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Diffstat (limited to 'java/com/android/contacts/common/util/DateUtils.java')
-rw-r--r-- | java/com/android/contacts/common/util/DateUtils.java | 283 |
1 files changed, 283 insertions, 0 deletions
diff --git a/java/com/android/contacts/common/util/DateUtils.java b/java/com/android/contacts/common/util/DateUtils.java new file mode 100644 index 000000000..1935d727a --- /dev/null +++ b/java/com/android/contacts/common/util/DateUtils.java @@ -0,0 +1,283 @@ +/* + * Copyright (C) 2010 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.contacts.common.util; + +import android.content.Context; +import android.text.format.DateFormat; +import android.text.format.Time; +import java.text.ParsePosition; +import java.text.SimpleDateFormat; +import java.util.Calendar; +import java.util.Date; +import java.util.GregorianCalendar; +import java.util.Locale; +import java.util.TimeZone; + +/** Utility methods for processing dates. */ +public class DateUtils { + + public static final TimeZone UTC_TIMEZONE = TimeZone.getTimeZone("UTC"); + + /** + * When parsing a date without a year, the system assumes 1970, which wasn't a leap-year. Let's + * add a one-off hack for that day of the year + */ + public static final String NO_YEAR_DATE_FEB29TH = "--02-29"; + + // Variations of ISO 8601 date format. Do not change the order - it does affect the + // result in ambiguous cases. + private static final SimpleDateFormat[] DATE_FORMATS = { + CommonDateUtils.FULL_DATE_FORMAT, + CommonDateUtils.DATE_AND_TIME_FORMAT, + new SimpleDateFormat("yyyy-MM-dd'T'HH:mm'Z'", Locale.US), + new SimpleDateFormat("yyyyMMdd", Locale.US), + new SimpleDateFormat("yyyyMMdd'T'HHmmssSSS'Z'", Locale.US), + new SimpleDateFormat("yyyyMMdd'T'HHmmss'Z'", Locale.US), + new SimpleDateFormat("yyyyMMdd'T'HHmm'Z'", Locale.US), + }; + + static { + for (SimpleDateFormat format : DATE_FORMATS) { + format.setLenient(true); + format.setTimeZone(UTC_TIMEZONE); + } + CommonDateUtils.NO_YEAR_DATE_FORMAT.setTimeZone(UTC_TIMEZONE); + } + + /** + * Parses the supplied string to see if it looks like a date. + * + * @param string The string representation of the provided date + * @param mustContainYear If true, the string is parsed as a date containing a year. If false, the + * string is parsed into a valid date even if the year field is missing. + * @return A Calendar object corresponding to the date if the string is successfully parsed. If + * not, null is returned. + */ + public static Calendar parseDate(String string, boolean mustContainYear) { + ParsePosition parsePosition = new ParsePosition(0); + Date date; + if (!mustContainYear) { + final boolean noYearParsed; + // Unfortunately, we can't parse Feb 29th correctly, so let's handle this day seperately + if (NO_YEAR_DATE_FEB29TH.equals(string)) { + return getUtcDate(0, Calendar.FEBRUARY, 29); + } else { + synchronized (CommonDateUtils.NO_YEAR_DATE_FORMAT) { + date = CommonDateUtils.NO_YEAR_DATE_FORMAT.parse(string, parsePosition); + } + noYearParsed = parsePosition.getIndex() == string.length(); + } + + if (noYearParsed) { + return getUtcDate(date, true); + } + } + for (int i = 0; i < DATE_FORMATS.length; i++) { + SimpleDateFormat f = DATE_FORMATS[i]; + synchronized (f) { + parsePosition.setIndex(0); + date = f.parse(string, parsePosition); + if (parsePosition.getIndex() == string.length()) { + return getUtcDate(date, false); + } + } + } + return null; + } + + private static final Calendar getUtcDate(Date date, boolean noYear) { + final Calendar calendar = Calendar.getInstance(UTC_TIMEZONE, Locale.US); + calendar.setTime(date); + if (noYear) { + calendar.set(Calendar.YEAR, 0); + } + return calendar; + } + + private static final Calendar getUtcDate(int year, int month, int dayOfMonth) { + final Calendar calendar = Calendar.getInstance(UTC_TIMEZONE, Locale.US); + calendar.clear(); + calendar.set(Calendar.YEAR, year); + calendar.set(Calendar.MONTH, month); + calendar.set(Calendar.DAY_OF_MONTH, dayOfMonth); + return calendar; + } + + public static boolean isYearSet(Calendar cal) { + // use the Calendar.YEAR field to track whether or not the year is set instead of + // Calendar.isSet() because doing Calendar.get() causes Calendar.isSet() to become + // true irregardless of what the previous value was + return cal.get(Calendar.YEAR) > 1; + } + + /** + * Same as {@link #formatDate(Context context, String string, boolean longForm)}, with longForm + * set to {@code true} by default. + * + * @param context Valid context + * @param string String representation of a date to parse + * @return Returns the same date in a cleaned up format. If the supplied string does not look like + * a date, return it unchanged. + */ + public static String formatDate(Context context, String string) { + return formatDate(context, string, true); + } + + /** + * Parses the supplied string to see if it looks like a date. + * + * @param context Valid context + * @param string String representation of a date to parse + * @param longForm If true, return the date formatted into its long string representation. If + * false, return the date formatted using its short form representation (i.e. 12/11/2012) + * @return Returns the same date in a cleaned up format. If the supplied string does not look like + * a date, return it unchanged. + */ + public static String formatDate(Context context, String string, boolean