src/stringfilter.cpp

   1 /* $Id: stringfilter.cpp 24632 2012-10-27 15:26:17Z frosch $ */
   2
   3 /*
   4  * This file is part of OpenTTD.
   5  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
   6  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   7  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
   8  */
   9
  10 /** @file stringfilter.cpp Searching and filtering using a stringterm. */
  11
  12 #include "stdafx.h"
  13 #include "string_func.h"
  14 #include "strings_func.h"
  15 #include "stringfilter_type.h"
  16 #include "gfx_func.h"
  17
  18 #include "safeguards.h"
  19
  20 static const WChar STATE_WHITESPACE = ' ';
  21 static const WChar STATE_WORD = 'w';
  22 static const WChar STATE_QUOTE1 = '\'';
  23 static const WChar STATE_QUOTE2 = '"';
  24
  25 /**
  26  * Set the term to filter on.
  27  * @param str Filter term
  28  */
  29 void StringFilter::SetFilterTerm(const char *str)
  30 {
  31         this->word_index.Reset();
  32         this->word_matches = 0;
  33         free(this->filter_buffer);
  34
  35         assert(str != nullptr);
  36
  37         char *dest = MallocT<char>(strlen(str) + 1);
  38         this->filter_buffer = dest;
  39
  40         WChar state = STATE_WHITESPACE;
  41         const char *pos = str;
  42         WordState *word = nullptr;
  43         size_t len;
  44         for (;; pos += len) {
  45                 WChar c;
  46                 len = Utf8Decode(&c, pos);
  47
  48                 if (c == 0 || (state == STATE_WORD && IsWhitespace(c))) {
  49                         /* Finish word */
  50                         if (word != nullptr) {
  51                                 *(dest++) = '\0';
  52                                 word = nullptr;
  53                         }
  54                         state = STATE_WHITESPACE;
  55                         if (c != 0) continue; else break;
  56                 }
  57
  58                 if (state == STATE_WHITESPACE) {
  59                         /* Skip whitespace */
  60                         if (IsWhitespace(c)) continue;
  61                         state = STATE_WORD;
  62                 }
  63
  64                 if (c == STATE_QUOTE1 || c == STATE_QUOTE2) {
  65                         if (state == c) {
  66                                 /* Stop quoting */
  67                                 state = STATE_WORD;
  68                                 continue;
  69                         } else if (state == STATE_WORD) {
  70                                 /* Start quoting */
  71                                 state = c;
  72                                 continue;
  73                         }
  74                 }
  75
  76                 /* Add to word */
  77                 if (word == nullptr) {
  78                         word = this->word_index.Append();
  79                         word->start = dest;
  80                         word->match = false;
  81                 }
  82
  83                 memcpy(dest, pos, len);
  84                 dest += len;
  85         }
  86 }
  87
  88 /**
  89  * Reset the matching state to process a new item.
  90  */
  91 void StringFilter::ResetState()
  92 {
  93         this->word_matches = 0;
  94         const WordState *end = this->word_index.End();
  95         for (WordState *it = this->word_index.Begin(); it != end; ++it) {
  96                 it->match = false;
  97         }
  98 }
  99
 100 /**
 101  * Pass another text line from the current item to the filter.
 102  *
 103  * You can call this multiple times for a single item, if the filter shall apply to multiple things.
 104  * Before processing the next item you have to call ResetState().
 105  *
 106  * @param str Another line from the item.
 107  */
 108 void StringFilter::AddLine(const char *str)
 109 {
 110         if (str == nullptr) return;
 111
 112         bool match_case = this->case_sensitive != nullptr && *this->case_sensitive;
 113         const WordState *end = this->word_index.End();
 114         for (WordState *it = this->word_index.Begin(); it != end; ++it) {
 115                 if (!it->match) {
 116                         if ((match_case ? strstr(str, it->start) : strcasestr(str, it->start)) != nullptr) {
 117                                 it->match = true;
 118                                 this->word_matches++;
 119                         }
 120                 }
 121         }
 122 }
 123
 124 /**
 125  * Pass another text line from the current item to the filter.
 126  *
 127  * You can call this multiple times for a single item, if the filter shall apply to multiple things.
 128  * Before processing the next item you have to call ResetState().
 129  *
 130  * @param str Another line from the item.
 131  */
 132 void StringFilter::AddLine(StringID str)
 133 {
 134         char buffer[DRAW_STRING_BUFFER];
 135         GetString(buffer, str, lastof(buffer));
 136         AddLine(buffer);
 137 }