menu(3Tk) menu(3Tk)
menu - Create and manipulate menu widgets
menu pathName ?options?
activeBackground background disabledForegroundrelief |
activeBorderWidth borderWidth fonttakeFocus
activeForeground cursor foreground
See the ``options'' manual entry for details on the standard options.
WIDGET-SPECIFIC OPTIONS
Name: postCommand
Class: Command
Command-Line Switch:-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.
Name: selectColor
Class: Background |
Command-Line Switch:-selectcolor |
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.
Name: tearOff |
Class: TearOff |
Command-Line Switch:-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.
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.
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menu(3Tk) menu(3Tk)
A menu is a widget that displays a collection of one-line entries
arranged in a column. 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 reenabled,
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 command is specified with the -command option.
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
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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 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. |
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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.
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 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
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menu(3Tk) menu(3Tk)
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 but may be reset to an empty
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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
For command, checkbutton, and radiobutton entries, specifies a
Tcl command to execute when the menu entry is invoked. For
cascade entries, specifies a Tcl command to execute when the
entry is activated (i.e. just before its submenu is posted).
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 tearoff
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.
-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 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.
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menu(3Tk) menu(3Tk)
-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.
-variable value
Available only for checkbutton and radiobutton entries.
Specifies the name of a global value to set when the entry is
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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 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.
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menu(3Tk) menu(3Tk)
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 rootwindow
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 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 lowerlevel
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.
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menu(3Tk) menu(3Tk)
The default bindings support four different ways of using menus: |
Pulldown Menus [Toc] [Back]
This is the most common case. 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 [Toc] [Back]
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 [Toc] [Back]
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 [Toc] [Back]
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.
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[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 with
-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 don't activate and they
ignore mouse button presses and releases.
The behavior of menus can be changed by defining new bindings for
individual widgets or by redefining the class bindings.
At present it isn't possible to use the option database to specify values
for the options to individual entries.
menu, widget
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