/*
* Copyright (C) 2006 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.format;
import android.content.res.Resources;
import java.util.Locale;
import java.util.TimeZone;
/**
* The Time class is a faster replacement for the java.util.Calendar and
* java.util.GregorianCalendar classes. An instance of the Time class represents
* a moment in time, specified with second precision. It is modelled after
* struct tm, and in fact, uses struct tm to implement most of the
* functionality.
*/
public class Time {
private static final String Y_M_D_T_H_M_S_000 = "%Y-%m-%dT%H:%M:%S.000";
private static final String Y_M_D_T_H_M_S_000_Z = "%Y-%m-%dT%H:%M:%S.000Z";
private static final String Y_M_D = "%Y-%m-%d";
public static final String TIMEZONE_UTC = "UTC";
/**
* The Julian day of the epoch, that is, January 1, 1970 on the Gregorian
* calendar.
*/
public static final int EPOCH_JULIAN_DAY = 2440588;
/**
* True if this is an allDay event. The hour, minute, second fields are
* all zero, and the date is displayed the same in all time zones.
*/
public boolean allDay;
/**
* Seconds [0-61] (2 leap seconds allowed)
*/
public int second;
/**
* Minute [0-59]
*/
public int minute;
/**
* Hour of day [0-23]
*/
public int hour;
/**
* Day of month [1-31]
*/
public int monthDay;
/**
* Month [0-11]
*/
public int month;
/**
* Year. TBD. Is this years since 1900 like in struct tm?
*/
public int year;
/**
* Day of week [0-6]
*/
public int weekDay;
/**
* Day of year [0-365]
*/
public int yearDay;
/**
* This time is in daylight savings time. One of:
* <ul>
* <li><b>positive</b> - in dst</li>
* <li><b>0</b> - not in dst</li>
* <li><b>negative</b> - unknown</li>
* </ul>
*/
public int isDst;
/**
* Offset from UTC (in seconds).
*/
public long gmtoff;
/**
* The timezone for this Time. Should not be null.
*/
public String timezone;
/*
* Define symbolic constants for accessing the fields in this class. Used in
* getActualMaximum().
*/
public static final int SECOND = 1;
public static final int MINUTE = 2;
public static final int HOUR = 3;
public static final int MONTH_DAY = 4;
public static final int MONTH = 5;
public static final int YEAR = 6;
public static final int WEEK_DAY = 7;
public static final int YEAR_DAY = 8;
public static final int WEEK_NUM = 9;
public static final int SUNDAY = 0;
public static final int MONDAY = 1;
public static final int TUESDAY = 2;
public static final int WEDNESDAY = 3;
public static final int THURSDAY = 4;
public static final int FRIDAY = 5;
public static final int SATURDAY = 6;
/*
* The Locale for which date formatting strings have been loaded.
*/
private static Locale sLocale;
private static String[] sShortMonths;
private static String[] sLongMonths;
private static String[] sShortWeekdays;
private static String[] sLongWeekdays;
private static String sTimeOnlyFormat;
private static String sDateOnlyFormat;
private static String sDateTimeFormat;
private static String sAm;
private static String sPm;
private static String sDateCommand = "%a %b %e %H:%M:%S %Z %Y";
/**
* Construct a Time object in the timezone named by the string
* argument "timezone". The time is initialized to Jan 1, 1970.
* @param timezone string containing the timezone to use.
* @see TimeZone
*/
public Time(String timezone) {
if (timezone == null) {
throw new NullPointerException("timezone is null!");
}
this.timezone = timezone;
this.year = 1970;
this.monthDay = 1;
// Set the daylight-saving indicator to the unknown value -1 so that
// it will be recomputed.
this.isDst = -1;
}
/**
* Construct a Time object in the default timezone. The time is initialized to
* Jan 1, 1970.
*/
public Time() {
this(TimeZone.getDefault().getID());
}
/**
* A copy constructor. Construct a Time object by copying the given
* Time object. No normalization occurs.
*
* @param other
*/
public Time(Time other) {
set(other);
}
/**
* Ensures the values in each field are in range. For example if the
* current value of this calendar is March 32, normalize() will convert it
* to April 1. It also fills in weekDay, yearDay, isDst and gmtoff.
*
* <p>
* If "ignoreDst" is true, then this method sets the "isDst" field to -1
* (the "unknown" value) before normalizing. It then computes the
* correct value for "isDst".
*
* <p>
* See {@link #toMillis(boolean)} for more information about when to
* use <tt>true</tt> or <tt>false</tt> for "ignoreDst".
