menubutton - Create and manipulate menubutton widgets

SYNOPSIS

Switch:  -height  
Name: height
Class: Height

Specifies a desired height for the menubutton. If an image or bitmap is being displayed in the menubutton then the value is in screen units (i.e. any of the forms acceptable to Tk_GetPixels); for text it is in lines of text. If this option isn't specified, the menubutton's desired height is computed from the size of the image or bitmap or text being displayed in it.

Switch:  -indicatoron  
Name: indicatorOn
Class: IndicatorOn

The value must be a proper boolean value. If it is true then a small indicator rectangle will be displayed on the right side of the menubutton and the default menu bindings will treat this as an option menubutton. If false then no indicator will be displayed.

Switch:  -menu  
Name: menu
Class: MenuName

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

Switch:  -state  
Name: state
Class: State

Specifies one of three states for the menubutton: normal, active, or disabled. In normal state the menubutton is displayed using the foreground and background options. The active state is typically used when the pointer is over the menubutton. In active state the menubutton is displayed using the activeForeground and activeBackground 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 disabledForeground and background options determine how the button is displayed.

Switch:  -width  
Name: width
Class: Width

Specifies a desired width for the menubutton. If an image or bitmap is being displayed in the menubutton then the value is in screen units (i.e. any of the forms acceptable to Tk_GetPixels); for text it is in characters. If this option isn't specified, the menubutton's desired width is computed from the size of the image or bitmap or text being displayed in it.

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INTRODUCTION

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

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 or if wrapping occurs because of the wrapLength option) and one of the characters may optionally be underlined using the underline 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 is moved over the menu before releasing the mouse button, the button release causes the underlying menu entry to be invoked. When the button is released, the menu is unposted.

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 in the same menu bar without releasing the mouse button, then the menu of the first menubutton is unposted and the menu of the new menubutton is posted instead.

There are several interactions between menubuttons and menus; see the menu manual entry for information on various menu configurations, such as pulldown menus and option menus.

WIDGET COMMAND

The menubutton command creates a new Tcl command whose name is pathName. This command may be used to invoke various operations on the widget. It has the following general form: pathName option ?arg arg ...? Option and the args determine the exact behavior of the command. The following commands are possible for menubutton widgets:

pathName cget option

Returns the current value of the configuration option given by option. Option may have any of the values accepted by the menubutton command.

pathName configure ?option? ?value option value ...?

Query or modify the configuration options of the widget. If no option is specified, returns a list describing all of the available options for pathName (see Tk_ConfigureInfo for information on the format of this list). If option is specified with no value, then the command returns a list describing the one named option (this list will be identical to the corresponding sublist of the value returned if no option is specified). 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 menubutton command.

DEFAULT BINDINGS

Tk automatically creates class bindings for menubuttons that give them the following default behavior:

[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 menubutton: its relief changes to raised and its associated menu is posted under the menubutton. If the mouse is dragged down into the menu with the button still down, and if the mouse button is then released over an entry in the menu, the menubutton is unposted and the menu entry is invoked.

[3]
If button 1 is pressed over a menubutton and then released over that menubutton, the menubutton stays posted: you can still move the mouse over the menu and click button 1 on an entry to invoke it. Once a menu entry has been invoked, the menubutton unposts itself.

[4]
If button 1 is pressed over a menubutton and then dragged over some other menubutton, the original menubutton unposts itself and the new menubutton posts.

[5]
If button 1 is pressed over a menubutton and released outside any menubutton or menu, the menubutton unposts without invoking any menu entry.

[6]
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 manual entry for details on these bindings.

[7]
If the underline option has been specified for a menubutton then keyboard traversal may be used to post the menubutton: Alt+x, where x is the underlined character (or its lower-case or upper-case equivalent), may be typed in any window under the menubutton's toplevel to post the menubutton.

[8]
The F10 key may be typed in any window to post the first menubutton under its toplevel window that isn't disabled.

[9]
If a menubutton has the input focus, the space and return keys post the menubutton.

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

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

KEYWORDS