XmCascadeButton

Motif 2.1 Programmer's Reference

XmCascadeButton

The CascadeButton widget class

Format

#include <Xm/CascadeB.h>

DESCRIPTION

CascadeButton links two menu panes or a MenuBar 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 or XmMENU_PULLDOWN.

It is the only widget that can have a Pulldown menu pane 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 menu pane; or it can include only a label or a pixmap when it is in a MenuBar. The positioning of the PulldownMenu with respect to the CascadeButton depends on the XmNlayoutDirection resource of the MenuShell.

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 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 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 menu pane 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 using 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 using the keyboard interface.

If the Cascadebutton 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 Label's default, which is 2.

CascadeButton uses the XmQTmenuSystem and XmQTspecifyRenderTable traits.

Classes

CascadeButton inherits behavior, resources, and traits 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 when a mouse button is released or when the mnemonic associated with the widget is typed. 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 menu pane 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. The positioning of the cascade pixmap to either the left of right of the widget, and the direction of the arrow, depend on the XmNlayoutDirection resource of the MenuShell.

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 menu pane. The value must not be negative.

XmNsubMenuId

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

Inherited Resources

CascadeButton inherits behavior and resources from the superclasses described in the following tables. For a complete description of each resource, refer to the reference 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
XmNrenderTable	XmCRenderTable	XmRenderTable	dynamic	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
XmNconvertCallback	XmCCallback	XtCallbackList	NULL	C
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
XmNlayoutDirection	XmCLayoutDirection	XmDirection	dynamic	CG
XmNnavigationType	XmCNavigationType	XmNavigationType	XmNONE	CSG
XmNpopupHandlerCallback	XmCCallback	XtCallbackList	NULL	C
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 XmPrimitive. XmCascadeButton includes the menu traversal translations from XmLabel.

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

The following list describes the translations for a CascadeButton in a MenuBar. The following key names are listed in the X standard key event translation table syntax. This format is the one used by Motif to specify the widget actions corresponding to a given key. A brief overview of the format is provided under VirtualBindings (3). For a complete description of the format, please refer to the X Toolkit Instrinsics Documentation.

EnterWindowNormal :

MenuBarEnter()

LeaveWindowNormal :

MenuBarLeave()

Btn2Down:

ProcessDrag()

c<BtnDown> :

MenuButtonTakeFocusUp()

c<BtnUp> :

MenuButtonTakeFocusUp()

c BtnDown:

MenuBarSelect()

c BtnUp:

DoSelect()

: KeyosfSelect:

KeySelect()

: KeyosfActivate:

KeySelect()

: KeyosfHelp:

Help()

: KeyosfCancel:

CleanupMenuBar()

s KeyReturn :

KeySelect()

s Keyspace :

KeySelect()

The following list describes the translations for a CascadeButton in a PullDown or Popup MenuPane. In a Popup menu system, Btn3 also performs the Btn1 actions.

EnterWindow:

DelayedArm()

LeaveWindow:

CheckDisarm()

Btn2Down:

ProcessDrag()

c<BtnDown> :

MenuButtonTakeFocus()

c<BtnUp> :

MenuButtonTakeFocusUp()

c BtnDown:

StartDrag()

c BtnUp:

DoSelect()

: KeyosfSelect:

KeySelect()

: KeyosfActivate:

KeySelect()

: KeyosfHelp:

Help()

: KeyosfCancel:

CleanupMenuBar()

s KeyReturn :

KeySelect()

s Keyspace :

KeySelect()

Action Routines

The XmCascadeButton action routines are

CleanupMenuBar() :

In a MenuBar, disarms the CascadeButton and the menu and, when the shell's keyboard focus policy is XmEXPLICIT, 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 XmEXPLICIT, 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 XmEXPLICIT, 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, this action calls the callbacks in XmNactivateCallback, activates the CascadeButton, and unposts all posted menus in the cascade.

Help() :

Unposts all menus in the menu hierarchy and, when the shell's keyboard focus policy is XmEXPLICIT, 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, this action calls the callbacks in XmNactivateCallback, activates the CascadeButton, and unposts all posted menus in the cascade.

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 following additional behavior:

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 (3).

RELATED

Core (3), XmCascadeButtonHighlight (3), XmCreateCascadeButton (3), XmCreateMenuBar (3), XmCreatePulldownMenu (3), XmCreatePopupMenu (3), XmLabel (3), XmPrimitive (3), and XmRowColumn (3).