menu(n) Tk Built-In Commands menu(n)______________________________________________________________________________NAME
menu, tk_menuSetFocus - Create and manipulate menu widgets
SYNOPSIS
menu pathName ?options?
tk_menuSetFocus pathName
STANDARD OPTIONS-activebackground-borderwidth-foreground
-activeborderwidth-cursor-relief
-activeforeground-disabledforeground-takefocus
-background-font
See the options manual entry for details on the standard options.
WIDGET-SPECIFIC OPTIONS
[-postcommand postCommand] 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. Note that │
in Tk 8.0 on Macintosh and Windows, all post-commands in a system of │
menus are executed before any of those menus are posted. This is due │
to the limitations in the individual platforms' menu managers.
[-selectcolor selectColor] For menu entries that are check buttons or
radio buttons, this option specifies the color to display in the indi‐
cator when the check button or radio button is selected.
[-tearoff 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 number starting at 1. The default menu bindings arrange
for the menu to be torn off when the tear-off entry is invoked.
[-tearoffcommand tearOffCommand] If this option has a non-empty value,
then it specifies a Tcl command to invoke whenever the menu is torn
off. The actual command will consist of the value of this option, fol‐
lowed 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. [-title title] The string will be used │
to title the window created when this menu is torn off. If the title is │
NULL, then the window will have the title of the menubutton or the text │
of the cascade item from which this menu was invoked. [-type type] │
This option can be one of menubar, tearoff, or normal, and is set when │
the menu is created. While the string returned by the configuration │
database will change if this option is changed, this does not affect │
the menu widget's behavior. This is used by the cloning mechanism and │
is not normally set outside of the Tk library.
_________________________________________________________________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 com‐
mand 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 one or more columns. There exist several different 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 second
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 check‐
button or radiobutton entries. It indicates whether the entry is
selected or not, and is displayed to the left of the entry's string.
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 invo‐
cation 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. │
Whenever a menu's active entry is changed, a <<MenuSelect>> virtual │
event is send to the menu. The active item can then be queried from the │
menu, and an action can be taken, such as setting context-sensitive │
help text for the entry.
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 com‐
mand is executed. The Tcl command 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 dese‐
lected states. When the entry is selected, a particular value is
stored in a particular global variable (as determined by the -onvalue
and -variable options for the entry); when the entry is deselected
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 indi‐
cator's center is displayed in the color given by the -selectcolor
option for the entry; otherwise the indicator's center is displayed in
the background color for the menu. If a -command 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 value into a particular global variable (as deter‐
mined 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 variable then they are in the same
group. An indicator diamond 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 indicator's center is displayed in the back‐
ground 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 construction of cascading menus.
The postcascade widget command can be used to post and unpost the asso‐
ciated menu just next to 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. │
On Unix, 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. On other platforms, the │
platform's native code takes care of unposting the menu.
If a -command option is specified for a cascade entry then it is evalu‐ │
ated as a Tcl command whenever the entry is invoked. This is not sup‐ │
ported on Windows.
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 command. 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.
MENUBARS │
Any menu can be set as a menubar for a toplevel window (see toplevel │
command for syntax). On the Macintosh, whenever the toplevel is in │
front, this menu's cascade items will appear in the menubar across the │
top of the main monitor. On Windows and Unix, this menu's items will be │
displayed in a menubar across the top of the window. These menus will │
behave according to the interface guidelines of their platforms. For │
every menu set as a menubar, a clone menu is made. See the CLONES sec‐ │
tion for more information. │
As noted, menubars may behave differently on different platforms. One │
example of this concerns the handling of checkbuttons and radiobuttons │
within the menu. While it is permitted to put these menu elements on │
menubars, they may not be drawn with indicators on some platforms, due │
to system restrictions.
SPECIAL MENUS IN MENUBARS │
Certain menus in a menubar will be treated specially. On the Macin‐ │
tosh, access to the special Apple and Help menus is provided. On Win‐ │
dows, access to the Windows System menu in each window is provided. On │
X Windows, a special right-justified help menu is provided. In all │
cases, these menus must be created with the command name of the menubar │
menu concatenated with the special name. So for a menubar named │
.menubar, on the Macintosh, the special menus would be .menubar.apple │
and .menubar.help; on Windows, the special menu would be .menubar.sys‐ │
tem; on X Windows, the help menu would be .menubar.help. │
When Tk sees an Apple menu on the Macintosh, that menu's contents make │
up the first items of the Apple menu on the screen whenever the window │
containing the menubar is in front. The menu is the first one that the │
user sees and has a title which is an Apple logo. After all of the Tk- │
defined items, the menu will have a separator, followed by all of the │
items in the user's Apple Menu Items folder. Since the System uses a │
different menu definition procedure for the Apple menu than Tk uses for │
its menus, and the system APIs do not fully support everything Tk tries │
to do, the menu item will only have its text displayed. No font │
attributes, images, bitmaps, or colors will be displayed. In addition, │
a menu with a tearoff item will have the tearoff item displayed as │
"(TearOff)". │
When Tk see a Help menu on the Macintosh, the menu's contents are │
appended to the standard help menu on the right of the user's menubar │
whenever the user's menubar is in front. The first items in the menu │
are provided by Apple. Similar to the Apple Menu, customization in this │
menu is limited to what the system provides. │
When Tk sees a System menu on Windows, its items are appended to the │
system menu that the menubar is attached to. This menu has an icon rep‐ │
resenting a spacebar, and can be invoked with the mouse or by typing │
Alt+Spacebar. Due to limitations in the Windows API, any font changes, │
colors, images, bitmaps, or tearoff images will not appear in the sys‐ │
tem menu. │
When Tk see a Help menu on X Windows, the menu is moved to be last in │
the menubar and is right justified.
