To update only partial components of a keyboard description, modify the appropriate fields in the server and map components of a local copy of the keyboard description, then call XkbChangeMap with an XkbMapChangesRec structure indicating which components have changed.
XkbChangeMap copies any components specified by the changes structure from the keyboard description, xkb, to the X server specified by dpy.
If any components specified by changes are not present in the xkb parameter, XkbChangeMap returns False. Otherwise, it sends a request to the server and returns True.
XkbChangeMap can generate BadAlloc, BadLength, and BadValue protocol errors.
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;