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1 /*
2  * Copyright (C) 2010 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.contacts.util;
18 
19 import android.content.Context;
20 import android.text.format.DateFormat;
21 
22 import java.text.ParsePosition;
23 import java.text.SimpleDateFormat;
24 import java.util.Calendar;
25 import java.util.Date;
26 import java.util.GregorianCalendar;
27 import java.util.Locale;
28 import java.util.TimeZone;
29 
30 /**
31  * Utility methods for processing dates.
32  */
33 public class DateUtils {
34     public static final TimeZone UTC_TIMEZONE = TimeZone.getTimeZone("UTC");
35 
36     /**
37      * When parsing a date without a year, the system assumes 1970, which wasn't a leap-year.
38      * Let's add a one-off hack for that day of the year
39      */
40     public static final String NO_YEAR_DATE_FEB29TH = "--02-29";
41 
42     // Variations of ISO 8601 date format.  Do not change the order - it does affect the
43     // result in ambiguous cases.
44     private static final SimpleDateFormat[] DATE_FORMATS = {
45         CommonDateUtils.FULL_DATE_FORMAT,
46         CommonDateUtils.DATE_AND_TIME_FORMAT,
47         new SimpleDateFormat("yyyy-MM-dd'T'HH:mm'Z'", Locale.US),
48         new SimpleDateFormat("yyyyMMdd", Locale.US),
49         new SimpleDateFormat("yyyyMMdd'T'HHmmssSSS'Z'", Locale.US),
50         new SimpleDateFormat("yyyyMMdd'T'HHmmss'Z'", Locale.US),
51         new SimpleDateFormat("yyyyMMdd'T'HHmm'Z'", Locale.US),
52     };
53 
54     static {
55         for (SimpleDateFormat format : DATE_FORMATS) {
56             format.setLenient(true);
57             format.setTimeZone(UTC_TIMEZONE);
58         }
59         CommonDateUtils.NO_YEAR_DATE_FORMAT.setTimeZone(UTC_TIMEZONE);
60     }
61 
62     /**
63      * Parses the supplied string to see if it looks like a date.
64      *
65      * @param string The string representation of the provided date
66      * @param mustContainYear If true, the string is parsed as a date containing a year. If false,
67      * the string is parsed into a valid date even if the year field is missing.
68      * @return A Calendar object corresponding to the date if the string is successfully parsed.
69      * If not, null is returned.
70      */
parseDate(String string, boolean mustContainYear)71     public static Calendar parseDate(String string, boolean mustContainYear) {
72         ParsePosition parsePosition = new ParsePosition(0);
73         Date date;
74         if (!mustContainYear) {
75             final boolean noYearParsed;
76             // Unfortunately, we can't parse Feb 29th correctly, so let's handle this day seperately
77             if (NO_YEAR_DATE_FEB29TH.equals(string)) {
78                 return getUtcDate(0, Calendar.FEBRUARY, 29);
79             } else {
80                 synchronized (CommonDateUtils.NO_YEAR_DATE_FORMAT) {
81                     date = CommonDateUtils.NO_YEAR_DATE_FORMAT.parse(string, parsePosition);
82                 }
83                 noYearParsed = parsePosition.getIndex() == string.length();
84             }
85 
86             if (noYearParsed) {
87                 return getUtcDate(date, true);
88             }
89         }
90         for (int i = 0; i < DATE_FORMATS.length; i++) {
91             SimpleDateFormat f = DATE_FORMATS[i];
92             synchronized (f) {
93                 parsePosition.setIndex(0);
94                 date = f.parse(string, parsePosition);
95                 if (parsePosition.getIndex() == string.length()) {
96                     return getUtcDate(date, false);
97                 }
98             }
99         }
100         return null;
101     }
102 
getUtcDate(Date date, boolean noYear)103     private static final Calendar getUtcDate(Date date, boolean noYear) {
104         final Calendar calendar = Calendar.getInstance(UTC_TIMEZONE, Locale.US);
105         calendar.setTime(date);
106         if (noYear) {
107             calendar.set(Calendar.YEAR, 0);
108         }
109         return calendar;
110     }
111 
getUtcDate(int year, int month, int dayOfMonth)112     private static final Calendar getUtcDate(int year, int month, int dayOfMonth) {
113         final Calendar calendar = Calendar.getInstance(UTC_TIMEZONE, Locale.US);
114         calendar.clear();
115         calendar.set(Calendar.YEAR, year);
116         calendar.set(Calendar.MONTH, month);
117         calendar.set(Calendar.DAY_OF_MONTH, dayOfMonth);
118         return calendar;
119     }
120 
isYearSet(Calendar cal)121     public static boolean isYearSet(Calendar cal) {
122         // use the Calendar.YEAR field to track whether or not the year is set instead of
123         // Calendar.isSet() because doing Calendar.get() causes Calendar.isSet() to become
124         // true irregardless of what the previous value was
125         return cal.get(Calendar.YEAR) > 1;
126     }
127 
128     /**
129      * Same as {@link #formatDate(Context context, String string, boolean longForm)}, with
130      * longForm set to {@code true} by default.
131      *
132      * @param context Valid context
133      * @param string String representation of a date to parse
134      * @return Returns the same date in a cleaned up format. If the supplied string does not look
135      * like a date, return it unchanged.
136      */
137 
formatDate(Context context, String string)138     public static String formatDate(Context context, String string) {
139         return formatDate(context, string, true);
140     }
141 
142     /**
143      * Parses the supplied string to see if it looks like a date.
144      *
145      * @param context Valid context
146      * @param string String representation of a date to parse
147      * @param longForm If true, return the date formatted into its long string representation.
