Add support for Russian spell checking. (bb2b30fc) · Commits · e / os / android_packages_inputmethods_LatinIME

java/res/xml/spellchecker.xml

+12 −0

Original line number	Diff line number	Diff line
		@@ -43,4 +43,16 @@
		android:label="@string/subtype_generic"
		android:subtypeLocale="es"
		/>
		<subtype
		android:label="@string/subtype_generic"
		android:subtypeLocale="ru"
		/>
		<subtype
		android:label="@string/subtype_generic"
		android:subtypeLocale="cs"
		/>
		<subtype
		android:label="@string/subtype_generic"
		android:subtypeLocale="nl"
		/>
		</spell-checker>

java/src/com/android/inputmethod/latin/spellcheck/AndroidSpellCheckerService.java

+57 −18

Original line number	Diff line number	Diff line
		@@ -415,10 +415,31 @@ public class AndroidSpellCheckerService extends SpellCheckerService
		}

		private static class AndroidSpellCheckerSession extends Session {
		private static final int SCRIPT_LATIN = 0;
		private static final int SCRIPT_CYRILLIC = 1;
		private static final TreeMap<String, Integer> mLanguageToScript;
		static {
		// List of the supported languages and their associated script. We won't check
		// words written in another script than the selected script, because we know we
		// don't have those in our dictionary so we will underline everything and we
		// will never have any suggestions, so it makes no sense checking them.
		mLanguageToScript = new TreeMap<String, Integer>();
		mLanguageToScript.put("en", SCRIPT_LATIN);
		mLanguageToScript.put("fr", SCRIPT_LATIN);
		mLanguageToScript.put("de", SCRIPT_LATIN);
		mLanguageToScript.put("nl", SCRIPT_LATIN);
		mLanguageToScript.put("cs", SCRIPT_LATIN);
		mLanguageToScript.put("es", SCRIPT_LATIN);
		mLanguageToScript.put("it", SCRIPT_LATIN);
		mLanguageToScript.put("ru", SCRIPT_CYRILLIC);
		}

		// Immutable, but need the locale which is not available in the constructor yet
		private DictionaryPool mDictionaryPool;
		// Likewise
		private Locale mLocale;
		// Cache this for performance
		private int mScript; // One of SCRIPT_LATIN or SCRIPT_CYRILLIC for now.

		private final AndroidSpellCheckerService mService;

		@@ -431,38 +452,56 @@ public class AndroidSpellCheckerService extends SpellCheckerService
		final String localeString = getLocale();
		mDictionaryPool = mService.getDictionaryPool(localeString);
		mLocale = LocaleUtils.constructLocaleFromString(localeString);
		final Integer script = mLanguageToScript.get(mLocale.getLanguage());
		if (null == script) {
		throw new RuntimeException("We have been called with an unsupported language: \""
		+ mLocale.getLanguage() + "\". Framework bug?");
		}
		mScript = script;
		}

		/*
		* Returns whether the code point is a letter that makes sense for the specified
		* locale for this spell checker.
		* The dictionaries supported by Latin IME are described in res/xml/spellchecker.xml
		* and is limited to EFIGS language.
		* Hence at the moment this explicitly excludes non-Latin scripts, including CJK
		* characters, but also Cyrillic, Arabic or Hebrew characters.
		* The locale should be used to rule out inappropriate characters when we support
		* spellchecking other languages like Russian.
		* and is limited to EFIGS languages and Russian.
		* Hence at the moment this explicitly tests for Cyrillic characters or Latin characters
		* as appropriate, and explicitly excludes CJK, Arabic and Hebrew characters.
		*/
		private static boolean isLetterCheckableByLanguage(final int codePoint,
		final Locale locale) {
		// Our supported dictionaries (EFIGS) at the moment only includes characters
		// in the C0, C1, Latin Extended A and B, IPA extensions unicode blocks.
		// As it happens, those are back-to-back in the code range 0x40 to 0x2AF, so
		// the below is a very efficient way to test for it. As for the 0-0x3F, it's
		final int script) {
		switch (script) {
		case SCRIPT_LATIN:
		// Our supported latin script dictionaries (EFIGS) at the moment only include
		// characters in the C0, C1, Latin Extended A and B, IPA extensions unicode
		// blocks. As it happens, those are back-to-back in the code range 0x40 to 0x2AF,
		// so the below is a very efficient way to test for it. As for the 0-0x3F, it's
		// excluded from isLetter anyway.
		// TODO: change this to use locale when we support other scripts
		return codePoint <= 0x2AF && Character.isLetter(codePoint);
		case SCRIPT_CYRILLIC:
		// All Cyrillic characters are in the 400~52F block. There are some in the upper
		// Unicode range, but they are archaic characters that are not used in modern
		// russian and are not used by our dictionary.
		return codePoint >= 0x400 && codePoint <= 0x52F && Character.isLetter(codePoint);
		default:
		// Should never come here
		throw new RuntimeException("Impossible value of script: " + script);
		}
		}

		/**
		* Finds out whether a particular string should be filtered out of spell checking.
		*
		* This will loosely match URLs, numbers, symbols.
		* This will loosely match URLs, numbers, symbols. To avoid always underlining words that
		* we know we will never recognize, this accepts a script identifier that should be one
		* of the SCRIPT_* constants defined above, to rule out quickly characters from very
		* different languages.
		*
		* @param text the string to evaluate.
		* @param script the identifier for the script this spell checker recognizes
		* @return true if we should filter this text out, false otherwise
		*/
		private static boolean shouldFilterOut(final String text, final Locale locale) {
		private static boolean shouldFilterOut(final String text, final int script) {
		if (TextUtils.isEmpty(text) \|\| text.length() <= 1) return true;

		// TODO: check if an equivalent processing can't be done more quickly with a
		@@ -470,7 +509,7 @@ public class AndroidSpellCheckerService extends SpellCheckerService
		// Filter by first letter
		final int firstCodePoint = text.codePointAt(0);
		// Filter out words that don't start with a letter or an apostrophe
		if (!isLetterCheckableByLanguage(firstCodePoint, locale)
		if (!isLetterCheckableByLanguage(firstCodePoint, script)
		&& '\'' != firstCodePoint) return true;

		// Filter contents
		@@ -483,7 +522,7 @@ public class AndroidSpellCheckerService extends SpellCheckerService
		// words or a URI - in either case we don't want to spell check that
		if ('@' == codePoint
		\|\| '/' == codePoint) return true;
		if (isLetterCheckableByLanguage(codePoint, locale)) ++letterCount;
		if (isLetterCheckableByLanguage(codePoint, script)) ++letterCount;
		}
		// Guestimate heuristic: perform spell checking if at least 3/4 of the characters
		// in this word are letters
		@@ -502,7 +541,7 @@ public class AndroidSpellCheckerService extends SpellCheckerService
		try {
		final String text = textInfo.getText();

		if (shouldFilterOut(text, mLocale)) {
		if (shouldFilterOut(text, mScript)) {
		DictAndProximity dictInfo = null;
		try {
		dictInfo = mDictionaryPool.takeOrGetNull();