X Version 11 (Release 5) XSelectExtensionEvent(3X11)
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.
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X Version 11 (ReleX
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ctExtensionEvent(3X11)
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 making XSelectExtensionEvent requests.
Currently defined macros include DeviceKeyPress,
DeviceKeyRelease, DeviceButtonPress, DeviceButtonRelese,
DeviceMotionNotify, DeviceFocusIn, DeviceFocusOut,
ProximityIn, ProximityOut, DeviceStateNotify,
DeviceMappiingNotify, ChangeDeviceNotify,
DevicePointerMotionHint, DeviceButton1Motion,
DeviceButton2Motion, DeviceButton3Motion,
DeviceButton4Motion, DeviceButton5Motion,
DeviceButtonMotion, DeviceOwnerGrabButton,
DeviceButtonPressGrab, 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
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X Version 11 (ReleX
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ctExtensionEvent(3X11)
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 window. 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 Window.
BadClass A value for an XEventClass argument is invalid.
SEE ALSO
Programming with Xlib
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