focal (3) menu.3tk.gz

Provided by: tk8.6-doc_8.6.10-1_all bug

NAME

       menu, tk_menuSetFocus - Create and manipulate 'menu' widgets and menubars

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

       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.   This option is ignored under Aqua/Mac OS X, where menus
              cannot be torn off.

       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.   This
              option is ignored under Aqua/Mac OS X, where menus cannot be torn off.

       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.   That menu widget can either be used as a pop-up window or applied to a toplevel (with its -menu
       option) to make it into the menubar for that toplevel.   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 used in the
       application to cause the same result as invoking the menu entry.  This is a display option, it  does  not
       actually  set  the corresponding binding (which can be achieved using the bind command).  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.

   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  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.

   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 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
              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 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.

   SPECIAL MENUS IN MENUBARS
       Certain menus in a menubar  will  be  treated  specially.   On  the  Macintosh,  access  to  the  special
       Application,  Window  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, .menubar.window 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 as the first menu in a menubar 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.   Such  a  .apple  menu  must  be  present in a menu when that menu is first configured as a
       toplevel's menubar, otherwise a default application menu (hidden from  Tk)  will  be  inserted  into  the
       menubar  at  that  time and subsequent addition of a .apple menu will no longer result in it becoming the
       Application menu.

       When Tk sees a .menubar.window menu on the Macintosh, the menu's contents are inserted into the  standard
       Window  menu 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, and the names of the current toplevels are automatically appended after all the
       Tk-defined  items  and  a  separator.  The  Window menu on the Mac also allows toggling the window into a
       fullscreen state, and managing a tabbed window interface (multiple windows grouped into a single  window)
       if supported by that version of the operating system.

       When Tk sees a .menubar.help menu on the Macintosh, the menu's contents are appended to the standard Help
       menu 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 is tied to the application icon 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.

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 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:

       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.

       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.

       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 string match are used.

       If the index could match more than one of the above forms, then the form earlier in the above list  takes
       precedence.

       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 the options listed in the MENU ENTRY
              OPTIONS section below.  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 names described in the MENU ENTRY OPTIONS section below.

       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  described  in  the  MENU  ENTRY OPTIONS section below.  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 ?index?
              Arrange for the menu to be displayed on the screen at the root-window coordinates given by  x  and
              y.   If  an  index  is  specified  the  menu  will be located so that the entry with that index is
              displayed at the point.  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 or
              insert  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.

MENU ENTRY OPTIONS

       The following options are allowed on menu entries. Most options are not supported by all entry types.

       -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 used to invoke the same function as the menu entry.
              This is a display option, it does not  actually  set  the  corresponding  binding  (which  can  be
              achieved using the bind command). 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.  This option is ignored on Aqua/Mac OS X,
              where menus are always a single column.

       -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.

              For checkbutton entries, the default value of this option is taken from the -label option, and for
              radiobutton entries a single fixed value is used. It  is  recommended  that  you  always  set  the
              -variable option when creating either a checkbutton or a radiobutton.

       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