menu(n) Tk Built-In Commands menu(n)_________________________________________________________________NAMEmenu - Create and manipulate menu widgets
SYNOPSISmenu pathName ?options?
STANDARD OPTIONS-activebackground-background-disabledforeground-relief
-activeborderwidth-borderwidth-font-takefocus
-activeforeground-cursor-foreground
See the options manual entry for details on the standard
options.
WIDGET-SPECIFIC OPTIONS
Command-Line Name:-postcommand
Database Name: postCommand
Database Class: Command
If this option is specified then it provides a Tcl
command to execute each time the menu is posted.
The command is invoked by the post widget command
before posting the menu.
Command-Line Name:-selectcolor
Database Name: selectColor
Database Class: Background
For menu entries that are check buttons or radio
buttons, this option specifies the color to display
in the indicator when the check button or radio
button is selected.
Command-Line Name:-tearoff
Database Name: tearOff
Database Class: TearOff
This option must have a proper boolean value, which
specifies whether or not the menu should include a
tear-off entry at the top. If so, it will exist as
entry 0 of the menu and the other entries will num-
ber starting at 1. The default menu bindings
arrange for the menu to be torn off when the tear-
off entry is invoked.
Command-Line Name:-tearoffcommand
Database Name: tearOffCommand
Database Class: TearOffCommand
If this option has a non-empty value, then it spec-
ifies a Tcl command to invoke whenever the menu is
torn off. The actual command will consist of the
Tk 4.1 1
menu(n) Tk Built-In Commands menu(n)
value of this option, followed by a space, followed
by the name of the menu window, followed by a
space, followed by the name of the name of the torn
off menu window. For example, if the option's is
``a b'' and menu .x.y is torn off to create a new
menu .x.tearoff1, then the command ``a b .x.y
.x.tearoff1'' will be invoked.
Command-Line Name:-transient
Database Name: transient
Database Class: Transient
This option must have a boolean value. True means
that the menu is used on a transient basis, e.g. as
a pop-up, pull-down, or cascaded menu. False means
that the menu will be displayed on the screen con-
tinuously, for example as a torn-off menu. If the
option is true, no window manager border will be
displayed around the menu and redisplay will be
optimized using X's ``save under'' facility.
_________________________________________________________________INTRODUCTION
The menu command creates a new top-level window (given by
the pathName argument) and makes it into a menu widget.
Additional options, described above, may be specified on
the command line or in the option database to configure
aspects of the menu such as its colors and font. The menu
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 menu is a widget that displays a collection of one-line
entries arranged in a column. There exist several differ-
ent types of entries, each with different properties.
Entries of different types may be combined in a single
menu. Menu entries are not the same as entry widgets. In
fact, menu entries are not even distinct widgets; the
entire menu is one widget.
Menu entries are displayed with up to three separate
fields. The main field is a label in the form of a text
string, a bitmap, or an image, controlled by the -label,
-bitmap, and -image options for the entry. If the
-accelerator option is specified for an entry then a sec-
ond textual field is displayed to the right of the label.
The accelerator typically describes a keystroke sequence
that may be typed in the application to cause the same
result as invoking the menu entry. The third field is an
indicator. The indicator is present only for checkbutton
or radiobutton entries. It indicates whether the entry is
selected or not, and is displayed to the left of the
entry's string.
Tk 4.1 2
menu(n) Tk Built-In Commands menu(n)
In normal use, an entry becomes active (displays itself
differently) whenever the mouse pointer is over the entry.
If a mouse button is released over the entry then the
entry is invoked. The effect of invocation is different
for each type of entry; these effects are described below
in the sections on individual entries.
Entries may be disabled, which causes their labels and
accelerators to be displayed with dimmer colors. The
default menu bindings will not allow a disabled entry to
be activated or invoked. Disabled entries may be re-
enabled, at which point it becomes possible to activate
and invoke them again.
COMMAND ENTRIES
The most common kind of menu entry is a command entry,
which behaves much like a button widget. When a command
entry is invoked, a Tcl command is executed. The Tcl com-
mand is specified with the -command option.
SEPARATOR ENTRIES
A separator is an entry that is displayed as a horizontal
dividing line. A separator may not be activated or
invoked, and it has no behavior other than its display
appearance.
