XSelectExtensionEvent(3)

NAME

       XSelectExtensionEvent,  XGetSelectedExtensionEvents  - select extension
       events, get the list of currently selected extension events

SYNTAX

       XSelectExtensionEvent(display, w, event_list, event_count)
             Display *display;
             Window w;
             XEventClass *event_list;
             int event_count;

       XGetSelectedExtensionEvents(display, w, this_client_event_count_return,
       this_client_event_list_return,          all_clients_event_count_return,
       all_clients_event_list_return)
             Display *display;
             Window w;
             int this_client_event_count_return;
             XEventClass *this_client_event_list_return;
             int all_clients_event_count_return;
             XEventClass *all_clients_event_list_return;

ARGUMENTS

       display     Specifies the connection to the X server.

       w           Specifies the window whose events you are interested in.

       event_list  Specifies  the  list  of  event  classes  that describe the
                   events you are interested in.

       event_count Specifies the count of event classes in the event list.

       this_client_event_count_return
                   Returns the count of event classes selected by this client.

       this_client_event_list_return
                   Returns a pointer to the list of event classes selected  by
                   this client.

       all_clients_event_count_return
                   Returns the count of event classes selected by all clients.

       all_clients_event_list_return
                   Returns  a pointer to the list of event classes selected by
                   all clients.

DESCRIPTION

       The XSelectExtensionEvent request causes the X  server  to  report  the
       events associated with the specified list of event classes.  Initially,
       X will not report any of these events.  Events are reported relative to
       a  window.  If a window is not interested in a device event, it usually
       propagates to the closest  ancestor  that  is  interested,  unless  the
       do_not_propagate mask prohibits it.

       Multiple clients can select for the same events on the same window with
       the following restrictions:

       o    Multiple clients can select events  on  the  same  window  because
            their  event  masks  are disjoint.  When the X server generates an
            event, it reports it to all interested clients.

       o    Only one client at a time can  select  a  DeviceButtonPress  event
            with  automatic passive grabbing enabled, which is associated with
            the event class DeviceButtonPressGrab.  To  receive  DeviceButton-
            Press  events  without automatic passive grabbing, use event class
            DeviceButtonPress but do not  specify  event  class  DeviceButton-
            PressGrab.

       The server reports the event to all interested clients.

       Information  contained in the XDevice structure returned by XOpenDevice
       is used by macros to obtain the event classes that clients use in  mak-
       ing  XSelectExtensionEvent  requests.  Currently defined macros include
       DeviceKeyPress,  DeviceKeyRelease,  DeviceButtonPress,  DeviceButtonRe-
       lese,  DeviceMotionNotify,  DeviceFocusIn, DeviceFocusOut, ProximityIn,
       ProximityOut, DeviceStateNotify, DeviceMappiingNotify,  ChangeDeviceNo-
       tify,    DevicePointerMotionHint,    DeviceButton1Motion,    DeviceBut-
       ton2Motion,   DeviceButton3Motion,   DeviceButton4Motion,    DeviceBut-
       ton5Motion,  DeviceButtonMotion,  DeviceOwnerGrabButton,  DeviceButton-
       PressGrab, and NoExtensionEvent.

       To obtain the proper event class for a particular device,  one  of  the
       above  macros  is  invoked using the XDevice structure for that device.
       For example,

       DeviceKeyPress (*device, type, eventclass);

       returns the DeviceKeyPress event type and the eventclass for  selecting
       DeviceKeyPress events from this device.

       XSelectExtensionEvent  can generate a BadWindow or BadClass error.  The
       XGetSelectedExtensionEvents  request  reports  the   extension   events
       selected by this client and all clients for the specified window.  This
       request returns pointers to two  XEventClass  arrays.   One  lists  the
       input  extension events selected by this client from the specified win-
       dow.  The other lists the event classes selected by  all  clients  from
       the specified window.  You should use XFree to free these two arrays.

       XGetSelectedExtensionEvents can generate a BadWindow error.

DIAGNOSTICS

       BadWindow   A  value for a Window argument does not name a defined Win-
                   dow.

       BadClass    A value for an XEventClass argument is invalid.

SEE ALSO

       Programming with Xlib

X Version 11                      libXi 1.0.2      XSelectExtensionEvent(3X11)