For native file dialogs, see the methods file_dialog* in https://docs.godotengine.org/en/stable/classes/class_display...
Not quite sure what you meant by drag & drop, but godot has API for getting the files dropped onto the window: https://docs.godotengine.org/en/stable/classes/class_window....
Finally, you can create (or customize?) native menus: https://docs.godotengine.org/en/stable/classes/class_nativem...
Also, slightly unrelated, I have WIP useless desktop widget created with godot https://github.com/nvlled/fps-desktop that shoots a gun on mouseclick. Tested only on linux.
For native file dialogs, see the methods file_dialog* in https://docs.godotengine.org/en/stable/classes/class_display...
Not quite sure what you meant by drag & drop, but godot has API for getting the files dropped onto the window: https://docs.godotengine.org/en/stable/classes/class_window....
Finally, you can create (or customize?) native menus: https://docs.godotengine.org/en/stable/classes/class_nativem...
Also, slightly unrelated, I have WIP useless desktop widget created with godot https://github.com/nvlled/fps-desktop that shoots a gun on mouseclick. Tested only on linux.