android-34/com/android/settingslib/datetime/ZoneGetter.java - platform/prebuilts/fullsdk/sources - Git at Google

 /*
  * 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 com.android.settingslib.datetime;

 import android.annotation.Nullable;
 import android.content.Context;
 import android.content.res.XmlResourceParser;
 import android.icu.text.TimeZoneFormat;
 import android.icu.text.TimeZoneNames;
 import android.text.SpannableString;
 import android.text.SpannableStringBuilder;
 import android.text.TextUtils;
 import android.text.format.DateUtils;
 import android.text.style.TtsSpan;
 import android.util.Log;
 import android.view.View;

 import androidx.annotation.VisibleForTesting;
 import androidx.core.text.BidiFormatter;
 import androidx.core.text.TextDirectionHeuristicsCompat;

 import com.android.i18n.timezone.CountryTimeZones;
 import com.android.i18n.timezone.CountryTimeZones.TimeZoneMapping;
 import com.android.i18n.timezone.TimeZoneFinder;
 import com.android.internal.app.LocaleHelper;
 import com.android.settingslib.R;

 import org.xmlpull.v1.XmlPullParserException;

 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 import java.util.Set;
 import java.util.TimeZone;

 /**
  * ZoneGetter is the utility class to get time zone and zone list, and both of them have display
  * name in time zone. In this class, we will keep consistency about display names for all
  * the methods.
  *
  * The display name chosen for each zone entry depends on whether the zone is one associated
  * with the country of the user's chosen locale. For "local" zones we prefer the "long name"
  * (e.g. "Europe/London" -> "British Summer Time" for people in the UK). For "non-local"
  * zones we prefer the exemplar location (e.g. "Europe/London" -> "London" for English
  * speakers from outside the UK). This heuristic is based on the fact that people are
  * typically familiar with their local timezones and exemplar locations don't always match
  * modern-day expectations for people living in the country covered. Large countries like
  * China that mostly use a single timezone (olson id: "Asia/Shanghai") may not live near
  * "Shanghai" and prefer the long name over the exemplar location. The only time we don't
  * follow this policy for local zones is when Android supplies multiple olson IDs to choose
  * from and the use of a zone's long name leads to ambiguity. For example, at the time of
  * writing Android lists 5 olson ids for Australia which collapse to 2 different zone names
  * in winter but 4 different zone names in summer. The ambiguity leads to the users
  * selecting the wrong olson ids.
  *
  */
 public class ZoneGetter {
     private static final String TAG = "ZoneGetter";

     public static final String KEY_ID = "id";  // value: String

     /**
      * @deprecated Use {@link #KEY_DISPLAY_LABEL} instead.
      */
     @Deprecated
     public static final String KEY_DISPLAYNAME = "name";  // value: String

     public static final String KEY_DISPLAY_LABEL = "display_label"; // value: CharSequence

     /**
      * @deprecated Use {@link #KEY_OFFSET_LABEL} instead.
      */
     @Deprecated
     public static final String KEY_GMT = "gmt";  // value: String
     public static final String KEY_OFFSET = "offset";  // value: int (Integer)
     public static final String KEY_OFFSET_LABEL = "offset_label";  // value: CharSequence

     private static final String XMLTAG_TIMEZONE = "timezone";

     public static CharSequence getTimeZoneOffsetAndName(Context context, TimeZone tz, Date now) {
         Locale locale = context.getResources().getConfiguration().locale;
         TimeZoneFormat tzFormatter = TimeZoneFormat.getInstance(locale);
         CharSequence gmtText = getGmtOffsetText(tzFormatter, locale, tz, now);
         TimeZoneNames timeZoneNames = TimeZoneNames.getInstance(locale);
         String zoneNameString = capitalizeForStandaloneDisplay(
                 locale, getZoneLongName(locale, timeZoneNames, tz, now));
         if (zoneNameString == null) {
             return gmtText;
         }

         // We don't use punctuation here to avoid having to worry about localizing that too!
         return TextUtils.concat(gmtText, " ", zoneNameString);
     }

     /**
      * Capitalizes {@code toCapitalize} for standalone display, i.e. in lists. This is intended for
      * use with "display name" strings from sources like ICU/CLDR which typically capitalize strings
      * for the inclusion in the middle of sentences. Some locales (such as Polish) do not capitalize
      * terms like "Coordinated Universal Time" as in English but do capitalize the first letter for
      * standalone locations like lists, and so must be explicitly capitalized.
      *
      * @return the capitalized string, or {@code null} if the argument is null
      */
     @Nullable
     public static String capitalizeForStandaloneDisplay(
             Locale locale, @Nullable String toCapitalize) {
         if (TextUtils.isEmpty(toCapitalize)) {
             return toCapitalize;
         }
         return LocaleHelper.toSentenceCase(toCapitalize, locale);
     }

     public static List<Map<String, Object>> getZonesList(Context context) {
         final Locale locale = context.getResources().getConfiguration().locale;
         final Date now = new Date();
         final TimeZoneNames timeZoneNames = TimeZoneNames.getInstance(locale);
         final ZoneGetterData data = new ZoneGetterData(context);

