XmCascadeButton(3X)

NAME
XmCascadeButton - The CascadeButton widget class

SYNOPSIS
#include <Xm/CascadeB.h>

DESCRIPTION
CascadeButton links two MenuPanes or a MenuBar to a MenuPane.

It is used in menu systems and must have a RowColumn parent with its XmNrowColumnType resource set to XmMENU_BAR, XmMENU_POPUP or XmMENU_PULLDOWN.

It is the only widget that can have a Pulldown MenuPane attached to it as a submenu. The submenu is displayed when this widget is activated within a MenuBar, a PopupMenu, or a PulldownMenu. Its visuals can include a label or pixmap and a cascading indicator when it is in a Popup or Pulldown MenuPane; or, it can include only a label or a pixmap when it is in a MenuBar.

The default behavior associated with a CascadeButton depends on the type of menu system in which it resides. By default, BSelect controls the behavior of the CascadeButton. In addition, BMenu controls the behavior of the CascadeButton if it resides in a Menu system. The actual mouse button used is determined by its RowColumn parent.

A CascadeButton'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 CascadeButton within a Pulldown or Popup MenuPane is armed as the result of the user moving the mouse pointer into the widget, it does not immediately display its submenu. Instead, it waits a short amount of time to see if the arming was temporary (that is, the user was simply passing through the widget), or whether the user really wanted the submenu posted. This time delay is configurable via XmNmappingDelay.

CascadeButton provides a single mechanism for activating the widget from the keyboard. This mechanism is referred to as a keyboard mnemonic. If a mnemonic has been specified for the widget, the user may activate the CascadeButton by simply typing the mnemonic while the CascadeButton is visible. If the CascadeButton is in a MenuBar and the MenuBar does not have the focus, the MAlt modifier must be pressed with the mnemonic. Mnemonics are typically used to interact with a menu via the keyboard interface.

If in a Pulldown or Popup MenuPane 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 Label's default, which is 2.

  Classes
CascadeButton inherits behavior and resources from Core, XmPrimitive, and XmLabel classes.

The class pointer is xmCascadeButtonWidgetClass.

The class name is XmCascadeButton.

  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).

XmCascadeButton Resource Set
Name | Class | Type | Default | Access
XmNactivateCallback | XmCCallback | XtCallbackList | NULL | C
XmNcascadePixmap | XmCPixmap | Pixmap | dynamic | CSG
XmNcascadingCallback | XmCCallback | XtCallbackList | NULL | C
XmNmappingDelay | XmCMappingDelay | int | 180 ms | CSG
XmNsubMenuId | XmCMenuWidget | Widget | NULL | CSG

XmNactivateCallback
    Specifies the list of callbacks that is called when the user activates the CascadeButton widget, and there is no submenu attached to pop up. The activation occurs by releasing a mouse button or by typing the mnemonic associated with the widget. The specific mouse button depends on information in the RowColumn parent. The reason sent by the callback is XmCR_ACTIVATE.

XmNcascadePixmap
    Specifies the cascade pixmap displayed on one end of the widget when a CascadeButton is used within a Popup or Pulldown MenuPane and a submenu is attached. The Label class resources XmNmarginBottom, XmNmarginLeft, XmNmarginRight, and XmNmarginTop may be modified to ensure that room is left for the cascade pixmap. The default cascade pixmap is an arrow pointing to the side of the menu where the submenu will appear.

XmNcascadingCallback
    Specifies the list of callbacks that is called just prior to the mapping of the submenu associated with CascadeButton. The reason sent by the callback is XmCR_CASCADING.

XmNmappingDelay
    Specifies the amount of time, in milliseconds, between when a CascadeButton becomes armed and when it maps its submenu. This delay is used only when the widget is within a Popup or Pulldown MenuPane. The value must not be negative.

XmNsubMenuId
    Specifies the widget ID for the Pulldown MenuPane to be associated with this CascadeButton. The specified MenuPane is displayed when the CascadeButton becomes armed. The MenuPane must have been created with the appropriate parentage depending on the type of menu used. See XmCreateMenuBar(3X), XmCreatePulldownMenu(3X), and XmCreatePopupMenu(3X) for more information on the menu systems.

  Inherited Resources
CascadeButton inherits behavior and resources from the following superclasses. For a complete description of each resource, refer to the man page for that superclass.

