source/characterencoding.cc

   1 /* This file is part of Shapes.
   2  *
   3  * Shapes is free software: you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation, either version 3 of the License, or
   6  * any later version.
   7  *
   8  * Shapes is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with Shapes.  If not, see <http://www.gnu.org/licenses/>.
  15  *
  16  * Copyright 2008 Henrik Tidefelt
  17  */
  18
  19 #include "characterencoding.h"
  20 #include "shapesexceptions.h"
  21
  22
  23 using namespace FontMetrics;
  24
  25 //       class CharacterEncoding
  26 //       {
  27 //       public:
  28 //               // A character encoding is a primitive thing which can only handle 256 code points.
  29 //               typedef unsigned char PositionType;
  30 //       private:
  31 //               RefCountPtr< const char > encodingName_;
  32
  33 //               // This is only a memory, with no particular order of its items.
  34 //               PtrOwner_back_Access< std::vector< const char * > > nameMem_;
  35
  36 //               // This is idexed by size_t and maps to a name or a null pointer.
  37 //               static const size_t TABLE_SIZE = 256;
  38 //               std::vector< const char * > namePtrs_;
  39
  40 //               // This is the reverse map.
  41 //               std::map< const char *, PositionType, charPtrLess > nameMap_;
  42
  43 //       public:
  44
  45 CharacterEncoding::CharacterEncoding( std::istream & iFile )
  46         : encodingName_( NullPtr< const char >( ) )
  47 {
  48         namePtrs_.resize( TABLE_SIZE, 0 );
  49         readfile( iFile );
  50 }
  51
  52 CharacterEncoding::~CharacterEncoding( )
  53 { }
  54
  55 // Returns true on success.
  56 bool
  57 CharacterEncoding::position_to_name( PositionType code, const char ** dst ) const
  58 {
  59         *dst = nameMem_[ code ];
  60         return *dst != 0;
  61 }
  62
  63 // Returns true on success.
  64 bool
  65 CharacterEncoding::name_to_position( const char * name, PositionType * dst ) const
  66 {
  67         typedef typeof nameMap_ MapType;
  68         MapType::const_iterator i = nameMap_.find( name );
  69         if( i == nameMap_.end( ) )
  70                 {
  71                         return false;
  72                 }
  73         *dst = i->second;
  74         return true;
  75 }
  76
  77 void
  78 CharacterEncoding::readfile( std::istream & iFile )
  79 {
  80         std::string token;
  81         getToken( iFile, & token );
  82         if( token[0] != '/' )
  83                 {
  84                         throw "Expected a leading / in the name of the character encoding.";
  85                 }
  86         encodingName_ = strrefdup( token.c_str( ) + 1 );
  87
  88         getToken( iFile, & token );
  89         // This is a bracket.   Skip it.
  90
  91         getToken( iFile, & token );
  92
  93         for( unsigned char pos = 0; token[ 0 ] != ']'; ++pos, getToken( iFile, & token ) )
  94                 {
  95                         if( token[ 1 ] != '.' )
  96                                 {
  97                                         nameMem_.push_back( strdup( token.c_str( ) + 1 ) );
  98                                         namePtrs_[ pos ] = nameMem_.back( );
  99                                         nameMap_[ nameMem_.back( ) ] = pos;
 100                                         //                                      std::cerr << nameMem_.back( ) << " --> " << static_cast< int >( pos ) << std::endl ;
 101                                 }
 102                 }
 103 }
 104
 105 void
 106 CharacterEncoding::getToken( std::istream & iFile, std::string * dst )
 107 {
 108         iFile >> *dst ;
 109         while( (*dst)[ 0 ] == '%' )
 110                 {
 111                         std::getline( iFile, *dst );
 112                         iFile >> *dst ;
 113                 }
 114 }