From e799b4ba108a31ba04d66c9d7eeacd65a5d8dfc5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Henrik=20Rydg=C3=A5rd?= <hrydgard@gmail.com>
Date: Sun, 26 May 2024 09:55:50 +0200
Subject: [PATCH] iOS: Pass through touches near the task switcher only
 in-game. Makes the UI better behaved.

---
 Common/System/System.h     |  1 +
 ios/ViewController.mm      | 17 ++++++++++++++++-
 ios/ViewControllerCommon.h |  2 ++
 ios/ViewControllerMetal.mm | 17 ++++++++++++++++-
 ios/main.mm                | 10 +++++++++-
 5 files changed, 44 insertions(+), 3 deletions(-)

diff --git a/Common/System/System.h b/Common/System/System.h
index a5d87e479668..7c7b3c4c1b30 100644
--- a/Common/System/System.h
+++ b/Common/System/System.h
@@ -229,6 +229,7 @@ enum class SystemNotification {
 	TEST_JAVA_EXCEPTION,
 	KEEP_SCREEN_AWAKE,
 	ACTIVITY,
+	UI_STATE_CHANGED,
 };
 
 // I guess it's not super great architecturally to centralize this, since it's not general - but same with a lot of
diff --git a/ios/ViewController.mm b/ios/ViewController.mm
index 48afd931e3c2..224b22cc6559 100644
--- a/ios/ViewController.mm
+++ b/ios/ViewController.mm
@@ -392,7 +392,22 @@ - (void)controllerDidDisconnect:(NSNotification *)note
 // Enables tapping for edge area.
 -(UIRectEdge)preferredScreenEdgesDeferringSystemGestures
 {
-	return UIRectEdgeAll;
+	if (GetUIState() == UISTATE_INGAME) {
+		// In-game, we need all the control we can get. Though, we could possibly
+		// allow the top edge?
+		INFO_LOG(SYSTEM, "Defer system gestures on all edges");
+		return UIRectEdgeAll;
+	} else {
+		INFO_LOG(SYSTEM, "Allow system gestures on the bottom");
+		// Allow task switching gestures to take precedence, without causing
+		// scroll events in the UI.
+		return UIRectEdgeTop | UIRectEdgeLeft | UIRectEdgeRight;
+	}
+}
+
+- (void)uiStateChanged
+{
+	[self setNeedsUpdateOfScreenEdgesDeferringSystemGestures];
 }
 
 - (UIView *)getView {
diff --git a/ios/ViewControllerCommon.h b/ios/ViewControllerCommon.h
index cfbe5e7daf99..1e955b66ce39 100644
--- a/ios/ViewControllerCommon.h
+++ b/ios/ViewControllerCommon.h
@@ -20,6 +20,8 @@
 - (void)didBecomeActive;
 - (void)willResignActive;
 
+- (void)uiStateChanged;
+
 @end
 
 extern id <PPSSPPViewController> sharedViewController;
diff --git a/ios/ViewControllerMetal.mm b/ios/ViewControllerMetal.mm
index 1fd177a8f36c..43038c8e6191 100644
--- a/ios/ViewControllerMetal.mm
+++ b/ios/ViewControllerMetal.mm
@@ -477,7 +477,22 @@ - (void)viewSafeAreaInsetsDidChange {
 // Enables tapping for edge area.
 -(UIRectEdge)preferredScreenEdgesDeferringSystemGestures
 {
-	return UIRectEdgeAll;
+	if (GetUIState() == UISTATE_INGAME) {
+		// In-game, we need all the control we can get. Though, we could possibly
+		// allow the top edge?
+		INFO_LOG(SYSTEM, "Defer system gestures on all edges");
+		return UIRectEdgeAll;
+	} else {
+		INFO_LOG(SYSTEM, "Allow system gestures on the bottom");
+		// Allow task switching gestures to take precedence, without causing
+		// scroll events in the UI.
+		return UIRectEdgeTop | UIRectEdgeLeft | UIRectEdgeRight;
+	}
+}
+
+- (void)uiStateChanged
+{
+	[self setNeedsUpdateOfScreenEdgesDeferringSystemGestures];
 }
 
 - (void)bindDefaultFBO
diff --git a/ios/main.mm b/ios/main.mm
index 48690865b21d..f0de32c9960e 100644
--- a/ios/main.mm
+++ b/ios/main.mm
@@ -386,7 +386,15 @@ bool System_GetPropertyBool(SystemProperty prop) {
 
 void System_Notify(SystemNotification notification) {
 	switch (notification) {
-	default: break;
+	case SystemNotification::UI_STATE_CHANGED:
+		dispatch_async(dispatch_get_main_queue(), ^{
+			if (sharedViewController) {
+				[sharedViewController uiStateChanged];
+			}
+		});
+		break;
+	default:
+		break;
 	}
 }