XSelectExtensionEvent(3X11)XSelectExtensionEvent(3X11)NAME
XSelectExtensionEvent, XGetSelectedExtensionEvents - select extension
events, get the list of currently selected extension events
SYNOPSIS
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
Specifies the connection to the X server. Specifies the window whose
events you are interested in. Specifies the list of event classes that
describe the events you are interested in. Specifies the count of
event classes in the event list. Returns the count of event classes
selected by this client. Returns a pointer to the list of event
classes selected by this client. Returns the count of event classes
selected by all clients. 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: 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. 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 DeviceButtonPress events without
automatic passive grabbing, use event class DeviceButtonPress but do
not specify event class DeviceButtonPressGrab.
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
A value for a Window argument does not name a defined Window. A value
for an XEventClass argument is invalid.
SEE ALSO
Programming with Xlib
XSelectExtensionEvent(3X11)
