If the widget's parent is a subclass of constraintWidgetClass, XtSetValues also updates the widget's constraints. It starts with the constraint resources specified for constraintWidgetClass and proceeds down the subclass chain to the parent's class. At each stage, it writes the new value or the existing value to a new constraint record. It then calls the constraint set_values procedures from constraintWidgetClass down to the parent's class. The constraint set_values procedures are called with widget arguments, as for all set_values procedures, not just the constraint record arguments, so that they can make adjustments to the desired values based on full information about the widget.
XtSetValues determines if a geometry request is needed by comparing the current widget to the new widget. If any geometry changes are required, it makes the request, and the geometry manager returns XtGeometryYes, XtGeometryAlmost, or XtGeometryNo. If XtGeometryYes, XtSetValues calls the widget's resize procedure. If XtGeometryNo, XtSetValues resets the geometry fields to their original values. If XtGeometryAlmost, XtSetValues calls the set_values_almost procedure, which determines what should be done and writes new values for the geometry fields into the new widget. XtSetValues then repeats this process, deciding once more whether the geometry manager should be called.
Finally, if any of the set_values procedures returned True, XtSetValues causes the widget's expose procedure to be invoked by calling the Xlib XClearArea function on the widget's window.
The XtSetSubvalues function stores resources into the structure identified by base.
The XtGetValues function starts with the resources specified for the core widget fields and proceeds down the subclass chain to the widget. The value field of a passed argument list should contain the address into which to store the corresponding resource value. It is the caller's responsibility to allocate and deallocate this storage according to the size of the resource representation type used within the widget.
If the widget's parent is a subclass of constraintWidgetClass, XtGetValues then fetches the values for any constraint resources requested. It starts with the constraint resources specified for constraintWidgetClass and proceeds down to the subclass chain to the parent's constraint resources. If the argument list contains a resource name that is not found in any of the resource lists searched, the value at the corresponding address is not modified. Finally, if the get_values_hook procedures are non-NULL, they are called in superclass-to-subclass order after all the resource values have been fetched by XtGetValues. This permits a subclass to provide nonwidget resource data to XtGetValues.