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      1 /*
      2  * Copyright (C) 2013 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #include "suggest/core/dictionary/digraph_utils.h"
     18 
     19 #include <cstdlib>
     20 
     21 #include "defines.h"
     22 #include "suggest/core/policy/dictionary_header_structure_policy.h"
     23 #include "utils/char_utils.h"
     24 
     25 namespace latinime {
     26 
     27 const DigraphUtils::digraph_t DigraphUtils::GERMAN_UMLAUT_DIGRAPHS[] =
     28         { { 'a', 'e', 0x00E4 }, // U+00E4 : LATIN SMALL LETTER A WITH DIAERESIS
     29         { 'o', 'e', 0x00F6 },   // U+00F6 : LATIN SMALL LETTER O WITH DIAERESIS
     30         { 'u', 'e', 0x00FC } }; // U+00FC : LATIN SMALL LETTER U WITH DIAERESIS
     31 const DigraphUtils::digraph_t DigraphUtils::FRENCH_LIGATURES_DIGRAPHS[] =
     32         { { 'a', 'e', 0x00E6 }, // U+00E6 : LATIN SMALL LETTER AE
     33         { 'o', 'e', 0x0153 } }; // U+0153 : LATIN SMALL LIGATURE OE
     34 const DigraphUtils::DigraphType DigraphUtils::USED_DIGRAPH_TYPES[] =
     35         { DIGRAPH_TYPE_GERMAN_UMLAUT, DIGRAPH_TYPE_FRENCH_LIGATURES };
     36 
     37 /* static */ bool DigraphUtils::hasDigraphForCodePoint(
     38         const DictionaryHeaderStructurePolicy *const headerPolicy,
     39         const int compositeGlyphCodePoint) {
     40     const DigraphUtils::DigraphType digraphType = getDigraphTypeForDictionary(headerPolicy);
     41     if (DigraphUtils::getDigraphForDigraphTypeAndCodePoint(digraphType, compositeGlyphCodePoint)) {
     42         return true;
     43     }
     44     return false;
     45 }
     46 
     47 // Returns the digraph type associated with the given dictionary.
     48 /* static */ DigraphUtils::DigraphType DigraphUtils::getDigraphTypeForDictionary(
     49         const DictionaryHeaderStructurePolicy *const headerPolicy) {
     50     if (headerPolicy->requiresGermanUmlautProcessing()) {
     51         return DIGRAPH_TYPE_GERMAN_UMLAUT;
     52     }
     53     if (headerPolicy->requiresFrenchLigatureProcessing()) {
     54         return DIGRAPH_TYPE_FRENCH_LIGATURES;
     55     }
     56     return DIGRAPH_TYPE_NONE;
     57 }
     58 
     59 // Returns the digraph codepoint for the given composite glyph codepoint and digraph codepoint index
     60 // (which specifies the first or second codepoint in the digraph).
     61 /* static */ int DigraphUtils::getDigraphCodePointForIndex(const int compositeGlyphCodePoint,
     62         const DigraphCodePointIndex digraphCodePointIndex) {
     63     if (digraphCodePointIndex == NOT_A_DIGRAPH_INDEX) {
     64         return NOT_A_CODE_POINT;
     65     }
     66     const DigraphUtils::digraph_t *const digraph =
     67             DigraphUtils::getDigraphForCodePoint(compositeGlyphCodePoint);
     68     if (!digraph) {
     69         return NOT_A_CODE_POINT;
     70     }
     71     if (digraphCodePointIndex == FIRST_DIGRAPH_CODEPOINT) {
     72         return digraph->first;
     73     } else if (digraphCodePointIndex == SECOND_DIGRAPH_CODEPOINT) {
     74         return digraph->second;
     75     }
     76     ASSERT(false);
     77     return NOT_A_CODE_POINT;
     78 }
     79 
     80 // Retrieves the set of all digraphs associated with the given digraph type.
     81 // Returns the size of the digraph array, or 0 if none exist.
     82 /* static */ int DigraphUtils::getAllDigraphsForDigraphTypeAndReturnSize(
     83         const DigraphUtils::DigraphType digraphType,
     84         const DigraphUtils::digraph_t **const digraphs) {
     85     if (digraphType == DigraphUtils::DIGRAPH_TYPE_GERMAN_UMLAUT) {
     86         *digraphs = GERMAN_UMLAUT_DIGRAPHS;
     87         return NELEMS(GERMAN_UMLAUT_DIGRAPHS);
     88     }
     89     if (digraphType == DIGRAPH_TYPE_FRENCH_LIGATURES) {
     90         *digraphs = FRENCH_LIGATURES_DIGRAPHS;
     91         return NELEMS(FRENCH_LIGATURES_DIGRAPHS);
     92     }
     93     return 0;
     94 }
     95 
     96 /**
     97  * Returns the digraph for the input composite glyph codepoint, or 0 if none exists.
     98  * compositeGlyphCodePoint: the method returns the digraph corresponding to this codepoint.
     99  */
    100 /* static */ const DigraphUtils::digraph_t *DigraphUtils::getDigraphForCodePoint(
    101         const int compositeGlyphCodePoint) {
    102     for (size_t i = 0; i < NELEMS(USED_DIGRAPH_TYPES); i++) {
    103         const DigraphUtils::digraph_t *const digraph = getDigraphForDigraphTypeAndCodePoint(
    104                 USED_DIGRAPH_TYPES[i], compositeGlyphCodePoint);
    105         if (digraph) {
    106             return digraph;
    107         }
    108     }
    109     return 0;
    110 }
    111 
    112 /**
    113  * Returns the digraph for the input composite glyph codepoint, or 0 if none exists.
    114  * digraphType: the type of digraphs supported.
    115  * compositeGlyphCodePoint: the method returns the digraph corresponding to this codepoint.
    116  */
    117 /* static */ const DigraphUtils::digraph_t *DigraphUtils::getDigraphForDigraphTypeAndCodePoint(
    118         const DigraphUtils::DigraphType digraphType, const int compositeGlyphCodePoint) {
    119     const DigraphUtils::digraph_t *digraphs = 0;
    120     const int compositeGlyphLowerCodePoint = CharUtils::toLowerCase(compositeGlyphCodePoint);
    121     const int digraphsSize =
    122             DigraphUtils::getAllDigraphsForDigraphTypeAndReturnSize(digraphType, &digraphs);
    123     for (int i = 0; i < digraphsSize; i++) {
    124         if (digraphs[i].compositeGlyph == compositeGlyphLowerCodePoint) {
    125             return &digraphs[i];
    126         }
    127     }
    128     return 0;
    129 }
    130 
    131 } // namespace latinime
    132