DEFINE_WIDGET_CLASS

    Defines a widget class for later use in creating widgets of that class
    using the XUI intrinsics or the XUI Toolkit low-level creation
    routines.  Each call returns a different class integer.  You use the
    integer to specify the class of a widget when you create the widget.

    Syntax

    integer := DEFINE_WIDGET_CLASS (widget_class_name
                                    [, creation_routine_name
                                    [, creation_routine_image_name]])



 Parameters

    integer                        An integer used to identify the class of
                                   widget to be created by CREATE_WIDGET.

    widget_class_name              A string that is the name of the widget
                                   class record.  This is a universal
                                   symbol exported by the toolkit or widget
                                   writer.

    creation_routine_name          A case-sensitive string that is the name
                                   of the low-level widget creation routine
                                   for this widget class.

    creation_routine_image_name    A string that is the name of the
                                   shareable image in which the class
                                   record can be found.

 Example

    The following procedure defines a class of widget created by the
    routine "dwt$dialog_box_popup_create".  The built-in
    DEFINE_WIDGET_CLASS returns a widget id for the widget class.  After
    defining the class, the procedure creates a widget of that class.  To
    see a longer example using DEFINE_WIDGET_CLASS, refer to the DECwindows
    VAXTPU documentation.

    PROCEDURE user_demonstrate_define_class

    CONSTANT
        sample_k_closure := ' ',
        sample_k_cstyle := "style",
        sample_k_modeless := 2,
        sample_k_nunits := "units",
        sample_k_pixelunits := 1,
        sample_k_ntitle := "title",
        sample_k_pad_title := "Sample mouse pad",
        sample_k_nheight := "height",
        sample_k_key_height := 30,
        sample_k_keypad_border := 5,
        sample_k_overall_ht := (sample_k_key_height  5)
                                    + ((sample_k_key_height
                                        / sample_k_button_border_frac)  5)
                                    + sample_k_keypad_border,
        sample_k_nwidth := "width",
        sample_k_key_width := 60,
        sample_k_button_border_frac := 3,
        sample_k_overall_wth := (sample_k_key_width  4)
                                   + ((sample_k_key_width
                                       / sample_k_button_border_frac)  4)
                                   + sample_k_keypad_border,
        sample_k_nx := "x",
        sample_k_ny := "y",
        sample_k_x_pos := 500,
        sample_k_y_pos := 500;

    LOCAL sample_x_dialog_class;

    sample_x_dialog_class :=
            DEFINE_WIDGET_CLASS ("dialogwidgetclassrec",
                                 "dwt$dialog_box_popup_create");

    sample_x_keypad := CREATE_WIDGET (sample_x_dialog_class, "Keypad",
                                     SCREEN,
                                     "MESSAGE('CALLBACK activated')",
                                     "sample_k_closure ",
                                     sample_k_cstyle, sample_k_modeless,
                                     sample_k_nunits, sample_k_pixelunits,
                                     sample_k_ntitle, sample_k_pad_title,
                                     sample_k_nheight, sample_k_overall_ht,
                                     sample_k_nwidth, sample_k_overall_wth,
                                     sample_k_nx, sample_k_x_pos,
                                     sample_k_nx, sample_k_x_pos);

    ENDPROCEDURE;