*
* @return the UTC milliseconds since the epoch
*/
native public long normalize(boolean ignoreDst);
/**
* Convert this time object so the time represented remains the same, but is
* instead located in a different timezone. This method automatically calls
* normalize() in some cases
*/
native public void switchTimezone(String timezone);
private static final int[] DAYS_PER_MONTH = { 31, 28, 31, 30, 31, 30, 31,
31, 30, 31, 30, 31 };
/**
* Return the maximum possible value for the given field given the value of
* the other fields. Requires that it be normalized for MONTH_DAY and
* YEAR_DAY.
* @param field one of the constants for HOUR, MINUTE, SECOND, etc.
* @return the maximum value for the field.
*/
public int getActualMaximum(int field) {
switch (field) {
case SECOND:
return 59; // leap seconds, bah humbug
case MINUTE:
return 59;
case HOUR:
return 23;
case MONTH_DAY: {
int n = DAYS_PER_MONTH[this.month];
if (n != 28) {
return n;
} else {
int y = this.year;
return ((y % 4) == 0 && ((y % 100) != 0 || (y % 400) == 0)) ? 29 : 28;
}
}
case MONTH:
return 11;
case YEAR:
return 2037;
case WEEK_DAY:
return 6;
case YEAR_DAY: {
int y = this.year;
// Year days are numbered from 0, so the last one is usually 364.
return ((y % 4) == 0 && ((y % 100) != 0 || (y % 400) == 0)) ? 365 : 364;
}
case WEEK_NUM:
throw new RuntimeException("WEEK_NUM not implemented");
default:
throw new RuntimeException("bad field=" + field);
}
}
/**
* Clears all values, setting the timezone to the given timezone. Sets isDst
* to a negative value to mean "unknown".
* @param timezone the timezone to use.
*/
public void clear(String timezone) {
if (timezone == null) {
throw new NullPointerException("timezone is null!");
}
this.timezone = timezone;
this.allDay = false;
this.second = 0;
this.minute = 0;
this.hour = 0;
this.monthDay = 0;
this.month = 0;
this.year = 0;
this.weekDay = 0;
this.yearDay = 0;
this.gmtoff = 0;
this.isDst = -1;
}
/**
* return a negative number if a is less than b, a positive number if a is
* greater than b, and 0 if they are equal.
*/
native public static int compare(Time a, Time b);
/**
* Print the current value given the format string provided. See man
* strftime for what means what. The final string must be less than 256
* characters.
* @param format a string containing the desired format.
* @return a String containing the current time expressed in the current locale.
*/
public String format(String format) {
synchronized (Time.class) {
Locale locale = Locale.getDefault();
if (sLocale == null || locale == null || !(locale.equals(sLocale))) {
Resources r = Resources.getSystem();
sShortMonths = new String[] {
r.getString(com.android.internal.R.string.month_medium_january),
r.getString(com.android.internal.R.string.month_medium_february),
r.getString(com.android.internal.R.string.month_medium_march),
r.getString(com.android.internal.R.string.month_medium_april),
r.getString(com.android.internal.R.string.month_medium_may),
r.getString(com.android.internal.R.string.month_medium_june),
r.getString(com.android.internal.R.string.month_medium_july),
r.getString(com.android.internal.R.string.month_medium_august),
r.getString(com.android.internal.R.string.month_medium_september),
r.getString(com.android.internal.R.string.month_medium_october),
r.getString(com.android.internal.R.string.month_medium_november),
r.getString(com.android.internal.R.string.month_medium_december),
};
sLongMonths = new String[] {
r.getString(com.android.internal.R.string.month_long_january),
r.getString(com.android.internal.R.string.month_long_february),
r.getString(com.android.internal.R.string.month_long_march),
r.getString(com.android.internal.R.string.month_long_april),
r.getString(com.android.internal.R.string.month_long_may),
r.getString(com.android.internal.R.string.month_long_june),
r.getString(com.android.internal.R.string.month_long_july),
r.getString(com.android.internal.R.string.month_long_august),
r.getString(com.android.internal.R.string.month_long_september),
r.getString(com.android.internal.R.string.month_long_october),
r.getString(com.android.internal.R.string.month_long_november),
r.getString(com.android.internal.R.string.month_long_december),
};
sShortWeekdays = new String[] {
r.getString(com.android.internal.R.string.day_of_week_medium_sunday),
r.getString(com.android.internal.R.string.day_of_week_medium_monday),
r.getString(com.android.internal.R.string.day_of_week_medium_tuesday),
r.getString(com.android.internal.R.string.day_of_week_medium_wednesday),
r.getString(com.android.internal.R.string.day_of_week_medium_thursday),
