Tribblix: manual page: XSendEvent.3

XSendEvent(3) XLIB FUNCTIONS XSendEvent(3)

NAME

XSendEvent, XDisplayMotionBufferSize, XGetMotionEvents, XTimeCoord -
send events and pointer motion history structure

SYNTAX

Status XSendEvent(Display *display, Window w, Bool propagate, long
event_mask, XEvent *event_send);

unsigned long XDisplayMotionBufferSize(Display *display);

XTimeCoord *XGetMotionEvents(Display *display, Window w, Time start,
Time stop, int *nevents_return);

ARGUMENTS

display Specifies the connection to the X server.

event_mask
Specifies the event mask.

event_send
Specifies the event that is to be sent.

nevents_return
Returns the number of events from the motion history
buffer.

propagate Specifies a Boolean value.

start

stop Specify the time interval in which the events are returned
from the motion history buffer. You can pass a timestamp
or CurrentTime. PointerWindow, or InputFocus.

w Specifies the window the window the event is to be sent to.

DESCRIPTION

The XSendEvent function identifies the destination window, determines
which clients should receive the specified events, and ignores any
active grabs. This function requires you to pass an event mask. For
a discussion of the valid event mask names, see section 10.3. This
function uses the w argument to identify the destination window as
follows:

+o If w is PointerWindow, the destination window is the window that
contains the pointer.

+o If w is InputFocus and if the focus window contains the pointer,
the destination window is the window that contains the pointer;
otherwise, the destination window is the focus window.

To determine which clients should receive the specified events,
XSendEvent uses the propagate argument as follows:

+o If event_mask is the empty set, the event is sent to the client
that created the destination window. If that client no longer
exists, no event is sent.

+o If propagate is False, the event is sent to every client
selecting on destination any of the event types in the
event_mask argument.

+o If propagate is True and no clients have selected on destination
any of the event types in event-mask, the destination is
replaced with the closest ancestor of destination for which some
client has selected a type in event-mask and for which no
intervening window has that type in its do-not-propagate-mask.
If no such window exists or if the window is an ancestor of the
focus window and InputFocus was originally specified as the
destination, the event is not sent to any clients. Otherwise,
the event is reported to every client selecting on the final
destination any of the types specified in event_mask.

The event in the XEvent structure must be one of the core events or
one of the events defined by an extension (or a BadValue error
results) so that the X server can correctly byte-swap the contents as
necessary. The contents of the event are otherwise unaltered and
unchecked by the X server except to force send_event to True in the
forwarded event and to set the serial number in the event correctly;
therefore these fields and the display field are ignored by
XSendEvent.

XSendEvent returns zero if the conversion to wire protocol format
failed and returns nonzero otherwise. XSendEvent can generate
BadValue and BadWindow errors.

The server may retain the recent history of the pointer motion and do
so to a finer granularity than is reported by MotionNotify events.
The XGetMotionEvents function makes this history available.

The XGetMotionEvents function returns all events in the motion
history buffer that fall between the specified start and stop times,
inclusive, and that have coordinates that lie within the specified
window (including its borders) at its present placement. If the
server does not support motion history, if the start time is later
than the stop time, or if the start time is in the future, no events
are returned; XGetMotionEvents returns NULL. If the stop time is in
the future, it is equivalent to specifying CurrentTime.
XGetMotionEvents can generate a BadWindow error.

STRUCTURES

The XTimeCoord structure contains:

typedef struct {
Time time;
short x, y;
} XTimeCoord;

The time member is set to the time, in milliseconds. The x and y
members are set to the coordinates of the pointer and are reported
relative to the origin of the specified window.

DIAGNOSTICS