NAME

DtComboBox − the ComboBox widget class

SYNOPSIS

#include <Dt/ComboBox.h>

DESCRIPTION

The DtComboBox widget is a combination of a TextField and a List widget that provides a list of valid choices for the TextField.  Selecting an item from this list automatically fills in the TextField with that list item. 

Widget subclassing is not supported for the DtComboBox widget class. 

The resources for the XmList and XmTextField widgets that are created by the DtComboBox are accessible by using the XtNameToWidget(3X) function.  The names of these widgets are ∗List and Text, respectively. 

Classes

The DtComboBox widget inherits behavior and resources from the Core, Composite and XmManager classes. 

The class pointer is dtComboBoxWidgetClass. 

The class name is DtComboBoxWidget.

New Resources

The following table defines a set of widget resources used by the application to specify data.  The application 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, the application must remove the DtN or DtC prefix and use the remaining letters.  To specify one of the defined values for a resource in a .Xdefaults file, the application remove the Dt prefix and use the remaining letters (in either lower case or upper case, but including 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).

DtNmarginHeight
Specifies the number of pixels added between the top and bottom of the text widget and the start of the shadow.

DtNmarginWidth
Specifies the number of pixels added between the right and left sides of the text widget and the start of the shadow.

DtNselectedItem
This resource is passed through to the XmList to set the XmNselectedItemCount and XmNselectedItems as the single item in the XmNitems that matches this specified XmString in the List.  Setting both DtNselectedItem and DtNselectedPosition in the same argument list produces undefined behavior. 

DtNselectedPosition
This resource is passed through to the XmList to set the XmNselectedItemCount and XmNselectedItems as the single item at this specified position in the List.  Setting both DtNselectedItem and DtNselectedPosition in the same argument list produces undefined behavior. 

DtNselectionCallback
This callback list is issued when an item is selected from the DtComboBox widget’s List. The call_data structure contains a DtComboBoxCallbackStruct with the reason DtCR_SELECT. 

DtNcomboBoxType
This resource determines the style of the DtComboBox. There are two choices:

DtDROP_DOWN_COMBO_BOX
Provides an editable text area.

DtDROP_DOWN_LIST
Provides a static text area.

Inherited Resources

The DtComboBox widget inherits behavior and resources from the following named superclasses.  For a complete description of each resource, see the man page for that superclass. 

Callback Information

A pointer to the following structure is passed to each DtComboBox callback:

typedef struct {
int reason;
XEvent∗event;
XmStringitem_or_text;
intitem_position;
} DtComboBoxCallbackStruct;

The reason argument indicates why the callback was invoked; it is always DtCR_SELECT. 

The event argument points to the XEvent that triggered the callback, or NULL if the callback was not triggered by an XEvent. 

The item_or_text argument is the contents of the Text widget at the time the event caused the callback to be invoked.  This data is only valid within the scope of the call_data structure, so the application must copy it when it is used outside of this scope. 

The item_position argument is the new value of the DtNselectedPosition resource in the DtComboBox’s List.  If this is zero, it means the user entered a value in the XmTextField widget. 

SEE ALSO

DtComboBoxAddItem(3X), DtComboBoxDeletePos(3X), DtComboBoxSelectItem(3X), DtComboBoxSetItem(3X), DtCreateComboBox(3X), Composite(3X), Constraint(3X), Core(3X), XmList(3X), XmManager(3X), XmText(3X), XmTextField(3X), XtGetValues(3X), XtSetValues(3X). 

  —  7 Jun 94