XkbVirtualModsToReal - Man Page

Bool XkbVirtualModsToReal (XkbDescPtr xkb, unsigned int virtual_mask, unsigned int *mask_rtrn);

xkb

keyboard description for input device

virtual_mask

virtual modifier mask to translate

mask_rtrn

backfilled with real modifiers

Xkb maintains a virtual modifier mapping, which lists the virtual modifiers associated with, or bound to, each key. The  real modifiers bound to a virtual modifier always include all of the modifiers  bound to any of the keys that specify that virtual modifier in their virtual  modifier mapping. The server.vmodmap array indicates which virtual modifiers are bound to each key; each entry is a  bitmask for the virtual modifier bits. The server.vmodmap array is indexed by keycode.

The vmodmap and vmods members of the server map are the "master" virtual modifier definitions. Xkb  automatically propagates any changes to these fields to all other fields that  use virtual modifier mappings.

For example, if Mod3 is bound to the Num_Lock key by the core protocol modifier  mapping, and the NumLock virtual modifier is bound to they Num_Lock key by the  virtual modifier mapping, Mod3 is added to the set of modifiers associated with  NumLock.

The virtual modifier mapping is normally updated whenever actions are  automatically applied to symbols and few applications should need to change the  virtual modifier mapping explicitly.

Use XkbGetMap to get the virtual modifiers from the server or use XkbGetVirtualMods to update a local copy of the virtual modifiers bindings from the server. To set  the binding of a virtual modifier to a real modifier, use XkbGetVirtualMods

If the keyboard description defined by xkb includes bindings for virtual modifiers, XkbVirtualModsToReal uses those bindings to determine the set of real modifiers that correspond to  the set of virtual modifiers specified in virtual_mask. The virtual_mask parameter is a mask specifying the virtual modifiers to translate; the i-th bit  (0 relative) of the mask represents the i-th virtual modifier. If mask_rtrn is non-NULL, XkbVirtualModsToReal backfills it with the resulting real modifier mask. If the keyboard description  in xkb does not include virtual modifier bindings, XkbVirtualModsToReal returns False; otherwise, it returns True.

True

The XkbVirtualModsToReal function returns True if the keyboard description  in xkb does include virtual modifier bindings.

False

The XkbVirtualModsToReal function returns False if the keyboard description  in xkb does not include virtual modifier bindings.

XkbGetMap(3), XkbGetVirtualMods(3)

It is possible for a local (client-side) keyboard description (the xkb parameter) to not contain any virtual modifier information (simply because the  client has not requested it) while the server's corresponding definition may  contain virtual modifier information.