CLONES │
When a menu is set as a menubar for a toplevel window, or when a menu │
is torn off, a clone of the menu is made. This clone is a menu widget │
in its own right, but it is a child of the original. Changes in the │
configuration of the original are reflected in the clone. Additionally, │
any cascades that are pointed to are also cloned so that menu traversal │
will work right. Clones are destroyed when either the tearoff or │
menubar goes away, or when the original menu is destroyed.
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 argument an indica‐
tor of which entry of the menu to operate on. These indicators are
called indexes and may be specified in any of the following forms:
number Specifies the entry numerically, where 0 corresponds 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 equivalent to none. This form
may not be abbreviated.
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-coordinate 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 pattern-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 widgets:
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, com‐
mand, radiobutton, or separator, 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 displaying 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_strictMo‐
tif variable has been set to request strict Motif compli‐
ance, then this option is ignored and the -background
option is used in its place. This option is not avail‐
able for separator or tear-off entries.
-activeforeground value
Specifies a foreground color to use for displaying 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 separa‐
tor or tear-off entries.
-background value
Specifies a background color to use for displaying 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.
-bitmap value
Specifies a bitmap to display in the menu instead of a
textual label, in any of the forms accepted by Tk_Get‐
Bitmap. This option overrides the -label option (as con‐
trolled by the -compound 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 -bit‐
map. This option is not available for separator or tear-
off entries.
-columnbreak value
When this option is zero, the entry appears below the │
previous entry. When this option is one, the entry │
appears at the top of a new column in the menu.
-command value
Specifies a Tcl command to execute when the menu entry is
invoked. Not available for separator or tear-off
entries. │
-compound value │
Specifies whether the menu entry 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.
-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 displaying 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. │
-hidemargin value │
Specifies whether the standard margins should be drawn │
for this menu entry. This is useful when creating palette │
with images in them, i.e., color palettes, pattern pal‐ │
ettes, etc. 1 indicates that the margin for the entry is │
hidden; 0 means that the margin is used.
-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 (as controlled
by the -compound option) but may be reset to an empty
string to enable a textual or bitmap label to be dis‐
played. This option is not available for separator or
tear-off entries.
-indicatoron value
Available only for checkbutton and radiobutton entries.
Value is a boolean that determines whether or not the
indicator should be displayed.
-label value
Specifies a string to display as an identifying label in
the menu entry. Not available for separator or tear-off
entries.
-menu value
Available only for cascade entries. Specifies the path
name of the submenu associated with this entry. The sub‐
menu 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 deselected.
-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 radiobutton 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 deter‐
mines the indicator color.
-selectimage value
Available only for checkbutton and radiobutton 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 dis‐
played using the foreground option for the menu and the
background 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
activeForeground 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 to the dis‐
abledForeground 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 sep‐
arator 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 radiobutton 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 radiobut‐
ton entries, changing the variable causes the currently-
selected entry to deselect 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 clone newPathname ?cloneType? │
Makes a clone of the current menu named newPathName. This clone │
is a menu in its own right, but any changes to the clone are │
propogated to the original menu and vice versa. cloneType can be │
normal, menubar, or tearoff. Should not normally be called out‐ │
side of the Tk library. See the CLONES section for more informa‐ │
tion.
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 avail‐
able 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 menu command.
pathName delete index1 ?index2?
Delete all of the menu entries between index1 and index2 inclu‐
sive. 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 individual entry, whereas config‐
ure applies to the options for the menu as a whole. Options may
have any of the values accepted by the add widget command. If
options are specified, options are modified as indicated in the
command and the command returns an empty string. If no options
are specified, returns a list describing the current options for
entry index (see Tk_ConfigureInfo for information 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 command. 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 sections 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 command. 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
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 visi‐
ble on the screen. This command normally returns an empty
string. If the postCommand option has been specified, 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 com‐
mand, 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. This subcommand does not work on Windows and the │
Macintosh, as those platforms have their own way of unposting │
menus.
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 in Menubar │
This is the most command case. You create a menu widget that │
will become the menu bar. You then add cascade entries to this │
menu, specifying the pull down menus you wish to use in your │
menu bar. You then create all of the pulldowns. Once you have │
done this, specify the menu using the -menu option of the │
toplevel's widget command. See the toplevel manual entry for │
details.
Pulldown Menus in Menu Buttons
This is the compatible way to do menu bars. You create one
menubutton widget for each top-level menu, and typically 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 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 sub‐
menus, 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 variable. 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 perma‐
nently 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 underlined with the
-underline option, then pressing one of the underlined letters
(or its upper-case or 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 stacking
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 cur‐
rent 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.
Several of the bindings make use of the command tk_menuSetFocus. It │
saves the current focus and sets the focus to its pathName argument, │
which is a menu widget.
The behavior of menus can be changed by defining new bindings for indi‐
vidual widgets or by redefining the class bindings.
BUGS
At present it isn't possible to use the option database to specify val‐
ues for the options to individual entries.
KEYWORDS
menu, widget
Tk 4.1 menu(n)