         // Work out whether the display names we would show by default would be ambiguous.
         final boolean useExemplarLocationForLocalNames =
                 shouldUseExemplarLocationForLocalNames(locale, data, timeZoneNames);

         // Generate the list of zone entries to return.
         List<Map<String, Object>> zones = new ArrayList<Map<String, Object>>();
         for (int i = 0; i < data.zoneCount; i++) {
             TimeZone tz = data.timeZones[i];
             CharSequence gmtOffsetText = data.gmtOffsetTexts[i];

             CharSequence displayName = getTimeZoneDisplayName(locale, data, timeZoneNames,
                     useExemplarLocationForLocalNames, tz, data.olsonIdsToDisplay[i]);
             if (TextUtils.isEmpty(displayName)) {
                 displayName = gmtOffsetText;
             }

             int offsetMillis = tz.getOffset(now.getTime());
             Map<String, Object> displayEntry =
                     createDisplayEntry(tz, gmtOffsetText, displayName, offsetMillis);
             zones.add(displayEntry);
         }
         return zones;
     }

     private static Map<String, Object> createDisplayEntry(
             TimeZone tz, CharSequence gmtOffsetText, CharSequence displayName, int offsetMillis) {
         Map<String, Object> map = new HashMap<>();
         map.put(KEY_ID, tz.getID());
         map.put(KEY_DISPLAYNAME, displayName.toString());
         map.put(KEY_DISPLAY_LABEL, displayName);
         map.put(KEY_GMT, gmtOffsetText.toString());
         map.put(KEY_OFFSET_LABEL, gmtOffsetText);
         map.put(KEY_OFFSET, offsetMillis);
         return map;
     }

     private static List<String> readTimezonesToDisplay(Context context) {
         List<String> olsonIds = new ArrayList<String>();
         try (XmlResourceParser xrp = context.getResources().getXml(R.xml.timezones)) {
             while (xrp.next() != XmlResourceParser.START_TAG) {
                 continue;
             }
             xrp.next();
             while (xrp.getEventType() != XmlResourceParser.END_TAG) {
                 while (xrp.getEventType() != XmlResourceParser.START_TAG) {
                     if (xrp.getEventType() == XmlResourceParser.END_DOCUMENT) {
                         return olsonIds;
                     }
                     xrp.next();
                 }
                 if (xrp.getName().equals(XMLTAG_TIMEZONE)) {
                     String olsonId = xrp.getAttributeValue(0);
                     olsonIds.add(olsonId);
                 }
                 while (xrp.getEventType() != XmlResourceParser.END_TAG) {
                     xrp.next();
                 }
                 xrp.next();
             }
         } catch (XmlPullParserException xppe) {
             Log.e(TAG, "Ill-formatted timezones.xml file");
         } catch (java.io.IOException ioe) {
             Log.e(TAG, "Unable to read timezones.xml file");
         }
         return olsonIds;
     }

     private static boolean shouldUseExemplarLocationForLocalNames(Locale locale,
             ZoneGetterData data, TimeZoneNames timeZoneNames) {
         final Set<CharSequence> localZoneNames = new HashSet<>();
         final Date now = new Date();
         for (int i = 0; i < data.zoneCount; i++) {
             final String olsonId = data.olsonIdsToDisplay[i];
             if (data.localZoneIds.contains(olsonId)) {
                 final TimeZone tz = data.timeZones[i];
                 CharSequence displayName = getZoneLongName(locale, timeZoneNames, tz, now);
                 if (displayName == null) {
                     displayName = data.gmtOffsetTexts[i];
                 }
                 final boolean nameIsUnique = localZoneNames.add(displayName);
                 if (!nameIsUnique) {
                     return true;
                 }
             }
         }

         return false;
     }

     private static CharSequence getTimeZoneDisplayName(Locale locale, ZoneGetterData data,
             TimeZoneNames timeZoneNames, boolean useExemplarLocationForLocalNames, TimeZone tz,
             String olsonId) {
         final Date now = new Date();
         final boolean isLocalZoneId = data.localZoneIds.contains(olsonId);
         final boolean preferLongName = isLocalZoneId && !useExemplarLocationForLocalNames;
         String displayName;

