Add DigraphUtils class

Add a new DigraphUtils class to manage digraph handling for both
gesture and typing input.

Bug: 8493920
Change-Id: I3a509e1311b9039653f9f488d3c28bb54205f416

native/jni/Android.mk

@@ -59,6 +59,7 @@ LATIN_IME_CORE_SRC_FILES := \
     correction.cpp \
     dictionary.cpp \
     dic_traverse_wrapper.cpp \
+    digraph_utils.cpp \
     proximity_info.cpp \
     proximity_info_params.cpp \
     proximity_info_state.cpp \

native/jni/src/digraph_utils.cpp

@@ -0,0 +1,93 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "binary_format.h"
+#include "defines.h"
+#include "digraph_utils.h"
+
+namespace latinime {
+
+const DigraphUtils::digraph_t DigraphUtils::GERMAN_UMLAUT_DIGRAPHS[] =
+        { { 'a', 'e', 0x00E4 }, // U+00E4 : LATIN SMALL LETTER A WITH DIAERESIS
+        { 'o', 'e', 0x00F6 },   // U+00F6 : LATIN SMALL LETTER O WITH DIAERESIS
+        { 'u', 'e', 0x00FC } }; // U+00FC : LATIN SMALL LETTER U WITH DIAERESIS
+const DigraphUtils::digraph_t DigraphUtils::FRENCH_LIGATURES_DIGRAPHS[] =
+        { { 'a', 'e', 0x00E6 }, // U+00E6 : LATIN SMALL LETTER AE
+        { 'o', 'e', 0x0153 } }; // U+0153 : LATIN SMALL LIGATURE OE
+
+/* static */ bool DigraphUtils::hasDigraphForCodePoint(
+        const int dictFlags, const int compositeGlyphCodePoint) {
+    if (DigraphUtils::getDigraphForCodePoint(dictFlags, compositeGlyphCodePoint)) {
+        return true;
+    }
+    return false;
+}
+
+// Retrieves the set of all digraphs associated with the given dictionary.
+// Returns the size of the digraph array, or 0 if none exist.
+/* static */ int DigraphUtils::getAllDigraphsForDictionaryAndReturnSize(
+        const int dictFlags, const DigraphUtils::digraph_t **digraphs) {
+    if (BinaryFormat::REQUIRES_GERMAN_UMLAUT_PROCESSING & dictFlags) {
+        *digraphs = DigraphUtils::GERMAN_UMLAUT_DIGRAPHS;
+        return NELEMS(DigraphUtils::GERMAN_UMLAUT_DIGRAPHS);
+    }
+    if (BinaryFormat::REQUIRES_FRENCH_LIGATURES_PROCESSING & dictFlags) {
+        *digraphs = DigraphUtils::FRENCH_LIGATURES_DIGRAPHS;
+        return NELEMS(DigraphUtils::FRENCH_LIGATURES_DIGRAPHS);
+    }
+    return 0;
+}
+
+// Returns the digraph codepoint for the given composite glyph codepoint and digraph codepoint index
+// (which specifies the first or second codepoint in the digraph).
+/* static */ int DigraphUtils::getDigraphCodePointForIndex(const int dictFlags,
+        const int compositeGlyphCodePoint, const DigraphCodePointIndex digraphCodePointIndex) {
+    if (digraphCodePointIndex == NOT_A_DIGRAPH_INDEX) {
+        return NOT_A_CODE_POINT;
+    }
+    const DigraphUtils::digraph_t *digraph =
+            DigraphUtils::getDigraphForCodePoint(dictFlags, compositeGlyphCodePoint);
+    if (!digraph) {
+        return NOT_A_CODE_POINT;
+    }
+    if (digraphCodePointIndex == FIRST_DIGRAPH_CODEPOINT) {
+        return digraph->first;
+    } else if (digraphCodePointIndex == SECOND_DIGRAPH_CODEPOINT) {
+        return digraph->second;
+    }
+    ASSERT(false);
+    return NOT_A_CODE_POINT;
+}
+
+/**
+ * Returns the digraph for the input composite glyph codepoint, or 0 if none exists.
+ * dictFlags: the dictionary flags needed to determine which digraphs are supported.
+ * compositeGlyphCodePoint: the method returns the digraph corresponding to this codepoint.
+ */
+/* static */ const DigraphUtils::digraph_t *DigraphUtils::getDigraphForCodePoint(
+        const int dictFlags, const int compositeGlyphCodePoint) {
+    const DigraphUtils::digraph_t *digraphs = 0;
+    const int digraphsSize =
+            DigraphUtils::getAllDigraphsForDictionaryAndReturnSize(dictFlags, &digraphs);
+    for (int i = 0; i < digraphsSize; i++) {
+        if (digraphs[i].compositeGlyph == compositeGlyphCodePoint) {
+            return &digraphs[i];
+        }
+    }
+    return 0;
+}
+
+} // namespace latinime

