menu.n

linux系统下的音频通信

\fB\-underline \fIvalue\fR
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.
.TP
\fB\-value \fIvalue\fR
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 \fB\-label\fR option
for the entry as the value to store in the variable.
.TP
\fB\-variable \fIvalue\fR
Available only for checkbutton and radiobutton entries.  Specifies
the name of a global value to set when the entry is selected.
For checkbutton entries the variable is also set when the entry
is deselected.  For radiobutton entries, changing the variable
causes the currently-selected entry to deselect itself.
.LP
The \fBadd\fR widget command returns an empty string.
.RE
.TP
\fIpathName \fBcget\fR \fIoption\fR
Returns the current value of the configuration option given
by \fIoption\fR.
\fIOption\fR may have any of the values accepted by the \fBmenu\fR
command.
.VS
.TP
\fIpathName\fR \fBclone\fR \fInewPathname ?cloneType?\fR
Makes a clone of the current menu named \fInewPathName\fR. This clone
is a menu in its own right, but any changes to the clone are
propogated to the original menu and vice versa. \fIcloneType\fR can be
\fBnormal\fR, \fBmenubar\fR, or \fBtearoff\fR. Should not normally be
called outside of the Tk library. See the \fBCLONES\fR section for
more information.
.VE
.TP
\fIpathName \fBconfigure\fR ?\fIoption\fR? ?\fIvalue option value ...\fR?
Query or modify the configuration options of the widget.
If no \fIoption\fR is specified, returns a list describing all of
the available options for \fIpathName\fR (see \fBTk_ConfigureInfo\fR for
information on the format of this list).  If \fIoption\fR is specified
with no \fIvalue\fR, 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 \fIoption\fR is specified).  If
one or more \fIoption\-value\fR 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.
\fIOption\fR may have any of the values accepted by the \fBmenu\fR
command.
.TP
\fIpathName \fBdelete \fIindex1\fR ?\fIindex2\fR?
Delete all of the menu entries between \fIindex1\fR and
\fIindex2\fR inclusive.
If \fIindex2\fR is omitted then it defaults to \fIindex1\fR.
Attempts to delete a tear-off menu entry are ignored (instead, you
should change the \fBtearOff\fR option to remove the tear-off entry).
.TP
\fIpathName \fBentrycget\fR \fIindex option\fR
Returns the current value of a configuration option for
the entry given by \fIindex\fR.
\fIOption\fR may have any of the values accepted by the \fBadd\fR
widget command.
.TP
\fIpathName \fBentryconfigure \fIindex \fR?\fIoptions\fR?
This command is similar to the \fBconfigure\fR command, except that
it applies to the options for an individual entry, whereas \fBconfigure\fR
applies to the options for the menu as a whole.
\fIOptions\fR may have any of the values accepted by the \fBadd\fR
widget command.  If \fIoptions\fR are specified, options are modified
as indicated
in the command and the command returns an empty string.
If no \fIoptions\fR are specified, returns a list describing
the current options for entry \fIindex\fR (see \fBTk_ConfigureInfo\fR for
information on the format of this list).
.TP
\fIpathName \fBindex \fIindex\fR
Returns the numerical index corresponding to \fIindex\fR, or
\fBnone\fR if \fIindex\fR was specified as \fBnone\fR.
.TP
\fIpathName \fBinsert \fIindex\fR \fItype \fR?\fIoption value option value ...\fR?
Same as the \fBadd\fR widget command except that it inserts the new
entry just before the entry given by \fIindex\fR, instead of appending
to the end of the menu.  The \fItype\fR, \fIoption\fR, and \fIvalue\fR
arguments have the same interpretation as for the \fBadd\fR widget
command.  It is not possible to insert new menu entries before the
tear-off entry, if the menu has one.
.TP
\fIpathName \fBinvoke \fIindex\fR
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 \fBinvoke\fR 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 \fBinvoke\fR
widget command.
.TP
\fIpathName \fBpost \fIx y\fR
Arrange for the menu to be displayed on the screen at the root-window
coordinates given by \fIx\fR and \fIy\fR.  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 \fBpostCommand\fR 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 \fBpost\fR widget
command.
If an error returns while executing the command, then the error is
returned without posting the menu.
.TP
\fIpathName \fBpostcascade \fIindex\fR
Posts the submenu associated with the cascade entry given by
\fIindex\fR, and unposts any previously posted submenu.
If \fIindex\fR doesn't correspond to a cascade entry,
or if \fIpathName\fR isn't posted,
the command has no effect except to unpost any currently posted
submenu.
.TP
\fIpathName \fBtype \fIindex\fR
Returns the type of the menu entry given by \fIindex\fR.
This is the \fItype\fR argument passed to the \fBadd\fR widget
command when the entry was created, such as \fBcommand\fR
or \fBseparator\fR, or \fBtearoff\fR for a tear-off entry.
.TP
.VS
\fIpathName \fBunpost\fR
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.
.VE
.TP
\fIpathName \fByposition \fIindex\fR
Returns a decimal string giving the y-coordinate within the menu
window of the topmost pixel in the entry specified by \fIindex\fR.

.SH "MENU CONFIGURATIONS"
.PP
The default bindings support four different ways of using menus:
.VS
.TP
\fBPulldown Menus in Menubar\fR
This is the most command case. You create a menu widget that will become the
menu bar. You then add cascade entries to this menu, specifying the
pull down menus you wish to use in your menu bar. You then create all
of the pulldowns. Once you have done this, specify the menu using the
\fB-menu\fR option of the toplevel's widget command. See the
\fBtoplevel\fR manual entry for details.
.VE
.TP
\fBPulldown Menus in Menu Buttons\fR
This is the compatable 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 \fB\-menu\fR
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 \fBmenubutton\fR manual entry for details.
.TP
\fBPopup Menus\fR
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 \fBtk_popup\fR procedure at the appropriate time
to post the top-level menu.
.TP
\fBOption Menus\fR
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 \fBtk_optionMenu\fR procedure to create option
menubuttons and their menus.
.TP
\fBTorn-off Menus\fR
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.

.SH "DEFAULT BINDINGS"
.PP
Tk automatically creates class bindings for menus that give them
the following default behavior:
.IP [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.
.IP [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.
.IP [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.
.IP [4]
The Space and Return keys invoke the active entry and
unpost the menu.
.IP [5]
If any of the entries in a menu have letters underlined with
with \fB\-underline\fR option, then pressing one of the underlined
letters (or its upper-case or lower-case equivalent) invokes that
entry and unposts the menu.
.IP [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.
.IP [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.
.IP [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.
.IP [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.
.PP
Disabled menu entries are non-responsive:  they don't activate and
they ignore mouse button presses and releases.
.PP
The behavior of menus can be changed by defining new bindings for
individual widgets or by redefining the class bindings.

.SH BUGS
.PP
At present it isn't possible to use the
option database to specify values for the options to individual
entries.

.SH KEYWORDS
menu, widget