         if (preferLongName) {
             displayName = getZoneLongName(locale, timeZoneNames, tz, now);
         } else {
             // Canonicalize the zone ID for ICU. It will only return valid strings for zone IDs
             // that match ICUs zone IDs (which are similar but not guaranteed the same as those
             // in timezones.xml). timezones.xml and related files uses the IANA IDs. ICU IDs are
             // stable and IANA IDs have changed over time so they have drifted.
             // See http://bugs.icu-project.org/trac/ticket/13070 / http://b/36469833.
             String canonicalZoneId = android.icu.util.TimeZone.getCanonicalID(tz.getID());
             if (canonicalZoneId == null) {
                 canonicalZoneId = tz.getID();
             }
             displayName = capitalizeForStandaloneDisplay(
                     locale, timeZoneNames.getExemplarLocationName(canonicalZoneId));
             if (displayName == null || displayName.isEmpty()) {
                 // getZoneExemplarLocation can return null. Fall back to the long name.
                 displayName = getZoneLongName(locale, timeZoneNames, tz, now);
             }
         }

         return displayName;
     }

     /**
      * Returns the long name for the timezone for the given locale at the time specified.
      * Can return {@code null}.
      */
     private static String getZoneLongName(
             Locale locale, TimeZoneNames names, TimeZone tz, Date now) {
         final TimeZoneNames.NameType nameType =
                 tz.inDaylightTime(now) ? TimeZoneNames.NameType.LONG_DAYLIGHT
                         : TimeZoneNames.NameType.LONG_STANDARD;
         return capitalizeForStandaloneDisplay(locale,
                 names.getDisplayName(getCanonicalZoneId(tz), nameType, now.getTime()));
     }

     private static String getCanonicalZoneId(TimeZone timeZone) {
         final String id = timeZone.getID();
         final String canonicalId = android.icu.util.TimeZone.getCanonicalID(id);
         if (canonicalId != null) {
             return canonicalId;
         }
         return id;
     }

     private static void appendWithTtsSpan(SpannableStringBuilder builder, CharSequence content,
             TtsSpan span) {
         int start = builder.length();
         builder.append(content);
         builder.setSpan(span, start, builder.length(), 0);
     }

     // Input must be positive. minDigits must be 1 or 2.
     private static String formatDigits(int input, int minDigits, String localizedDigits) {
         final int tens = input / 10;
         final int units = input % 10;
         StringBuilder builder = new StringBuilder(minDigits);
         if (input >= 10 || minDigits == 2) {
             builder.append(localizedDigits.charAt(tens));
         }
         builder.append(localizedDigits.charAt(units));
         return builder.toString();
     }

     /**
      * Get the GMT offset text label for the given time zone, in the format "GMT-08:00". This will
      * also add TTS spans to give hints to the text-to-speech engine for the type of data it is.
      *
      * @param tzFormatter The timezone formatter to use.
      * @param locale The locale which the string is displayed in. This should be the same as the
      *               locale of the time zone formatter.
      * @param tz Time zone to get the GMT offset from.
      * @param now The current time, used to tell whether daylight savings is active.
      * @return A CharSequence suitable for display as the offset label of {@code tz}.
      */
     public static CharSequence getGmtOffsetText(TimeZoneFormat tzFormatter, Locale locale,
             TimeZone tz, Date now) {
         final SpannableStringBuilder builder = new SpannableStringBuilder();

         final String gmtPattern = tzFormatter.getGMTPattern();
         final int placeholderIndex = gmtPattern.indexOf("{0}");
         final String gmtPatternPrefix, gmtPatternSuffix;
         if (placeholderIndex == -1) {
             // Bad pattern. Replace with defaults.
             gmtPatternPrefix = "GMT";
             gmtPatternSuffix = "";
         } else {
             gmtPatternPrefix = gmtPattern.substring(0, placeholderIndex);
             gmtPatternSuffix = gmtPattern.substring(placeholderIndex + 3); // After the "{0}".
         }

         if (!gmtPatternPrefix.isEmpty()) {
             appendWithTtsSpan(builder, gmtPatternPrefix,
                     new TtsSpan.TextBuilder(gmtPatternPrefix).build());
         }

         int offsetMillis = tz.getOffset(now.getTime());
         final boolean negative = offsetMillis < 0;
         final TimeZoneFormat.GMTOffsetPatternType patternType;
         if (negative) {
             offsetMillis = -offsetMillis;
             patternType = TimeZoneFormat.GMTOffsetPatternType.NEGATIVE_HM;
         } else {
             patternType = TimeZoneFormat.GMTOffsetPatternType.POSITIVE_HM;
         }
         final String gmtOffsetPattern = tzFormatter.getGMTOffsetPattern(patternType);
         final String localizedDigits = tzFormatter.getGMTOffsetDigits();