XmLabel Resource Set
Name | Class | Type | Default | Access
XmNaccelerator | XmCAccelerator | String | NULL | N/A
XmNacceleratorText | XmCAcceleratorText | XmString | NULL | N/A
XmNalignment | XmCAlignment | unsigned char | dynamic | CSG
XmNfontList | XmCFontList | XmFontList | dynamic | CSG
XmNlabelInsensitivePixmap | XmCLabelInsensitivePixmap | Pixmap | XmUNSPECIFIED_PIXMAP | CSG
XmNlabelPixmap | XmCLabelPixmap | Pixmap | XmUNSPECIFIED_PIXMAP | CSG
XmNlabelString | XmCXmString | XmString | dynamic | CSG
XmNlabelType | XmCLabelType | unsigned char | XmSTRING | CSG
XmNmarginBottom | XmCMarginBottom | Dimension | dynamic | CSG
XmNmarginHeight | XmCMarginHeight | Dimension | 2 | CSG
XmNmarginLeft | XmCMarginLeft | Dimension | 0 | CSG
XmNmarginRight | XmCMarginRight | Dimension | dynamic | CSG
XmNmarginTop | XmCMarginTop | Dimension | dynamic | CSG
XmNmarginWidth | XmCMarginWidth | Dimension | dynamic | CSG
XmNmnemonic | XmCMnemonic | KeySym | NULL | CSG
XmNmnemonicCharSet | XmCMnemonicCharSet | String | XmFONTLIST_DEFAULT_TAG | CSG
XmNrecomputeSize | XmCRecomputeSize | Boolean | True | CSG
XmNstringDirection | XmCStringDirection | XmStringDirection | dynamic | CSG

XmPrimitive Resource Set
Name | Class | Type | Default | Access
XmNbottomShadowColor | XmCBottomShadowColor | Pixel | dynamic | CSG
XmNbottomShadowPixmap | XmCBottomShadowPixmap | Pixmap | XmUNSPECIFIED_PIXMAP | CSG
XmNforeground | XmCForeground | Pixel | dynamic | CSG
XmNhelpCallback | XmCCallback | XtCallbackList | NULL | C
XmNhighlightColor | XmCHighlightColor | Pixel | dynamic | CSG
XmNhighlightOnEnter | XmCHighlightOnEnter | Boolean | False | CSG
XmNhighlightPixmap | XmCHighlightPixmap | Pixmap | dynamic | CSG
XmNhighlightThickness | XmCHighlightThickness | Dimension | 0 | CSG
XmNnavigationType | XmCNavigationType | XmNavigationType | XmNONE | CSG
XmNshadowThickness | XmCShadowThickness | Dimension | 2 | CSG
XmNtopShadowColor | XmCTopShadowColor | Pixel | dynamic | CSG
XmNtopShadowPixmap | XmCTopShadowPixmap | Pixmap | dynamic | CSG
XmNtraversalOn | XmCTraversalOn | Boolean | dynamic | G
XmNunitType | XmCUnitType | unsigned char | dynamic | CSG
XmNuserData | XmCUserData | XtPointer | NULL | CSG

Core Resource Set
Name | Class | Type | Default | Access
XmNaccelerators | XmCAccelerators | XtAccelerators | dynamic | CSG
XmNancestorSensitive | XmCSensitive | Boolean | dynamic | G
XmNbackground | XmCBackground | Pixel | dynamic | CSG
XmNbackgroundPixmap | XmCPixmap | Pixmap | XmUNSPECIFIED_PIXMAP | CSG
XmNborderColor | XmCBorderColor | Pixel | XtDefaultForeground | CSG
XmNborderPixmap | XmCPixmap | Pixmap | XmUNSPECIFIED_PIXMAP | CSG
XmNborderWidth | XmCBorderWidth | Dimension | 0 | CSG
XmNcolormap | XmCColormap | Colormap | dynamic | CG
XmNdepth | XmCDepth | int | dynamic | CG
XmNdestroyCallback | XmCCallback | XtCallbackList | NULL | C
XmNheight | XmCHeight | Dimension | dynamic | CSG
XmNinitialResourcesPersistent | XmCInitialResourcesPersistent | Boolean | True | C
XmNmappedWhenManaged | XmCMappedWhenManaged | Boolean | True | CSG
XmNscreen | XmCScreen | Screen * | dynamic | CG
XmNsensitive | XmCSensitive | Boolean | True | CSG
XmNtranslations | XmCTranslations | XtTranslations | dynamic | CSG
XmNwidth | XmCWidth | Dimension | dynamic | CSG
XmNx | XmCPosition | Position | 0 | CSG
XmNy | XmCPosition | Position | 0 | CSG

  Callback Information
A pointer to the following structure is passed to each callback:
typedef struct
{
	int	reason;
	XEvent	* event;
} XmAnyCallbackStruct;

reason
    Indicates why the callback was invoked.

event
    Points to the XEvent that triggered the callback or is NULL if this callback was not triggered due to an XEvent.

