Package org.eclipse.core.databinding.observable

Class Observables

java.lang.Object
org.eclipse.core.databinding.observable.Observables
public class Observables extends Object
Contains static methods to operate on or return Observables.
Since:
1.0

  • Constructor Details

    • Observables

      public Observables()

  • Method Details

    • observeDelayedValue

      public static <T> IObservableValue<T> observeDelayedValue(int delay, IObservableValue<T> observable)
      Returns an observable which delays notification of value change events from observable until delay milliseconds have elapsed since the last change event. This observable helps to boost performance in situations where an observable has computationally expensive listeners or many dependencies. A common use of this observable is to delay validation of user input until the user stops typing in a UI field.

      To notify about pending changes, the returned observable fires a stale event when the wrapped observable value fires a change event, and remains stale until the delay has elapsed and the value change is fired. A call to getValue() while a value change is pending will fire the value change immediately, short-circuiting the delay.

      Note:

      • Use SWTObservables.observeDelayedValue() instead when the target observable is observing a SWT Control, or ViewersObservables.observeDelayedValue() when the target observable is observing a JFace Viewer. These observables ensure that pending value changes are fired when the underlying control loses focus. (Otherwise, it is possible for pending changes to be lost if a window is closed before the delay has elapsed.)
      • This observable does not forward ValueChangingEvent events from a wrapped IVetoableValue.
      Type Parameters:
      T - the value type
      Parameters:
      delay - the delay in milliseconds
      observable - the observable being delayed
      Returns:
      an observable which delays notification of value change events from observable until delay milliseconds have elapsed since the last change event.
      Since:
      1.2

    • unmodifiableObservableValue

      public static <T> IObservableValue<T> unmodifiableObservableValue(IObservableValue<T> value)
      Returns an unmodifiable observable value backed by the given observable value.
      Type Parameters:
      T - the value type
      Parameters:
      value - the value to wrap in an unmodifiable value
      Returns:
      an unmodifiable observable value backed by the given observable value
      Since:
      1.1

    • constantObservableValue

      public static <T> IObservableValue<T> constantObservableValue(Realm realm, T value, Object valueType)
      Returns an observable value with the given constant value.
      Type Parameters:
      T - the value type
      Parameters:
      realm - the observable's realm
      value - the observable's constant value
      valueType - the observable's value type
      Returns:
      an immutable observable value with the given constant value
      Since:
      1.1

    • constantObservableValue

      public static <T> IObservableValue<T> constantObservableValue(Realm realm, T value)
      Returns an observable value with the given constant value.
      Type Parameters:
      T - the value type
      Parameters:
      realm - the observable's realm
      value - the observable's constant value
      Returns:
      an immutable observable value with the given constant value
      Since:
      1.1

    • constantObservableValue

      public static <T> IObservableValue<T> constantObservableValue(T value, Object valueType)
      Returns an observable value with the given constant value.
      Type Parameters:
      T - the value type
      Parameters:
      value - the observable's constant value
      valueType - the observable's value type
      Returns:
      an immutable observable value with the given constant value
      Since:
      1.1

    • constantObservableValue

      public static <T> IObservableValue<T> constantObservableValue(T value)
      Returns an observable value with the given constant value.
      Type Parameters:
      T - the value type
      Parameters:
      value - the observable's constant value
      Returns:
      an immutable observable value with the given constant value
      Since:
      1.1

    • unmodifiableObservableList

      public static <E> IObservableList<E> unmodifiableObservableList(IObservableList<E> list)
      Returns an unmodifiable observable list backed by the given observable list.
      Type Parameters:
      E - the element type
      Parameters:
      list - the list to wrap in an unmodifiable list
      Returns:
      an unmodifiable observable list backed by the given observable list

    • unmodifiableObservableSet

      public static <E> IObservableSet<E> unmodifiableObservableSet(IObservableSet<E> set)
      Returns an unmodifiable observable set backed by the given observable set.
      Type Parameters:
      E - the element type
      Parameters:
      set - the set to wrap in an unmodifiable set
      Returns:
      an unmodifiable observable set backed by the given observable set
      Since:
      1.1

