NAME

menubutton − Create and manipulate menubutton widgets

SYNOPSIS

menubutton pathName ?options? 

STANDARD OPTIONS

activeBackgroundbitmapfontrelief
activeForegroundborderWidthforegroundtext
anchorcursorpadXtextVariable
backgrounddisabledForegroundpadY underline

See the “options” manual entry for details on the standard options. 

WIDGET-SPECIFIC OPTIONS

Name:height
Class:Height
Command-Line Switch: −height

Specifies a desired height for the menu button.  If a bitmap is being displayed in the menu button 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 menu button’s desired height is computed from the size of the bitmap or text being displayed in it. 

Name:menu
Class:MenuName
Command-Line Switch: −menu

Specifies the path name of the menu associated with this menubutton. 

Name:state
Class:State
Command-Line Switch: −state

Specifies one of three states for the menu button:  normal, active, or disabled.  In normal state the menu button is displayed using the foreground and background options.  The active state is typically used when the pointer is over the menu button.  In active state the menu button is displayed using the activeForeground and activeBackground options.  Disabled state means that the menu button is insensitive:  it doesn’t activate and doesn’t respond to mouse button presses.  In this state the disabledForeground and background options determine how the button is displayed. 

Name:variable
Class:Variable
Command-Line Switch: −variable

Specifies the name of a global variable to set whenever this menubutton posts its menu.  Also serves as name of group of related menubuttons (allows event sharing between menubuttons and menus).  Defaults to postedMenu. 

Name:width
Class:Width
Command-Line Switch: −width

Specifies a desired width for the menu button.  If a bitmap is being displayed in the menu button 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 menu button’s desired width is computed from the size of the bitmap or text being displayed in it. 

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 or bitmap

and is associated with a menu widget.  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 organized into groups to allow menu 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 group without releasing the mouse button, then the menu of the first menubutton is unposted and the menu of the new menubutton is posted instead.  This makes it possible to scan a row of pull-down menus to find a particular entry.  Typically, all of the menubuttons for an application are in the same group, but it is possible to assign multiple groups:  this allows scanning within a group but not between them. 

Each menubutton is associated with a particular global variable, determined by the variable option, and the variable determines the menubutton’s group:  all menubuttons with the same associated variable are in the same group.  Whenever a menubutton posts its menu it stores the path name of the menubutton in the associated variable.  Furthermore, the menubutton monitors the value of that variable continuously.  When the variable changes value (e.g. because some other menubutton posted its menu) then the menubutton will unpost its menu if the new value is different than the menubutton’s name or post its menu if the new value is the same as the menubutton’s name.  This means you can cause a menu to be posted or unposted just by changing the value of the variable. 

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 activate
Change the menu button’s state to active and redisplay the menu button using its active foreground and background colors instead of normal colors.  The command returns an empty string.  This command is ignored if the menu button’s state is disabled.  This command is obsolete and will eventually be removed; use “pathName configure −state active” instead. 

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. 

pathName deactivate
Change the menu button’s state to normal and redisplay the menu button using its normal foreground and background colors.  The command returns an empty string.  This command is ignored if the menu button’s state is disabled.  This command is obsolete and will eventually be removed; use “pathName configure −state normal” instead. 

pathName post
Arrange for the menubutton’s associated menu to be posted.  This is done by executing a Tcl command with the form

menu post x y group

where menu is the path name of the associated menu, x and y are the root-window coordinates of the lower-left corner of the menubutton, and group is the name of the menubutton’s group (its variable option).  As a side effect, the path name of the associated menu is stored in the global variable associated with the menubutton.  Returns an empty string.  This command is ignored if the menu button’s state is disabled. 

pathName unpost
Store an empty string in the variable associated with the menubutton.  If the menubutton has posted its menu, this will cause it to unpost its menu by executing a command of the form

menu unpost

where menu is the name of the associated menu.  If any other menubutton sharing the same variable has posted its menu, then that menubutton will unpost its menu in a similar fashion.  Returns an empty string. 
 

DEFAULT BINDINGS

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

[1]A menu button activates whenever the mouse passes over it and deactivates whenever the mouse leaves it. 

[2]A menu button’s relief is changed to raised whenever mouse button 1 is pressed over it, and the relief is restored to its original value when button 1 is later released or the mouse is dragged into another menu button in the same group. 

[3]When mouse button 1 is pressed over a menu button, or when the mouse is dragged into a menu button with mouse button 1 pressed, the associated menu is posted;  the mouse can be dragged across the menu and released over an entry in the menu to invoke that entry.  The menu is unposted when button 1 is released outside either the menu or the menu button.  The menu is also unposted when the mouse is dragged into another menu button in the same group. 

[4]If mouse button 1 is pressed and released within the menu button, then the menu stays posted and keyboard traversal is possible as described in the manual entry for tk_menus. 

[5]Menubuttons may also be posted by typing characters on the keyboard.  See the manual entry for tk_menus for full details on keyboard menu traversal. 

[6]If mouse button 2 is pressed over a menu button then the associated menu is posted and also torn off:  it can then be dragged around on the screen with button 2 and the menu will not automatically unpost when entries in it are invoked.  To close a torn off menu, click mouse button 1 over the associated menu button. 

If the menu button’s state is disabled then none of the above actions occur:  the menu button is completely non-responsive. 

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

KEYWORDS

menubutton, widget

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