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 isn't specified, this command returns the name of the
application (the name that may be used in send commands to com‐
municate 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 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 │
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 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 accomo‐ │
date the new scaling factor. │
KEYWORDS
application name, send
Tk 4.0 tk(n)
