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C++ API DOCUMENTATION |
00001 /***************************************************************************** 00002 * 00003 * This file is part of Mapnik (c++ mapping toolkit) 00004 * 00005 * Copyright (C) 2006 Artem Pavlenko 00006 * 00007 * This library is free software; you can redistribute it and/or 00008 * modify it under the terms of the GNU Lesser General Public 00009 * License as published by the Free Software Foundation; either 00010 * version 2.1 of the License, or (at your option) any later version. 00011 * 00012 * This library is distributed in the hope that it will be useful, 00013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00015 * Lesser General Public License for more details. 00016 * 00017 * You should have received a copy of the GNU Lesser General Public 00018 * License along with this library; if not, write to the Free Software 00019 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 00020 * 00021 *****************************************************************************/ 00022 00023 //$Id$ 00024 00025 #include <mapnik/datasource.hpp> 00026 00027 namespace mapnik { 00028 00029 template <typename T> 00030 class filter_featureset : public Featureset 00031 { 00032 typedef T filter_type; 00033 00034 public: 00035 filter_featureset(featureset_ptr fs, filter_type const& filter) 00036 : fs_(fs), filter_(filter) {} 00037 00038 feature_ptr next() 00039 { 00040 feature_ptr feature = fs_->next(); 00041 while (feature && !filter_.pass(*feature)) 00042 { 00043 feature = fs_->next(); 00044 } 00045 return feature; 00046 } 00047 00048 private: 00049 featureset_ptr fs_; 00050 filter_type filter_; 00051 }; 00052 }