Remove a boundary from a hatch

By Augusto Goncalves

The class AcDbHatch provides methods for getting the boundaries and for removing boundaries. Each boundary is a so-called loop. With AcDbHatch you can iterate all loops. Then you can get all entities belonging to a single loop. All you have to do is to compare the handles of the loop entities with the handle of the boundary object which should be removed from the hatch object. If one of the entities of the loop has the handle you are looking for you can use AcDbHatch::removeLoopAt() to remove the loop from the hatch.

The following function will do this. The parameter handleRemove is the handle of an entity belonging to a loop which should be removed.

void removeHandleFromHatch(const ACHAR* handleRemove)    {      // Create an AcDbHandle object from the input handle       AcDbHandle removeHandle(handleRemove);      //      //  Get the hatch       //      ads_point dummy;       ads_name ename;      if (RTNORM != ads_entsel(L"nSelect a hatch: ", ename, dummy))          return; AcDbObjectId hatchId;       AcDbHatch *pHatch;       if (Acad::eOk != acdbGetObjectId(hatchId, ename))       {          ads_printf(L"nCannot get objectId from hatch entity.");          return;       }      if (Acad::eOk != acdbOpenObject(pHatch, hatchId, AcDb::kForRead))      {           ads_printf(L"nCannot open hatch");         return;       }       //       // Analyze hatch      //      int loops = pHatch->numLoops();   // number of loops       ads_printf(L"nNumber of loops: %i", loops);       // Get all loops       AcDbObjectIdArray loopIds;       for (int i = 0; i < loops; ++i)      {         // Get the object ID's of all entities         // belonging to this loop          pHatch->getAssocObjIdsAt(i, loopIds);         // Get all objects from this loop          int numOfObjects = loopIds.logicalLength();         AcDbEntity *pEnt;   AcDbHandle handle;          for (int j = 0; j < numOfObjects; ++j)         {            if (Acad::eOk != acdbOpenObject(pEnt, loopIds[j],             AcDb::kForRead))          {               ads_printf(L"nCannot get object from loop %i.", i);              continue;            }               // Get handle of current loop entity            // and compare it with the input handle            pEnt->getAcDbHandle(handle);            pEnt->close();          // no longer needed            if (handle == removeHandle)          {              ads_printf(L"nBoundary entity found.");             // Remove loop from hatch entity             pHatch->upgradeOpen();               pHatch->removeLoopAt(i);              pHatch->downgradeOpen();             break;               }           }          loopIds.setLogicalLength(0);      }       // Close hatch       pHatch->close();    }