XSetInputFocus
Syntax
XSetInputFocus(display, focus, revert_to, time)
Display *display;
Window focus;
int revert_to;
Time time;
Arguments
| display
| Specifies the connection to the X server.
|
| focus
| Specifies the 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.
|
| 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.
Diagnostics
| BadMatch
| An
InputOnly
window is used as a Drawable.
|
| BadMatch
| Some argument or pair of arguments has the correct type and range but fails
to match in some other way required by the request.
|
| BadMatch
| An
InputOnly
window is used as a Drawable.
|
| BadMatch
| Some argument or pair of arguments has the correct type and range but fails
to match in some other way required by the request.
|
| 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
XGetInputFocus(),
XWarpPointer(),
"
Controlling Input Focus".
Christophe Tronche, [email protected]
