tk(n) Tk Built-In Commands tk(n)______________________________________________________________________________NAMEtk - Manipulate Tk internal state
SYNOPSIStk option ?arg arg ...?
_________________________________________________________________DESCRIPTION
The tk command provides access to miscellaneous elements of Tk's inter‐
nal state. Most of the information manipulated by this command per‐
tains to the application as a whole, or to a screen or display, rather
than to a particular window. The command can take any of a number of
different forms depending on the option argument. The legal forms are:
tk appname ?newName?
If newName is not specified, this command returns the name of
the application (the name that may be used in send commands to
communicate with the application). If newName is specified,
then the name of the application is changed to newName. If the
given name is already in use, then a suffix of the form “ #2” or
“ #3” is appended in order to make the name unique. The com‐
mand's result is the name actually chosen. newName should not
start with a capital letter. This will interfere with option
processing, since names starting with capitals are assumed to be
classes; as a result, Tk may not be able to find some options
for the application. If sends have been disabled by deleting
the send command, this command will reenable them and recreate
the send command.
tk busy subcommand ...
This command controls the marking of window hierarchies as
“busy”, rendering them non-interactive while some other opera‐
tion is proceeding. For more details see the busy manual page.
tk caret window ?-x x? ?-y y? ?-height height?
Sets and queries the caret location for the display of the spec‐
ified Tk window window. The caret is the per-display cursor
location used for indicating global focus (e.g. to comply with
Microsoft Accessibility guidelines), as well as for location of
the over-the-spot XIM (X Input Methods) or Windows IME windows.
If no options are specified, the last values used for setting
the caret are return in option-value pair format. -x and -y
represent window-relative coordinates, and -height is the height
of the current cursor location, or the height of the specified
window if none is given.
tk inactive ?-displayof window? ?reset?
Returns a positive integer, the number of milliseconds since the
last time the user interacted with the system. If the -displayof
option is given then the return value refers to the display of
window; otherwise it refers to the display of the application's
main window.
tk inactive will return -1, if querying the user inactive time
is not supported by the system, and in safe interpreters.
If the literal string reset is given as an additional argument,
the timer is reset and an empty string is returned. Resetting
the inactivity time is forbidden in safe interpreters and will
throw an error if tried.
tk fontchooser subcommand ...
Controls the Tk font selection dialog. For more details see the
fontchooser manual page.
tk scaling ?-displayof window? ?number?
Sets and queries the current scaling factor used by Tk to con‐
vert between physical units (for example, points, inches, or
millimeters) and pixels. The number argument is a floating
point number that specifies the number of pixels per point on
window's display. If the window argument is omitted, it
defaults to the main window. If the number argument is omitted,
the current value of the scaling factor is returned.
A “point” is a unit of measurement equal to 1/72 inch. A scal‐
ing factor of 1.0 corresponds to 1 pixel per point, which is
equivalent to a standard 72 dpi monitor. A scaling factor of
1.25 would mean 1.25 pixels per point, which is the setting for
a 90 dpi monitor; setting the scaling factor to 1.25 on a 72 dpi
monitor would cause everything in the application to be dis‐
played 1.25 times as large as normal. The initial value for the
scaling factor is set when the application starts, based on
properties of the installed monitor, but it can be changed at
any time. Measurements made after the scaling factor is changed
will use the new scaling factor, but it is undefined whether
existing widgets will resize themselves dynamically to accommo‐
date the new scaling factor.
tk useinputmethods ?-displayof window? ?boolean?
Sets and queries the state of whether Tk should use XIM (X Input
Methods) for filtering events. The resulting state is returned.
XIM is used in some locales (i.e., Japanese, Korean), to handle
special input devices. This feature is only significant on X.
If XIM support is not available, this will always return 0. If
the window argument is omitted, it defaults to the main window.
If the boolean argument is omitted, the current state is
returned. This is turned on by default for the main display.
tk windowingsystem
Returns the current Tk windowing system, one of x11 (X11-based),
win32 (MS Windows), or aqua (Mac OS X Aqua).
SEE ALSObusy(n), fontchooser(n), send(n), winfo(n)KEYWORDS
application name, send
Tk 8.4 tk(n)
