src/stringfilter.cpp

   1 /*
   2  * This file is part of OpenTTD.
   3  * 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.
   4  * 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.
   5  * 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/>.
   6  */
   7
   8 /** @file stringfilter.cpp Searching and filtering using a stringterm. */
   9
  10 #include "stdafx.h"
  11 #include "string_func.h"
  12 #include "strings_func.h"
  13 #include "stringfilter_type.h"
  14 #include "gfx_func.h"
  15
  16 #include "safeguards.h"
  17
  18 static const WChar STATE_WHITESPACE = ' ';
  19 static const WChar STATE_WORD = 'w';
  20 static const WChar STATE_QUOTE1 = '\'';
  21 static const WChar STATE_QUOTE2 = '"';
  22
  23 /**
  24  * Set the term to filter on.
  25  * @param str Filter term
  26  */
  27 void StringFilter::SetFilterTerm(const char *str)
  28 {
  29         this->word_index.clear();
  30         this->word_index.shrink_to_fit();
  31         this->word_matches = 0;
  32         free(this->filter_buffer);
  33
  34         assert(str != nullptr);
  35
  36         char *dest = MallocT<char>(strlen(str) + 1);
  37         this->filter_buffer = dest;
  38
  39         WChar state = STATE_WHITESPACE;
  40         const char *pos = str;
  41         WordState *word = nullptr;
  42         size_t len;
  43         for (;; pos += len) {
  44                 WChar c;
  45                 len = Utf8Decode(&c, pos);
  46
  47                 if (c == 0 || (state == STATE_WORD && IsWhitespace(c))) {
  48                         /* Finish word */
  49                         if (word != nullptr) {
  50                                 *(dest++) = '\0';
  51                                 word = nullptr;
  52                         }
  53                         state = STATE_WHITESPACE;
  54                         if (c != 0) continue; else break;
  55                 }
  56
  57                 if (state == STATE_WHITESPACE) {
  58                         /* Skip whitespace */
  59                         if (IsWhitespace(c)) continue;
  60                         state = STATE_WORD;
  61                 }
  62
  63                 if (c == STATE_QUOTE1 || c == STATE_QUOTE2) {
  64                         if (state == c) {
  65                                 /* Stop quoting */
  66                                 state = STATE_WORD;
  67                                 continue;
  68                         } else if (state == STATE_WORD) {
  69                                 /* Start quoting */
  70                                 state = c;
  71                                 continue;
  72                         }
  73                 }
  74
  75                 /* Add to word */
  76                 if (word == nullptr) {
  77                         /*C++17: word = &*/ this->word_index.push_back({dest, false});
  78                         word = &this->word_index.back();
  79                 }
  80
  81                 memcpy(dest, pos, len);
  82                 dest += len;
  83         }
  84 }
  85
  86 /**
  87  * Reset the matching state to process a new item.
  88  */
  89 void StringFilter::ResetState()
  90 {
  91         this->word_matches = 0;
  92         for (WordState &ws : this->word_index) {
  93                 ws.match = false;
  94         }
  95 }
  96
  97 /**
  98  * Pass another text line from the current item to the filter.
  99  *
 100  * You can call this multiple times for a single item, if the filter shall apply to multiple things.
 101  * Before processing the next item you have to call ResetState().
 102  *
 103  * @param str Another line from the item.
 104  */
 105 void StringFilter::AddLine(const char *str)
 106 {
 107         if (str == nullptr) return;
 108
 109         bool match_case = this->case_sensitive != nullptr && *this->case_sensitive;
 110         for (WordState &ws : this->word_index) {
 111                 if (!ws.match) {
 112                         if ((match_case ? strstr(str, ws.start) : strcasestr(str, ws.start)) != nullptr) {
 113                                 ws.match = true;
 114                                 this->word_matches++;
 115                         }
 116                 }
 117         }
 118 }
 119
 120 /**
 121  * Pass another text line from the current item to the filter.
 122  *
 123  * You can call this multiple times for a single item, if the filter shall apply to multiple things.
 124  * Before processing the next item you have to call ResetState().
 125  *
 126  * @param str Another line from the item.
 127  */
 128 void StringFilter::AddLine(StringID str)
 129 {
 130         char buffer[DRAW_STRING_BUFFER];
 131         GetString(buffer, str, lastof(buffer));
 132         AddLine(buffer);
 133 }