  Translations
XmCascadeButton includes translations from Primitive. XmCascadeButton includes the menu traversal translations from XmLabel. These translations may not directly correspond to a translation table.

Note that altering translations in #override or #augment mode is undefined.

The translations for a CascadeButton in a MenuBar are listed below. These translations may not directly correspond to a translation table.
BSelect Press:	MenuBarSelect()
BSelect Release:	DoSelect()
KActivate:	KeySelect()
KSelect:	KeySelect()
KHelp:	Help()
MAny KCancel:	CleanupMenuBar()

The translations for a CascadeButton in a PullDown or Popup MenuPane are listed below. In a menu system, BMenu also performs the BSelect actions. These translations may not directly correspond to a translation table.
BSelect Press:	StartDrag()
BSelect Release:	DoSelect()
KActivate:	KeySelect()
KSelect:	KeySelect()
KHelp:	Help()
MAny KCancel:	CleanupMenuBar()

  Action Routines
The XmCascadeButton action routines are described below:

CleanupMenuBar():
    In a MenuBar, disarms the CascadeButton and the menu and, when the shell's keyboard focus policy is XmEXPLICT, restores keyboard focus to the widget that had the focus before the menu was entered.

In a toplevel Pulldown MenuPane from a MenuBar, unposts the menu, disarms the MenuBar CascadeButton and the MenuBar, and, when the shell's keyboard focus policy is XmEXPLICT, restores keyboard focus to the widget that had the focus before the MenuBar was entered. In other Pulldown MenuPanes, unposts the menu.

In a Popup MenuPane, unposts the menu and, when the shell's keyboard focus policy is XmEXPLICT, restores keyboard focus to the widget from which the menu was posted.

DoSelect():
    Calls the callbacks in XmNcascadingCallback, posts the submenu attached to the CascadeButton and enables keyboard traversal within the menu. If the CascadeButton does not have a submenu attached, calls the callbacks in XmNactivateCallback, the CascadeButton is activated and all posted menus in the cascade are unposted.

Help():
    Unposts all menus in the menu hierarchy and, when the shell's keyboard focus policy is XmEXPLICT, restores keyboard focus to the widget that had the focus before the menu system was entered. Calls the callbacks for XmNhelpCallback if any exist. If there are no help callbacks for this widget, this action calls the help callbacks for the nearest ancestor that has them.

KeySelect():
    Calls the callbacks in XmNcascadingCallback, and posts the submenu attached to the CascadeButton if keyboard traversal is enabled in the menu. If the CascadeButton does not have a submenu attached, calls the callbacks in XmNactivateCallback, the CascadeButton is activated and all posted menus in the cascade are unposted.

MenuBarSelect():
    Unposts any menus posted by the parent menu. Arms both the CascadeButton and the MenuBar, posts the associated submenu, and enables mouse traversal. If the menu is already active, this event disables keyboard traversal for the menu and returns the menu to mouse traversal mode.

StartDrag():
    Arms the CascadeButton, posts the associated submenu, and enables mouse traversal. If the menu is already active, this event disables keyboard traversal for the menu and returns the menu to mouse traversal mode.

  Additional Behavior
Posting a submenu calls the XmNcascadingCallback callbacks. This widget has the additional behavior described below:

<EnterWindow>:
    If keyboard traversal is enabled does nothing. Otherwise, in a MenuBar that is armed, unposts any MenuPanes associated with another MenuBar entry, arms the CascadeButton, and posts the associated submenu. In other menus, arms the CascadeButton and posts the associated submenu after the delay specified by XmNmappingDelay.

<LeaveWindow>:
    If keyboard traversal is enabled does nothing. Otherwise, in a MenuBar that is armed, disarms the CascadeButton if the submenu associated with the CascadeButton is not currently posted or if there is no submenu associated with the CascadeButton.

In other menus, if the pointer moves anywhere except into a submenu associated with the CascadeButton, the CascadeButton is disarmed and its submenu is unposted.

  Virtual Bindings
The bindings for virtual keys are vendor specific. For information about bindings for virtual buttons and keys, see VirtualBindings(3X).

RELATED INFORMATION
Core(3X), XmCascadeButtonHighlight(3X), XmCreateCascadeButton(3X),XmCreateMenuBar(3X), XmCreatePulldownMenu(3X), XmCreatePopupMenu(3X), XmDisplay(3X), XmLabel(3X), XmPrimitive(3X), and XmRowColumn(3X).