packages/SettingsLib/src/com/android/settingslib/datetime/ZoneGetter.java - platform/frameworks/base - Gitiles

 /*
  * 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.content.Context;
 import android.content.res.XmlResourceParser;
 import android.icu.text.TimeZoneNames;
 import android.text.BidiFormatter;
 import android.text.TextDirectionHeuristics;
 import android.text.TextUtils;
 import android.util.Log;
 import android.view.View;

 import com.android.settingslib.R;

 import org.xmlpull.v1.XmlPullParserException;

 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
 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;

 public class ZoneGetter {
     private static final String TAG = "ZoneGetter";

     private static final String XMLTAG_TIMEZONE = "timezone";

     public static final String KEY_ID = "id";  // value: String
     public static final String KEY_DISPLAYNAME = "name";  // value: String
     public static final String KEY_GMT = "gmt";  // value: String
     public static final String KEY_OFFSET = "offset";  // value: int (Integer)

     private ZoneGetter() {}

     public static String getTimeZoneOffsetAndName(TimeZone tz, Date now) {
         Locale locale = Locale.getDefault();
         String gmtString = getGmtOffsetString(locale, tz, now);
         TimeZoneNames timeZoneNames = TimeZoneNames.getInstance(locale);
         String zoneNameString = getZoneLongName(timeZoneNames, tz, now);
         if (zoneNameString == null) {
             return gmtString;
         }

         // We don't use punctuation here to avoid having to worry about localizing that too!
         return gmtString + " " + zoneNameString;
     }

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

         // 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.

         // Get the list of olson ids to display to the user.
         List<String> olsonIdsToDisplayList = readTimezonesToDisplay(context);

         // Store the information we are going to need more than once.
         final int zoneCount = olsonIdsToDisplayList.size();
         final String[] olsonIdsToDisplay = new String[zoneCount];
         final TimeZone[] timeZones = new TimeZone[zoneCount];
         final String[] gmtOffsetStrings = new String[zoneCount];
         for (int i = 0; i < zoneCount; i++) {
             String olsonId = olsonIdsToDisplayList.get(i);
             olsonIdsToDisplay[i] = olsonId;
             TimeZone tz = TimeZone.getTimeZone(olsonId);
             timeZones[i] = tz;
             gmtOffsetStrings[i] = getGmtOffsetString(locale, tz, now);
         }

         // Create a lookup of local zone IDs.
         Set<String> localZoneIds = new HashSet<String>();
         for (String olsonId : libcore.icu.TimeZoneNames.forLocale(locale)) {
             localZoneIds.add(olsonId);
         }

         // Work out whether the display names we would show by default would be ambiguous.
         Set<String> localZoneNames = new HashSet<String>();
         boolean useExemplarLocationForLocalNames = false;
         for (int i = 0; i < zoneCount; i++) {
             String olsonId = olsonIdsToDisplay[i];
             if (localZoneIds.contains(olsonId)) {
                 TimeZone tz = timeZones[i];
                 String displayName = getZoneLongName(timeZoneNames, tz, now);
                 if (displayName == null) {
                     displayName = gmtOffsetStrings[i];
                 }
                 boolean nameIsUnique = localZoneNames.add(displayName);
                 if (!nameIsUnique) {
                     useExemplarLocationForLocalNames = true;
                     break;
                 }
             }
         }

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

             boolean isLocalZoneId = localZoneIds.contains(olsonId);
             boolean preferLongName = isLocalZoneId && !useExemplarLocationForLocalNames;
             String displayName;
             if (preferLongName) {
                 displayName = getZoneLongName(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 = timeZoneNames.getExemplarLocationName(canonicalZoneId);
                 if (displayName == null || displayName.isEmpty()) {
                     // getZoneExemplarLocation can return null. Fall back to the long name.
                     displayName = getZoneLongName(timeZoneNames, tz, now);
                 }
             }
             if (displayName == null  || displayName.isEmpty()) {
                 displayName = gmtOffsetString;
             }

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

     private static Map<String, Object> createDisplayEntry(
             TimeZone tz, String gmtOffsetString, String displayName, int offsetMillis) {
         Map<String, Object> map = new HashMap<String, Object>();
         map.put(KEY_ID, tz.getID());
         map.put(KEY_DISPLAYNAME, displayName);
         map.put(KEY_GMT, gmtOffsetString);
         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;
     }

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

     private static String getGmtOffsetString(Locale locale, TimeZone tz, Date now) {
         // Use SimpleDateFormat to format the GMT+00:00 string.
         SimpleDateFormat gmtFormatter = new SimpleDateFormat("ZZZZ");
         gmtFormatter.setTimeZone(tz);
         String gmtString = gmtFormatter.format(now);