         final int offsetHours = (int) (offsetMillis / DateUtils.HOUR_IN_MILLIS);
         final int offsetMinutes = (int) (offsetMillis / DateUtils.MINUTE_IN_MILLIS);
         final int offsetMinutesRemaining = Math.abs(offsetMinutes) % 60;

         for (int i = 0; i < gmtOffsetPattern.length(); i++) {
             char c = gmtOffsetPattern.charAt(i);
             if (c == '+' || c == '-' || c == '\u2212' /* MINUS SIGN */) {
                 final String sign = String.valueOf(c);
                 appendWithTtsSpan(builder, sign, new TtsSpan.VerbatimBuilder(sign).build());
             } else if (c == 'H' || c == 'm') {
                 final int numDigits;
                 if (i + 1 < gmtOffsetPattern.length() && gmtOffsetPattern.charAt(i + 1) == c) {
                     numDigits = 2;
                     i++; // Skip the next formatting character.
                 } else {
                     numDigits = 1;
                 }
                 final int number;
                 final String unit;
                 if (c == 'H') {
                     number = offsetHours;
                     unit = "hour";
                 } else { // c == 'm'
                     number = offsetMinutesRemaining;
                     unit = "minute";
                 }
                 appendWithTtsSpan(builder, formatDigits(number, numDigits, localizedDigits),
                         new TtsSpan.MeasureBuilder().setNumber(number).setUnit(unit).build());
             } else {
                 builder.append(c);
             }
         }

         if (!gmtPatternSuffix.isEmpty()) {
             appendWithTtsSpan(builder, gmtPatternSuffix,
                     new TtsSpan.TextBuilder(gmtPatternSuffix).build());
         }

         CharSequence gmtText = new SpannableString(builder);

         // Ensure that the "GMT+" stays with the "00:00" even if the digits are RTL.
         final BidiFormatter bidiFormatter = BidiFormatter.getInstance();
         boolean isRtl = TextUtils.getLayoutDirectionFromLocale(locale) == View.LAYOUT_DIRECTION_RTL;
         gmtText = bidiFormatter.unicodeWrap(gmtText,
                 isRtl ? TextDirectionHeuristicsCompat.RTL : TextDirectionHeuristicsCompat.LTR);
         return gmtText;
     }

     @VisibleForTesting
     public static final class ZoneGetterData {
         public final String[] olsonIdsToDisplay;
         public final CharSequence[] gmtOffsetTexts;
         public final TimeZone[] timeZones;
         public final Set<String> localZoneIds;
         public final int zoneCount;

         public ZoneGetterData(Context context) {
             final Locale locale = context.getResources().getConfiguration().locale;
             final TimeZoneFormat tzFormatter = TimeZoneFormat.getInstance(locale);
             final Date now = new Date();
             final List<String> olsonIdsToDisplayList = readTimezonesToDisplay(context);

             // Load all the data needed to display time zones
             zoneCount = olsonIdsToDisplayList.size();
             olsonIdsToDisplay = new String[zoneCount];
             timeZones = new TimeZone[zoneCount];
             gmtOffsetTexts = new CharSequence[zoneCount];
             for (int i = 0; i < zoneCount; i++) {
                 final String olsonId = olsonIdsToDisplayList.get(i);
                 olsonIdsToDisplay[i] = olsonId;
                 final TimeZone tz = TimeZone.getTimeZone(olsonId);
                 timeZones[i] = tz;
                 gmtOffsetTexts[i] = getGmtOffsetText(tzFormatter, locale, tz, now);
             }

             // Create a lookup of local zone IDs.
             final List<String> zoneIds = lookupTimeZoneIdsByCountry(locale.getCountry());
             localZoneIds = zoneIds != null ? new HashSet<>(zoneIds) : new HashSet<>();
         }

         @VisibleForTesting
         public List<String> lookupTimeZoneIdsByCountry(String country) {
             final CountryTimeZones countryTimeZones =
                     TimeZoneFinder.getInstance().lookupCountryTimeZones(country);
             if (countryTimeZones == null) {
                 return null;
             }
             final List<TimeZoneMapping> mappings = countryTimeZones.getTimeZoneMappings();
             return extractTimeZoneIds(mappings);
         }

         private static List<String> extractTimeZoneIds(List<TimeZoneMapping> timeZoneMappings) {
             final List<String> zoneIds = new ArrayList<>(timeZoneMappings.size());
             for (TimeZoneMapping timeZoneMapping : timeZoneMappings) {
                 zoneIds.add(timeZoneMapping.getTimeZoneId());
             }
             return Collections.unmodifiableList(zoneIds);
         }
     }
 }
	/*
	* 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 com.android.settingslib.datetime;

