xref: /inferno-os/man/9/menubutton (revision 46439007cf417cbd9ac8049bb4122c890097a0fa)
MENUBUTTON 9
NAME
menubutton - Create and manipulate menubutton widgets
SYNOPSIS
\f5menubutton pathName ?options?
STANDARD OPTIONS
.EX -activebackground -disabledcolor -justify -activeforeground -font -relief -anchor -foreground -takefocus -background -highlightcolor -text -bitmap -highlightthickness -underline -borderwidth -image
"WIDGET-SPECIFIC OPTIONS"

-height state Specifies a desired height for the menubutton. If this option is not specified, the menubutton's desired height is computed from the size of the image or bitmap or text being displayed in it.

-menu widgetname Specifies the path name of the menu associated with this menubutton. The menu must be a child of the menubutton.

-state state Specifies one of three states for the menubutton: \f5normal, \f5active, or \f5disabled. In normal state the menubutton is displayed using the \f5foreground and \f5background options. The active state is typically used when the pointer is over the menubutton. In active state the menubutton is displayed using the \f5activeforeground and \f5activebackground options. Disabled state means that the menubutton should be insensitive: the default bindings will refuse to activate the widget and will ignore mouse button presses. In this state the \f5disabledcolor and \f5background options determine how the button is displayed.

-width dist Specifies a desired width for the menubutton. If this option is not specified, the menubutton's desired width is computed from the size of the image or bitmap or text being displayed in it.

INTRODUCTION

The \f5menubutton command creates a new window (given by the pathName argument) and makes it into a menubutton widget. Additional options, described above, may be specified to configure aspects of the menubutton such as its colors, font, text, and initial relief. The \f5menubutton command returns its pathName argument. At the time this command is invoked, there must not exist a window named pathName.

A menubutton is a widget that displays a textual string, bitmap, or image and is associated with a menu widget. If text is displayed, it must all be in a single font, but it can occupy multiple lines on the screen (if it contains newlines) and one of the characters may optionally be underlined using the \f5underline option. In normal usage, pressing mouse button 1 over the menubutton causes the associated menu to be posted just underneath the menubutton. If the mouse button is released over the menubutton then the menu remains posted; clicking on the menubutton again unposts the menu. Releasing the mouse button over a menu entry invokes the entry, while releasing mouse button elsewhere unposts the menu.

Menubuttons are typically organized into groups called menu bars that allow scanning: if the mouse button is pressed over one menubutton (causing it to post its menu) and the mouse is moved over another menubutton without releasing the mouse button, then the menu of the first menubutton is unposted and the menu of the new menubutton is posted instead.

"WIDGET COMMAND"

The \f5menubutton command creates a new Tk command whose name is pathName. This command may be used to invoke various operations on the widget. It has the following general form:

.EX pathName option ?arg arg ...?

Option and the args determine the exact behaviour of the command. The following commands are possible for menubutton widgets:

pathName \f5cget option Returns the current value of the configuration option given by option. Option may have any of the values accepted by the \f5menubutton command.

pathName \f5configure ?option? ?value option value ...? Query or modify the configuration options of the widget. If no option is specified, returns a list of all of the available options for pathName. If one or more option-value pairs are specified, then the command modifies the given widget option(s) to have the given value(s); in this case the command returns an empty string. Option may have any of the values accepted by the \f5menubutton command.

"DEFAULT BINDINGS"
Tk automatically creates class bindings for menubuttons that give them the following default behaviour:
[1]
A menubutton activates whenever the mouse passes over it and deactivates whenever the mouse leaves it.
[2]
Pressing mouse button 1 over a menubutton posts the menu specified by the -menu option. If the menu is already posted then it is unposted.
[3]
Releasing mouse button 1 over the menubutton leaves the menu posted. Releasing the button over a menu entry, if the menu is posted, invokes that entry. Releaseing the button anywhere else unposts the menu.
[4]
When a menubutton is posted, its associated menu claims the input focus to allow keyboard traversal of the menu and its submenus. See the menu (9) manual entry for details on these bindings.

If the menubutton's state is \f5disabled then none of the above actions occur: the menubutton is completely non-responsive.

The behaviour of menubuttons can be changed by defining new bindings for individual widgets or by redefining the class bindings.

SEE ALSO
menu (9), options (9), types (9)