[ Previous | Next | Contents | Glossary | Home | Search ]
Motif 2.1 Programmer's Reference


The Command widget class


#include <Xm/Command.h>


Command is a special-purpose composite widget for command entry that provides a built-in command-history mechanism. Command includes a command-line text-input field, a command-line prompt, and a command-history list region.

One additional WorkArea child may be added to the Command after creation.

Whenever a command is entered, it is automatically added to the end of the command-history list and made visible. This does not change the selected item in the list, if there is one.

Many of the new resources specified for Command are actually SelectionBox resources that have been renamed for clarity and ease of use.


Command automatically creates the descendants shown in the following table. An application can use XtNameToWidget to gain access to the named descendant. In addition, a user or an application can use the named descendant when specifying resource values.

Named Descendant Class Identity

ItemsList XmList command-history list region
ItemsListSW XmScrolledWindow the ScrolledWindow parent of ItemsList
Selection XmLabelGadget command-line prompt
Text XmTextField command-line text-input field


Command inherits behavior, resources, and traits from Core, Composite, Constraint, XmManager, XmBulletinBoard, and XmSelectionBox.

The class pointer is xmCommandWidgetClass.

The class name is XmCommand.

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).

XmCommand Resource Set
Name Class Type Default Access
XmNcommand XmCTextString XmString "" CSG
XmNcommandChangedCallback XmCCallback XtCallbackList NULL C
XmNcommandEnteredCallback XmCCallback XtCallbackList NULL C
XmNhistoryItems XmCItems XmStringTable NULL CSG
XmNhistoryItemCount XmCItemCount int 0 CSG
XmNhistoryMaxItems XmCMaxItems int 100 CSG
XmNhistoryVisibleItemCount XmCVisibleItemCount int dynamic CSG
XmNpromptString XmCPromptString XmString dynamic CSG

Contains the current command-line text. This is the XmNtextString resource in SelectionBox, renamed for Command. This resource can also be modified with XmCommandSetValue and XmCommandAppendValue functions. The command area is a Text widget.

Specifies the list of callbacks that is called after each time the value of the command changes. The callback reason is XmCR_COMMAND_CHANGED. This is equivalent to the XmNvalueChangedCallback of the Text widget, except that a pointer to an XmCommandCallbackStructure is passed, and the structure's value member contains the XmString.

Specifies the list of callbacks that is called when a command is entered in the Command. The callback reason is XmCR_COMMAND_ENTERED. A pointer to an XmCommandCallback structure is passed.

Lists XmString items that make up the contents of the history list. This is the XmNlistItems resource in SelectionBox, renamed for Command. XtGetValues for this resource returns the list items themselves, not a copy of the list items. The application must not free the returned items.

Specifies the number of XmStrings in XmNhistoryItems. This is the XmNlistItemCount resource in SelectionBox, renamed for Command. The value must not be negative.

Specifies the maximum number of items allowed in the history list. Once this number is reached, an existing list item must be removed before a new item can be added to the list. For each command entered, the first list item is removed from the list, so the new command can be added to the list. The value must be greater than 0 (zero).

Specifies the number of items in the history list that should be visible at one time. In effect, it sets the height (in lines) of the history list window. This is the XmNlistVisibleItemCount resource in SelectionBox, renamed for Command. The value must be greater than 0 (zero). The default is dynamic based on the height of the list.

Specifies a prompt for the command line. This is the XmNselectionLabelString resource in SelectionBox, renamed for Command. The default may vary depending on the value of the XmNlayoutDirection resource and the locale. In the C locale the default is > (right angle bracket).

Now that some default localized label strings are provided through message catalogs for the children of composite widgets, the labelString resources cannot be set on the child through default resource files. Instead, the resource provided at the parent level must be used.

Inherited Resources

Command 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.

XmSelectionBox Resource Set
Name Class Type Default Access
XmNapplyCallback XmCCallback XtCallbackList NULL N/A
XmNapplyLabelString XmCApplyLabelString XmString dynamic N/A
XmNcancelCallback XmCCallback XtCallbackList NULL N/A
XmNcancelLabelString XmCCancelLabelString XmString dynamic N/A
XmNchildPlacement XmCChildPlacement unsigned char XmPLACE_ABOVE_SELECTION CSG
XmNdialogType XmCDialogType unsigned char XmDIALOG_COMMAND G
XmNhelpLabelString XmCHelpLabelString XmString dynamic N/A
XmNlistItemCount XmCItemCount int 0 CSG
XmNlistItems XmCItems XmStringTable NULL CSG
XmNlistLabelString XmCListLabelString XmString NULL N/A
XmNlistVisibleItemCount XmCVisibleItemCount int dynamic CSG
XmNminimizeButtons XmCMinimizeButtons Boolean False N/A
XmNmustMatch XmCMustMatch Boolean False N/A
XmNnoMatchCallback XmCCallback XtCallbackList NULL N/A
XmNokCallback XmCCallback XtCallbackList NULL N/A
XmNokLabelString XmCOkLabelString XmString dynamic N/A
XmNselectionLabelString XmCSelectionLabelString XmString dynamic CSG
XmNtextAccelerators XmCTextAccelerators XtAccelerators default C
XmNtextColumns XmCColumns short dynamic CSG
XmNtextString XmCTextString XmString "" CSG