	import android.annotation.Nullable;
	import android.content.Context;
	import android.content.res.XmlResourceParser;
	import android.icu.text.TimeZoneFormat;
	import android.icu.text.TimeZoneNames;
	import android.text.SpannableString;
	import android.text.SpannableStringBuilder;
	import android.text.TextUtils;
	import android.text.format.DateUtils;
	import android.text.style.TtsSpan;
	import android.util.Log;
	import android.view.View;

	import androidx.annotation.VisibleForTesting;
	import androidx.core.text.BidiFormatter;
	import androidx.core.text.TextDirectionHeuristicsCompat;

	import com.android.i18n.timezone.CountryTimeZones;
	import com.android.i18n.timezone.CountryTimeZones.TimeZoneMapping;
	import com.android.i18n.timezone.TimeZoneFinder;
	import com.android.internal.app.LocaleHelper;
	import com.android.settingslib.R;

	import org.xmlpull.v1.XmlPullParserException;

	import java.util.ArrayList;
	import java.util.Collections;
	import java.util.Date;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.List;
	import java.util.Locale;
	import java.util.Map;
	import java.util.Set;
	import java.util.TimeZone;

	/**
	* ZoneGetter is the utility class to get time zone and zone list, and both of them have display
	* name in time zone. In this class, we will keep consistency about display names for all
	* the methods.
	*
	* The display name chosen for each zone entry depends on whether the zone is one associated
	* with the country of the user's chosen locale. For "local" zones we prefer the "long name"
	* (e.g. "Europe/London" -> "British Summer Time" for people in the UK). For "non-local"
	* zones we prefer the exemplar location (e.g. "Europe/London" -> "London" for English
	* speakers from outside the UK). This heuristic is based on the fact that people are
	* typically familiar with their local timezones and exemplar locations don't always match
	* modern-day expectations for people living in the country covered. Large countries like
	* China that mostly use a single timezone (olson id: "Asia/Shanghai") may not live near
	* "Shanghai" and prefer the long name over the exemplar location. The only time we don't
	* follow this policy for local zones is when Android supplies multiple olson IDs to choose
	* from and the use of a zone's long name leads to ambiguity. For example, at the time of
	* writing Android lists 5 olson ids for Australia which collapse to 2 different zone names
	* in winter but 4 different zone names in summer. The ambiguity leads to the users
	* selecting the wrong olson ids.
	*
	*/
	public class ZoneGetter {
	private static final String TAG = "ZoneGetter";

	public static final String KEY_ID = "id"; // value: String

	/**
	* @deprecated Use {@link #KEY_DISPLAY_LABEL} instead.
	*/
	@Deprecated
	public static final String KEY_DISPLAYNAME = "name"; // value: String

	public static final String KEY_DISPLAY_LABEL = "display_label"; // value: CharSequence

	/**
	* @deprecated Use {@link #KEY_OFFSET_LABEL} instead.
	*/
	@Deprecated
	public static final String KEY_GMT = "gmt"; // value: String
	public static final String KEY_OFFSET = "offset"; // value: int (Integer)
	public static final String KEY_OFFSET_LABEL = "offset_label"; // value: CharSequence

	private static final String XMLTAG_TIMEZONE = "timezone";

	public static CharSequence getTimeZoneOffsetAndName(Context context, TimeZone tz, Date now) {
	Locale locale = context.getResources().getConfiguration().locale;
	TimeZoneFormat tzFormatter = TimeZoneFormat.getInstance(locale);
	CharSequence gmtText = getGmtOffsetText(tzFormatter, locale, tz, now);
	TimeZoneNames timeZoneNames = TimeZoneNames.getInstance(locale);
	String zoneNameString = capitalizeForStandaloneDisplay(
	locale, getZoneLongName(locale, timeZoneNames, tz, now));
	if (zoneNameString == null) {
	return gmtText;
	}

	// We don't use punctuation here to avoid having to worry about localizing that too!
	return TextUtils.concat(gmtText, " ", zoneNameString);
	}

	/**
	* Capitalizes {@code toCapitalize} for standalone display, i.e. in lists. This is intended for
	* use with "display name" strings from sources like ICU/CLDR which typically capitalize strings
	* for the inclusion in the middle of sentences. Some locales (such as Polish) do not capitalize
	* terms like "Coordinated Universal Time" as in English but do capitalize the first letter for
	* standalone locations like lists, and so must be explicitly capitalized.
	*
	* @return the capitalized string, or {@code null} if the argument is null
	*/
	@Nullable
	public static String capitalizeForStandaloneDisplay(
	Locale locale, @Nullable String toCapitalize) {
	if (TextUtils.isEmpty(toCapitalize)) {
	return toCapitalize;
	}
	return LocaleHelper.toSentenceCase(toCapitalize, locale);
	}

	public static List<Map<String, Object>> getZonesList(Context context) {
	final Locale locale = context.getResources().getConfiguration().locale;
	final Date now = new Date();
	final TimeZoneNames timeZoneNames = TimeZoneNames.getInstance(locale);
	final ZoneGetterData data = new ZoneGetterData(context);

