case IFACE_NULL : ret = tr("A parameter of type AbstractInterface* has been provided with NULL value."); break;
case IFACE_INVALID_TYPE : ret = tr("A parameter of type AbstractInterface* is used with an incorrect instance type."); break;
case IFACE_MULTIPLICITY_REACHED : ret = tr("Impossible to create another instance of a GraphInterface: the maximum multiplicity is reached."); break;
case IFACE_NULL : ret = tr("A parameter of type AbstractInterface* has been provided with NULL value."); break;
case IFACE_INVALID_TYPE : ret = tr("A parameter of type AbstractInterface* is used with an incorrect instance type."); break;
case IFACE_MULTIPLICITY_REACHED : ret = tr("Impossible to create another instance of a GraphInterface: the maximum multiplicity is reached."); break;
case BLOCKITEM_NULL : ret = tr("A parameter of type AbstractBlockItem* has been provided with NULL value."); break;
case BLOCKITEM_INVALID_TYPE : ret = tr("A parameter of type AbstractBlockItem* is used with an incorrect instance type."); break;
case WIDTHS_NOT_EQUALS : ret = tr("Two interfaces are connected but don't have the same widths."); break;
case BLOCKITEM_NULL : ret = tr("A parameter of type AbstractBlockItem* has been provided with NULL value."); break;
case BLOCKITEM_INVALID_TYPE : ret = tr("A parameter of type AbstractBlockItem* is used with an incorrect instance type."); break;
case WIDTHS_NOT_EQUALS : ret = tr("Two interfaces are connected but don't have the same widths."); break;