CHECKBUTTON ENTRIES
A checkbutton menu entry behaves much like a checkbutton
widget. When it is invoked it toggles back and forth
between the selected and deselected states. When the
entry is selected, a particular value is stored in a par-
ticular global variable (as determined by the -onvalue and
-variable options for the entry); when the entry is dese-
lected another value (determined by the -offvalue option)
is stored in the global variable. An indicator box is
displayed to the left of the label in a checkbutton entry.
If the entry is selected then the indicator's center is
displayed in the color given by the -selectcolor option
for the entry; otherwise the indicator's center is dis-
played in the background color for the menu. If a -com-
mand option is specified for a checkbutton entry, then its
value is evaluated as a Tcl command each time the entry is
invoked; this happens after toggling the entry's selected
state.
RADIOBUTTON ENTRIES
A radiobutton menu entry behaves much like a radiobutton
widget. Radiobutton entries are organized in groups of
which only one entry may be selected at a time. Whenever
a particular entry becomes selected it stores a particular
Tk 4.1 3
menu(n) Tk Built-In Commands menu(n)
value into a particular global variable (as determined by
the -value and -variable options for the entry). This
action causes any previously-selected entry in the same
group to deselect itself. Once an entry has become
selected, any change to the entry's associated variable
will cause the entry to deselect itself. Grouping of
radiobutton entries is determined by their associated
variables: if two entries have the same associated vari-
able then they are in the same group. An indicator dia-
mond is displayed to the left of the label in each
radiobutton entry. If the entry is selected then the
indicator's center is displayed in the color given by the
-selectcolor option for the entry; otherwise the indica-
tor's center is displayed in the background color for the
menu. If a -command option is specified for a radiobutton
entry, then its value is evaluated as a Tcl command each
time the entry is invoked; this happens after selecting
the entry.
CASCADE ENTRIES
A cascade entry is one with an associated menu (determined
by the -menu option). Cascade entries allow the construc-
tion of cascading menus. The postcascade widget command
can be used to post and unpost the associated menu just to
the right of the cascade entry. The associated menu must
be a child of the menu containing the cascade entry (this
is needed in order for menu traversal to work correctly).
A cascade entry posts its associated menu by invoking a
Tcl command of the form
menu post x y
where menu is the path name of the associated menu, and x
and y are the root-window coordinates of the upper-right
corner of the cascade entry. The lower-level menu is
unposted by executing a Tcl command with the form
menu unpost
where menu is the name of the associated menu.
If a -command option is specified for a cascade entry then
it is evaluated as a Tcl command whenever the entry is
invoked.
TEAR-OFF ENTRIES
A tear-off entry appears at the top of the menu if enabled
with the tearOff option. It is not like other menu
entries in that it cannot be created with the add widget
command and cannot be deleted with the delete widget com-
mand. When a tear-off entry is created it appears as a
dashed line at the top of the menu. Under the default
bindings, invoking the tear-off entry causes a torn-off
copy to be made of the menu and all of its submenus.
Tk 4.1 4
menu(n) Tk Built-In Commands menu(n)WIDGET COMMAND
The menu 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.
Many of the widget commands for a menu take as one argu-
ment an indicator of which entry of the menu to operate
on. These indicators are called indexes and may be speci-
fied in any of the following forms:
number Specifies the entry numerically, where 0 cor-
responds to the top-most entry of the menu, 1
to the entry below it, and so on.
active Indicates the entry that is currently active.
If no entry is active then this form is equiv-
alent to none. This form may not be abbrevi-
ated.
end Indicates the bottommost entry in the menu.
If there are no entries in the menu then this
form is equivalent to none. This form may not
be abbreviated.
last Same as end.
none Indicates ``no entry at all''; this is used
most commonly with the activate option to
deactivate all the entries in the menu. In
most cases the specification of none causes
nothing to happen in the widget command. This
form may not be abbreviated.
@number In this form, number is treated as a y-coordi-
nate in the menu's window; the entry closest
to that y-coordinate is used. For example,
``@0'' indicates the top-most entry in the
window.
pattern If the index doesn't satisfy one of the above
forms then this form is used. Pattern is pat-
tern-matched against the label of each entry
in the menu, in order from the top down, until
a matching entry is found. The rules of
Tcl_StringMatch are used.
