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.
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. 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.
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 number 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 specifies a
Tcl command to invoke whenever the menu is torn off. The actual command
will consist of the 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 value
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: -title
Database Name: title
Database Class: 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.
Command-Line Name: -type
Database Name: type
Database Class: 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
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
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 checkbutton 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 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.
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.
TYPES OF ENTRIES¶
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 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.
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 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 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 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.
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 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 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
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 construction of cascading menus. The
postcascade widget command can be used to post and unpost the
associated 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
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
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
evaluated as a Tcl command whenever the entry is invoked. This is not
supported 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.
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 section 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.
Certain menus in a menubar will be treated specially. On the Macintosh, access
to the special Application and Help menus is provided. On Windows, access to
the Windows System menu in each window is provided. On X Windows, a special
right-justified help menu may be provided if Motif menu compatibility is
enabled. 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.system; on X
Windows, the help menu would be .menubar.help.
When Tk sees a .menubar.apple menu on the Macintosh, that menu's contents make
up the first items of the Application menu whenever the window containing the
menubar is in front. After all of the Tk-defined items, the menu will have a
separator, followed by all standard Application menu items.
When Tk sees 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
window's menubar is in front. The first items in the menu are provided by Mac
OS X.
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 representing 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 system menu.
When Tk sees a Help menu on X Windows and Motif menu compatibility is enabled
the menu is moved to be last in the menubar and is right justified. Motif menu
compatibility is enabled by setting the Tk option
*Menu.useMotifHelp to
true or by calling
tk::classic::restore menu.
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.
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 indicator 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 does not 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, command, 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_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 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 separator 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_GetBitmap. This
option overrides the -label option (as controlled 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 -bitmap. 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 palettes, 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 displayed. 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 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
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 determines 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 displayed
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 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 radiobutton entries.
Specifies the name of a global variable 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 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
propagated to the original menu and vice versa. cloneType can be
normal, menubar, or tearoff. Should not normally be
called outside of the Tk library. See the CLONES section for more
information.
- 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 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 individual 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 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 visible 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 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 does not correspond to a cascade entry, or if pathName
is not 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 xposition index
- Returns a decimal string giving the x-coordinate within the
menu window of the leftmost pixel in the entry specified by
index.
- 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.
The default bindings support four different ways of using menus:
- Pulldown Menus in Menubar
- This is the most common 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 cascade 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 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 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 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 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
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 do not 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 individual
widgets or by redefining the class bindings.
BUGS¶
At present it is not possible to use the option database to specify values for
the options to individual entries.
SEE ALSO¶
bind(3tk), menubutton(3tk), ttk::menubutton(3tk), toplevel(3tk)
KEYWORDS¶
menu, widget