A menu may be viewed as a heirarchical collection of buttons, each
invoked by clicking on the button. These buttons are exposed
through submenus. More generally, a widget may replace the
button. This widget intends to support buttons (gactions),
separators (gseparator), radio button (gradio) and checkbutton
(gcheckbox), but this may be toolkit independent. When using a
radio button or checkbox, one should pass in a parent
argument to the constructor -- not a container.
For a menubar, svalue returns the list of action items
etc. that defined the menubar. This can be useful to access the
underlying item being proxied. (For gaction items the
enabled<- method may be used on the item, but this may not
extend to gradio and gcheckbox items)
for a menubar, svalue<- replaces the menubar items with new
ones specified by value.
gmenu(menu.list, popup = FALSE, container = NULL, ..., toolkit = guiToolkit()).gmenu(toolkit, menu.list = list(), popup = FALSE, container = NULL, ...)
# S3 method for GMenuBar
add(obj, child, expand = FALSE, fill = NULL, anchor = NULL, ...)
# S3 method for GMenuBar
svalue(obj, index = NULL, drop = NULL, ...)
# S3 method for GMenuBar
svalue (obj, index=NULL, ...) <- value
A list defining the menu structure. Named sub
lists determine the submenu titles and structure. The list may
have components of class: GAction, mapped to a button;
GSeparator, mapped to a horizontal separator;
GRadio, mapped to linked buttons; or GCheckbox,
mapped to a checkbox button.
logical. If true, make a popup window to be added through a handler call
A parent container. When a widget is created it can be incorporated into the widget heirarchy by passing in a parent container at construction time. (For some toolkits this is not optional, e.g. gWidgets2tcltk or gWidgets2WWW2.)
These values are passed to the add method of the
parent container. Examples of values are expand,
fill, and anchor, although they're not always
supported by a given widget. For more details see add.
Occasionally the variable arguments feature has been used to sneak
in hidden arguments to toolkit implementations. For example, when
using a widget as a menubar object one can specify a parent
argument to pass in parent information, similar to how the
argument is used with gaction and the dialogs.
Each widget constructor is passed in the toolkit it
will use. This is typically done using the default, which will
lookup the toolkit through guiToolkit.
parent object
list. a menubar list or gmenu instance.
NULL or logical. For box containers controls whether a child will expand to fill the allocated space.
NULL or character. For box containers. The value of fill (not
always respected) is used to control if expansion happens
vertically (y), horizontally (x) or both
(both or TRUE). For vertically filled box
containers, children always fill horizontally (atleast) and for
horizontally filled box containers, children always fill
vertically (atleast). This is important to realize when trying to
size buttons, say.
NULL or integer. For box containers. The anchor argument is used to position the child within the parent when there is more space allocated than the child requests. This is specified with a Cartesian pair in -1,0,1 x -1, 0, 1.
ignored
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a list or menu bar specifying the new men ubar