Selecting Viewport with clipping

By Adam Nagy

I prompt the user to select a Viewport. This works fine, unless the Viewport has a clipping polyline in which case I get back the polyline instead of the Viewport. How could I get back the Viewport from the polyline?

ads_name ss; ads_name eName; ads_point pt; if( RTNORM != acedEntSel(_T("nPlease pick a viewport"), eName, pt ))   return; // eName might be a polyline even though the user selected a Viewport

Solution

You can get back the Viewport (if the selected entity is a clipping boundary of a viewport) using AcDbLayoutManager::getNonRectVPIdFromClipId():

AcDbObjectId polyId; acdbGetObjectId(polyId, eName);   AcDbLayoutManager *layoutMgr; layoutMgr = acdbHostApplicationServices()->layoutManager();   AcDbObjectId viewportId =    layoutMgr->getNonRectVPIdFromClipId(polyId);    if (viewportId.isNull()) {   // not a viewport clipping polyline }

You could also restrict the user to selecting Viewports only:

ads_name ss; ads_name eName; ads_point pt;   // instead of... // if( RTNORM != acedEntSel( //   _T("nPlease pick a viewport"), eName, pt ))  // return;   resbuf filter; filter.resval.rstring = _T("VIEWPORT"); filter.rbnext = NULL; filter.restype = 0;   ACHAR* texts[] = {_T("nPlease pick a viewport"), _T("")};    int ret = acedSSGet(_T("_-M:S:$"), texts, NULL, &filter, ss); if (RTNORM != ret)   return;   acedSSName(ss, 0, eName);