|
Table of Contents
XSelectExtensionEvent, XGetSelectedExtensionEvents -
select extension events, get the list of currently selected extension events
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;
- 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.
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 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.
- BadWindow
- A value for a Window
argument does not name a defined Window.
- BadClass
- A value for an XEventClass
argument is invalid.
Programming with Xlib
Table of Contents
|