The following widget commands are possible for menu wid-
gets:
Tk 4.1 5
menu(n) Tk Built-In Commands menu(n)
pathName activate index
Change the state of the entry indicated by index to
active and redisplay it using its active colors.
Any previously-active entry is deactivated. If
index is specified as none, or if the specified
entry is disabled, then the menu ends up with no
active entry. Returns an empty string.
pathName add type ?option value option value ...?
Add a new entry to the bottom of the menu. The new
entry's type is given by type and must be one of
cascade, checkbutton, command, radiobutton, or sep-
arator, or a unique abbreviation of one of the
above. If additional arguments are present, they
specify any of the following options:
-activebackground value
Specifies a background color to use for dis-
playing this entry when it is active. If
this option is specified as an empty string
(the default), then the activeBackground
option for the overall menu is used. If the
tk_strictMotif variable has been set to
request strict Motif compliance, then this
option is ignored and the -background option
is used in its place. This option is not
available for separator or tear-off entries.
-activeforeground value
Specifies a foreground color to use for dis-
playing this entry when it is active. If
this option is specified as an empty string
(the default), then the activeForeground
option for the overall menu is used. This
option is not available for separator or
tear-off entries.
-accelerator value
Specifies a string to display at the right
side of the menu entry. Normally describes
an accelerator keystroke sequence that may
be typed to invoke the same function as the
menu entry. This option is not available
for separator or tear-off entries.
-background value
Specifies a background color to use for dis-
playing this entry when it is in the normal
state (neither active nor disabled). If
this option is specified as an empty string
(the default), then the background option
for the overall menu is used. This option
is not available for separator or tear-off
entries.
Tk 4.1 6
menu(n) Tk Built-In Commands menu(n)-bitmap value
Specifies a bitmap to display in the menu
instead of a textual label, in any of the
forms accepted by Tk_GetBitmap. This option
overrides the -label option but may be reset
to an empty string to enable a textual label
to be displayed. If a -image option has
been specified, it overrides -bitmap. This
option is not available for separator or
tear-off entries.
-command value
Specifies a Tcl command to execute when the
menu entry is invoked. Not available for
separator or tear-off entries.
-font value
Specifies the font to use when drawing the
label or accelerator string in this entry.
If this option is specified as an empty
string (the default) then the font option
for the overall menu is used. This option
is not available for separator or tear-off
entries.
-foreground value
Specifies a foreground color to use for dis-
playing this entry when it is in the normal
state (neither active nor disabled). If
this option is specified as an empty string
(the default), then the foreground option
for the overall menu is used. This option
is not available for separator or tear-off
entries.
-image value
Specifies an image to display in the menu
instead of a text string or bitmap The image
must have been created by some previous
invocation of image create. This option
overrides the -label and -bitmap options but
may be reset to an empty string to enable a
textual or bitmap label to be displayed.
This option is not available for separator
or tear-off entries.
-indicatoron value
Available only for checkbutton and radiobut-
ton entries. Value is a boolean that deter-
mines whether or not the indicator should be
displayed.
-label value
Specifies a string to display as an
Tk 4.1 7
menu(n) Tk Built-In Commands menu(n)
identifying label in the menu entry. Not
available for separator or tear-off entries.
-menu value
Available only for cascade entries. Speci-
fies the path name of the submenu associated
with this entry. The submenu must be a
child of the menu.
-offvalue value
Available only for checkbutton entries.
Specifies the value to store in the entry's
associated variable when the entry is dese-
lected.
-onvalue value
Available only for checkbutton entries.
Specifies the value to store in the entry's
associated variable when the entry is
selected.
-selectcolor value
Available only for checkbutton and radiobut-
ton entries. Specifies the color to display
in the indicator when the entry is selected.
If the value is an empty string (the
default) then the selectColor option for the
menu determines the indicator color.
-selectimage value
Available only for checkbutton and radiobut-
ton entries. Specifies an image to display
in the entry (in place of the -image option)
when it is selected. Value is the name of
an image, which must have been created by
some previous invocation of image create.
