Tk::Menubutton - Create and manipulate Menubutton widgets
$menubutton =
$parent->Menubutton(?options?);
-activebackground -cursor -highlightthickness -takefocus
-activeforeground -disabledforeground -image -text
-anchor -font -justify -textvariable
-background -foreground -padx -underline
-bitmap -highlightbackground -pady -wraplength
-borderwidth -highlightcolor -relief
See Tk::options for details of the standard options.
- Command-Line
Name: -compound
- Database Name:
compound
- Database Class:
Compound
- Specifies whether the button should display both an image and text, and if
so, where the image should be placed relative to the text. Valid values
for this option are bottom, center, left,
none, right and top. The default value is
none, meaning that the button will display either an image or text,
depending on the values of the -image and -bitmap options.
- Name: direction
- Class: Height
- Switch: -direction
- Specifies where the menu is going to be popup up. above tries to
pop the menu above the menubutton. below tries to pop the menu
below the menubutton. left tries to pop the menu to the left of the
menubutton. right tries to pop the menu to the right of the menu
button. flush pops the menu directly over the menubutton.
- Name: height
- Class: Height
- Switch: -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.
- Name: indicatorOn
- Class: IndicatorOn
- Switch: -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.
- Name: menu
- Class: MenuName
- Switch: -menu
- Specifies the path name of the menu associated with this menubutton. The
menu must be a child of the menubutton.
- Name: state
- Class: State
- Switch: -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.
- Name: width
- Class: Width
- Switch: -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.
The Menubutton method creates a new window (given by the
$widget 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 $widget argument. At the time this
command is invoked, there must not exist a window named
$widget, but $widget'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.
The Menubutton method creates a widget object. This object
supports the configure and cget methods described in
Tk::options which can be used to enquire and modify the options described
above. The menu method returns the menu associated with the widget.
The widget also inherits all the methods provided by the generic Tk::Widget
class.
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
documentation 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.