XSelectExtensionEvent(3X11)X FUNCTIONSXSelectExtensionEvent(3X11)
NAME
XSelectExtensionEvent, XGetSelectedExtensionEvents -
select extension events, get the list of currently
selected extension events
SYNTAX
XSelectExtensionEvent(display, w, eventlist, eventcount)
Display *display;
Window w;
XEventClass *eventlist;
int eventcount;
XGetSelectedExtensionEvents(display, w,
thisclienteventcountreturn,
thisclienteventlistreturn,
allclientseventcountreturn,
allclientseventlistreturn)
Display *display;
Window w;
int thisclienteventcountreturn;
XEventClass *thisclienteventlistreturn;
int allclientseventcountreturn;
XEventClass *allclientseventlistreturn;
ARGUMENTS
display Specifies the connection to the X server.
w Specifies the window whose events you are
interested in.
eventlist Specifies the list of event classes that
describe the events you are interested in.
eventcount Specifies the count of event classes in the
event list.
thisclienteventcountreturn
Returns the count of event classes selected by
this client.
thisclienteventlistreturn
Returns a pointer to the list of event classes
selected by this client.
allclientseventcountreturn
Returns the count of event classes selected by
all clients.
allclientseventlistreturn
Returns a pointer to the list of event classes
selected by all clients.
DESCRIPTION
The XSelectExtensionEvent request causes the X server to
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XSelectExtensionEvent(3X11)X FUNCTIONSXSelectExtensionEvent(3X11)
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 DeviceButton-
Press event with automatic passive grabbing enabled,
which is associated with the event class DeviceBut-
tonPressGrab. 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, Proxim-
ityIn, ProximityOut, DeviceStateNotify, DeviceMappiingNo-
tify, ChangeDeviceNotify, DevicePointerMotionHint, Device-
Button1Motion, DeviceButton2Motion, DeviceButton3Motion,
DeviceButton4Motion, DeviceButton5Motion, DeviceButtonMo-
tion, 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 speci-
fied window. The other lists the event classes selected
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XSelectExtensionEvent(3X11)X FUNCTIONSXSelectExtensionEvent(3X11)
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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