	// Work out whether the display names we would show by default would be ambiguous.
	final boolean useExemplarLocationForLocalNames =
	shouldUseExemplarLocationForLocalNames(locale, data, timeZoneNames);

	// Generate the list of zone entries to return.
	List<Map<String, Object>> zones = new ArrayList<Map<String, Object>>();
	for (int i = 0; i < data.zoneCount; i++) {
	TimeZone tz = data.timeZones[i];
	CharSequence gmtOffsetText = data.gmtOffsetTexts[i];

	CharSequence displayName = getTimeZoneDisplayName(locale, data, timeZoneNames,
	useExemplarLocationForLocalNames, tz, data.olsonIdsToDisplay[i]);
	if (TextUtils.isEmpty(displayName)) {
	displayName = gmtOffsetText;
	}

	int offsetMillis = tz.getOffset(now.getTime());
	Map<String, Object> displayEntry =
	createDisplayEntry(tz, gmtOffsetText, displayName, offsetMillis);
	zones.add(displayEntry);
	}
	return zones;
	}

	private static Map<String, Object> createDisplayEntry(
	TimeZone tz, CharSequence gmtOffsetText, CharSequence displayName, int offsetMillis) {
	Map<String, Object> map = new HashMap<>();
	map.put(KEY_ID, tz.getID());
	map.put(KEY_DISPLAYNAME, displayName.toString());
	map.put(KEY_DISPLAY_LABEL, displayName);
	map.put(KEY_GMT, gmtOffsetText.toString());
	map.put(KEY_OFFSET_LABEL, gmtOffsetText);
	map.put(KEY_OFFSET, offsetMillis);
	return map;
	}

	private static List<String> readTimezonesToDisplay(Context context) {
	List<String> olsonIds = new ArrayList<String>();
	try (XmlResourceParser xrp = context.getResources().getXml(R.xml.timezones)) {
	while (xrp.next() != XmlResourceParser.START_TAG) {
	continue;
	}
	xrp.next();
	while (xrp.getEventType() != XmlResourceParser.END_TAG) {
	while (xrp.getEventType() != XmlResourceParser.START_TAG) {
	if (xrp.getEventType() == XmlResourceParser.END_DOCUMENT) {
	return olsonIds;
	}
	xrp.next();
	}
	if (xrp.getName().equals(XMLTAG_TIMEZONE)) {
	String olsonId = xrp.getAttributeValue(0);
	olsonIds.add(olsonId);
	}
	while (xrp.getEventType() != XmlResourceParser.END_TAG) {
	xrp.next();
	}
	xrp.next();
	}
	} catch (XmlPullParserException xppe) {
	Log.e(TAG, "Ill-formatted timezones.xml file");
	} catch (java.io.IOException ioe) {
	Log.e(TAG, "Unable to read timezones.xml file");
	}
	return olsonIds;
	}

	private static boolean shouldUseExemplarLocationForLocalNames(Locale locale,
	ZoneGetterData data, TimeZoneNames timeZoneNames) {
	final Set<CharSequence> localZoneNames = new HashSet<>();
	final Date now = new Date();
	for (int i = 0; i < data.zoneCount; i++) {
	final String olsonId = data.olsonIdsToDisplay[i];
	if (data.localZoneIds.contains(olsonId)) {
	final TimeZone tz = data.timeZones[i];
	CharSequence displayName = getZoneLongName(locale, timeZoneNames, tz, now);
	if (displayName == null) {
	displayName = data.gmtOffsetTexts[i];
	}
	final boolean nameIsUnique = localZoneNames.add(displayName);
	if (!nameIsUnique) {
	return true;
	}
	}
	}

	return false;
	}

	private static CharSequence getTimeZoneDisplayName(Locale locale, ZoneGetterData data,
	TimeZoneNames timeZoneNames, boolean useExemplarLocationForLocalNames, TimeZone tz,
	String olsonId) {
	final Date now = new Date();
	final boolean isLocalZoneId = data.localZoneIds.contains(olsonId);
	final boolean preferLongName = isLocalZoneId && !useExemplarLocationForLocalNames;
	String displayName;

