---
name: "usual"
section: "n"
platform: "macos"
package: "tcl"
version: "152"
release: "macOS 26.5"
platforms: ["macos"]
url: "https://new.carta.tech/usual/n"
---

# usual(n)

access default option-handling commands for a mega-widget component

## NAME

usual - access default option-handling commands\
\
 	for a mega-widget component

## SYNOPSIS

**usual ?***tag*? ?*commands*?

## DESCRIPTION

The **usual** command is used outside of an **\[incr Tcl\]** class definition to define the usual set of option-handling commands for a component widget.  Option-handling commands are used when a component is registered with the **Archetype** base class via the "**itk\_component add**" method.  They specify how the component's configuration options should be integrated into the composite option list for the mega-widget. Options can be kept, renamed, or ignored, as described in the **Archetype** man page.

It is tedious to include the same declarations again and again whenever components are added.  The **usual** command allows a standard code fragment to be registered for each widget class, which is used by default to handle the options.  All of the standard Tk widgets have **usual** declarations defined in the **\[incr Tk\]** library.  Similar **usual** declarations should be created whenever a new mega-widget class is conceived. Only the most-generic options should be included in the **usual** declaration.

The *tag* name is usually the name of a widget class, which starts with a capital letter; however, any string registered here can be used later with the **usual** command described on the **Archetype** man page.

If the *commands* argument is specified, it is associated with the *tag* string, and can be accessed later via **itk\_component add**.

If only the *tag* argument is specified, this command looks for an existing *tag* name and returns the commands associated with it.  If there are no commands associated with *tag*, this command returns the null string.

If no arguments are specified, this command returns a list of all *tag* names previously registered.

## EXAMPLE

Following is the **usual** declaration for the standard Tk button widget: itk::usual Button {\
     keep -background -cursor -foreground -font\
     keep -activebackground -activeforeground -disabledforeground\
     keep -highlightcolor -highlightthickness\
     rename -highlightbackground -background background Background } Only the options that would be common to all buttons in a single mega-widget are kept or renamed.  Options like "-text" that would be unique to a particular button are ignored.

## KEYWORDS

itk, Archetype, component, mega-widget