The need to allocate an XkbControlsRec structure seldom arises; Xkb creates one when an application calls XkbGetControls or a related function. For those situations where there is not an XkbControlsRec structure allocated in the XkbDescRec, allocate one by calling XkbAllocControls.
XkbAllocControls allocates the ctrls field of the xkb parameter, initializes all fields to zero, and returns Success. If the ctrls field is not NULL, XkbAllocControls simply returns Success. If xkb is NULL, XkbAllocControls reports a BadMatch error. If the ctrls field could not be allocated, it reports a BadAlloc error.
The which mask specifies the individual fields of the ctrls structure to be allocated and can contain any of the valid masks defined in Table 1. (SHOULD THIS COMMENT BE LEFT IN????) Because none of the currently existing controls have any structures associated with them, which is currently of little practical value in this call.
Table 1 shows the actual values for the individual mask bits used to select controls for modification and to enable and disable the control. Note that the same mask bit is used to specify general modifications to the parameters used to configure the control (which), and to enable and disable the control (enabled_ctrls). The anomalies in the table (no "ok" in column) are for controls that have no configurable attributes; and for controls that are not boolean controls and therefore cannot be enabled or disabled.
| Table 1 Controls Mask Bits |
| Mask Bit which or enabled Value |
| changed_ctrls _ctrls |
| XkbRepeatKeysMask ok ok (1L<<0) |
| XkbSlowKeysMask ok ok (1L<<1) |
| XkbBounceKeysMask ok ok (1L<<2) |
| XkbStickyKeysMask ok ok (1L<<3) |
| XkbMouseKeysMask ok ok (1L<<4) |
| XkbMouseKeysAccelMask ok ok (1L<<5) |
| XkbAccessXKeysMask ok ok (1L<<6) |
| XkbAccessXTimeoutMask ok ok (1L<<7) |
| XkbAccessXFeedbackMask ok ok (1L<<8) |
| XkbAudibleBellMask ok (1L<<9) |
| XkbOverlay1Mask ok (1L<<10) |
| XkbOverlay2Mask ok (1L<<11) |
| XkbIgnoreGroupLockMask ok (1L<<12) |
| XkbGroupsWrapMask ok (1L<<27) |
| XkbInternalModsMask ok (1L<<28) |
| XkbIgnoreLockModsMask ok (1L<<29) |
| XkbPerKeyRepeatMask ok (1L<<30) |
| XkbControlsEnabledMask ok (1L<<31) |
| XkbAccessXOptionsMask ok ok (XkbStickyKeysMask | |
| XkbAccessXFeedbackMask) |
| XkbAllBooleanCtrlsMask ok (0x00001FFF) |
| XkbAllControlsMask ok (0xF8001FFF) |
the ctrls field is not NULL