An
IObservableValue <
java.util.Date > which supports
scenarios where the date and time are presented as separate elements in the
user interface. This class combines the year, month, and day portion of the
date observable (an
IObservableValue <
java.util.Date>) and the hour, minute, second, and millisecond portion of the time
observable (also an
IObservableValue <
java.util.Date>).
This observable's value will be null whenever the date observable's value is
null. Otherwise the value is the combination of the date portion of the date
observable and the time portion of the time observable (a time observable
value of null is treated the same as 0:00:00.000).
When setting the value of this observable, setting a null value will set null
on the date observable, and set a time of 0:00:00.000 on the time observable.
When setting non-null values, the non-applicable fields of each observable
are left intact. That is, the hour, minute, second and millisecond components
of the date observable are preserved, and the year, month and day components
of the time observable are preserved.
The observables used for the date and time component may impose their own
restrictions with regard to supported values. For example some observables do
not allow a null value, because the underlying widget lacks support for a
null value (example: DateTime).
One use for this class is binding a date-and-time value to two separate user
interface elements, one for editing date and one for editing time:
DataBindingContext dbc = new DataBindingContext();
IObservableValue beanValue = BeansObservables.observeValue(...);
IObservableValue dateObservable = WidgetProperties.selection().observe(
dateWidget);
IObservableValue timeObservable = WidgetProperties.selection().observe(
timeWidget);
dbc.bindValue(new DateAndTimeObservableValue(dateObservable, timeObservable),
beanValue);
A second use is editing only the date or time value of a date-and-time value.
This can be accomplished by using a widget-specific observable for the
editable value and a WritableValue as a container for the fixed value. The
example below allows editing the date while preserving the time:
DataBindingContext dbc = new DataBindingContext();
IObservableValue beanValue = BeansObservables.observeValue(...);
IObservableValue dateObservable = WidgetProperties.selection().observe(
dateWidget);
IObservableValue timeObservable = new WritableValue(dateObservable.getRealm(),
beanValue.getValue(), Date.class);
dbc.bindValue(new DateAndTimeObservableValue(dateObservable, timeObservable), beanValue);