This option is ignored unless the -image
option has been specified.
-state value
Specifies one of three states for the entry:
normal, active, or disabled. In normal
state the entry is displayed using the fore-
ground option for the menu and the back-
ground option from the entry or the menu.
The active state is typically used when the
pointer is over the entry. In active state
the entry is displayed using the activeFore-
ground option for the menu along with the
activebackground option from the entry.
Disabled state means that the entry should
be insensitive: the default bindings will
refuse to activate or invoke the entry. In
this state the entry is displayed according
Tk 4.1 8
menu(n) Tk Built-In Commands menu(n)
to the disabledForeground option for the
menu and the background option from the
entry. This option is not available for
separator entries.
-underline value
Specifies the integer index of a character
to underline in the entry. This option is
also queried by the default bindings and
used to implement keyboard traversal. 0
corresponds to the first character of the
text displayed in the entry, 1 to the next
character, and so on. If a bitmap or image
is displayed in the entry then this option
is ignored. This option is not available
for separator or tear-off entries.
-value value
Available only for radiobutton entries.
Specifies the value to store in the entry's
associated variable when the entry is
selected. If an empty string is specified,
then the -label option for the entry as the
value to store in the variable.
-variable value
Available only for checkbutton and radiobut-
ton entries. Specifies the name of a global
value to set when the entry is selected.
For checkbutton entries the variable is also
set when the entry is deselected. For
radiobutton entries, changing the variable
causes the currently-selected entry to dese-
lect itself.
The add widget command returns an empty string.
pathName cget option
Returns the current value of the configuration
option given by option. Option may have any of the
values accepted by the menu 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 path-
Name (see Tk_ConfigureInfo for information on the
format of this list). If option is specified with
no value, then the command returns a list describ-
ing the one named option (this list will be identi-
cal 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
Tk 4.1 9
menu(n) Tk Built-In Commands menu(n)
the given value(s); in this case the command
returns an empty string. Option may have any of
the values accepted by the menu command.
pathName delete index1 ?index2?
Delete all of the menu entries between index1 and
index2 inclusive. If index2 is omitted then it
defaults to index1. Attempts to delete a tear-off
menu entry are ignored (instead, you should change
the tearOff option to remove the tear-off entry).
pathName entrycget index option
Returns the current value of a configuration option
for the entry given by index. Option may have any
of the values accepted by the add widget command.
pathName entryconfigure index ?options?
This command is similar to the configure command,
except that it applies to the options for an indi-
vidual entry, whereas configure applies to the
options for the menu as a whole. Options may have
any of the values accepted by the add widget com-
mand. If options are specified, options are modi-
fied as indicated in the command and the command
returns an empty string. If no options are speci-
fied, returns a list describing the current options
for entry index (see Tk_ConfigureInfo for informa-
tion on the format of this list).
pathName index index
Returns the numerical index corresponding to index,
or none if index was specified as none.
pathName insert index type ?option value option value ...?
Same as the add widget command except that it
inserts the new entry just before the entry given
by index, instead of appending to the end of the
menu. The type, option, and value arguments have
the same interpretation as for the add widget com-
mand. It is not possible to insert new menu
entries before the tear-off entry, if the menu has
one.
pathName invoke index
Invoke the action of the menu entry. See the sec-
tions on the individual entries above for details
on what happens. If the menu entry is disabled
then nothing happens. If the entry has a command
associated with it then the result of that command
is returned as the result of the invoke widget com-
mand. Otherwise the result is an empty string.
Note: invoking a menu entry does not automatically
unpost the menu; the default bindings normally
take care of this before invoking the invoke widget
Tk 4.1 10
menu(n) Tk Built-In Commands menu(n)
command.
pathName post x y
Arrange for the menu to be displayed on the screen
at the root-window coordinates given by x and y.
These coordinates are adjusted if necessary to
guarantee that the entire menu is visible on the
screen. This command normally returns an empty
string. If the postCommand option has been speci-
fied, then its value is executed as a Tcl script
before posting the menu and the result of that
script is returned as the result of the post widget
command. If an error returns while executing the
command, then the error is returned without posting
the menu.
pathName postcascade index
Posts the submenu associated with the cascade entry
given by index, and unposts any previously posted
submenu. If index doesn't correspond to a cascade
entry, or if pathName isn't posted, the command has
no effect except to unpost any currently posted
submenu.
pathName type index
Returns the type of the menu entry given by index.
