NAME

       XmResolveAllPartOffsets  —  A  function that allows writing of upward-compatible applications and widgets
       "XmResolveAllPartOffsets"

SYNOPSIS

       #include <Xm/Xm.h>
       void XmResolveAllPartOffsets(
       WidgetClass widget_class,
       XmOffsetPtr * offset,
       XmOffsetPtr * constraint_offset);

DESCRIPTION

              Note:

              This routine is obsolete and exists for compatibility with  previous  releases.  You  should  call
              XmeResolvePartOffsets instead.

       The use of offset records requires two extra global variables per widget class.  The variables consist of
       pointers  to  arrays  of offsets into the widget record and constraint record for each part of the widget
       structure.  The XmResolveAllPartOffsets function allocates the offset records needed by an application to
       guarantee upward-compatible access to widget instance and constraint records by applications and widgets.
       These offset records are used by the widget to access all of the widget's variables.  A widget  needs  to
       take the steps described in the following paragraphs.

       Instead of creating a resource list, the widget creates an offset resource list.  To accomplish this, use
       the  XmPartResource  structure  and the XmPartOffset macro.  The XmPartResource data structure looks just
       like a resource list, but instead of having one  integer  for  its  offset,  it  has  two  shorts.   This
       structure  is  put  into the class record as if it were a normal resource list. Instead of using XtOffset
       for the offset, the widget uses XmPartOffset.

       If the widget is a subclass of the Constraint class  and  it  defines  additional  constraint  resources,
       create  an  offset  resource  list  for  the  constraint part as well.  Instead of using XtOffset for the
       offset, the widget uses XmConstraintPartOffset in the constraint resource list.

       XmPartResource resources[] = {
               {       BarNxyz, BarCXyz, XmRBoolean, sizeof(Boolean),
                       XmPartOffset(Bar,xyz), XmRImmediate, (XtPointer)False } };
       XmPartResource constraints[] = {
               {       BarNmaxWidth, BarNMaxWidth,
                 XmRDimension, sizeof(Dimension),
                 XmConstraintPartOffset(Bar,max_width),
                 XmRImmediate, (XtPointer)100 } };

       Instead of putting the widget size in the class record, the widget puts the widget part size in the  same
       field.   If  the  widget  is a subclass of the Constraint class, instead of putting the widget constraint
       record size in the class record, the widget puts the widget constraint part size in the same field.

       Instead of putting XtVersion in the class record, the widget puts XtVersionDontCheck in the class record.

       Define a variable, of type XmOffsetPtr, to point to the offset record.  If the widget is  a  subclass  of
       the  Constraint  class,  define  a variable of type XmOffsetPtr to point to the constraint offset record.
       These can be part of the widget's class record or separate global variables.

       In class initialization, the widget calls XmResolveAllPartOffsets,  passing  it  pointers  to  the  class
       record, the address of the offset record, and the address of the constraint offset record.  If the widget
       not  is  a  subclass of the Constraint class, it should pass NULL as the address of the constraint offset
       record.  This does several things:

          •  Adds the superclass (which, by definition, has already been initialized) size  field  to  the  part
             size field

          •  If  the  widget is a subclass of the Constraint class, adds the superclass constraint size field to
             the constraint size field

          •  Allocates an array based upon the number of superclasses

          •  If the widget is a subclass of the constraint class, allocates an array for the  constraint  offset
             record

          •  Fills  in  the  offsets  of  all the widget parts and constraint parts with the appropriate values,
             determined by examining the size fields of all superclass records

          •  Uses the part offset array to modify the offset entries in the resource list to be real offsets, in
             place

       The widget defines a constant that will be the index to its part structure in  the  offsets  array.   The
       value  should  be  1  greater  than  the  index of the widget's superclass.  Constants defined for all Xm
       widgets can be found in XmP.h.

       #define BarIndex (XmBulletinBIndex + 1)

       Instead of accessing fields directly, the widget must always go through the offset  table.   The  XmField
       and   XmConstraintField   macros   help   you   access   these   fields.    Because   the   XmPartOffset,
       XmConstraintPartOffset, XmField, and XmConstraintField macros concatenate things, you  must  ensure  that
       there  is no space after the part argument.  For example, the following macros do not work because of the
       space after the part (Label) argument:

       XmField(w, offset, Label, text, char *)
       XmPartOffset(Label, text).

       Therefore, you must not have any spaces after the part (Label) argument, as illustrated here:

       XmField(w, offset, Label, text, char *)

       You can define macros for each field to make this easier.  Assume an integer field xyz:

       #define BarXyz(w) (*(int *)(((char *) w) + \
               offset[BarIndex] + XtOffset(BarPart,xyz)))

       For constraint field max_width:

       #define BarMaxWidth(w) \
               XmConstraintField(w,constraint_offsets,Bar,max_width,Dimension)

       The parameters for XmResolveAllPartOffsets are

       widget_class
                 Specifies the widget class pointer for the created widget

       offset    Returns the offset record

       constraint_offset
                 Returns the constraint offset record

RELATED INFORMATION

       XmResolvePartOffsets(3).

                                                                                      XmResolveAllPartOffsets(3)