Provided by: libmotif-dev_2.3.8-3_amd64 
NAME
XmCascadeButtonGadget — The CascadeButtonGadget widget class "XmCascadeButtonGadget"
"widget class" "CascadeButtonGadget"
SYNOPSIS
#include <Xm/CascadeBG.h>
DESCRIPTION
CascadeButtonGadget links two menu panes, a MenuBar to a menu pane, or an OptionMenu to a
menu pane.
It is used in menu systems and must have a RowColumn parent with its XmNrowColumnType
resource set to XmMENU_BAR, XmMENU_POPUP, XmMENU_PULLDOWN, or XmMENU_OPTION.
It is the only gadget that can have a Pulldown menu pane attached to it as a submenu. The
submenu is displayed when this gadget is activated within a PopupMenu, a PulldownMenu, or
an OptionMenu. Its visuals can include a label or pixmap and a cascading indicator when it
is in a Popup or Pulldown menu pane; or it can include only a label or a pixmap when it is
in an OptionMenu. The positioning of the PulldownMenu with respect to the CascadeButton
depends on the XmNlayoutDirection resource of the MenuShell.
The default behavior associated with a CascadeButtonGadget depends on the type of menu
system in which it resides. By default, BSelect controls the behavior of the
CascadeButtonGadget. In addition, BMenu controls the behavior of the CascadeButtonGadget
if it resides in a PopupMenu system. The actual mouse button used is determined by its
RowColumn parent. BMenu also performs the BSelect actions in all types of menu systems.
A CascadeButtonGadget's visuals differ from most other button gadgets. When the button
becomes armed, its visuals change from a 2-D to a 3-D look, and it displays the submenu
that has been attached to it. If no submenu is attached, it simply changes its visuals.
When a CascadeButtonGadget within a Pulldown or Popup menu pane is armed as the result of
the user moving the mouse pointer into the gadget, it does not immediately display its
submenu. Instead, it waits a short time to see if the arming was temporary (that is, the
user was simply passing through the gadget), or the user really wanted the submenu posted.
This delay is configurable using XmNmappingDelay.
CascadeButtonGadget provides a single mechanism for activating the gadget from the
keyboard. This mechanism is referred to as a keyboard mnemonic. If a mnemonic has been
specified for the gadget, the user may activate it by simply typing the mnemonic while the
CascadeButtonGadget is visible. If the CascadeButtonGadget is in a MenuBar and the
MenuBar does not have focus, the MAlt modifier must be pressed with the mnemonic.
Mnemonics are typically used to interact with a menu using the keyboard.
If a CascadeButtonGadget is in a Pulldown or Popup menu pane and there is a submenu
attached, the XmNmarginBottom, XmNmarginLeft, XmNmarginRight, and XmNmarginTop resources
may enlarge to accommodate XmNcascadePixmap. XmNmarginWidth defaults to 6 if this
resource is in a MenuBar; otherwise, it takes LabelGadget's default, which is 2.
CascadeButtonGadget uses the XmQTmenuSystem and XmQTspecifyRenderTable traits.
Classes
CascadeButtonGadget inherits behavior, resources, and traits from the Object, RectObj,
XmGadget, and XmLabelGadget classes.
The class pointer is xmCascadeButtonGadgetClass.
The class name is XmCascadeButtonGadget.
New Resources
The following table defines a set of widget resources used by the programmer to specify
data. The programmer can also set the resource values for the inherited classes to set
attributes for this widget. To reference a resource by name or by class in a .Xdefaults
file, remove the XmN or XmC prefix and use the remaining letters. To specify one of the
defined values for a resource in a .Xdefaults file, remove the Xm prefix and use the
remaining letters (in either lowercase or uppercase, but include any underscores between
words). The codes in the access column indicate if the given resource can be set at
creation time (C), set by using XtSetValues (S), retrieved by using XtGetValues (G), or is
not applicable (N/A).
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RELATED
Object(3), RectObj(3), XmCascadeButtonHighlight(3), XmCreateCascadeButtonGadget(3),
XmCreatePulldownMenu(3), XmCreatePopupMenu(3), XmCreateOptionMenu(3), XmGadget(3),
XmLabelGadget(3), XmRowColumn(3), XmVaCreateCascadeButtonGadget(3), and
XmVaCreateManagedCascadeButtonGadget(3).
XmCascadeButtonGadget(3)