XkbNoteDeviceChanges(3) Note device changes reported in an XkbExtensionDeviceNotify event


void XkbNoteDeviceChanges (XkbDeviceChangesPtr old, XkbExtensionDeviceNotifyEvent *new, unsigned int wanted);


- old
structure tracking state changes
- new
event indicating state changes
- wanted
mask indicating changes to note


The wanted field specifies the changes that should be noted in old, and is composed of the bitwise inclusive OR of one or more of the masks from Table 1. The reason field of the event in new indicates the types of changes the event is reporting. XkbNoteDeviceChanges updates the XkbDeviceChangesRec specified by old with the changes that are both specified in wanted and contained in new->reason.

                         Table 1 XkbDeviceInfoRec Mask Bits                        
Name                         XkbDeviceInfoRec Value     Capability If Set
                             Fields Effected            
XkbXI_KeyboardsMask                           (1L <<0) Clients can use all
                                                       Xkb requests and events
                                                       with KeyClass devices 
                                                       supported by the input
                                                       device extension.
XkbXI_ButtonActionsMask       num_btns        (1L <<1) Clients can assign key 
                              btn_acts                 actions to buttons 
                                                       non-KeyClass input
                                                       extension devices.
XkbXI_IndicatorNamesMask      leds->names     (1L <<2) Clients can assign
                                                       names to indicators on
                                                       non-KeyClass input
                                                       extension devices.
XkbXI_IndicatorMapsMask       leds->maps      (1L <<3) Clients can assign
                                                       indicator maps to
                                                       indicators on 
                                                       non-KeyClass input
                                                       extension devices.
XkbXI_IndicatorStateMask      leds->state     (1L <<4) Clients can request 
                                                       the status of indicators
                                                       on non-KeyClass input
                                                       extension devices.
XkbXI_IndicatorsMask          sz_leds         (0x1c)   XkbXI_IndicatorNamesMask |
                              num_leds                 XkbXI_IndicatorMapsMask |
                              leds->*                  XkbXI_IndicatorStateMask
XkbXI_UnsupportedFeaturesMask unsupported     (1L <<15)
XkbXI_AllDeviceFeaturesMask   Those selected  (0x1e)   XkbXI_IndicatorsMask |
                              by Value Column          XkbSI_ButtonActionsMask
XkbXI_AllFeaturesMask         Those selected  (0x1f)   XkbSI_AllDeviceFeaturesMask |
                              by Value Column          XkbSI_KeyboardsMask
XkbXI_AllDetailsMask          Those selected  (0x801f) XkbXI_AllFeaturesMask |
                              by Value column          XkbXI_UnsupportedFeaturesMask

To update a local copy of the state and configuration of an X input extension device with the changes previously noted in an XkbDeviceChangesRec structure, use XkbGetDeviceInfoChanges.


Changes to an Xkb extension device may be tracked by listening to XkbDeviceExtensionNotify events and accumulating the changes in an XkbDeviceChangesRec structure. The changes noted in the structure may then be used in subsequent operations to update either a server configuration or a local copy of an Xkb extension device configuration. The changes structure is defined as follows:

typedef struct _XkbDeviceChanges {
    unsigned int         changed;       /* bits indicating what has changed */
    unsigned short       first_btn;     /* number of first button which changed, if any */
    unsigned short       num_btns;      /* number of buttons that have changed */
    XkbDeviceLedChangesRec leds;
} XkbDeviceChangesRec,*XkbDeviceChangesPtr;