DwtMenuBar(3Dwt)

Name

DwtMenuBar, DwtMenuBarCreate − Creates a menu bar widget to contain menus.

Syntax

Widget DwtMenuBar(parent_widget, name, entry_callback,
                     help_callback)
     Widget parent_widget;
     char *name;
     DwtCallbackPtr entry_callback;
     DwtCallbackPtr help_callback;

Widget DwtMenuBarCreate (parent_widget, name,
                         override_arglist, override_argcount)
     Widget parent_widget;
     char *name;
     ArgList override_arglist;
     int override_argcount;

Arguments

parent_widget
Specifies the parent widget ID.

nameSpecifies the name of the created widget.

entry_callback
If this callback is defined, all menu entry activation callbacks are revectored to call back through this callback. If this callback is NULL, the individual menu entry callbacks work as usual. For this callback, the reason is DwtCRActivate. This argument sets the DwtNentryCallback attribute associated with DwtMenuCreate.

help_callbackSpecifies the callback function or functions called when a help request is made. This argument sets the DwtNhelpCallback common widget attribute.

parent_widget
Specifies the parent widget ID.

nameSpecifies the name of the created widget.

override_arglist
Specifies the application override argument list.

override_argcount
Specifies the number of attributes in the application override argument list (override_arglist).

Description

The DwtMenuBar and DwtMenuBarCreate functions create an instance of the menu bar widget and return its associated widget ID. When calling DwtMenuBar, you set the menu bar widget attributes presented in the formal parameter list. For DwtMenuBarCreate, you specify a list of attribute name/value pairs that represent all the possible menu bar widget attributes.

A menu bar widget is a composite widget that contains pull-down menu entry subwidgets. The subwidgets handle most of the I/O activity that display information and query the user for input. The menu bar widget provides no input semantics over and above those provided by its subwidgets.

If the menu bar does not have enough room to fit all its subwidgets on a single line, the menu bar attempts to wrap the remaining entries onto additional lines (if allowed by the geometry manager of the parent widget).

The menu bar widget works with these widget classes: pull-down menu entries, labels, and separators.

If DwtNentryCallback is not NULL when it is activated, all subwidgets call back to this callback. Otherwise, the individual subwidgets handle the activation callbacks.

Inherited Attributes

Attribute Name	Data Type	Default
Core Attributes
DwtNx	Position	Determined by the geometry manager
DwtNy	Position	Determined by the geometry manager
DwtNwidth	Dimension	16 pixels
DwtNheight	Dimension	Number of lines needed to display all entries
DwtNborderWidth	Dimension	One pixel
DwtNborder	Pixel	Default foreground color
DwtNborderPixmap	Pixmap	NULL
DwtNbackground	Pixel	Default background color
DwtNbackgroundPixmap	Pixmap	NULL
DwtNcolormap	Colormap	Default color map
DwtNsensitive	Boolean	True
		Note that setting the sensitivity of the menu bar causes all widgets contained in that menu bar to be set to the same sensitivity as the menu bar.
DwtNancestorSensitive	Boolean	The bitwise AND of the parent widget’s DwtNsensitive and DwtNancestorSensitive attributes
DwtNaccelerators	XtTranslations	NULL
DwtNdepth	int	Depth of the parent window
DwtNtranslations	XtTranslations	NULL
DwtNmappedWhenManaged	Boolean	True
DwtNscreen	Screen *	The parent screen
DwtNdestroyCallback	DwtCallbackPtr	NULL
Common Attributes
DwtNforeground	Pixel	Default foreground color
DwtNhighlight	Pixel	Default foreground color
DwtNhighlightPixmap	Pixmap	NULL
DwtNuserData	Opaque *	NULL
DwtNdirectionRToL	unsigned char	DwtDirectionRightDown
DwtNfont	DwtFontList	Used only by gadget children
DwtNhelpCallback	DwtCallbackPtr	NULL
Menu Attributes
DwtNspacing	Dimension	One pixel
DwtNmarginHeight	Dimension	Zero pixels
DwtNmarginWidth	Dimension	Three pixels
DwtNorientation	unsigned char	DwtOrientationVertical
DwtNadjustMargin	Boolean	True
DwtNentryBorder	short	Zero pixels
DwtNmenuAlignment	Boolean	True
DwtNentryAlignment	unsigned char	DwtAlignmentBeginning
DwtNmenuPacking	unsigned char	DwtMenuPackingTight (for all menu types except for radio boxes)
		DwtMenuPackingColumn (for radio boxes)
DwtNmenuNumColumns	short	One row or column
DwtNmenuRadio	Boolean	False
		True (for radio boxes)
DwtNradioAlwaysOne	Boolean	True
DwtNmenuIsHomogeneous	Boolean	False
		True (for radio boxes)
DwtNmenuEntryClass	WidgetClass	NULL Radio boxes, however, default to the togglebuttonwidgetclass.
DwtNmenuHistory	Widget	Zero
DwtNentryCallback	DwtCallbackPtr	NULL
DwtNmenuHelpWidget	Widget	NULL
DwtNchangeVisAtts	Boolean	True
DwtNmenuExtendLastRow	Boolean	True

Widget-Specific Attributes

The menu bar widget does not currently support any widget-specific attributes.

Return Values

These functions return the ID of the created widget.

Callback Information

The following structure is returned to your callback:

typedef struct {
int reason;
XEvent *event;
Widget s_widget;
char *s_tag;
char *s_callbackstruct;
} DwtMenuCallbackStruct;

The reason member is set to a constant that represents the reason why this callback was invoked. For this callback, the reason member can be set to:

DwtCRActivate	The user selected a menu entry.
DwtCRMap	The menu window is about to be mapped.
DwtCRUnmap	The menu window was just unmapped.
DwtCRHelpRequested	The user selected help.

The event member is a pointer to the Xlib structure XEvent, which describes the event that generated this callback. This structure is a union of the individual structures declared for each event type. For information on XEvent and event processing, see the Guide to the Xlib Library: C Language Binding. The s_widget member is set to the ID of the activating subwidget. The s_tag member is set to the tag supplied by the application programmer when the subwidget callback function was specified. The s_callbackstruct member is set to the subwidget’s callback structure.

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