gcvirtualcontroller

A simple gamepad configuration with a dPad and A and B buttons
is added. The user can enable/disable the virtual game controller
swiping two fingers right to left, or through the port-specific
option dialog.

backends/platform/ios7/ios7_gamepad_controller.h

@@ -28,6 +28,7 @@ API_AVAILABLE(ios(7.0))
 @interface GamepadController : GameController
 
 - (id)initWithView:(iPhoneView *)view;
+- (void)virtualController:(bool)connect;
 
 @end
 

backends/platform/ios7/ios7_gamepad_controller.mm

@@ -29,6 +29,14 @@
 
 @implementation GamepadController {
 	GCController *_controller;
+#if TARGET_OS_IOS
+#ifdef __IPHONE_15_0
+	API_AVAILABLE(ios(15.0))
+	GCVirtualController *_virtualController;
+	API_AVAILABLE(ios(15.0))
+	GCVirtualControllerConfiguration *_config;
+#endif
+#endif
 }
 
 @dynamic view;
@@ -42,9 +50,34 @@
 												 name:@"GCControllerDidConnectNotification"
 											   object:nil];
 
+#if TARGET_OS_IOS
+#ifdef __IPHONE_15_0
+	if (@available(iOS 15.0, *)) {
+		// Configure a simple game controller with dPad and A and B buttons
+		_config = [[GCVirtualControllerConfiguration alloc] init];
+		_config.elements = [[NSSet alloc] initWithObjects:GCInputDirectionPad, GCInputButtonA, GCInputButtonB, nil];
+		_virtualController = [[GCVirtualController alloc] initWithConfiguration:_config];
+	}
+#endif
+#endif
 	return self;
 }
 
+- (void)virtualController:(bool)connect {
+#if TARGET_OS_IOS
+#ifdef __IPHONE_15_0
+	if (@available(iOS 15.0, *)) {
+		if (connect && ![self isConnected]) {
+			[_virtualController connectWithReplyHandler:^(NSError * _Nullable error) { }];		}
+		else if (!connect && [self isConnected]) {
+			[_virtualController disconnect];
+			[self setIsConnected:NO];
+		}
+	}
+#endif
+#endif
+}
+
 - (void)controllerDidConnect:(NSNotification *)notification {
 	_controller = (GCController*)notification.object;
 

backends/platform/ios7/ios7_options.mm

@@ -189,6 +189,7 @@ void OSystem_iOS7::registerDefaultSettings(const Common::String &target) const {
 }
 
 void OSystem_iOS7::applyBackendSettings() {
+	virtualController(ConfMan.getBool("onscreen_control"));
 	_touchpadModeEnabled = ConfMan.getBool("touchpad_mode");
 	_mouseClickAndDragEnabled = ConfMan.getBool("clickanddrag_mode");
 }

backends/platform/ios7/ios7_osys_events.cpp

@@ -440,6 +440,15 @@ bool OSystem_iOS7::handleEvent_swipe(Common::Event &event, int direction, int to
 			return false;
 		}
 
+		case kUIViewSwipeLeft: {
+			// Swipe left
+			bool connect = !ConfMan.getBool("onscreen_control");
+			ConfMan.setBool("onscreen_control", connect);
+			ConfMan.flushToDisk();
+			virtualController(connect);
+			return false;
+		}
+
 		default:
 			break;
 		}

backends/platform/ios7/ios7_osys_main.h

@@ -207,6 +207,7 @@ public:
 	Common::String getSystemLanguage() const override;
 
 	bool isConnectionLimited() override;
+	void virtualController(bool connect);
 
 	virtual Common::String getDefaultLogFileName() override { return Common::String("/scummvm.log"); }
 

backends/platform/ios7/ios7_osys_video.mm

@@ -486,6 +486,12 @@ void OSystem_iOS7::warpMouse(int x, int y) {
 	_mouseDirty = true;
 }
 
+void OSystem_iOS7::virtualController(bool connect) {
+	execute_on_main_thread(^ {
+		[[iOS7AppDelegate iPhoneView] virtualController:connect];
+	});
+}
+
 void OSystem_iOS7::dirtyFullScreen() {
 	if (!_fullScreenIsDirty) {
 		_dirtyRects.clear();

backends/platform/ios7/ios7_video.h

@@ -143,6 +143,7 @@ uint getSizeNextPOT(uint size);
 - (BOOL)isTouchControllerConnected;
 - (BOOL)isMouseControllerConnected;
 - (BOOL)isGamepadControllerConnected;
+- (void)virtualController:(bool)connect;
 @end
 
 #endif

backends/platform/ios7/ios7_video.mm

@@ -931,6 +931,16 @@ uint getSizeNextPOT(uint size) {
 	}
 }
 
+- (void)virtualController:(bool)connect {
+	if (@available(iOS 15.0, *)) {
+		for (GameController *c : _controllers) {
+			if ([c isKindOfClass:GamepadController.class]) {
+				[(GamepadController*)c virtualController:connect];
+			}
+		}
+	}
+}
+
 #if TARGET_OS_IOS
 - (void)interfaceOrientationChanged:(UIInterfaceOrientation)orientation {
 	[self addEvent:InternalEvent(kInputOrientationChanged, orientation, 0)];