Implement SDL_GetPenDeviceType() for Android

src/events/SDL_pen.c

@@ -199,6 +199,15 @@ SDL_PenInputFlags SDL_GetPenStatus(SDL_PenID instance_id, float *axes, int num_a
     return result;
 }
 
+SDL_PenDeviceType SDL_GetPenDeviceType(SDL_PenID instance_id)
+{
+    SDL_LockRWLockForReading(pen_device_rwlock);
+    const SDL_Pen *pen = FindPenByInstanceId(instance_id);
+    const SDL_PenDeviceType result = pen ? pen->info.device_type : SDL_PEN_DEVICE_TYPE_INVALID;
+    SDL_UnlockRWLock(pen_device_rwlock);
+    return result;
+}
+
 SDL_PenCapabilityFlags SDL_GetPenCapabilityFromAxis(SDL_PenAxis axis)
 {
     // the initial capability bits happen to match up, but as

src/events/SDL_pen_c.h

@@ -36,6 +36,8 @@ typedef Uint32 SDL_PenCapabilityFlags;
 #define SDL_PEN_CAPABILITY_TANGENTIAL_PRESSURE (1u << 6)  /**< Provides barrel pressure on SDL_PEN_AXIS_TANGENTIAL_PRESSURE. */
 #define SDL_PEN_CAPABILITY_ERASER    (1u << 7)  /**< Pen also has an eraser tip. */
 
+// Rename before making this public as it clashes with SDL_PenDeviceType.
+// Prior art in Android calls this "tool type".
 typedef enum SDL_PenSubtype
 {
     SDL_PEN_TYPE_UNKNOWN,   /**< Unknown pen device */
@@ -53,6 +55,7 @@ typedef struct SDL_PenInfo
     Uint32 wacom_id;   /**< For Wacom devices: wacom tool type ID, otherwise 0 (useful e.g. with libwacom) */
     int num_buttons; /**< Number of pen buttons (not counting the pen tip), or -1 if unknown. */
     SDL_PenSubtype subtype;  /**< type of pen device */
+    SDL_PenDeviceType device_type;
 } SDL_PenInfo;
 
 // Backend calls this when a new pen device is hotplugged, plus once for each pen already connected at startup.