	if (preferLongName) {
	displayName = getZoneLongName(locale, timeZoneNames, tz, now);
	} else {
	// Canonicalize the zone ID for ICU. It will only return valid strings for zone IDs
	// that match ICUs zone IDs (which are similar but not guaranteed the same as those
	// in timezones.xml). timezones.xml and related files uses the IANA IDs. ICU IDs are
	// stable and IANA IDs have changed over time so they have drifted.
	// See http://bugs.icu-project.org/trac/ticket/13070 / http://b/36469833.
	String canonicalZoneId = android.icu.util.TimeZone.getCanonicalID(tz.getID());
	if (canonicalZoneId == null) {
	canonicalZoneId = tz.getID();
	}
	displayName = capitalizeForStandaloneDisplay(
	locale, timeZoneNames.getExemplarLocationName(canonicalZoneId));
	if (displayName == null \|\| displayName.isEmpty()) {
	// getZoneExemplarLocation can return null. Fall back to the long name.
	displayName = getZoneLongName(locale, timeZoneNames, tz, now);
	}
	}

	return displayName;
	}

	/**
	* Returns the long name for the timezone for the given locale at the time specified.
	* Can return {@code null}.
	*/
	private static String getZoneLongName(
	Locale locale, TimeZoneNames names, TimeZone tz, Date now) {
	final TimeZoneNames.NameType nameType =
	tz.inDaylightTime(now) ? TimeZoneNames.NameType.LONG_DAYLIGHT
	: TimeZoneNames.NameType.LONG_STANDARD;
	return capitalizeForStandaloneDisplay(locale,
	names.getDisplayName(getCanonicalZoneId(tz), nameType, now.getTime()));
	}

	private static String getCanonicalZoneId(TimeZone timeZone) {
	final String id = timeZone.getID();
	final String canonicalId = android.icu.util.TimeZone.getCanonicalID(id);
	if (canonicalId != null) {
	return canonicalId;
	}
	return id;
	}

	private static void appendWithTtsSpan(SpannableStringBuilder builder, CharSequence content,
	TtsSpan span) {
	int start = builder.length();
	builder.append(content);
	builder.setSpan(span, start, builder.length(), 0);
	}

	// Input must be positive. minDigits must be 1 or 2.
	private static String formatDigits(int input, int minDigits, String localizedDigits) {
	final int tens = input / 10;
	final int units = input % 10;
	StringBuilder builder = new StringBuilder(minDigits);
	if (input >= 10 \|\| minDigits == 2) {
	builder.append(localizedDigits.charAt(tens));
	}
	builder.append(localizedDigits.charAt(units));
	return builder.toString();
	}

	/**
	* Get the GMT offset text label for the given time zone, in the format "GMT-08:00". This will
	* also add TTS spans to give hints to the text-to-speech engine for the type of data it is.
	*
	* @param tzFormatter The timezone formatter to use.
	* @param locale The locale which the string is displayed in. This should be the same as the
	* locale of the time zone formatter.
	* @param tz Time zone to get the GMT offset from.
	* @param now The current time, used to tell whether daylight savings is active.
	* @return A CharSequence suitable for display as the offset label of {@code tz}.
	*/
	public static CharSequence getGmtOffsetText(TimeZoneFormat tzFormatter, Locale locale,
	TimeZone tz, Date now) {
	final SpannableStringBuilder builder = new SpannableStringBuilder();

	final String gmtPattern = tzFormatter.getGMTPattern();
	final int placeholderIndex = gmtPattern.indexOf("{0}");
	final String gmtPatternPrefix, gmtPatternSuffix;
	if (placeholderIndex == -1) {
	// Bad pattern. Replace with defaults.
	gmtPatternPrefix = "GMT";
	gmtPatternSuffix = "";
	} else {
	gmtPatternPrefix = gmtPattern.substring(0, placeholderIndex);
	gmtPatternSuffix = gmtPattern.substring(placeholderIndex + 3); // After the "{0}".
	}

	if (!gmtPatternPrefix.isEmpty()) {
	appendWithTtsSpan(builder, gmtPatternPrefix,
	new TtsSpan.TextBuilder(gmtPatternPrefix).build());
	}

	int offsetMillis = tz.getOffset(now.getTime());
	final boolean negative = offsetMillis < 0;
	final TimeZoneFormat.GMTOffsetPatternType patternType;
	if (negative) {
	offsetMillis = -offsetMillis;
	patternType = TimeZoneFormat.GMTOffsetPatternType.NEGATIVE_HM;
	} else {
	patternType = TimeZoneFormat.GMTOffsetPatternType.POSITIVE_HM;
	}
	final String gmtOffsetPattern = tzFormatter.getGMTOffsetPattern(patternType);
	final String localizedDigits = tzFormatter.getGMTOffsetDigits();

