src/IO/LineReader.hpp

   1 /*
   2 Copyright_License {
   3
   4   XCSoar Glide Computer - http://www.xcsoar.org/
   5   Copyright (C) 2000-2013 The XCSoar Project
   6   A detailed list of copyright holders can be found in the file "AUTHORS".
   7
   8   This program is free software; you can redistribute it and/or
   9   modify it under the terms of the GNU General Public License
  10   as published by the Free Software Foundation; either version 2
  11   of the License, or (at your option) any later version.
  12
  13   This program is distributed in the hope that it will be useful,
  14   but WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16   GNU General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with this program; if not, write to the Free Software
  20   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  21 }
  22 */
  23
  24 #ifndef XCSOAR_IO_LINE_READER_HPP
  25 #define XCSOAR_IO_LINE_READER_HPP
  26
  27 #include "Compiler.h"
  28
  29 #include <tchar.h>
  30
  31 template<class T>
  32 class LineReader {
  33 public:
  34   virtual ~LineReader() {}
  35
  36   /**
  37    * Read one line, and returns a it as a null-terminated string
  38    * (without the trailing line feed character).  The returned buffer
  39    * is writable, and may be modified by the caller while parsing it.
  40    * It is Invalidated by the next call.  After the last line has been
  41    * read, this method returns NULL.
  42    */
  43   virtual T *ReadLine() = 0;
  44
  45   /**
  46    * Determins the size of the file.  Returns -1 if the size is
  47    * unknown.
  48    */
  49   gcc_pure
  50   virtual long GetSize() const {
  51     return -1;
  52   }
  53
  54   /**
  55    * Determins the current position within the file.  Returns -1 if
  56    * this is unknown.
  57    */
  58   gcc_pure
  59   virtual long Tell() const {
  60     return -1;
  61   }
  62 };
  63
  64 class TLineReader : public LineReader<TCHAR> {};
  65
  66 #ifdef _UNICODE
  67 class NLineReader : public LineReader<char> {};
  68 #else
  69 class NLineReader : public TLineReader {};
  70 #endif
  71
  72 #endif