XSelectExtensionEvent(3X11) X11 SDE 5.4R3.00 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.
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
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XSelectExtensionEvent(3X11) X11 SDE 5.4R3.00 XSelectExtensionEvent(3X11)
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 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.
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XSelectExtensionEvent(3X11) X11 SDE 5.4R3.00 XSelectExtensionEvent(3X11)
BadClass A value for an XEventClass argument is invalid.
SEE ALSO
Programming with Xlib
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