Add option to control the iOS app switching mode

Common/System/System.h

@@ -231,6 +231,7 @@ enum class SystemNotification {
 	ACTIVITY,
 	UI_STATE_CHANGED,
 	AUDIO_MODE_CHANGED,
+	APP_SWITCH_MODE_CHANGED,
 };
 
 // I guess it's not super great architecturally to centralize this, since it's not general - but same with a lot of

Core/Config.cpp

@@ -644,6 +644,10 @@ static const ConfigSetting graphicsSettings[] = {
 	ConfigSetting("FullScreenMulti", &g_Config.bFullScreenMulti, false, CfgFlag::DEFAULT),
 #endif
 
+#if PPSSPP_PLATFORM(IOS)
+	ConfigSetting("AppSwitchMode", &g_Config.iAppSwitchMode, (int)AppSwitchMode::DOUBLE_SWIPE_INDICATOR, CfgFlag::DEFAULT),
+#endif
+
 	ConfigSetting("BufferFiltering", &g_Config.iDisplayFilter, SCALE_LINEAR, CfgFlag::PER_GAME),
 	ConfigSetting("DisplayOffsetX", &g_Config.fDisplayOffsetX, 0.5f, CfgFlag::PER_GAME),
 	ConfigSetting("DisplayOffsetY", &g_Config.fDisplayOffsetY, 0.5f, CfgFlag::PER_GAME),

Core/Config.h

@@ -210,6 +210,7 @@ public:
 
 	bool bTextureBackoffCache;
 	bool bVertexDecoderJit;
+	int iAppSwitchMode;
 	bool bFullScreen;
 	bool bFullScreenMulti;
 	int iForceFullScreen = -1; // -1 = nope, 0 = force off, 1 = force on (not saved.)

Core/ConfigValues.h

@@ -126,6 +126,12 @@ enum class BackgroundAnimation {
 	MOVING_BACKGROUND = 4,
 };
 
+// iOS only
+enum class AppSwitchMode {
+	SINGLE_SWIPE_NO_INDICATOR = 0,
+	DOUBLE_SWIPE_INDICATOR = 1,
+};
+
 // for Config.iShowStatusFlags
 enum class ShowStatusFlags {
 	FPS_COUNTER = 1 << 1,

UI/GameSettingsScreen.cpp

@@ -1048,6 +1048,17 @@ void GameSettingsScreen::CreateSystemSettings(UI::ViewGroup *systemSettings) {
 		screenManager()->push(langScreen);
 		return UI::EVENT_DONE;
 	});
+
+	static const char *indicator[] = {
+		"Swipe once to switch app (indicator auto-hides)",
+		"Swipe twice to switch app (indicator stays visible)"
+	};
+	PopupMultiChoice *switchMode = systemSettings->Add(new PopupMultiChoice(&g_Config.iAppSwitchMode, sy->T("App switching mode"), indicator, 0, ARRAY_SIZE(indicator), I18NCat::SYSTEM, screenManager()));
+	switchMode->OnChoice.Add([](EventParams &e) {
+		System_Notify(SystemNotification::APP_SWITCH_MODE_CHANGED);
+		return UI::EVENT_DONE;
+	});
+
 	systemSettings->Add(new CheckBox(&g_Config.bUISound, sy->T("UI Sound")));
 	const Path bgPng = GetSysDirectory(DIRECTORY_SYSTEM) / "background.png";
 	const Path bgJpg = GetSysDirectory(DIRECTORY_SYSTEM) / "background.jpg";

ios/ViewController.mm

@@ -134,8 +134,16 @@ id<PPSSPPViewController> sharedViewController;
 }
 
 - (BOOL)prefersHomeIndicatorAutoHidden {
-	// Would love to hide it, but it prevents the double-swipe protection from working.
+	if (g_Config.iAppSwitchMode == (int)AppSwitchMode::DOUBLE_SWIPE_INDICATOR) {
 		return NO;
+	} else {
+		return YES;
+	}
+}
+
+- (void)appSwitchModeChanged
+{
+	[self setNeedsUpdateOfHomeIndicatorAutoHidden];
 }
 
 - (void)shareText:(NSString *)text {

ios/ViewControllerCommon.h

@@ -15,6 +15,7 @@
 - (void)stopLocation;
 - (void)startVideo:(int)width height:(int)height;
 - (void)stopVideo;
+- (void)appSwitchModeChanged;
 
 // Forwarded from the AppDelegate
 - (void)didBecomeActive;

ios/ViewControllerMetal.mm

@@ -481,8 +481,16 @@ void VulkanRenderLoop(IOSVulkanContext *graphicsContext, CAMetalLayer *metalLaye
 }
 
 - (BOOL)prefersHomeIndicatorAutoHidden {
-	// Would love to hide it, but it prevents the double-swipe protection from working.
+	if (g_Config.iAppSwitchMode == (int)AppSwitchMode::DOUBLE_SWIPE_INDICATOR) {
 		return NO;
+	} else {
+		return YES;
+	}
+}
+
+- (void)appSwitchModeChanged
+{
+	[self setNeedsUpdateOfHomeIndicatorAutoHidden];
 }
 
 - (void)shareText:(NSString *)text {

ios/main.mm

@@ -387,6 +387,13 @@ bool System_GetPropertyBool(SystemProperty prop) {
 
 void System_Notify(SystemNotification notification) {
 	switch (notification) {
+	case SystemNotification::APP_SWITCH_MODE_CHANGED:
+		dispatch_async(dispatch_get_main_queue(), ^{
+			if (sharedViewController) {
+				[sharedViewController appSwitchModeChanged];
+			}
+		});
+		break;
 	case SystemNotification::UI_STATE_CHANGED:
 		dispatch_async(dispatch_get_main_queue(), ^{
 			if (sharedViewController) {