pen: Offer the current window during promixity-in events on most platforms.

Fixes #12356.

Author: icculus

include/SDL3/SDL_events.h

@@ -818,6 +818,9 @@ typedef struct SDL_PinchFingerEvent
  * is there." The pen touching and lifting off from the tablet while not
  * leaving the area are handled by SDL_EVENT_PEN_DOWN and SDL_EVENT_PEN_UP.
  *
+ * Not all platforms have a window associated with the pen during proximity
+ * events. Some wait until motion/button/etc events to offer this info.
+ *
  * \since This struct is available since SDL 3.2.0.
  */
 typedef struct SDL_PenProximityEvent

src/events/SDL_pen.c

@@ -218,7 +218,7 @@ SDL_PenCapabilityFlags SDL_GetPenCapabilityFromAxis(SDL_PenAxis axis)
     return 0;  // oh well.
 }
 
-SDL_PenID SDL_AddPenDevice(Uint64 timestamp, const char *name, const SDL_PenInfo *info, void *handle)
+SDL_PenID SDL_AddPenDevice(Uint64 timestamp, const char *name, SDL_Window *window, const SDL_PenInfo *info, void *handle)
 {
     SDL_assert(handle != NULL);  // just allocate a Uint8 so you have a unique pointer if not needed!
     SDL_assert(SDL_FindPenByHandle(handle) == 0);  // Backends shouldn't double-add pens!
@@ -262,6 +262,7 @@ SDL_PenID SDL_AddPenDevice(Uint64 timestamp, const char *name, const SDL_PenInfo
         event.pproximity.type = SDL_EVENT_PEN_PROXIMITY_IN;
         event.pproximity.timestamp = timestamp;
         event.pproximity.which = result;
+        event.pproximity.windowID = window ? window->id : 0;
         SDL_PushEvent(&event);
     }
 

src/events/SDL_pen_c.h

@@ -61,7 +61,7 @@ typedef struct SDL_PenInfo
 // Backend calls this when a new pen device is hotplugged, plus once for each pen already connected at startup.
 // Note that name and info are copied but currently unused; this is placeholder for a potentially more robust API later.
 // Both are allowed to be NULL.
-extern SDL_PenID SDL_AddPenDevice(Uint64 timestamp, const char *name, const SDL_PenInfo *info, void *handle);
+extern SDL_PenID SDL_AddPenDevice(Uint64 timestamp, const char *name, SDL_Window *window, const SDL_PenInfo *info, void *handle);
 
 // Backend calls this when an existing pen device is disconnected during runtime. They must free their own stuff separately.
 extern void SDL_RemovePenDevice(Uint64 timestamp, SDL_PenID instance_id);

src/video/android/SDL_androidpen.c

@@ -51,7 +51,7 @@ void Android_OnPen(SDL_Window *window, int pen_id_in, SDL_PenDeviceType device_t
         peninfo.num_buttons = 2;
         peninfo.subtype = SDL_PEN_TYPE_PEN;
         peninfo.device_type = device_type;
-        pen = SDL_AddPenDevice(0, NULL, &peninfo, (void *) (size_t) pen_id_in);
+        pen = SDL_AddPenDevice(0, NULL, window, &peninfo, (void *) (size_t) pen_id_in);
         if (!pen) {
             SDL_Log("error: can't add a pen device %d", pen_id_in);
             return;

src/video/cocoa/SDL_cocoapen.m

@@ -105,7 +105,7 @@ static void Cocoa_HandlePenProximityEvent(SDL_CocoaWindowData *_data, NSEvent *e
         handle->deviceid = devid;
         handle->toolid = toolid;
         handle->is_eraser = is_eraser;
-        handle->pen = SDL_AddPenDevice(Cocoa_GetEventTimestamp([event timestamp]), NULL, &peninfo, handle);
+        handle->pen = SDL_AddPenDevice(Cocoa_GetEventTimestamp([event timestamp]), NULL, _data.window, &peninfo, handle);
         if (!handle->pen) {
             SDL_free(handle);  // oh well.
         }

src/video/emscripten/SDL_emscriptenevents.c

@@ -855,7 +855,7 @@ static void Emscripten_HandlePenEnter(SDL_WindowData *window_data, const Emscrip
     peninfo.max_tilt = 90.0f;
     peninfo.num_buttons = 2;
     peninfo.subtype = SDL_PEN_TYPE_PEN;
-    SDL_AddPenDevice(0, NULL, &peninfo, (void *) (size_t) event->pointerid);
+    SDL_AddPenDevice(0, NULL, window_data->window, &peninfo, (void *) (size_t) event->pointerid);
     Emscripten_UpdatePenFromEvent(window_data, event);
 }
 

src/video/uikit/SDL_uikitpen.m

@@ -63,7 +63,7 @@ bool UIKit_InitPen(SDL_VideoDevice *_this)
 // we only have one Apple Pencil at a time, and it must be paired to the iOS device.
 // We only know about its existence when it first sends an event, so add an single SDL pen
 // device here if we haven't already.
-static SDL_PenID UIKit_AddPenIfNecesary()
+static SDL_PenID UIKit_AddPenIfNecesary(SDL_Window *window)
 {
     if (!apple_pencil_id) {
         SDL_PenInfo info;
@@ -86,7 +86,7 @@ static SDL_PenID UIKit_AddPenIfNecesary()
         // so we can't use it for tangential pressure.
 
