Man page 3 : XkbSetMap

XkbSetMap - Send a complete new set of values for entire components to the server.

Bool XkbSetMap (Display * dpy , unsigned int which , XkbDescPtr xkb );

• - dpy
      connection to X server
• - which
      mask selecting subcomponents to update
• - xkb
      description from which new values are taken

There are two ways to make changes to map components: either change a local copy of the keyboard map and call XkbSetMapto send the modified map to the server, or, to reduce network traffic, use an XkbMapChangesRec structure and call XkbChangeMap. Use XkbSetMapto send a complete new set of values for entire components (for example, all symbols, all actions, and so on) to the server. The whichparameter specifies the components to be sent to the server, and is a bitwise inclusive OR of the masks listed in Table 1. The xkbparameter is a pointer to an XkbDescRec structure and contains the information to be copied to the server. For each bit set in the whichparameter, XkbSetMaptakes the corresponding structure values from the xkbparameter and sends it to the server specified by dpy. If any components specified by whichare not present in the xkbparameter, XkbSetMapreturns False. Otherwise, it sends the update request to the server and returns True. XkbSetMapcan generate BadAlloc, BadLength, and BadValue protocol errors. Key types, symbol maps, and actions are all interrelated; changes in one require changes in the others. Xkb provides functions to make it easier to edit these components and handle the interdependencies. Table 1 lists these helper functions and provides a pointer to where they are defined.

The changedfield identifies the map components that have changed in an XkbDescRec structure and may contain any of the bits in Table 1, which are also shown in Table 2. Every 1 bit in changedalso identifies which other fields in the XkbMapChangesRec structure contain valid values, as indicated in Table 2. The min_key_codeand max_key_codefields are for reference only; they are ignored on any requests sent to the server and are always updated by the server whenever it returns the data for an XkbMapChangesRec.

• True
                 The XkbSetMapfunction returns True all components specified by whichare present in the xkbparameter.
• False
                 The XkbSetMapfunction returns False if any component specified by whichis not present in the xkbparameter.

Use the XkbMapChangesRec structure to identify and track partial modifications to the mapping components and to reduce the amount of traffic between the server and clients.

typedef struct _XkbMapChanges {
    unsigned short   changed;            /(** identifies valid components in structure */
    KeyCode          min_key_code;       /(** lowest numbered keycode for device */
    KeyCode          max_key_code;       /(** highest numbered keycode for device */
    unsigned char    first_type;         /(** index of first key type modified */
    unsigned char    num_types;          /(** # types modified */
    KeyCode          first_key_sym;      /(** first key whose key_sym_map changed */
    unsigned char    num_key_syms;       /(** # key_sym_map entries changed */
    KeyCode          first_key_act;      /(** first key whose key_acts entry changed */
    unsigned char    num_key_acts;       /(** # key_acts entries changed */
    KeyCode          first_key_behavior; /(** first key whose behaviors changed */
    unsigned char    num_key_behaviors;  /(** # behaviors entries changed */
    KeyCode          first_key_explicit; /(** first key whose explicit entry changed */
    unsigned char    num_key_explicit;   /(** # explicit entries changed */
    KeyCode          first_modmap_key;   /(** first key whose modmap entry changed */
    unsigned char    num_modmap_keys;    /(** # modmap entries changed */
    KeyCode          first_vmodmap_key;  /(** first key whose vmodmap changed */
    unsigned char    num_vmodmap_keys;   /(** # vmodmap entries changed */
    unsigned char    pad1;               /(** reserved */
    unsigned short   vmods;              /(** mask indicating which vmods changed */
} XkbMapChangesRec,*XkbMapChangesPtr;

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 flags field is private to the library: modifyingflagsmay 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 3.

BadAlloc

               Unable to allocate storage

BadLength

               The length of a request is shorter or longer than that required to minimally contain the arguments

BadValue

               An argument is out of range

R XkbChangeMap (3),

R XkbChangeTypesOfKey (3),

R XkbCopyKeyType (3),

R XkbCopyKeyTypes (3),

R XkbGetKeyActions (3),

R XkbGetKeyBehaviors (3),

R XkbGetKeyExplicitComponents (3),

R XkbGetKeyModifierMap (3),

R XkbGetKeySyms (3),

R XkbGetKeyTypes (3),

R XkbResizeKeyActions (3),

R XkbResizeKeySyms (3),

R XkbResizeKeyType (3),

R XkbGetVirtualModMap (3),

R XkbGetVirtualMods (3)