/*
* Copyright (C) 2015 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.
*/
package android.text;
import com.android.internal.annotations.GuardedBy;
import android.annotation.Nullable;
import android.util.Log;
import libcore.io.IoUtils;
import java.io.File;
import java.io.IOException;
import java.util.HashMap;
import java.util.Locale;
/**
* Hyphenator is a wrapper class for a native implementation of automatic hyphenation,
* in essence finding valid hyphenation opportunities in a word.
*
* @hide
*/
public class Hyphenator {
// This class has deliberately simple lifetime management (no finalizer) because in
// the common case a process will use a very small number of locales.
private static String TAG = "Hyphenator";
private final static Object sLock = new Object();
@GuardedBy("sLock")
final static HashMap<Locale, Hyphenator> sMap = new HashMap<Locale, Hyphenator>();
final static Hyphenator sEmptyHyphenator = new Hyphenator(StaticLayout.nLoadHyphenator(""));
final private long mNativePtr;
private Hyphenator(long nativePtr) {
mNativePtr = nativePtr;
}
public static long get(@Nullable Locale locale) {
synchronized (sLock) {
Hyphenator result = sMap.get(locale);
if (result != null) {
return result.mNativePtr;
}
// TODO: Convert this a proper locale-fallback system
// Fall back to language-only, if available
Locale languageOnlyLocale = new Locale(locale.getLanguage());
result = sMap.get(languageOnlyLocale);
if (result != null) {
sMap.put(locale, result);
return result.mNativePtr;
}
// Fall back to script-only, if available
String script = locale.getScript();
if (!script.equals("")) {
Locale scriptOnlyLocale = new Locale.Builder()
.setLanguage("und")
.setScript(script)
.build();
result = sMap.get(scriptOnlyLocale);
if (result != null) {
sMap.put(locale, result);
return result.mNativePtr;
}
}
sMap.put(locale, sEmptyHyphenator); // To remember we found nothing.
}
return sEmptyHyphenator.mNativePtr;
}
private static Hyphenator loadHyphenator(String languageTag) {
String patternFilename = "hyph-"+languageTag.toLowerCase(Locale.US)+".pat.txt";
File patternFile = new File(getSystemHyphenatorLocation(), patternFilename);
try {
String patternData = IoUtils.readFileAsString(patternFile.getAbsolutePath());
long nativePtr = StaticLayout.nLoadHyphenator(patternData);
return new Hyphenator(nativePtr);
} catch (IOException e) {
Log.e(TAG, "error loading hyphenation " + patternFile, e);
return null;
}
}
private static File getSystemHyphenatorLocation() {
return new File("/system/usr/hyphen-data");
}
// This array holds pairs of language tags that are used to prefill the map from locale to
// hyphenation data: The hyphenation data for the first field will be prefilled from the
// hyphenation data for the second field.
//
// The aliases that are computable by the get() method above are not included.
private static final String[][] LOCALE_FALLBACK_DATA = {
// English locales that fall back to en-US. The data is
// from CLDR. It's all English locales, minus the locales whose
// parent is en-001 (from supplementalData.xml, under <parentLocales>).
// TODO: Figure out how to get this from ICU.
{"en-AS", "en-US"}, // English (American Samoa)
{"en-GU", "en-US"}, // English (Guam)
{"en-MH", "en-US"}, // English (Marshall Islands)
{"en-MP", "en-US"}, // English (Northern Mariana Islands)
{"en-PR", "en-US"}, // English (Puerto Rico)
{"en-UM", "en-US"}, // English (United States Minor Outlying Islands)
{"en-VI", "en-US"}, // English (Virgin Islands)
// Norwegian is very probably Norwegian Bokmål.
{"no", "nb"},
// Fall back to Ethiopic script for languages likely to be written in Ethiopic.
// Data is from CLDR's likelySubtags.xml.
// TODO: Convert this to a mechanism using ICU4J's ULocale#addLikelySubtags().
{"am", "und-Ethi"}, // Amharic
{"byn", "und-Ethi"}, // Blin
{"gez", "und-Ethi"}, // Geʻez
{"ti", "und-Ethi"}, // Tigrinya
{"wal", "und-Ethi"}, // Wolaytta
};
/**
* Load hyphenation patterns at initialization time. We want to have patterns
* for all locales loaded and ready to use so we don't have to do any file IO
* on the UI thread when drawing text in different locales.
*
* @hide
*/
public static void init() {
sMap.put(null, null);
// TODO: replace this with a discovery-based method that looks into /system/usr/hyphen-data
String[] availableLanguages = {"en-US", "eu", "hu", "hy", "nb", "nn", "sa", "und-Ethi"};
for (int i = 0; i < availableLanguages.length; i++) {
String languageTag = availableLanguages[i];
Hyphenator h = loadHyphenator(languageTag);
if (h != null) {
sMap.put(Locale.forLanguageTag(languageTag), h);
}
}
for (int i = 0; i < LOCALE_FALLBACK_DATA.length; i++) {
String language = LOCALE_FALLBACK_DATA[i][0];
String fallback = LOCALE_FALLBACK_DATA[i][1];
sMap.put(Locale.forLanguageTag(language), sMap.get(Locale.forLanguageTag(fallback)));
}
}
}