am f7fa231b: Merge "Add support for Russian spell checking."

* commit 'f7fa231b7ab5ba8bd495a68b6145f14f6e2480c3':
  Add support for Russian spell checking.
main
Jean Chalard 2011-12-05 02:32:05 -08:00 committed by Android Git Automerger
commit c9eacbc452
2 changed files with 69 additions and 18 deletions

View File

@ -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>

View File

@ -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
// excluded from isLetter anyway.
// TODO: change this to use locale when we support other scripts
return codePoint <= 0x2AF && Character.isLetter(codePoint);
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.
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();