         // There's only ever one Apple Pencil at most, so we just pass a non-zero value for the handle.
-        apple_pencil_id = SDL_AddPenDevice(0, "Apple Pencil", &info, (void *) (size_t) 0x1);
+        apple_pencil_id = SDL_AddPenDevice(0, "Apple Pencil", window, &info, (void *) (size_t) 0x1);
     }
 
     return apple_pencil_id;
@@ -95,7 +95,7 @@ static SDL_PenID UIKit_AddPenIfNecesary()
 static void UIKit_HandlePenAxes(SDL_Window *window, NSTimeInterval nstimestamp, float zOffset, const CGPoint *point, float force,
                                 float maximumPossibleForce, float azimuthAngleInView, float altitudeAngle, float rollAngle)
 {
-    const SDL_PenID penId = UIKit_AddPenIfNecesary();
+    const SDL_PenID penId = UIKit_AddPenIfNecesary(window);
     if (penId) {
         const Uint64 timestamp = UIKit_GetEventTimestamp(nstimestamp);
         const float radians_to_degrees = 180.0f / SDL_PI_F;
@@ -188,18 +188,20 @@ void UIKit_HandlePenMotion(SDL_uikitview *view, UITouch *pencil)
 
 void UIKit_HandlePenPress(SDL_uikitview *view, UITouch *pencil)
 {
-    const SDL_PenID penId = UIKit_AddPenIfNecesary();
+    SDL_Window *window = [view getSDLWindow];
+    const SDL_PenID penId = UIKit_AddPenIfNecesary(window);
     if (penId) {
         UIKit_HandlePenAxesFromUITouch(view, pencil);
-        SDL_SendPenTouch(UIKit_GetEventTimestamp([pencil timestamp]), penId, [view getSDLWindow], false, true);
+        SDL_SendPenTouch(UIKit_GetEventTimestamp([pencil timestamp]), penId, window, false, true);
     }
 }
 
 void UIKit_HandlePenRelease(SDL_uikitview *view, UITouch *pencil)
 {
-    const SDL_PenID penId = UIKit_AddPenIfNecesary();
+    SDL_Window *window = [view getSDLWindow];
+    const SDL_PenID penId = UIKit_AddPenIfNecesary(window);
     if (penId) {
-        SDL_SendPenTouch(UIKit_GetEventTimestamp([pencil timestamp]), penId, [view getSDLWindow], false, false);
+        SDL_SendPenTouch(UIKit_GetEventTimestamp([pencil timestamp]), penId, window, false, false);
         UIKit_HandlePenAxesFromUITouch(view, pencil);
     }
 }

src/video/wayland/SDL_waylandevents.c

@@ -3439,7 +3439,7 @@ static void tablet_tool_handle_frame(void *data, struct zwp_tablet_tool_v2 *tool
     if (sdltool->frame.have_proximity_in) {
         SDL_assert(sdltool->instance_id == 0);  // shouldn't be added at this point.
         if (sdltool->info.subtype != SDL_PEN_TYPE_UNKNOWN) {   // don't tell SDL about it if we don't know its role.
-            sdltool->instance_id = SDL_AddPenDevice(timestamp, NULL, &sdltool->info, sdltool);
+            sdltool->instance_id = SDL_AddPenDevice(timestamp, NULL, window, &sdltool->info, sdltool);
             Wayland_TabletToolUpdateCursor(sdltool);
         }
     }

src/video/windows/SDL_windowsevents.c

@@ -1277,7 +1277,7 @@ LRESULT CALLBACK WIN_WindowProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lPara
         info.max_tilt = 90.0f;
         info.num_buttons = 1;
         info.subtype = SDL_PEN_TYPE_PENCIL;
-        SDL_AddPenDevice(0, NULL, &info, hpointer);
+        SDL_AddPenDevice(0, NULL, data->window, &info, hpointer);
         returnCode = 0;
     } break;
 

src/video/x11/SDL_x11pen.c

@@ -272,7 +272,7 @@ static X11_PenHandle *X11_MaybeAddPen(SDL_VideoDevice *_this, const XIDeviceInfo
     handle->is_eraser = is_eraser;
     handle->x11_deviceid = dev->deviceid;
 
-    handle->pen = SDL_AddPenDevice(0, dev->name, &peninfo, handle);
+    handle->pen = SDL_AddPenDevice(0, dev->name, NULL, &peninfo, handle);
     if (!handle->pen) {
         SDL_free(handle);
         return NULL;