         // Ensure that the "GMT+" stays with the "00:00" even if the digits are RTL.
         BidiFormatter bidiFormatter = BidiFormatter.getInstance();
         boolean isRtl = TextUtils.getLayoutDirectionFromLocale(locale) == View.LAYOUT_DIRECTION_RTL;
         gmtString = bidiFormatter.unicodeWrap(gmtString,
                 isRtl ? TextDirectionHeuristics.RTL : TextDirectionHeuristics.LTR);
         return gmtString;
     }
 }
	/*
	* 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.content.Context;
	import android.content.res.XmlResourceParser;
	import android.icu.text.TimeZoneNames;
	import android.text.BidiFormatter;
	import android.text.TextDirectionHeuristics;
	import android.text.TextUtils;
	import android.util.Log;
	import android.view.View;

	import com.android.settingslib.R;

	import org.xmlpull.v1.XmlPullParserException;

	import java.text.SimpleDateFormat;
	import java.util.ArrayList;
	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;

	public class ZoneGetter {
	private static final String TAG = "ZoneGetter";

	private static final String XMLTAG_TIMEZONE = "timezone";

	public static final String KEY_ID = "id"; // value: String
	public static final String KEY_DISPLAYNAME = "name"; // value: String
	public static final String KEY_GMT = "gmt"; // value: String
	public static final String KEY_OFFSET = "offset"; // value: int (Integer)

	private ZoneGetter() {}

	public static String getTimeZoneOffsetAndName(TimeZone tz, Date now) {
	Locale locale = Locale.getDefault();
	String gmtString = getGmtOffsetString(locale, tz, now);
	TimeZoneNames timeZoneNames = TimeZoneNames.getInstance(locale);
	String zoneNameString = getZoneLongName(timeZoneNames, tz, now);
	if (zoneNameString == null) {
	return gmtString;
	}

	// We don't use punctuation here to avoid having to worry about localizing that too!
	return gmtString + " " + zoneNameString;
	}

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

	// 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.

	// Get the list of olson ids to display to the user.
	List<String> olsonIdsToDisplayList = readTimezonesToDisplay(context);

	// Store the information we are going to need more than once.
	final int zoneCount = olsonIdsToDisplayList.size();
	final String[] olsonIdsToDisplay = new String[zoneCount];
	final TimeZone[] timeZones = new TimeZone[zoneCount];
	final String[] gmtOffsetStrings = new String[zoneCount];
	for (int i = 0; i < zoneCount; i++) {
	String olsonId = olsonIdsToDisplayList.get(i);
	olsonIdsToDisplay[i] = olsonId;
	TimeZone tz = TimeZone.getTimeZone(olsonId);
	timeZones[i] = tz;
	gmtOffsetStrings[i] = getGmtOffsetString(locale, tz, now);
	}

	// Create a lookup of local zone IDs.
	Set<String> localZoneIds = new HashSet<String>();
	for (String olsonId : libcore.icu.TimeZoneNames.forLocale(locale)) {
	localZoneIds.add(olsonId);
	}

	// Work out whether the display names we would show by default would be ambiguous.
	Set<String> localZoneNames = new HashSet<String>();
	boolean useExemplarLocationForLocalNames = false;
	for (int i = 0; i < zoneCount; i++) {
	String olsonId = olsonIdsToDisplay[i];
	if (localZoneIds.contains(olsonId)) {
	TimeZone tz = timeZones[i];
	String displayName = getZoneLongName(timeZoneNames, tz, now);
	if (displayName == null) {
	displayName = gmtOffsetStrings[i];
	}
	boolean nameIsUnique = localZoneNames.add(displayName);
	if (!nameIsUnique) {
	useExemplarLocationForLocalNames = true;
	break;
	}
	}
	}

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

	boolean isLocalZoneId = localZoneIds.contains(olsonId);
	boolean preferLongName = isLocalZoneId && !useExemplarLocationForLocalNames;
	String displayName;
	if (preferLongName) {
	displayName = getZoneLongName(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 = timeZoneNames.getExemplarLocationName(canonicalZoneId);
	if (displayName == null \|\| displayName.isEmpty()) {
	// getZoneExemplarLocation can return null. Fall back to the long name.
	displayName = getZoneLongName(timeZoneNames, tz, now);
	}
	}
	if (displayName == null \|\| displayName.isEmpty()) {
	displayName = gmtOffsetString;
	}

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

	private static Map<String, Object> createDisplayEntry(
	TimeZone tz, String gmtOffsetString, String displayName, int offsetMillis) {
	Map<String, Object> map = new HashMap<String, Object>();
	map.put(KEY_ID, tz.getID());
	map.put(KEY_DISPLAYNAME, displayName);
	map.put(KEY_GMT, gmtOffsetString);
	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;
	}

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

	private static String getGmtOffsetString(Locale locale, TimeZone tz, Date now) {
	// Use SimpleDateFormat to format the GMT+00:00 string.
	SimpleDateFormat gmtFormatter = new SimpleDateFormat("ZZZZ");
	gmtFormatter.setTimeZone(tz);
	String gmtString = gmtFormatter.format(now);

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