Man page 3 : XkbGetVirtualMods

XkbGetVirtualMods - Obtain a subset of the virtual modifier bindings (the vmods array) in a keyboard description

Status XkbGetVirtualMods (Display * dpy , unsigned int which , XkbDescPtr xkb );

• - dpy
      connection to server
• - which
      mask indicating virtual modifier bindings to get
• - xkb
      Xkb description where results will be placed

XkbGetVirtualModssends a request to the server to obtain the vmodsentries for the virtual modifiers specified in the mask, which,and waits for a reply. Virtual modifiers are named by converting their string name to an X Atom and storing the Atom in the names.vmodsarray in an XkbDescRec structure. The position of a name Atom in the names.vmodsarray defines the bit position used to represent the virtual modifier and also the index used when accessing virtual modifier information in arrays: the name in the i-th (0 relative) entry of names.vmodsis the i-th virtual modifier, represented by the mask (1<<i). Throughout Xkb, various functions have a parameter that is a mask representing virtual modifier choices. In each case, the i-th bit (0 relative) of the mask represents the i-th virtual modifier. To set the name of a virtual modifier, use XkbSetNames,using XkbVirtualModNamesMask in whichand the name in the xkbargument; to retrieve indicator names, use XkbGetNames. For each bit set in which, XkbGetVirtualModsupdates the corresponding virtual modifier definition in the server->vmodsarray of xkb.The xkbparameter must be a pointer to a valid Xkb keyboard description. If successful, XkbGetVirtualModsreturns Success.

Virtual Modifier Names and Masks Virtual modifiers are named by converting their string name to an X Atom and storing the Atom in the names.vmodsarray in an XkbDescRec structure. The position of a name Atom in the names.vmodsarray defines the bit position used to represent the virtual modifier and also the index used when accessing virtual modifier information in arrays: the name in the i-th (0 relative) entry of names.vmodsis the i-th virtual modifier, represented by the mask (1<<i). Throughout Xkb, various functions have a parameter that is a mask representing virtual modifier choices. In each case, the i-th bit (0 relative) of the mask represents the i-th virtual modifier. To set the name of a virtual modifier, use XkbSetNames,using XkbVirtualModNamesMask in whichand the name in the xkbargument; to retrieve indicator names, use XkbGetNames. If the servermap has not been allocated in the xkbparameter, XkbGetVirtualModsallocates and initializes it before obtaining the virtual modifier bindings. If the server does not have a compatible version of Xkb, or the Xkb extension has not been properly initialized, XkbGetVirtualModsreturns BadMatch. Any errors in allocation cause XkbGetVirtualModsto return BadAlloc.

• Success
                 The XkbGetVirtualModsfunction returns Success when it successfully updates the corresponding virtual modifier definition in the server->vmodsarray of xkb.

The complete description of an Xkb keyboard is given by an XkbDescRec. The component structures in the XkbDescRec represent the major Xkb components.

typedef struct {
   struct _XDisplay * display;      /(** connection to X server */
   unsigned short     flags;        /(** private to Xkb, do not modify */
   unsigned short     device_spec;  /(** device of interest */
   KeyCode            min_key_code; /(** minimum keycode for device */
   KeyCode            max_key_code; /(** maximum keycode for device */
   XkbControlsPtr     ctrls;        /(** controls */
   XkbServerMapPtr    server;       /(** server keymap */
   XkbClientMapPtr    map;          /(** client keymap */
   XkbIndicatorPtr    indicators;   /(** indicator map */
   XkbNamesPtr        names;        /(** names for all components */
   XkbCompatMapPtr    compat;       /(** compatibility map */
   XkbGeometryPtr     geom;         /(** physical geometry of keyboard */
} XkbDescRec, *XkbDescPtr;

The displayfield points to an X display structure. The flagsfield is private to the library: modifying flagsmay yield unpredictable results. The device_specfield specifies the device identifier of the keyboard input device, or XkbUseCoreKeyboard, which specifies the core keyboard device. The min_key_codeand max_key_codefields specify the least and greatest keycode that can be returned by the keyboard. Each structure component has a corresponding mask bit that is used in function calls to indicate that the structure should be manipulated in some manner, such as allocating it or freeing it. These masks and their relationships to the fields in the XkbDescRec are shown in Table 1.

BadAlloc

               Unable to allocate storage

BadMatch

               A compatible version of Xkb was not available in the server or an argument has correct type and range, but is otherwise invalid

R XkbGetNames (3),

R XkbSetNames (3)