XkbSetServerInternalMods - Sets the modifiers that are consumed by the server before events are delivered to the client


Bool XkbSetServerInternalMods (Display * display , unsigned int device_spec , unsigned int affect_real , unsigned int real_values , unsigned int affect_virtual , unsigned int virtual_values );


  • - display
        connection to the X server
  • - device_spec
        device ID, or XkbUseCoreKbd
  • - affect_real
        mask of real modifiers affected by this call
  • - real_values
        values for affected real modifiers (1=>set, 0=>unset)
  • - affect_virtual
        mask of virtual modifiers affected by this call
  • - virtual_values
        values for affected virtual modifiers (1=>set, 0=>unset)


The core protocol does not provide any means to prevent a modifier from being reported in events sent to clients; Xkb, however makes this possible via the InternalMods control. It specifies modifiers that should be consumed by the server and not reported to clients. When a key is pressed and a modifier that has its bit set in the InternalMods control is reported to the server, the server uses the modifier when determining the actions to apply for the key. The server then clears the bit, so it is not actually reported to the client. In addition, modifiers specified in the InternalMods control are not used to determine grabs and are not used to calculate core protocol compatibility state. Manipulate the InternalMods control via the internalfield in the XkbControlsRec structure, using XkbSetControlsand XkbGetControls.Alternatively, use XkbSetServerInternalMods. XkbSetServerInternalModssends a request to the server to change the internal modifiers consumed by the server. affect_realand real_valuesare masks of real modifier bits indicating which real modifiers are to be added and removed from the server's internal modifiers control. Modifiers selected by both affect_realand real_valuesare added to the server's internal modifiers control; those selected by affect_realbut not by real_valuesare removed from the server's internal modifiers mask. Valid values for affect_realand real_valuesconsist of any combination of the eight core modifier bits: ShiftMask, LockMask, ControlMask, Mod1Mask - Mod5Mask. affect_virtualand virtual_valuesare masks of virtual modifier bits indicating which virtual modifiers are to be added and removed from the server's internal modifiers control. Modifiers selected by both affect_virtualand virtual_valuesare added to the server's internal modifiers control; those selected by affect_virtualbut not by virtual_valuesare removed from the server's internal modifiers control. See below for a discussion of virtual modifier masks to use in affect_virtualand virtual_values. XkbSetServerInternalModsdoes not wait for a reply from the server. It returns True if the request was sent and False otherwise. 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.


The complete description of an Xkb keyboard is given by an XkbDescRec. The component structures in the XkbDescRec represent the major Xkb components outlined in Figure 1.1.

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 display field points to an X display structure. The flags field is private to the library: modifying flags may yield unpredictable results. The device_spec field specifies the device identifier of the keyboard input device, or XkbUseCoreKeyboard, which specifies the core keyboard device. The min_key_code and max_key_code fields 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.

c s s
l l l
Table 1 Mask Bits for XkbDescRec
Mask Bit XkbDescRec Field Value
XkbControlsMask ctrls (1L<<0)
XkbServerMapMask server (1L<<1)
XkbIClientMapMask map (1L<<2)
XkbIndicatorMapMask indicators (1L<<3)
XkbNamesMask names (1L<<4)
XkbCompatMapMask compat (1L<<5)
XkbGeometryMask geom (1L<<6)
XkbAllComponentsMask All Fields (0x7f)


R XkbGetControls (3),

R XkbGetNames (3),

R XkbSetControls (3),

R XkbSetNames (3)