class EV_VIEWPORT_IMP Ancestors EV_CELL_IMP EV_VIEWPORT_I* Descendants EV_SCROLLABLE_AREA_IMP Clients EV_SCROLLABLE_AREA_IMP EV_VIEWPORT EV_VIEWPORT_IMP Suppliers BOOLEAN EV_GEOMETRY_ACTION_SEQUENCE EV_POS_INFO EV_VIEWPORT_IMP EV_WIDGET* EV_WIDGET_IMP* INTEGER_32 WEL_WINDOW_CONSTANTS