hpux man page for constraintc

Constraint initialize() 												   Constraint initialize()

Name
  Constraint initialize - Constraint class method to initialize a child object or widget's constraint record.

Synopsis
  typedef void (*XtInitProc)(Widget, Widget, ArgList, Cardinal *);
	 Widget request;
	 Widget init;
	 ArgList args;
	 Cardinal *num_args;

Inputs
  request   Specifies  the  newly  created child widget or object instance with its constraint record resource values set as requested by the
	    argument list, the resource database, and the constraint defaults.

  init	    Specifies the same widget or object with its constraint record fields as modified by any superclass Constraint initialize() meth-
	    ods.

  args	    Specifies the argument list that was passed to XtCreateWidget().

  num_args  Specifies the number of entries in the argument list.

Description
  The  Constraint  initialize()  method is registered on the initialize field of the Constraint class part structure, and is called by XtCre-
  ateWidget() when a child of the constraint widget is created.  The Constraint initialize() method performs the same sort of initializations
  on  the constraint record of a widget that the normal (Object, RectObj, or Core) initialize() method performs on the widget instance struc-
  ture.

  The request and init arguments specify the child widget that is being created.  The constraints field of the request	widget	points	to  a
  copy	of  the constraint record as it was after all of the constraint resources were initialized from the argument list, the resource data-
  base, or the resource list defaults.	The constraints field of the init widget points to the actual constraints record of the  widget,  and
  has  been further initialized by the Constraint initialize() method of any Constraint superclasses of the parent widget.  All modifications
  should be made to the init constraints record; the request argument exists so that the widget class can determine which field of  the  con-
  straints record have been modified by superclass Constraint initialize() methods.

  The  Constraint  initialize()  method  is  chained  in superclass-to-subclass order, and cannot be inherited.  If nothing in the constraint
  structure needs initialization, the Constraint class part initialize field should be NULL.

  The args and num_args arguments were added to this method in Release 4.

  See initialize(4) for an explanation of the things that an initialize procedure should do.  See XtCreateWidget(1) for full details  of  the
  widget creation process.

Example
  The following procedure is the Constraint initialize() method, slightly modified, of the Athena Form widget class.  Note how it obtains the
  constraint record and the parent form widget from the supplied child widget.	Note also that it provides "dynamic defaults" for two of  its
  constraint  resources:  if  dx or dy is equal to some default value (i.e., if it was not explicitly specified), then it will be replaced by
  the value of the XtNdefaultSpacing resource from the Form widget itself.

  Note that this procedure (and most other initialize() procedures in existence) has named its init argument new.  "new" is a  reserved  word
  in C++, and your programs will be more portable if you avoid using it in your C code.

     /* ARGSUSED */
     static void ConstraintInitialize(request, new, args, num_args)
	 Widget request, new;
	 ArgList args;
	 Cardinal *num_args;
     {
	 FormConstraints form = (FormConstraints)new->core.constraints;
	 FormWidget fw = (FormWidget)new->core.parent;

	 form->form.virtual_width = (int) new->core.width;
	 form->form.virtual_height = (int) new->core.height;

	 if (form->form.dx == default_value)
	     form->form.dx = fw->form.default_spacing;

	 if (form->form.dy == default_value)
	     form->form.dy = fw->form.default_spacing;

	 form->form.deferred_resize = False;
     }

See Also
  XtCreateWidget(1),
  Constraint(3), Core(3),
  Constraint destroy(4), initialize(4), Constraint set_values(4).

Xt - Intrinsics Methods 												   Constraint initialize()