Calling XkbGetMap should be sufficient for most applications to get client and server maps. As a result, most applications do not need to directly allocate client and server maps.
If you change the number of key types or construct map components without loading the necessary components from the X server, do not allocate any map components directly using malloc or Xmalloc. Instead, use the Xkb allocators, XkbAllocClientMap, and XkbAllocServerMap.
Similarly, use the Xkb destructors, XkbFreeClientMap, and XkbFreeServerMap instead of free or Xfree.
XkbAllocClientMap allocates and initializes an empty client map in the map field of the keyboard description specified by xkb. The which parameter specifies the particular components of the client map structure to allocate and is a mask composed by a bitwise inclusive OR of one or more of the masks shown in Table 1.
| Table 1 XkbAllocClientMap Masks | |
| Mask | Effect |
| XkbKeyTypesMask |
The type_count field specifies the number of entries to preallocate for the
types field of the client map. If the type_count field is less than
XkbNumRequiredTypes returns BadValue.
|
| XkbKeySymsMask |
The min_key_code and max_key_code fields of the xkb parameter are used to
allocate the syms and key_sym_map fields of the client map. The fields are
allocated to contain the maximum number of entries necessary for max_key_code -
min_key_code + 1 keys.
|
| XkbModifierMapMask |
The min_key_code and max_key_code fields of the xkb parameter are used to
allocate the modmap field of the client map. The field is allocated to contain
the maximum number of entries necessary for max_key_code - min_key_code + 1
keys.
|
NOTE: The min_key_code and max_key_code fields of the xkb parameter must be legal values if the XkbKeySymsMask or XkbModifierMapMask masks are set in the which parameter. If they are not valid, XkbAllocClientMap returns BadValue.
If the client map of the keyboard description is not NULL, and any fields are already allocated in the client map, XkbAllocClientMap does not overwrite the existing values; it simply ignores that part of the request. The only exception is the types array. If type_count is greater than the current num_types field of the client map, XkbAllocClientMap resizes the types array and resets the num_types field accordingly.
If XkbAllocClientMap is successful, it returns Success. Otherwise, it can return either BadMatch, BadAlloc, or BadValue errors.