Dlangui customize app icon on dock or menu bar

[Ivo]

I'm a macOs user and I need to build a application with a GUI.
I started using Dlangui with SDL2. I need to be able to call some 
functions of my program while working with other applications.
So I would like to personalize the app icon on the dock so that 
when right-clicking such icon the context menu lets me trigger 
some functions.
Otherwise the possibility to add the app icon in the menu bar 
(the bar containing wifi and bluetooth settings) and perform such 
actions from there is also fine.

Thanks in advance for any help.