Errors creating instance MenuBackend and MenuItem attributes in a display class

Hello everyone,

I am making a display class using 2*8 lcd on an arduino to display and navigate my menu using MenuBackend library. i have been ablle to make it work without using classes but when i use a class cann’t make instances of these variables. i want to declare the item in the header set their values in the constructor but there are bunch of errors i could not correct.
These are the errors:

/usr/share/arduino/libraries/MenuBackend/MenuBackend.h:557:5: note: MenuBackend::MenuBackend(cb_use, cb_change, cb_item_change)
MenuBackend(cb_use menuUse, cb_change menuChange = 0, cb_item_change itemChange = 0) : root(“MenuRoot”)
/usr/share/arduino/libraries/MenuBackend/MenuBackend.h:557:5: note: candidate expects 3 arguments, 0 provided
/usr/share/arduino/libraries/MenuBackend/MenuBackend.h:554:7: note: MenuBackend::MenuBackend(const MenuBackend&)
class MenuBackend
/usr/share/arduino/libraries/MenuBackend/MenuBackend.h:554:7: note: candidate expects 1 argument, 0 provided
GPSMenu.cpp:6:36: error: no matching function for call to ‘MenuItem::MenuItem()’
GPSMenu::GPSMenu(LiquidCrystal* lcd){
GPSMenu.cpp:6:36: note: candidates are:
In file included from GPSMenu.cpp:2:0:
/usr/share/arduino/libraries/MenuBackend/MenuBackend.h:94:5: note: MenuItem::MenuItem(MenuBackend&, const char*, unsigned char, char)
MenuItem(MenuBackend &mb, const char* itemName, unsigned char lvl = 0, char shortKey = ‘\0’) : name(itemName), shortkey(shortKey)

In file included from GPSMenu.cpp:2:0:
/usr/share/arduino/libraries/MenuBackend/MenuBackend.h: In member function ‘MenuItem& MenuItem::operator=(const MenuItem&)’:
/usr/share/arduino/libraries/MenuBackend/MenuBackend.h:57:7: error: non-static const member ‘const char MenuItem::shortkey’, can’t use default assignment operator
class MenuItem
GPSMenu.cpp: In constructor ‘GPSMenu::GPSMenu(LiquidCrystal*)’:
GPSMenu.cpp:12:15: note: synthesized method ‘MenuItem& MenuItem::operator=(const MenuItem&)’ first required here
Battery = MenuItem(menu, "Battery ", 1);//----usable

GPSMenu.cpp (2.87 KB)

GPSMenu.h (871 Bytes)

Without a link to the MenuBackend library, and your sketch, we can't really help you.

The codes(GPSMenu.cpp and GPSMenu.h) are in the question's attachement section and the link to the library is :

does anyone have an idea ?