longForm) { + if (string == null) { + return null; + } + + string = string.trim(); + if (string.length() == 0) { + return string; + } + final Calendar cal = parseDate(string, false); + + // we weren't able to parse the string successfully so just return it unchanged + if (cal == null) { + return string; + } + + final boolean isYearSet = isYearSet(cal); + final java.text.DateFormat outFormat; + if (!isYearSet) { + outFormat = getLocalizedDateFormatWithoutYear(context); + } else { + outFormat = + longForm ? DateFormat.getLongDateFormat(context) : DateFormat.getDateFormat(context); + } + synchronized (outFormat) { + outFormat.setTimeZone(UTC_TIMEZONE); + return outFormat.format(cal.getTime()); + } + } + + public static boolean isMonthBeforeDay(Context context) { + char[] dateFormatOrder = DateFormat.getDateFormatOrder(context); + for (int i = 0; i < dateFormatOrder.length; i++) { + if (dateFormatOrder[i] == 'd') { + return false; + } + if (dateFormatOrder[i] == 'M') { + return true; + } + } + return false; + } + + /** + * Returns a SimpleDateFormat object without the year fields by using a regular expression to + * eliminate the year in the string pattern. In the rare occurence that the resulting pattern + * cannot be reconverted into a SimpleDateFormat, it uses the provided context to determine + * whether the month field should be displayed before the day field, and returns either "MMMM dd" + * or "dd MMMM" converted into a SimpleDateFormat. + */ + public static java.text.DateFormat getLocalizedDateFormatWithoutYear(Context context) { + final String pattern = + ((SimpleDateFormat) SimpleDateFormat.getDateInstance(java.text.DateFormat.LONG)) + .toPattern(); + // Determine the correct regex pattern for year. + // Special case handling for Spanish locale by checking for "de" + final String yearPattern = + pattern.contains("de") ? "[^Mm]*[Yy]+[^Mm]*" : "[^DdMm]*[Yy]+[^DdMm]*"; + try { + // Eliminate the substring in pattern that matches the format for that of year + return new SimpleDateFormat(pattern.replaceAll(yearPattern, "")); + } catch (IllegalArgumentException e) { + return new SimpleDateFormat(DateUtils.isMonthBeforeDay(context) ? "MMMM dd" : "dd MMMM"); + } + } + + /** + * Given a calendar (possibly containing only a day of the year), returns the earliest possible + * anniversary of the date that is equal to or after the current point in time if the date does + * not contain a year, or the date converted to the local time zone (if the date contains a year. + * + * @param target The date we wish to convert(in the UTC time zone). + * @return If date does not contain a year (year < 1900), returns the next earliest anniversary + * that is after the current point in time (in the local time zone). Otherwise, returns the + * adjusted Date in the local time zone. + */ + public static Date getNextAnnualDate(Calendar target) { + final Calendar today = Calendar.getInstance(); + today.setTime(new Date()); + + // Round the current time to the exact start of today so that when we compare + // today against the target date, both dates are set to exactly 0000H. + today.set(Calendar.HOUR_OF_DAY, 0); + today.set(Calendar.MINUTE, 0); + today.set(Calendar.SECOND, 0); + today.set(Calendar.MILLISECOND, 0); + + final boolean isYearSet = isYearSet(target); + final int targetYear = target.get(Calendar.YEAR); + final int targetMonth = target.get(Calendar.MONTH); + final int targetDay = target.get(Calendar.DAY_OF_MONTH); + final boolean isFeb29 = (targetMonth == Calendar.FEBRUARY && targetDay == 29); + final GregorianCalendar anniversary = new GregorianCalendar(); + // Convert from the UTC date to the local date. Set the year to today's year if the + // there is no provided year (targetYear < 1900) + anniversary.set(!isYearSet ? today.get(Calendar.YEAR) : targetYear, targetMonth, targetDay); + // If the anniversary's date is before the start of today and there is no year set, + // increment the year by 1 so that the returned date is always equal to or greater than + // today. If the day is a leap year, keep going until we get the next leap year anniversary + // Otherwise if there is already a year set, simply return the exact date. + if (!isYearSet) { + int anniversaryYear = today.get(Calendar.YEAR); + if (anniversary.before(today) || (isFeb29 && !anniversary.isLeapYear(anniversaryYear))) { + // If the target date is not Feb 29, then set the anniversary to the next year. + // Otherwise, keep going until we find the next leap year (this is not guaranteed + // to be in 4 years time). + do { + anniversaryYear += 1; + } while (isFeb29 && !anniversary.isLeapYear(anniversaryYear)); + anniversary.set(anniversaryYear, targetMonth, targetDay); + } + } + return anniversary.getTime(); + } + + /** + * Determine the difference, in days between two dates. Uses similar logic as the {@link + * android.text.format.DateUtils.getRelativeTimeSpanString} method. + * + * @param time Instance of time object to use for calculations. + * @param date1 First date to check. + * @param date2 Second date to check. + * @return The absolute difference in days between the two dates. + */ + public static int getDayDifference(Time time, long date1, long date2) { + time.set(date1); + int startDay = Time.getJulianDay(date1, time.gmtoff); + + time.set(date2); + int currentDay = Time.getJulianDay(date2, time.gmtoff); + + return Math.abs(currentDay - startDay); + } +} |