native/jni/src/digraph_utils.h

@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef DIGRAPH_UTILS_H
+#define DIGRAPH_UTILS_H
+
+namespace latinime {
+
+class DigraphUtils {
+ public:
+    typedef enum {
+        NOT_A_DIGRAPH_INDEX,
+        FIRST_DIGRAPH_CODEPOINT,
+        SECOND_DIGRAPH_CODEPOINT
+    } DigraphCodePointIndex;
+
+    typedef struct { int first; int second; int compositeGlyph; } digraph_t;
+
+    static bool hasDigraphForCodePoint(const int dictFlags, const int compositeGlyphCodePoint);
+    static int getAllDigraphsForDictionaryAndReturnSize(
+            const int dictFlags, const digraph_t **digraphs);
+    static int getDigraphCodePointForIndex(const int dictFlags, const int compositeGlyphCodePoint,
+            const DigraphCodePointIndex digraphCodePointIndex);
+
+ private:
+    DISALLOW_IMPLICIT_CONSTRUCTORS(DigraphUtils);
+    static const digraph_t *getDigraphForCodePoint(
+            const int dictFlags, const int compositeGlyphCodePoint);
+
+    static const digraph_t GERMAN_UMLAUT_DIGRAPHS[];
+    static const digraph_t FRENCH_LIGATURES_DIGRAPHS[];
+};
+} // namespace latinime
+#endif // DIGRAPH_UTILS_H

native/jni/src/unigram_dictionary.cpp

@@ -22,6 +22,7 @@
 #include "char_utils.h"
 #include "defines.h"
 #include "dictionary.h"
+#include "digraph_utils.h"
 #include "proximity_info.h"
 #include "terminal_attributes.h"
 #include "unigram_dictionary.h"
@@ -30,15 +31,6 @@
 
 namespace latinime {
 
-const UnigramDictionary::digraph_t UnigramDictionary::GERMAN_UMLAUT_DIGRAPHS[] =
-        { { 'a', 'e', 0x00E4 }, // U+00E4 : LATIN SMALL LETTER A WITH DIAERESIS
-        { 'o', 'e', 0x00F6 }, // U+00F6 : LATIN SMALL LETTER O WITH DIAERESIS
-        { 'u', 'e', 0x00FC } }; // U+00FC : LATIN SMALL LETTER U WITH DIAERESIS
-
-const UnigramDictionary::digraph_t UnigramDictionary::FRENCH_LIGATURES_DIGRAPHS[] =
-        { { 'a', 'e', 0x00E6 }, // U+00E6 : LATIN SMALL LETTER AE
-        { 'o', 'e', 0x0153 } }; // U+0153 : LATIN SMALL LIGATURE OE
-
 // TODO: check the header
 UnigramDictionary::UnigramDictionary(const uint8_t *const streamStart, const unsigned int flags)
         : DICT_ROOT(streamStart), ROOT_POS(0),
@@ -58,7 +50,7 @@ static void addWord(int *word, int length, int probability, WordsPriorityQueue *
 
 // Return the replacement code point for a digraph, or 0 if none.
 int UnigramDictionary::getDigraphReplacement(const int *codes, const int i, const int inputSize,
-        const digraph_t *const digraphs, const unsigned int digraphsSize) const {
+        const DigraphUtils::digraph_t *const digraphs, const unsigned int digraphsSize) const {
 
     // There can't be a digraph if we don't have at least 2 characters to examine
     if (i + 2 > inputSize) return false;
@@ -74,7 +66,7 @@ int UnigramDictionary::getDigraphReplacement(const int *codes, const int i, cons
 