XmBulletinBoard Resource Set
Name Class Type Default Access
XmNallowOverlap XmCAllowOverlap Boolean True CSG
XmNautoUnmanage XmCAutoUnmanage Boolean False N/A
XmNbuttonFontList XmCButtonFontList XmFontList dynamic N/A
XmNbuttonRenderTable XmCButtonRenderTable XmRenderTable dynamic CSG
XmNcancelButton XmCWidget Widget NULL N/A
XmNdefaultButton XmCWidget Widget NULL N/A
XmNdefaultPosition XmCDefaultPosition Boolean False CSG
XmNdialogStyle XmCDialogStyle unsigned char dynamic CSG
XmNdialogTitle XmCDialogTitle XmString NULL CSG
XmNfocusCallback XmCCallback XtCallbackList NULL C
XmNlabelFontList XmCLabelFontList XmFontList dynamic CSG
XmNlabelRenderTable XmCLabelRenderTable XmRenderTable dynamic CSG
XmNmapCallback XmCCallback XtCallbackList NULL C
XmNmarginHeight XmCMarginHeight Dimension 10 CSG
XmNmarginWidth XmCMarginWidth Dimension 10 CSG
XmNnoResize XmCNoResize Boolean False CSG
XmNresizePolicy XmCResizePolicy unsigned char XmRESIZE_NONE CSG
XmNshadowType XmCShadowType unsigned char XmSHADOW_OUT CSG
XmNtextFontList XmCTextFontList XmFontList dynamic CSG
XmNtextRenderTable XmCTextRenderTable XmRenderTable dynamic CSG
XmNtextTranslations XmCTranslations XtTranslations NULL C
XmNunmapCallback XmCCallback XtCallbackList NULL C

XmManager 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
XmNhighlightPixmap XmCHighlightPixmap Pixmap dynamic CSG
XmNinitialFocus XmCInitialFocus Widget dynamic CSG
XmNlayoutDirection XmCLayoutDirection XmDirection dynamic CG
XmNnavigationType XmCNavigationType XmNavigationType XmTAB_GROUP CSG
XmNpopupHandlerCallback XmCCallback XtCallbackList NULL C
XmNshadowThickness XmCShadowThickness Dimension dynamic CSG
XmNstringDirection XmCStringDirection XmStringDirection dynamic CG
XmNtopShadowColor XmCTopShadowColor Pixel dynamic CSG
XmNtopShadowPixmap XmCTopShadowPixmap Pixmap dynamic CSG
XmNtraversalOn XmCTraversalOn Boolean True CSG
XmNunitType XmCUnitType unsigned char dynamic CSG
XmNuserData XmCUserData XtPointer NULL CSG

Composite Resource Set
Name Class Type Default Access
XmNchildren XmCReadOnly WidgetList NULL G
XmNinsertPosition XmCInsertPosition XtOrderProc NULL CSG
XmNnumChildren XmCReadOnly Cardinal 0 G

Core Resource Set
Name Class Type Default Access
XmNaccelerators XmCAccelerators XtAccelerators dynamic N/A
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
* event;
} XmCommandCallbackStruct;

Indicates why the callback was invoked

Points to the XEvent that triggered the callback

Specifies the XmString in the CommandArea

Specifies the size in bytes of the XmString value. This member is obsolete and exists for compatibility with earlier releases.


XmCommand inherits translations from XmSelectionBox.


The XmNtextAccelerators from XmSelectionBox are added to the Text descendant of XmCommand.

Action Routines

The XmCommand action routines are:

SelectionBoxUpOrDown( Previous|Next|First|Last) :
When called with an argument of Previous , or 0 (zero) for compatibility, selects the previous item in the history list and replaces the text with that item.

When called with an argument of Next , or 1 for compatibility, selects the next item in the history list and replaces the text with that item.

When called with an argument of First , or 2 for compatibility, selects the first item in the history list and replaces the text with that item.

When called with an argument of Last , or 3 for compatibility, selects the last item in the history list and replaces the text with that item.

Calls the callbacks for XmNcommandChangedCallback.

Additional Behavior

The Command widget has the following additional behavior:

If the parent of the Command is a manager, the event is passed to the parent.

KeyosfActivate in Text:
Calls the Text widget's XmNactivateCallback callbacks. If the text is empty, this action then returns. Otherwise, if the history list has XmNhistoryMaxItems items, it removes the first item in the list. It adds the text to the history list as the last item, clears the text, and calls the XmNcommandEnteredCallback callbacks.

Key in Text:
When any change is made to the text edit widget, this action calls the callbacks for XmNcommandChangedCallback.

BtnDown(2+)  or KeyosfActivate in List:
Calls the List widget's XmNdefaultActionCallback callbacks. If the history list has XmNhistoryMaxItems items, this action removes the first item in the list. It adds the selected List item to the history list as the last item, clears the text, and calls the XmNcommandEnteredCallback callbacks.

Calls the callbacks for XmNfocusCallback.

When a Command that is the child of a DialogShell is mapped, this action calls the callbacks for XmNmapCallback.

When a Command that is the child of a DialogShell is unmapped, this action calls the callbacks for XmNunmapCallback.

Virtual Bindings

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


Composite (3), Constraint (3), Core (3), XmBulletinBoard (3), XmCommandAppendValue (3), XmCommandError (3), XmCommandGetChild (3), XmCommandSetValue (3), XmCreateCommand (3), XmManager (3), and XmSelectionBox (3).

[ Previous | Next | Contents | Glossary | Home | Search ]