	final int offsetHours = (int) (offsetMillis / DateUtils.HOUR_IN_MILLIS);
	final int offsetMinutes = (int) (offsetMillis / DateUtils.MINUTE_IN_MILLIS);
	final int offsetMinutesRemaining = Math.abs(offsetMinutes) % 60;

	for (int i = 0; i < gmtOffsetPattern.length(); i++) {
	char c = gmtOffsetPattern.charAt(i);
	if (c == '+' \|\| c == '-' \|\| c == '\u2212' /* MINUS SIGN */) {
	final String sign = String.valueOf(c);
	appendWithTtsSpan(builder, sign, new TtsSpan.VerbatimBuilder(sign).build());
	} else if (c == 'H' \|\| c == 'm') {
	final int numDigits;
	if (i + 1 < gmtOffsetPattern.length() && gmtOffsetPattern.charAt(i + 1) == c) {
	numDigits = 2;
	i++; // Skip the next formatting character.
	} else {
	numDigits = 1;
	}
	final int number;
	final String unit;
	if (c == 'H') {
	number = offsetHours;
	unit = "hour";
	} else { // c == 'm'
	number = offsetMinutesRemaining;
	unit = "minute";
	}
	appendWithTtsSpan(builder, formatDigits(number, numDigits, localizedDigits),
	new TtsSpan.MeasureBuilder().setNumber(number).setUnit(unit).build());
	} else {
	builder.append(c);
	}
	}

	if (!gmtPatternSuffix.isEmpty()) {
	appendWithTtsSpan(builder, gmtPatternSuffix,
	new TtsSpan.TextBuilder(gmtPatternSuffix).build());
	}

	CharSequence gmtText = new SpannableString(builder);

	// Ensure that the "GMT+" stays with the "00:00" even if the digits are RTL.
	final BidiFormatter bidiFormatter = BidiFormatter.getInstance();
	boolean isRtl = TextUtils.getLayoutDirectionFromLocale(locale) == View.LAYOUT_DIRECTION_RTL;
	gmtText = bidiFormatter.unicodeWrap(gmtText,
	isRtl ? TextDirectionHeuristicsCompat.RTL : TextDirectionHeuristicsCompat.LTR);
	return gmtText;
	}

	@VisibleForTesting
	public static final class ZoneGetterData {
	public final String[] olsonIdsToDisplay;
	public final CharSequence[] gmtOffsetTexts;
	public final TimeZone[] timeZones;
	public final Set<String> localZoneIds;
	public final int zoneCount;

	public ZoneGetterData(Context context) {
	final Locale locale = context.getResources().getConfiguration().locale;
	final TimeZoneFormat tzFormatter = TimeZoneFormat.getInstance(locale);
	final Date now = new Date();
	final List<String> olsonIdsToDisplayList = readTimezonesToDisplay(context);

	// Load all the data needed to display time zones
	zoneCount = olsonIdsToDisplayList.size();
	olsonIdsToDisplay = new String[zoneCount];
	timeZones = new TimeZone[zoneCount];
	gmtOffsetTexts = new CharSequence[zoneCount];
	for (int i = 0; i < zoneCount; i++) {
	final String olsonId = olsonIdsToDisplayList.get(i);
	olsonIdsToDisplay[i] = olsonId;
	final TimeZone tz = TimeZone.getTimeZone(olsonId);
	timeZones[i] = tz;
	gmtOffsetTexts[i] = getGmtOffsetText(tzFormatter, locale, tz, now);
	}

	// Create a lookup of local zone IDs.
	final List<String> zoneIds = lookupTimeZoneIdsByCountry(locale.getCountry());
	localZoneIds = zoneIds != null ? new HashSet<>(zoneIds) : new HashSet<>();
	}

	@VisibleForTesting
	public List<String> lookupTimeZoneIdsByCountry(String country) {
	final CountryTimeZones countryTimeZones =
	TimeZoneFinder.getInstance().lookupCountryTimeZones(country);
	if (countryTimeZones == null) {
	return null;
	}
	final List<TimeZoneMapping> mappings = countryTimeZones.getTimeZoneMappings();
	return extractTimeZoneIds(mappings);
	}

	private static List<String> extractTimeZoneIds(List<TimeZoneMapping> timeZoneMappings) {
	final List<String> zoneIds = new ArrayList<>(timeZoneMappings.size());
	for (TimeZoneMapping timeZoneMapping : timeZoneMappings) {
	zoneIds.add(timeZoneMapping.getTimeZoneId());
	}
	return Collections.unmodifiableList(zoneIds);
	}
	}
	}