r.getString(com.android.internal.R.string.day_of_week_medium_friday),
r.getString(com.android.internal.R.string.day_of_week_medium_saturday),
};
sLongWeekdays = new String[] {
r.getString(com.android.internal.R.string.day_of_week_long_sunday),
r.getString(com.android.internal.R.string.day_of_week_long_monday),
r.getString(com.android.internal.R.string.day_of_week_long_tuesday),
r.getString(com.android.internal.R.string.day_of_week_long_wednesday),
r.getString(com.android.internal.R.string.day_of_week_long_thursday),
r.getString(com.android.internal.R.string.day_of_week_long_friday),
r.getString(com.android.internal.R.string.day_of_week_long_saturday),
};
sTimeOnlyFormat = r.getString(com.android.internal.R.string.time_of_day);
sDateOnlyFormat = r.getString(com.android.internal.R.string.month_day_year);
sDateTimeFormat = r.getString(com.android.internal.R.string.date_and_time);
sAm = r.getString(com.android.internal.R.string.am);
sPm = r.getString(com.android.internal.R.string.pm);
sLocale = locale;
}
return format1(format);
}
}
native private String format1(String format);
/**
* Return the current time in YYYYMMDDTHHMMSS<tz> format
*/
@Override
native public String toString();
/**
* Parses a date-time string in either the RFC 2445 format or an abbreviated
* format that does not include the "time" field. For example, all of the
* following strings are valid:
*
* <ul>
* <li>"20081013T160000Z"</li>
* <li>"20081013T160000"</li>
* <li>"20081013"</li>
* </ul>
*
* Returns whether or not the time is in UTC (ends with Z). If the string
* ends with "Z" then the timezone is set to UTC. If the date-time string
* included only a date and no time field, then the <code>allDay</code>
* field of this Time class is set to true and the <code>hour</code>,
* <code>minute</code>, and <code>second</code> fields are set to zero;
* otherwise (a time field was included in the date-time string)
* <code>allDay</code> is set to false. The fields <code>weekDay</code>,
* <code>yearDay</code>, and <code>gmtoff</code> are always set to zero,
* and the field <code>isDst</code> is set to -1 (unknown). To set those
* fields, call {@link #normalize(boolean)} after parsing.
*
* To parse a date-time string and convert it to UTC milliseconds, do
* something like this:
*
* <pre>
* Time time = new Time();
* String date = "20081013T160000Z";
* time.parse(date);
* long millis = time.normalize(false);
* </pre>
*
* @param s the string to parse
* @return true if the resulting time value is in UTC time
* @throws android.util.TimeFormatException if s cannot be parsed.
*/
public boolean parse(String s) {
if (nativeParse(s)) {
timezone = TIMEZONE_UTC;
return true;
}
return false;
}
/**
* Parse a time in the current zone in YYYYMMDDTHHMMSS format.
*/
native private boolean nativeParse(String s);
/**
* Parse a time in RFC 3339 format. This method also parses simple dates
* (that is, strings that contain no time or time offset). For example,
* all of the following strings are valid:
*
* <ul>
* <li>"2008-10-13T16:00:00.000Z"</li>
* <li>"2008-10-13T16:00:00.000+07:00"</li>
* <li>"2008-10-13T16:00:00.000-07:00"</li>
* <li>"2008-10-13"</li>
* </ul>
*
* <p>
* If the string contains a time and time offset, then the time offset will
* be used to convert the time value to UTC.
* </p>
*
* <p>
* If the given string contains just a date (with no time field), then
* the {@link #allDay} field is set to true and the {@link #hour},
* {@link #minute}, and {@link #second} fields are set to zero.
* </p>
*
* <p>
* Returns true if the resulting time value is in UTC time.
* </p>
*
* @param s the string to parse
* @return true if the resulting time value is in UTC time
*/
public boolean parse3339(String s) {
if (nativeParse3339(s)) {
timezone = TIMEZONE_UTC;
return true;
}
return false;
}
native private boolean nativeParse3339(String s);
/**
* Returns the timezone string that is currently set for the device.
*/
public static String getCurrentTimezone() {
return TimeZone.getDefault().getID();
}
/**
* Sets the time of the given Time object to the current time.
*/
native public void setToNow();
/**
* Converts this time to milliseconds. Suitable for interacting with the
* standard java libraries. The time is in UTC milliseconds since the epoch.
* This does an implicit normalization to compute the milliseconds but does
* <em>not</em> change any of the fields in this Time object. If you want
* to normalize the fields in this Time object and also get the milliseconds
* then use {@link #normalize(boolean)}.
