NAME
XSetInputFocus, XGetInputFocus - control input focus
SYNTAX
int XSetInputFocus(Display *display, Window focus, int revert_to, Time
time);
int XGetInputFocus(Display *display, Window *focus_return, int
*revert_to_return);
ARGUMENTS
display Specifies the connection to the X server.
focus Specifies the window, PointerRoot, or None.
focus_return
Returns the focus window, PointerRoot, or None.
revert_to Specifies where the input focus reverts to if the window
becomes not viewable. You can pass RevertToParent,
RevertToPointerRoot, or RevertToNone.
revert_to_return
Returns the current focus state (RevertToParent,
RevertToPointerRoot, or RevertToNone).
time Specifies the time. You can pass either a timestamp or
CurrentTime.
DESCRIPTION
The XSetInputFocus function changes the input focus and the last-focus-
change time. It has no effect if the specified time is earlier than
the current last-focus-change time or is later than the current X
server time. Otherwise, the last-focus-change time is set to the
specified time (CurrentTime is replaced by the current X server time).
XSetInputFocus causes the X server to generate FocusIn and FocusOut
events.
Depending on the focus argument, the following occurs:
· If focus is None, all keyboard events are discarded until a new
focus window is set, and the revert_to argument is ignored.
· If focus is a window, it becomes the keyboard’s focus window. If
a generated keyboard event would normally be reported to this
window or one of its inferiors, the event is reported as usual.
Otherwise, the event is reported relative to the focus window.
· If focus is PointerRoot, the focus window is dynamically taken to
be the root window of whatever screen the pointer is on at each
keyboard event. In this case, the revert_to argument is ignored.
The specified focus window must be viewable at the time XSetInputFocus
is called, or a BadMatch error results. If the focus window later
becomes not viewable, the X server evaluates the revert_to argument to
determine the new focus window as follows:
· If revert_to is RevertToParent, the focus reverts to the parent
(or the closest viewable ancestor), and the new revert_to value is
taken to be RevertToNone.
· If revert_to is RevertToPointerRoot or RevertToNone, the focus
reverts to PointerRoot or None, respectively. When the focus
reverts, the X server generates FocusIn and FocusOut events, but
the last-focus-change time is not affected.
XSetInputFocus can generate BadMatch, BadValue, and BadWindow errors.
The XGetInputFocus function returns the focus window and the current
focus state.
DIAGNOSTICS
BadValue Some numeric value falls outside the range of values accepted
by the request. Unless a specific range is specified for an
argument, the full range defined by the argument’s type is
accepted. Any argument defined as a set of alternatives can
generate this error.
BadWindow A value for a Window argument does not name a defined Window.
SEE ALSO
XWarpPointer(3)
Xlib - C Language X Interface