Package org.eclipse.core.databinding.observable.value

Class DateAndTimeObservableValue

java.lang.Object
org.eclipse.core.databinding.observable.AbstractObservable
org.eclipse.core.databinding.observable.value.AbstractObservableValue<Date>
org.eclipse.core.databinding.observable.value.DateAndTimeObservableValue
All Implemented Interfaces:
IObservable, IObservableValue<Date>
public class DateAndTimeObservableValue extends AbstractObservableValue<Date>
An IObservableValue < 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 < Date >) and the hour, minute, second, and millisecond portion of the time observable (also an IObservableValue < 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);
Since:
1.2

  • Constructor Details

    • DateAndTimeObservableValue

      public DateAndTimeObservableValue(IObservableValue<Date> dateObservable, IObservableValue<Date> timeObservable)
      Constructs a DateAndTimeObservableValue with the specified constituent observables.
      Parameters:
      dateObservable - the observable used for the date component (year, month and day) of the constructed observable.
      timeObservable - the observable used for the time component (hour, minute, second and millisecond) of the constructed observable.

  • Method Details

    • getValueType

      public Object getValueType()
      Description copied from interface: IObservableValue
      The value type of this observable value, or null if this observable value is untyped.
      Returns:
      the value type, or null

    • firstListenerAdded

      protected void firstListenerAdded()

    • lastListenerRemoved

      protected void lastListenerRemoved()

    • doGetValue

      protected Date doGetValue()
      Specified by:
      doGetValue in class AbstractObservableValue<Date>
      Since:
      1.6

    • doSetValue

      protected void doSetValue(Date combinedDate)
      Description copied from class: AbstractObservableValue
      Template method for setting the value of the observable. By default the method throws an UnsupportedOperationException.
      Overrides:
      doSetValue in class AbstractObservableValue<Date>
      Parameters:
      combinedDate - the value to set
      Since:
      1.6

    • isStale

      public boolean isStale()
      Description copied from interface: IObservable
      Returns whether the state of this observable is stale and is expected to change soon. A non-stale observable that becomes stale will notify its stale listeners. A stale object that becomes non-stale does so by changing its state and notifying its change listeners, it does not notify its stale listeners about becoming non-stale. Clients that do not expect asynchronous changes may ignore staleness of observable objects.
      Specified by:
      isStale in interface IObservable
      Overrides:
      isStale in class AbstractObservableValue<Date>
      Returns:
      true if this observable's state is stale and will change soon.

    • dispose

      public void dispose()
      Description copied from interface: IObservable
      Disposes of this observable object, removing all listeners registered with this object, and all listeners this object might have registered on other objects.
      Specified by:
      dispose in interface IObservable
      Overrides:
      dispose in class AbstractObservable

    • addListener

      protected void addListener(Object listenerType, IObservablesListener listener)
      Parameters:
      listenerType - arbitrary object to identify a type of the listener
      listener - the listener to add; not null

    • removeListener

      protected void removeListener(Object listenerType, IObservablesListener listener)
      Parameters:
      listenerType - arbitrary object to identify a type of the listener
      listener - the listener to remove; not null

    • hasListeners

      protected boolean hasListeners()

    • fireEvent

      protected void fireEvent(ObservableEvent event)

    • getRealm

      public Realm getRealm()
      Returns:
      Returns the realm.

    • clone

      protected Object clone() throws CloneNotSupportedException
      Overrides:
      clone in class Object
      Throws:
      CloneNotSupportedException