*
* <p>
* If "ignoreDst" is false, then this method uses the current setting of the
* "isDst" field and will adjust the returned time if the "isDst" field is
* wrong for the given time. See the sample code below for an example of
* this.
*
* <p>
* If "ignoreDst" is true, then this method ignores the current setting of
* the "isDst" field in this Time object and will instead figure out the
* correct value of "isDst" (as best it can) from the fields in this
* Time object. The only case where this method cannot figure out the
* correct value of the "isDst" field is when the time is inherently
* ambiguous because it falls in the hour that is repeated when switching
* from Daylight-Saving Time to Standard Time.
*
* <p>
* Here is an example where <tt>toMillis(true)</tt> adjusts the time,
* assuming that DST changes at 2am on Sunday, Nov 4, 2007.
*
* <pre>
* Time time = new Time();
* time.set(2007, 10, 4); // set the date to Nov 4, 2007, 12am
* time.normalize(); // this sets isDst = 1
* time.monthDay += 1; // changes the date to Nov 5, 2007, 12am
* millis = time.toMillis(false); // millis is Nov 4, 2007, 11pm
* millis = time.toMillis(true); // millis is Nov 5, 2007, 12am
* </pre>
*
* <p>
* To avoid this problem, use <tt>toMillis(true)</tt>
* after adding or subtracting days or explicitly setting the "monthDay"
* field. On the other hand, if you are adding
* or subtracting hours or minutes, then you should use
* <tt>toMillis(false)</tt>.
*
* <p>
* You should also use <tt>toMillis(false)</tt> if you want
* to read back the same milliseconds that you set with {@link #set(long)}
* or {@link #set(Time)} or after parsing a date string.
*/
native public long toMillis(boolean ignoreDst);
/**
* Sets the fields in this Time object given the UTC milliseconds. After
* this method returns, all the fields are normalized.
* This also sets the "isDst" field to the correct value.
*
* @param millis the time in UTC milliseconds since the epoch.
*/
native public void set(long millis);
/**
* Format according to RFC 2445 DATETIME type.
*
* <p>
* The same as format("%Y%m%dT%H%M%S").
*/
native public String format2445();
/**
* Copy the value of that to this Time object. No normalization happens.
*/
public void set(Time that) {
this.timezone = that.timezone;
this.allDay = that.allDay;
this.second = that.second;
this.minute = that.minute;
this.hour = that.hour;
this.monthDay = that.monthDay;
this.month = that.month;
this.year = that.year;
this.weekDay = that.weekDay;
this.yearDay = that.yearDay;
this.isDst = that.isDst;
this.gmtoff = that.gmtoff;
}
/**
* Sets the fields. Sets weekDay, yearDay and gmtoff to 0, and isDst to -1.
* Call {@link #normalize(boolean)} if you need those.
*/
public void set(int second, int minute, int hour, int monthDay, int month, int year) {
this.allDay = false;
this.second = second;
this.minute = minute;
this.hour = hour;
this.monthDay = monthDay;
this.month = month;
this.year = year;
this.weekDay = 0;
this.yearDay = 0;
this.isDst = -1;
this.gmtoff = 0;
}
/**
* Sets the date from the given fields. Also sets allDay to true.
* Sets weekDay, yearDay and gmtoff to 0, and isDst to -1.
* Call {@link #normalize(boolean)} if you need those.
*
* @param monthDay the day of the month (in the range [1,31])
* @param month the zero-based month number (in the range [0,11])
* @param year the year
*/
public void set(int monthDay, int month, int year) {
this.allDay = true;
this.second = 0;
this.minute = 0;
this.hour = 0;
this.monthDay = monthDay;
this.month = month;
this.year = year;
this.weekDay = 0;
this.yearDay = 0;
this.isDst = -1;
this.gmtoff = 0;
}
/**
* Returns true if the time represented by this Time object occurs before
* the given time.
*
* @param that a given Time object to compare against
* @return true if this time is less than the given time
*/
public boolean before(Time that) {
return Time.compare(this, that) < 0;
}
/**
* Returns true if the time represented by this Time object occurs after
* the given time.
*
* @param that a given Time object to compare against
* @return true if this time is greater than the given time
*/
public boolean after(Time that) {
return Time.compare(this, that) > 0;
}
/**
* This array is indexed by the weekDay field (SUNDAY=0, MONDAY=1, etc.)
* and gives a number that can be added to the yearDay to give the
* closest Thursday yearDay.
*/
private static final int[] sThursdayOffset = { -3, 3, 2, 1, 0, -1, -2 };
/**
* Computes the week number according to ISO 8601. The current Time
* object must already be normalized because this method uses the
* yearDay and weekDay fields.
