Activitydepository – MiG InfoCom MiG Calendar Tutorial User Manual

Page 13

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Setting a different time zone for the date area will generally only
change the times on the date/time headers. However if you create
a date range by saying it should span a day or a week and provide
a different time zone that will mean the date area will span another
physical time since the day/week boundary is probably different in
the other time zone.

The time zone generally affects calculations that deal with hour-of-
day and such properties of the time. Rounding to a date boundary
will for instance give different physical date/times in different time
zones.

When printing a

DateRange

to the command line the time zone

will be honored. Printing a

Date

object will always use in the

default time zone for the machine. By using a

SimpleDateFormat

you can choose the time zone used when

printing a

Date

by setting a different

Calendar

object on it or

changing the time zone for the current one.

If no time zone is specified (set to null) in an activity's date range,
that activity will get the default time zone. The default time zone will
not be set at creation time though, it will be re-evaluated for every
use, so changing the default time zone will affect all activities with
a

null

time zone set.

ActivityDepository

Where Activities are found

One problem with activities is that they are usually stored not withing
the calendaring component, in fact that would be a bad design. Also
they can be scattered over more than one storage medium, possibly
at least one that are not connected continuously. Since the can be
stored in multiple places they can also come out of sync, i.e. the same
activity exists in different versions on different storage mediums.
These situations have to be addressed by the

ActivityDepository

.

Subscriptions

From the MiG Calendar's positions things are quite simple. Every

DateArea

, or at least

DefaultDateArea

, only registers itself as

a listener on the depository and will as such get notified of changes in
the depository. This is normally handled automatically.

ActivityIOFilters

MiG Calendar Tutorial

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