From 2d602e67263bfb287d470f0bb6397ba2601409fd Mon Sep 17 00:00:00 2001
From: Susko3 <Susko3@protonmail.com>
Date: Tue, 27 Jan 2026 00:45:07 +0100
Subject: [PATCH] Add workaround to fix pen clicks not working on Android

---
 .../Platform/SDL3/SDL3Window_Input.cs         | 31 +++++++++++++++++--
 1 file changed, 28 insertions(+), 3 deletions(-)

diff --git a/osu.Framework/Platform/SDL3/SDL3Window_Input.cs b/osu.Framework/Platform/SDL3/SDL3Window_Input.cs
index 73cb15526..4f10522e6 100644
--- a/osu.Framework/Platform/SDL3/SDL3Window_Input.cs
+++ b/osu.Framework/Platform/SDL3/SDL3Window_Input.cs
@@ -533,11 +533,36 @@ namespace osu.Framework.Platform.SDL3
 
         private void handleKeymapChangedEvent() => KeymapChanged?.Invoke();
 
+        private readonly bool penProximityWorkaround = RuntimeInfo.OS == RuntimeInfo.Platform.Android;
+
+        private bool tryGetPenDeviceType(SDL_PenID penID, out TabletPenDeviceType deviceType)
+        {
+            if (penDeviceTypes.TryGetValue(penID, out deviceType))
+                return true;
+
+            // Workaround for Android: after clicking with a pen, it can send motion and touch events even though we've received SDL_EVENT_PEN_PROXIMITY_OUT.
+            // It's either a bug in Android or SDL.
+            // Instead of ignoring those events, fetch the type and store it.
+            if (penProximityWorkaround)
+            {
+                var sdlType = SDL_GetPenDeviceType(penID);
+
+                if (sdlType == SDL_PenDeviceType.SDL_PEN_DEVICE_TYPE_INVALID)
+                    return false;
+
+                deviceType = sdlType.ToTabletPenDeviceType();
+                penDeviceTypes[penID] = deviceType;
+                return true;
+            }
+
+            return false;
+        }
+
         private void handlePenProximityEvent(SDL_PenProximityEvent evtPenProximity)
         {
             if (evtPenProximity.type == SDL_EventType.SDL_EVENT_PEN_PROXIMITY_IN)
             {
-                if (penDeviceTypes.ContainsKey(evtPenProximity.which))
+                if (!penProximityWorkaround && penDeviceTypes.ContainsKey(evtPenProximity.which))
                     Logger.Log($"Unexpected SDL_EVENT_PEN_PROXIMITY_IN for pen id={evtPenProximity.which}. Pen already in proximity.", level: LogLevel.Important);
 
                 penDeviceTypes[evtPenProximity.which] = SDL_GetPenDeviceType(evtPenProximity.which).ThrowIfFailed().ToTabletPenDeviceType();
@@ -551,7 +576,7 @@ namespace osu.Framework.Platform.SDL3
 
         private void handlePenMotionEvent(SDL_PenMotionEvent evtPenMotion)
         {
-            if (penDeviceTypes.TryGetValue(evtPenMotion.which, out var type))
+            if (tryGetPenDeviceType(evtPenMotion.which, out var type))
                 PenMove?.Invoke(type, new Vector2(evtPenMotion.x, evtPenMotion.y) * Scale, evtPenMotion.pen_state.HasFlagFast(SDL_PenInputFlags.SDL_PEN_INPUT_DOWN));
             else
                 Logger.Log($"Unexpected SDL_EVENT_PEN_MOTION for pen id={evtPenMotion.which}. Pen not in proximity.", level: LogLevel.Important);
@@ -559,7 +584,7 @@ namespace osu.Framework.Platform.SDL3
 
         private void handlePenTouchEvent(SDL_PenTouchEvent evtPenTouch)
         {
-            if (penDeviceTypes.TryGetValue(evtPenTouch.which, out var type))
+            if (tryGetPenDeviceType(evtPenTouch.which, out var type))
                 PenTouch?.Invoke(type, evtPenTouch.down, new Vector2(evtPenTouch.x, evtPenTouch.y) * Scale);
             else
                 Logger.Log($"Unexpected {evtPenTouch.type} for pen id={evtPenTouch.which}. Pen not in proximity.", level: LogLevel.Important);