*
* <p>
* In IS0 8601, weeks start on Monday.
* The first week of the year (week 1) is defined by ISO 8601 as the
* first week with four or more of its days in the starting year.
* Or equivalently, the week containing January 4. Or equivalently,
* the week with the year's first Thursday in it.
* </p>
*
* <p>
* The week number can be calculated by counting Thursdays. Week N
* contains the Nth Thursday of the year.
* </p>
*
* @return the ISO week number.
*/
public int getWeekNumber() {
// Get the year day for the closest Thursday
int closestThursday = yearDay + sThursdayOffset[weekDay];
// Year days start at 0
if (closestThursday >= 0 && closestThursday <= 364) {
return closestThursday / 7 + 1;
}
// The week crosses a year boundary.
Time temp = new Time(this);
temp.monthDay += sThursdayOffset[weekDay];
temp.normalize(true /* ignore isDst */);
return temp.yearDay / 7 + 1;
}
/**
* Return a string in the RFC 3339 format.
* <p>
* If allDay is true, expresses the time as Y-M-D</p>
* <p>
* Otherwise, if the timezone is UTC, expresses the time as Y-M-D-T-H-M-S UTC</p>
* <p>
* Otherwise the time is expressed the time as Y-M-D-T-H-M-S +- GMT</p>
* @param allDay
* @return string in the RFC 3339 format.
*/
public String format3339(boolean allDay) {
if (allDay) {
return format(Y_M_D);
} else if (TIMEZONE_UTC.equals(timezone)) {
return format(Y_M_D_T_H_M_S_000_Z);
} else {
String base = format(Y_M_D_T_H_M_S_000);
String sign = (gmtoff < 0) ? "-" : "+";
int offset = (int)Math.abs(gmtoff);
int minutes = (offset % 3600) / 60;
int hours = offset / 3600;
return String.format("%s%s%02d:%02d", base, sign, hours, minutes);
}
}
/**
* Returns true if the day of the given time is the epoch on the Julian Calendar
* (January 1, 1970 on the Gregorian calendar).
*
* @param time the time to test
* @return true if epoch.
*/
public static boolean isEpoch(Time time) {
long millis = time.toMillis(true);
return getJulianDay(millis, 0) == EPOCH_JULIAN_DAY;
}
/**
* Computes the Julian day number, given the UTC milliseconds
* and the offset (in seconds) from UTC. The Julian day for a given
* date will be the same for every timezone. For example, the Julian
* day for July 1, 2008 is 2454649. This is the same value no matter
* what timezone is being used. The Julian day is useful for testing
* if two events occur on the same day and for determining the relative
* time of an event from the present ("yesterday", "3 days ago", etc.).
*
* <p>
* Use {@link #toMillis(boolean)} to get the milliseconds.
*
* @param millis the time in UTC milliseconds
* @param gmtoff the offset from UTC in seconds
* @return the Julian day
*/
public static int getJulianDay(long millis, long gmtoff) {
long offsetMillis = gmtoff * 1000;
long julianDay = (millis + offsetMillis) / DateUtils.DAY_IN_MILLIS;
return (int) julianDay + EPOCH_JULIAN_DAY;
}
/**
* <p>Sets the time from the given Julian day number, which must be based on
* the same timezone that is set in this Time object. The "gmtoff" field
* need not be initialized because the given Julian day may have a different
* GMT offset than whatever is currently stored in this Time object anyway.
* After this method returns all the fields will be normalized and the time
* will be set to 12am at the beginning of the given Julian day.
* </p>
*
* <p>
* The only exception to this is if 12am does not exist for that day because
* of daylight saving time. For example, Cairo, Eqypt moves time ahead one
* hour at 12am on April 25, 2008 and there are a few other places that
* also change daylight saving time at 12am. In those cases, the time
* will be set to 1am.
* </p>
*
* @param julianDay the Julian day in the timezone for this Time object
* @return the UTC milliseconds for the beginning of the Julian day
*/
public long setJulianDay(int julianDay) {
// Don't bother with the GMT offset since we don't know the correct
// value for the given Julian day. Just get close and then adjust
// the day.
long millis = (julianDay - EPOCH_JULIAN_DAY) * DateUtils.DAY_IN_MILLIS;
set(millis);
// Figure out how close we are to the requested Julian day.
// We can't be off by more than a day.
int approximateDay = getJulianDay(millis, gmtoff);
int diff = julianDay - approximateDay;
monthDay += diff;
// Set the time to 12am and re-normalize.
hour = 0;
minute = 0;
second = 0;
millis = normalize(true);
return millis;
}
}
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