This is the type argument passed to the add widget
command when the entry was created, such as command
or separator, or tearoff for a tear-off entry.
pathName unpost
Unmap the window so that it is no longer displayed.
If a lower-level cascaded menu is posted, unpost
that menu. Returns an empty string.
pathName yposition index
Returns a decimal string giving the y-coordinate
within the menu window of the topmost pixel in the
entry specified by index.
MENU CONFIGURATIONS
The default bindings support four different ways of using
menus:
Pulldown Menus
This is the most common case. You create one
menubutton widget for each top-level menu, and typ-
ically you arrange a series of menubuttons in a row
in a menubar window. You also create the top-level
menus and any cascaded submenus, and tie them
together with -menu options in menubuttons and cas-
cade menu entries. The top-level menu must be a
child of the menubutton, and each submenu must be a
Tk 4.1 11
menu(n) Tk Built-In Commands menu(n)
child of the menu that refers to it. Once you have
done this, the default bindings will allow users to
traverse and invoke the tree of menus via its
menubutton; see the menubutton manual entry for
details.
Popup Menus
Popup menus typically post in response to a mouse
button press or keystroke. You create the popup
menus and any cascaded submenus, then you call the
tk_popup procedure at the appropriate time to post
the top-level menu.
Option Menus
An option menu consists of a menubutton with an
associated menu that allows you to select one of
several values. The current value is displayed in
the menubutton and is also stored in a global vari-
able. Use the tk_optionMenu procedure to create
option menubuttons and their menus.
Torn-off Menus
You create a torn-off menu by invoking the tear-off
entry at the top of an existing menu. The default
bindings will create a new menu that is a copy of
the original menu and leave it permanently posted
as a top-level window. The torn-off menu behaves
just the same as the original menu.
DEFAULT BINDINGS
Tk automatically creates class bindings for menus that
give them the following default behavior:
[1] When the mouse enters a menu, the entry underneath
the mouse cursor activates; as the mouse moves
around the menu, the active entry changes to track
the mouse.
[2] When the mouse leaves a menu all of the entries in
the menu deactivate, except in the special case
where the mouse moves from a menu to a cascaded
submenu.
[3] When a button is released over a menu, the active
entry (if any) is invoked. The menu also unposts
unless it is a torn-off menu.
[4] The Space and Return keys invoke the active entry
and unpost the menu.
[5] If any of the entries in a menu have letters under-
lined with with -underline option, then pressing
one of the underlined letters (or its upper-case or
Tk 4.1 12
menu(n) Tk Built-In Commands menu(n)
lower-case equivalent) invokes that entry and
unposts the menu.
[6] The Escape key aborts a menu selection in progress
without invoking any entry. It also unposts the
menu unless it is a torn-off menu.
[7] The Up and Down keys activate the next higher or
lower entry in the menu. When one end of the menu
is reached, the active entry wraps around to the
other end.
[8] The Left key moves to the next menu to the left.
If the current menu is a cascaded submenu, then the
submenu is unposted and the current menu entry
becomes the cascade entry in the parent. If the
current menu is a top-level menu posted from a
menubutton, then the current menubutton is unposted
and the next menubutton to the left is posted.
Otherwise the key has no effect. The left-right
order of menubuttons is determined by their stack-
ing order: Tk assumes that the lowest menubutton
(which by default is the first one created) is on
the left.
[9] The Right key moves to the next menu to the right.
If the current entry is a cascade entry, then the
submenu is posted and the current menu entry
becomes the first entry in the submenu. Otherwise,
if the current menu was posted from a menubutton,
then the current menubutton is unposted and the
next menubutton to the right is posted.
Disabled menu entries are non-responsive: they don't
activate and they ignore mouse button presses and
releases.
The behavior of menus can be changed by defining new bind-
ings for individual widgets or by redefining the class
bindings.
BUGS
At present it isn't possible to use the option database to
specify values for the options to individual entries.
KEYWORDS
menu, widget
Tk 4.1 13
