Provide detection and help for unmapped gamepads. Fixes #70

app/streaming/input.h

@@ -39,8 +39,13 @@ public:
 
     void handleControllerDeviceEvent(SDL_ControllerDeviceEvent* event);
 
+    void handleJoystickArrivalEvent(SDL_JoyDeviceEvent* event);
+
     int getAttachedGamepadMask();
 
+    static
+    QString getUnmappedGamepads();
+
 private:
     GamepadState*
     findStateForGamepad(SDL_JoystickID id);