The gamepad vs joystick events always happen in this order:
SDL_EVENT_JOYSTICK_ADDED
SDL_EVENT_GAMEPAD_ADDED
SDL_EVENT_GAMEPAD_REMAPPED
SDL_EVENT_GAMEPAD_REMOVED
SDL_EVENT_JOYSTICK_REMOVED
Whenever a mapping is changed, any controller affected by that mapping will generate a gamepad event. You will only get one SDL_EVENT_GAMEPAD_REMAPPED event per controller per batch of mapping changes, where SDL_AddGamepadMappingsFromFile() and SDL_AddGamepadMapping() are each a batch of changes.
Also renamed most cases of SDL_GAMEPAD_TYPE_UNKNOWN to SDL_GAMEPAD_TYPE_STANDARD, and SDL_GetGamepadType() will return SDL_GAMEPAD_TYPE_UNKNOWN only if the gamepad is invalid.
Removing SDL_GAMEPAD_TYPE_VIRTUAL allows a virtual controller to emulate another gamepad type. The other controller types can be treated as generic controllers by applications without special glyph or functionality treatment.
Sam Lantinga