XmWidgetGetBaselines — Retrieves baseline information for a widget "XmWidgetGetBaselines"

XmWidgetGetBaselines  returns  an  array  that  contains  one or more baseline values associated with the
       specified widget. The baseline of any given line of text is a vertical offset in pixels from  the  origin
       of the widget's bounding box to the given baseline.

       widget    Specifies the ID of the widget for which baseline values are requested

       baselines Returns  an array that contains the value of each baseline of text in the widget.  The function
                 allocates space to hold the returned array.  The application is responsible  for  managing  the
                 allocated space.  The application can recover this allocated space by calling XtFree.

       line_count
                 Returns the number of lines in the widget

XmWidgetGetBaselines — Retrieves baseline information for a widget "XmWidgetGetBaselines"

XmWidgetGetDisplayRect(3).

                                                                                         XmWidgetGetBaselines(3)

       Returns  a Boolean value that indicates whether the widget contains a baseline. If the value is True, the
       function returns a value for each baseline of text. If it is False, the function was unable to  return  a
       baseline value.

       #include <Xm/Xm.h>
       BooleanXmWidgetGetBaselines(
       Widgetwidget,
       Dimension**baselines,
       int*line_count);