148      * If false, return the date formatted using its short form representation (i.e. 12/11/2012)
149      * @return Returns the same date in a cleaned up format. If the supplied string does not look
150      * like a date, return it unchanged.
151      */
formatDate(Context context, String string, boolean longForm)152     public static String formatDate(Context context, String string, boolean longForm) {
153         if (string == null) {
154             return null;
155         }
156 
157         string = string.trim();
158         if (string.length() == 0) {
159             return string;
160         }
161         final Calendar cal = parseDate(string, false);
162 
163         // we weren't able to parse the string successfully so just return it unchanged
164         if (cal == null) {
165             return string;
166         }
167 
168         final boolean isYearSet = isYearSet(cal);
169         final java.text.DateFormat outFormat;
170         if (!isYearSet) {
171             outFormat = getLocalizedDateFormatWithoutYear(context);
172         } else {
173             outFormat =
174                     longForm ? DateFormat.getLongDateFormat(context) :
175                     DateFormat.getDateFormat(context);
176         }
177         synchronized (outFormat) {
178             outFormat.setTimeZone(UTC_TIMEZONE);
179             return outFormat.format(cal.getTime());
180         }
181     }
182 
isMonthBeforeDay(Context context)183     public static boolean isMonthBeforeDay(Context context) {
184         char[] dateFormatOrder = DateFormat.getDateFormatOrder(context);
185         for (int i = 0; i < dateFormatOrder.length; i++) {
186             if (dateFormatOrder[i] == 'd') {
187                 return false;
188             }
189             if (dateFormatOrder[i] == 'M') {
190                 return true;
191             }
192         }
193         return false;
194     }
195 
196     /**
197      * Returns a SimpleDateFormat object without the year fields by using a regular expression
198      * to eliminate the year in the string pattern. In the rare occurence that the resulting
199      * pattern cannot be reconverted into a SimpleDateFormat, it uses the provided context to
200      * determine whether the month field should be displayed before the day field, and returns
201      * either "MMMM dd" or "dd MMMM" converted into a SimpleDateFormat.
202      */
getLocalizedDateFormatWithoutYear(Context context)203     public static java.text.DateFormat getLocalizedDateFormatWithoutYear(Context context) {
204         final String pattern = ((SimpleDateFormat) SimpleDateFormat.getDateInstance(
205                 java.text.DateFormat.LONG)).toPattern();
206         // Determine the correct regex pattern for year.
207         // Special case handling for Spanish locale by checking for "de"
208         final String yearPattern = pattern.contains(
209                 "de") ? "[^Mm]*[Yy]+[^Mm]*" : "[^DdMm]*[Yy]+[^DdMm]*";
210         try {
211          // Eliminate the substring in pattern that matches the format for that of year
212             return new SimpleDateFormat(pattern.replaceAll(yearPattern, ""));
213         } catch (IllegalArgumentException e) {
214             return new SimpleDateFormat(
215                     DateUtils.isMonthBeforeDay(context) ? "MMMM dd" : "dd MMMM");
216         }
217     }
218 
219     /**
220      * Given a calendar (possibly containing only a day of the year), returns the earliest possible
221      * anniversary of the date that is equal to or after the current point in time if the date
222      * does not contain a year, or the date converted to the local time zone (if the date contains
223      * a year.
224      *
225      * @param target The date we wish to convert(in the UTC time zone).
226      * @return If date does not contain a year (year < 1900), returns the next earliest anniversary
227      * that is after the current point in time (in the local time zone). Otherwise, returns the
228      * adjusted Date in the local time zone.
229      */
getNextAnnualDate(Calendar target)230     public static Date getNextAnnualDate(Calendar target) {
231         final Calendar today = Calendar.getInstance();
232         today.setTime(new Date());
233 
234         // Round the current time to the exact start of today so that when we compare
235         // today against the target date, both dates are set to exactly 0000H.
236         today.set(Calendar.HOUR_OF_DAY, 0);
237         today.set(Calendar.MINUTE, 0);
238         today.set(Calendar.SECOND, 0);
239         today.set(Calendar.MILLISECOND, 0);
240 
241         final boolean isYearSet = isYearSet(target);
242         final int targetYear = target.get(Calendar.YEAR);
243         final int targetMonth = target.get(Calendar.MONTH);
244         final int targetDay = target.get(Calendar.DAY_OF_MONTH);
245         final boolean isFeb29 = (targetMonth == Calendar.FEBRUARY && targetDay == 29);
246         final GregorianCalendar anniversary = new GregorianCalendar();
247         // Convert from the UTC date to the local date. Set the year to today's year if the
248         // there is no provided year (targetYear < 1900)
249         anniversary.set(!isYearSet ? today.get(Calendar.YEAR) : targetYear,
250                 targetMonth, targetDay);
251         // If the anniversary's date is before the start of today and there is no year set,
252         // increment the year by 1 so that the returned date is always equal to or greater than
253         // today. If the day is a leap year, keep going until we get the next leap year anniversary
254         // Otherwise if there is already a year set, simply return the exact date.
255         if (!isYearSet) {
256             int anniversaryYear = today.get(Calendar.YEAR);
257             if (anniversary.before(today) ||
258                     (isFeb29 && !anniversary.isLeapYear(anniversaryYear))) {
259                 // If the target date is not Feb 29, then set the anniversary to the next year.
260                 // Otherwise, keep going until we find the next leap year (this is not guaranteed
261                 // to be in 4 years time).
262                 do {
263                     anniversaryYear +=1;
264                 } while (isFeb29 && !anniversary.isLeapYear(anniversaryYear));
265                 anniversary.set(anniversaryYear, targetMonth, targetDay);
266             }
267         }
268         return anniversary.getTime();
269     }
270 }
271