     // It's an interesting digraph if the second char matches too.
     if (digraphs[lastDigraphIndex].second == codes[i + 1]) {
-        return digraphs[lastDigraphIndex].replacement;
+        return digraphs[lastDigraphIndex].compositeGlyph;
     } else {
         return 0;
     }
@@ -93,7 +85,7 @@ void UnigramDictionary::getWordWithDigraphSuggestionsRec(ProximityInfo *proximit
         const bool useFullEditDistance, const int *codesSrc,
         const int codesRemain, const int currentDepth, int *codesDest, Correction *correction,
         WordsPriorityQueuePool *queuePool,
-        const digraph_t *const digraphs, const unsigned int digraphsSize) const {
+        const DigraphUtils::digraph_t *const digraphs, const unsigned int digraphsSize) const {
     ASSERT(sizeof(codesDest[0]) == sizeof(codesSrc[0]));
     ASSERT(sizeof(xCoordinatesBuffer[0]) == sizeof(xcoordinates[0]));
     ASSERT(sizeof(yCoordinatesBuffer[0]) == sizeof(ycoordinates[0]));
@@ -169,7 +161,10 @@ int UnigramDictionary::getSuggestions(ProximityInfo *proximityInfo, const int *x
     queuePool.clearAll();
     Correction masterCorrection;
     masterCorrection.resetCorrection();
-    if (BinaryFormat::REQUIRES_GERMAN_UMLAUT_PROCESSING & FLAGS)
+    const DigraphUtils::digraph_t *digraphs = 0;
+    const int digraphsSize =
+            DigraphUtils::getAllDigraphsForDictionaryAndReturnSize(FLAGS, &digraphs);
+    if (digraphsSize > 0)
     { // Incrementally tune the word and try all possibilities
         int codesBuffer[sizeof(*inputCodePoints) * inputSize];
         int xCoordinatesBuffer[inputSize];
@@ -177,15 +172,7 @@ int UnigramDictionary::getSuggestions(ProximityInfo *proximityInfo, const int *x
         getWordWithDigraphSuggestionsRec(proximityInfo, xcoordinates, ycoordinates, codesBuffer,
                 xCoordinatesBuffer, yCoordinatesBuffer, inputSize, bigramMap, bigramFilter,
                 useFullEditDistance, inputCodePoints, inputSize, 0, codesBuffer, &masterCorrection,
-                &queuePool, GERMAN_UMLAUT_DIGRAPHS, NELEMS(GERMAN_UMLAUT_DIGRAPHS));
+                &queuePool, digraphs, digraphsSize);
-    } else if (BinaryFormat::REQUIRES_FRENCH_LIGATURES_PROCESSING & FLAGS) {
-        int codesBuffer[sizeof(*inputCodePoints) * inputSize];
-        int xCoordinatesBuffer[inputSize];
-        int yCoordinatesBuffer[inputSize];
-        getWordWithDigraphSuggestionsRec(proximityInfo, xcoordinates, ycoordinates, codesBuffer,
-                xCoordinatesBuffer, yCoordinatesBuffer, inputSize, bigramMap, bigramFilter,
-                useFullEditDistance, inputCodePoints, inputSize, 0, codesBuffer, &masterCorrection,
-                &queuePool, FRENCH_LIGATURES_DIGRAPHS, NELEMS(FRENCH_LIGATURES_DIGRAPHS));
     } else { // Normal processing
         getWordSuggestions(proximityInfo, xcoordinates, ycoordinates, inputCodePoints, inputSize,
                 bigramMap, bigramFilter, useFullEditDistance, &masterCorrection, &queuePool);

native/jni/src/unigram_dictionary.h

@@ -20,6 +20,7 @@
 #include <map>
 #include <stdint.h>
 #include "defines.h"
+#include "digraph_utils.h"
 
 namespace latinime {
 
@@ -29,8 +30,6 @@ class TerminalAttributes;
 class WordsPriorityQueuePool;
 
 class UnigramDictionary {
-    typedef struct { int first; int second; int replacement; } digraph_t;
-
  public:
     // Error tolerances
     static const int DEFAULT_MAX_ERRORS = 2;
@@ -57,13 +56,13 @@ class UnigramDictionary {
             const bool useFullEditDistance, Correction *correction,
             WordsPriorityQueuePool *queuePool) const;
     int getDigraphReplacement(const int *codes, const int i, const int inputSize,
-            const digraph_t *const digraphs, const unsigned int digraphsSize) const;
+            const DigraphUtils::digraph_t *const digraphs, const unsigned int digraphsSize) const;
     void getWordWithDigraphSuggestionsRec(ProximityInfo *proximityInfo, const int *xcoordinates,
             const int *ycoordinates, const int *codesBuffer, int *xCoordinatesBuffer,
             int *yCoordinatesBuffer, const int codesBufferSize, const std::map<int, int> *bigramMap,
             const uint8_t *bigramFilter, const bool useFullEditDistance, const int *codesSrc,
             const int codesRemain, const int currentDepth, int *codesDest, Correction *correction,
-            WordsPriorityQueuePool *queuePool, const digraph_t *const digraphs,
+            WordsPriorityQueuePool *queuePool, const DigraphUtils::digraph_t *const digraphs,
             const unsigned int digraphsSize) const;
     void initSuggestions(ProximityInfo *proximityInfo, const int *xcoordinates,
             const int *ycoordinates, const int *codes, const int inputSize,
@@ -111,9 +110,6 @@ class UnigramDictionary {
     const int ROOT_POS;
     const int MAX_DIGRAPH_SEARCH_DEPTH;
     const int FLAGS;
-
-    static const digraph_t GERMAN_UMLAUT_DIGRAPHS[];
-    static const digraph_t FRENCH_LIGATURES_DIGRAPHS[];
 };
 } // namespace latinime
 #endif // LATINIME_UNIGRAM_DICTIONARY_H