tk - Manipulate Tk internal state
?arg arg ...
command provides access to miscellaneous elements of Tk's internal
state. Most of the information manipulated by this command pertains 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
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 command'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
- tk caret window ?-x x? ?-y y?
- Sets and queries the caret location for the display of the specified 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 scaling ?-displayof window? ?number?
- Sets and queries the current scaling factor used by Tk to convert 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
A “point” is a unit of measurement equal to 1/72 inch. A scaling
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
displayed 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
accommodate the new scaling factor.
- 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.
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 and error if tried.
- tk useinputmethods ?-displayof window?
- 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
- tk windowingsystem
- Returns the current Tk windowing system, one of x11 (X11-based),
win32 (MS Windows), or aqua (Mac OS X Aqua).
application name, send