src/stringfilter_type.h

   1 /* $Id$ */
   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_type.h Searching and filtering using a stringterm. */
  11
  12 #ifndef STRINGFILTER_TYPE_H
  13 #define STRINGFILTER_TYPE_H
  14
  15 #include "core/smallvec_type.hpp"
  16 #include "strings_type.h"
  17
  18 /**
  19  * String filter and state.
  20  *
  21  * The filter takes a stringterm and parses it into words separated by whitespace.
  22  * The whitespace-separation can be avoided by quoting words in the searchterm using " or '.
  23  * The quotation characters can be nested or concatenated in a unix-shell style.
  24  *
  25  * When filtering an item, all words are checked for matches, and the filter matches if every word
  26  * matched. So, effectively this is a AND search for all entered words.
  27  *
  28  * Once the filter is set up using SetFilterTerm, multiple items can be filtered consecutively.
  29  *  1. For every item first call ResetState() which resets the matching-state.
  30  *  2. Pass all lines of the item via AddLine() to the filter.
  31  *  3. Check the matching-result for the item via GetState().
  32  */
  33 struct StringFilter {
  34 private:
  35         /** State of a single filter word */
  36         struct WordState {
  37                 const char *start;                         ///< Word to filter for.
  38                 bool match;                                ///< Already matched?
  39         };
  40
  41         const char *filter_buffer;                     ///< Parsed filter string. Words separated by 0.
  42         SmallVector<WordState, 4> word_index;          ///< Word index and filter state.
  43         uint word_matches;                             ///< Summary of filter state: Number of words matched.
  44
  45         const bool *case_sensitive;                    ///< Match case-sensitively (usually a static variable).
  46
  47 public:
  48         /**
  49          * Constructor for filter.
  50          * @param case_sensitive Pointer to a (usually static) variable controlling the case-sensitivity. NULL means always case-insensitive.
  51          */
  52         StringFilter(const bool *case_sensitive = NULL) : filter_buffer(NULL), word_matches(0), case_sensitive(case_sensitive) {}
  53         ~StringFilter() { free(this->filter_buffer); }
  54
  55         void SetFilterTerm(const char *str);
  56
  57         /**
  58          * Check whether any filter words were entered.
  59          * @return true if no words were entered.
  60          */
  61         bool IsEmpty() const { return this->word_index.Length() == 0; }
  62
  63         void ResetState();
  64         void AddLine(const char *str);
  65         void AddLine(StringID str);
  66
  67         /**
  68          * Get the matching state of the current item.
  69          * @return true if matched.
  70          */
  71         bool GetState() const { return this->word_matches == this->word_index.Length(); }
  72 };
  73
  74 #endif /* STRINGFILTER_TYPE_H */