digraph_utils.cpp revision bd0d1afdb28a28e2ddac1409208c59ba64350399 
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/dictionary/binary_dictionary_header.h"
23#include "utils/char_utils.h"
24
25namespace latinime {
26
27const 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
31const 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
34const DigraphUtils::DigraphType DigraphUtils::USED_DIGRAPH_TYPES[] =
35        { DIGRAPH_TYPE_GERMAN_UMLAUT, DIGRAPH_TYPE_FRENCH_LIGATURES };
36
37/* static */ bool DigraphUtils::hasDigraphForCodePoint(
38        const BinaryDictionaryHeader *const header, const int compositeGlyphCodePoint) {
39    const DigraphUtils::DigraphType digraphType = getDigraphTypeForDictionary(header);
40    if (DigraphUtils::getDigraphForDigraphTypeAndCodePoint(digraphType, compositeGlyphCodePoint)) {
41        return true;
42    }
43    return false;
44}
45
46// Returns the digraph type associated with the given dictionary.
47/* static */ DigraphUtils::DigraphType DigraphUtils::getDigraphTypeForDictionary(
48        const BinaryDictionaryHeader *const header) {
49    if (header->requiresGermanUmlautProcessing()) {
50        return DIGRAPH_TYPE_GERMAN_UMLAUT;
51    }
52    if (header->requiresFrenchLigatureProcessing()) {
53        return DIGRAPH_TYPE_FRENCH_LIGATURES;
54    }
55    return DIGRAPH_TYPE_NONE;
56}
57
58// Returns the digraph codepoint for the given composite glyph codepoint and digraph codepoint index
59// (which specifies the first or second codepoint in the digraph).
60/* static */ int DigraphUtils::getDigraphCodePointForIndex(const int compositeGlyphCodePoint,
61        const DigraphCodePointIndex digraphCodePointIndex) {
62    if (digraphCodePointIndex == NOT_A_DIGRAPH_INDEX) {
63        return NOT_A_CODE_POINT;
64    }
65    const DigraphUtils::digraph_t *const digraph =
66            DigraphUtils::getDigraphForCodePoint(compositeGlyphCodePoint);
67    if (!digraph) {
68        return NOT_A_CODE_POINT;
69    }
70    if (digraphCodePointIndex == FIRST_DIGRAPH_CODEPOINT) {
71        return digraph->first;
72    } else if (digraphCodePointIndex == SECOND_DIGRAPH_CODEPOINT) {
73        return digraph->second;
74    }
75    ASSERT(false);
76    return NOT_A_CODE_POINT;
77}
78
79// Retrieves the set of all digraphs associated with the given digraph type.
80// Returns the size of the digraph array, or 0 if none exist.
81/* static */ int DigraphUtils::getAllDigraphsForDigraphTypeAndReturnSize(
82        const DigraphUtils::DigraphType digraphType,
83        const DigraphUtils::digraph_t **const digraphs) {
84    if (digraphType == DigraphUtils::DIGRAPH_TYPE_GERMAN_UMLAUT) {
85        *digraphs = GERMAN_UMLAUT_DIGRAPHS;
86        return NELEMS(GERMAN_UMLAUT_DIGRAPHS);
87    }
88    if (digraphType == DIGRAPH_TYPE_FRENCH_LIGATURES) {
89        *digraphs = FRENCH_LIGATURES_DIGRAPHS;
90        return NELEMS(FRENCH_LIGATURES_DIGRAPHS);
91    }
92    return 0;
93}
94
95/**
96 * Returns the digraph for the input composite glyph codepoint, or 0 if none exists.
97 * compositeGlyphCodePoint: the method returns the digraph corresponding to this codepoint.
98 */
99/* static */ const DigraphUtils::digraph_t *DigraphUtils::getDigraphForCodePoint(
100        const int compositeGlyphCodePoint) {
101    for (size_t i = 0; i < NELEMS(USED_DIGRAPH_TYPES); i++) {
102        const DigraphUtils::digraph_t *const digraph = getDigraphForDigraphTypeAndCodePoint(
103                USED_DIGRAPH_TYPES[i], compositeGlyphCodePoint);
104        if (digraph) {
105            return digraph;
106        }
107    }
108    return 0;
109}
110
111/**
112 * Returns the digraph for the input composite glyph codepoint, or 0 if none exists.
113 * digraphType: the type of digraphs supported.
114 * compositeGlyphCodePoint: the method returns the digraph corresponding to this codepoint.
115 */
116/* static */ const DigraphUtils::digraph_t *DigraphUtils::getDigraphForDigraphTypeAndCodePoint(
117        const DigraphUtils::DigraphType digraphType, const int compositeGlyphCodePoint) {
118    const DigraphUtils::digraph_t *digraphs = 0;
119    const int compositeGlyphLowerCodePoint = CharUtils::toLowerCase(compositeGlyphCodePoint);
120    const int digraphsSize =
121            DigraphUtils::getAllDigraphsForDigraphTypeAndReturnSize(digraphType, &digraphs);
122    for (int i = 0; i < digraphsSize; i++) {
123        if (digraphs[i].compositeGlyph == compositeGlyphLowerCodePoint) {
124            return &digraphs[i];
125        }
126    }
127    return 0;
128}
129
130} // namespace latinime
131