menu.n

linux系统下的音频通信

When Tk sees an Apple menu on the Macintosh, that menu's contents make
up the first items of the Apple menu on the screen whenever the window
containing the menubar is in front. The menu is the
first one that the user sees and has a title which is an Apple logo.
After all of the Tk-defined items, the menu will have a separator,
followed by all of the items in the user's Apple Menu Items folder.
Since the System uses a different menu definition procedure for
the Apple menu than Tk uses for its menus, and the system APIs do
not fully support everything Tk tries to do, the menu item will only
have its text displayed. No font attributes, images, bitmaps, or colors
will be displayed. In addition, a menu with a tearoff item will have
the tearoff item displayed as "(TearOff)".
.PP
When Tk see a Help menu on the Macintosh, the menu's contents are
appended to the standard help menu on the right of the user's menubar
whenever the user's menubar is in front. The first items in the menu
are provided by Apple. Similar to the Apple Menu, cusomization in this
menu is limited to what the system provides.
.PP
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.
.PP
When Tk see a Help menu on X Windows, the menu is moved to be last in
the menubar and is right justified.
.VE

.VS
.SH "CLONES"
.PP
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. 
.VE

.SH "WIDGET COMMAND"
.PP
The \fBmenu\fR command creates a new Tcl command whose
name is \fIpathName\fR.  This
command may be used to invoke various
operations on the widget.  It has the following general form:
.CS
\fIpathName option \fR?\fIarg arg ...\fR?
.CE
\fIOption\fR and the \fIarg\fRs
determine the exact behavior of the command.
.PP
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 \fIindex\fRes and may be specified in
any of the following forms:
.TP 12
\fInumber\fR
Specifies the entry numerically, where 0 corresponds
to the top-most entry of the menu, 1 to the entry below it, and
so on.
.TP 12
\fBactive\fR
Indicates the entry that is currently active.  If no entry is
active then this form is equivalent to \fBnone\fR.  This form may
not be abbreviated.
.TP 12
\fBend\fR
Indicates the bottommost entry in the menu.  If there are no
entries in the menu then this form is equivalent to \fBnone\fR.
This form may not be abbreviated.
.TP 12
\fBlast\fR
Same as \fBend\fR.
.TP 12
\fBnone\fR
Indicates ``no entry at all'';  this is used most commonly with
the \fBactivate\fR option to deactivate all the entries in the
menu.  In most cases the specification of \fBnone\fR causes
nothing to happen in the widget command.
This form may not be abbreviated.
.TP 12
\fB@\fInumber\fR
In this form, \fInumber\fR is treated as a y-coordinate in the
menu's window;  the entry closest to that y-coordinate is used.
For example, ``\fB@0\fR'' indicates the top-most entry in the
window.
.TP 12
\fIpattern\fR
If the index doesn't satisfy one of the above forms then this
form is used.  \fIPattern\fR 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 \fBTcl_StringMatch\fR
are used.
.PP
The following widget commands are possible for menu widgets:
.TP
\fIpathName \fBactivate \fIindex\fR
Change the state of the entry indicated by \fIindex\fR to \fBactive\fR
and redisplay it using its active colors.
Any previously-active entry is deactivated.  If \fIindex\fR
is specified as \fBnone\fR, or if the specified entry is
disabled, then the menu ends up with no active entry.
Returns an empty string.
.TP
\fIpathName \fBadd \fItype \fR?\fIoption value option value ...\fR?
Add a new entry to the bottom of the menu.  The new entry's type
is given by \fItype\fR and must be one of \fBcascade\fR,
\fBcheckbutton\fR, \fBcommand\fR, \fBradiobutton\fR, or \fBseparator\fR,
or a unique abbreviation of one of the above.  If additional arguments
are present, they specify any of the following options:
.RS
.TP
\fB\-activebackground \fIvalue\fR
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
\fBactiveBackground\fR option for the overall menu is used.
If the \fBtk_strictMotif\fR variable has been set to request strict
Motif compliance, then this option is ignored and the \fB\-background\fR
option is used in its place.
This option is not available for separator or tear-off entries.
.TP
\fB\-activeforeground \fIvalue\fR
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
\fBactiveForeground\fR option for the overall menu is used.
This option is not available for separator or tear-off entries.
.TP
\fB\-accelerator \fIvalue\fR
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.
.TP
\fB\-background \fIvalue\fR
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
\fBbackground\fR option for the overall menu is used.
This option is not available for separator or tear-off entries.
.TP
\fB\-bitmap \fIvalue\fR
Specifies a bitmap to display in the menu instead of a textual
label, in any of the forms accepted by \fBTk_GetBitmap\fR.
This option overrides the \fB\-label\fR option but may be reset
to an empty string to enable a textual label to be displayed.
If a \fB\-image\fR option has been specified, it overrides
\fB\-bitmap\fR.
This option is not available for separator or tear-off entries.
.VS
.TP
\fB\-columnbreak \fIvalue\fR
When this option is zero, the appears below the previous entry. When
this option is one, the menu appears at the top of a new column in the
menu.
.VE
.TP
\fB\-command \fIvalue\fR
Specifies a Tcl command to execute when the menu entry is invoked.
Not available for separator or tear-off entries.
.TP
\fB\-font \fIvalue\fR
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 \fBfont\fR option for the overall menu is used.
This option is not available for separator or tear-off entries.
.TP
\fB\-foreground \fIvalue\fR
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
\fBforeground\fR option for the overall menu is used.
This option is not available for separator or tear-off entries.
.VS
.TP
\fB\-hidemargin \fIvalue\fR
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.
.VE
.TP
\fB\-image \fIvalue\fR
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
\fBimage create\fR.
This option overrides the \fB\-label\fR and \fB\-bitmap\fR 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.
.TP
\fB\-indicatoron \fIvalue\fR
Available only for checkbutton and radiobutton entries.
\fIValue\fR is a boolean that determines whether or not the
indicator should be displayed.
.TP
\fB\-label \fIvalue\fR
Specifies a string to display as an identifying label in the menu
entry.  Not available for separator or tear-off entries.
.TP
\fB\-menu \fIvalue\fR
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.
.TP
\fB\-offvalue \fIvalue\fR
Available only for checkbutton entries.  Specifies the value to
store in the entry's associated variable when the entry is
deselected.
.TP
\fB\-onvalue \fIvalue\fR
Available only for checkbutton entries.  Specifies the value to
store in the entry's associated variable when the entry is selected.
.TP
\fB\-selectcolor \fIvalue\fR
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 \fBselectColor\fR
option for the menu determines the indicator color.
.TP
\fB\-selectimage \fIvalue\fR
Available only for checkbutton and radiobutton entries.
Specifies an image to display in the entry (in place of
the \fB\-image\fR option) when it is selected.
\fIValue\fR is the name of an image, which must have been created
by some previous invocation of \fBimage create\fR.
This option is ignored unless the \fB\-image\fR option has
been specified.
.TP
\fB\-state \fIvalue\fR
Specifies one of three states for the entry:  \fBnormal\fR, \fBactive\fR,
or \fBdisabled\fR.  In normal state the entry is displayed using the
\fBforeground\fR option for the menu and the \fBbackground\fR
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 \fBactiveForeground\fR
option for the menu along with the \fBactivebackground\fR 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 
\fBdisabledForeground\fR option for the menu and the
\fBbackground\fR option from the entry.
This option is not available for separator entries.
.TP