Add DigraphUtils class

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

Bug: 8493920
Change-Id: I3a509e1311b9039653f9f488d3c28bb54205f416

1 files changed, 93 insertions, 0 deletions

diff --git a/native/jni/src/digraph_utils.cpp b/native/jni/src/digraph_utils.cpp
new file mode 100644
index 000000000..8781c5077
--- /dev/null
+++ b/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