ch.agent.t2.timeutil

Class DateHolder

java.lang.Object

ch.agent.t2.timeutil.DateHolder

public class DateHolder
extends Object

A DateHolder helps applications manipulate times. When necessary, times are adjusted downwards.

Author:

Jean-Paul Vetterli

Constructor Summary

Constructors

Constructor and Description
DateHolder() Construct a date holder in the daily domain and initialize it with the current time.
DateHolder(TimeDomain domain) Construct a date holder in the given time domain and initialize it with the current time.

Method Summary

Modifier and Type	Method and Description
void	allowEmptyDate(boolean allow) Set a flag to allow or disallow empty dates.
TimeIndex	getDate() Return the date evaluated in the time domain of the value holder.
TimeIndex	getDate(Range context) Return the date evaluated in the context of the given range.
String	getDateText() Return the text of the day expression set with setDate.
protected static int	getLargeIncrement(Resolution unit) Return the number of units for a large increment in the given resolution.
TimeDomain	getTimeDomain() Return the time domain.
void	incrDate(boolean up, boolean large) Increase or decrease the date by a unit or by a large amount.
void	incrDate(int increment) Increment the date by the given amount.
void	reset(TimeDomain domain) Change the time domain.
void	resetToCurrentTime() Change the date to the current time.
void	setDate(String date) Set the date.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DateHolder

public DateHolder(TimeDomain domain)

Construct a date holder in the given time domain and initialize it with the current time.

Parameters:

domain - a non-null time domain

DateHolder

public DateHolder()

Construct a date holder in the daily domain and initialize it with the current time.

Method Detail

getLargeIncrement

protected static int getLargeIncrement(Resolution unit)

Return the number of units for a large increment in the given resolution.

Parameters:

unit - a non-null resolution

Returns:

a number of units

getTimeDomain

public TimeDomain getTimeDomain()

Return the time domain.

Returns:

the time domain of the date holder

allowEmptyDate

public void allowEmptyDate(boolean allow)

Set a flag to allow or disallow empty dates.

Parameters:

allow - if true, empty dates will be allowed

reset

public void reset(TimeDomain domain)
           throws T2Exception

Change the time domain. The current day expression is retained.

Parameters:

domain - the non-null new time domain

Throws:

T2Exception

resetToCurrentTime

public void resetToCurrentTime()

Change the date to the current time.

setDate

public void setDate(String date)
             throws T2Exception

Set the date. A null or empty date is conditionally allowed. This is useful for signaling that no date is specified. Refer to DayExpression for the valid syntax of dates.

Parameters:

date - a day expression

Throws:

T2Exception

See Also:

allowEmptyDate(boolean)

incrDate

public void incrDate(int increment)
              throws T2Exception

Increment the date by the given amount. If no date is currently set, the method has the same effect as resetToToday().

Parameters:

increment - a positive or negative number

Throws:

T2Exception

incrDate

public void incrDate(boolean up,
                     boolean large)
              throws T2Exception

Increase or decrease the date by a unit or by a large amount. What constitutes a large amount depends on the resolution of the time domain.

Parameters:

up - if true increase, else decrease

large - if true use a large amount, else a single unit

Throws:

T2Exception

getDateText

public String getDateText()

Return the text of the day expression set with setDate. If a date was never set, an empty string is returned.

Do get a date as a string, use getDate() and toString().

The difference between the two ways becomes important when the date is a day expression: this method does not resolve the expression (and there is no risk of error caused by the presence of unresolved keywords in the day expression).

The method never returns null.

Returns:

the text of the current day expression or an empty string

getDate

public TimeIndex getDate()
                  throws T2Exception

Return the date evaluated in the time domain of the value holder.

Returns:

a time index or null when date is set

Throws:

T2Exception

getDate

public TimeIndex getDate(Range context)
                  throws T2Exception

Return the date evaluated in the context of the given range. Note that depending on the day expression used in the date, the context of a range is more than simply its time domain.

Parameters:

context - a non-null range

Returns:

a time index or null when no date is set

Throws:

T2Exception