    • unmodifiableObservableMap

      public static <K, V> IObservableMap<K,V> unmodifiableObservableMap(IObservableMap<K,V> map)
      Returns an unmodifiable observable map backed by the given observable map.
      Type Parameters:
      K - map key type
      V - map value type
      Parameters:
      map - the map to wrap in an unmodifiable map
      Returns:
      an unmodifiable observable map backed by the given observable map.
      Since:
      1.2

    • emptyObservableList

      public static <E> IObservableList<E> emptyObservableList()
      Returns an empty observable list. The returned list continues to work after it has been disposed of and can be disposed of multiple times.
      Type Parameters:
      E - the list element type
      Returns:
      an empty observable list.

    • emptyObservableList

      public static <E> IObservableList<E> emptyObservableList(Object elementType)
      Returns an empty observable list of the given element type. The returned list continues to work after it has been disposed of and can be disposed of multiple times.
      Type Parameters:
      E - the list element type
      Parameters:
      elementType - the element type of the returned list
      Returns:
      an empty observable list
      Since:
      1.1

    • emptyObservableList

      public static <E> IObservableList<E> emptyObservableList(Realm realm)
      Returns an empty observable list belonging to the given realm. The returned list continues to work after it has been disposed of and can be disposed of multiple times.
      Type Parameters:
      E - the list element type
      Parameters:
      realm - the realm of the returned list
      Returns:
      an empty observable list.

    • emptyObservableList

      public static <E> IObservableList<E> emptyObservableList(Realm realm, Object elementType)
      Returns an empty observable list of the given element type and belonging to the given realm. The returned list continues to work after it has been disposed of and can be disposed of multiple times.
      Type Parameters:
      E - the list element type
      Parameters:
      realm - the realm of the returned list
      elementType - the element type of the returned list
      Returns:
      an empty observable list
      Since:
      1.1

    • emptyObservableSet

      public static <E> IObservableSet<E> emptyObservableSet()
      Returns an empty observable set. The returned set continues to work after it has been disposed of and can be disposed of multiple times.
      Type Parameters:
      E - the set element type
      Returns:
      an empty observable set.

    • emptyObservableSet

      public static <E> IObservableSet<E> emptyObservableSet(Object elementType)
      Returns an empty observable set of the given element type. The returned set continues to work after it has been disposed of and can be disposed of multiple times.
      Type Parameters:
      E - the set element type
      Parameters:
      elementType - the element type of the returned set
      Returns:
      an empty observable set
      Since:
      1.1

    • emptyObservableSet

      public static <E> IObservableSet<E> emptyObservableSet(Realm realm)
      Returns an empty observable set belonging to the given realm. The returned set continues to work after it has been disposed of and can be disposed of multiple times.
      Type Parameters:
      E - the set element type
      Parameters:
      realm - the realm of the returned set
      Returns:
      an empty observable set.

    • emptyObservableSet

      public static <E> IObservableSet<E> emptyObservableSet(Realm realm, Object elementType)
      Returns an empty observable set of the given element type and belonging to the given realm. The returned set continues to work after it has been disposed of and can be disposed of multiple times.
      Type Parameters:
      E - the set element type
      Parameters:
      realm - the realm of the returned set
      elementType - the element type of the returned set
      Returns:
      an empty observable set
      Since:
      1.1

    • staticObservableSet

      public static <E> IObservableSet<E> staticObservableSet(Set<E> set)
      Returns an observable set backed by the given set.
      Type Parameters:
      E - the set element type
      Parameters:
      set - the set to wrap in an IObservableSet
      Returns:
      an observable set backed by the given set

    • staticObservableSet

      public static <E> IObservableSet<E> staticObservableSet(Set<E> set, Object elementType)
      Returns an observable set of the given element type, backed by the given set.
      Type Parameters:
      E - the set element type
      Parameters:
      set - the set to wrap in an IObservableSet
      elementType - the element type of the returned set
      Returns:
      Returns an observable set backed by the given unchanging set
      Since:
      1.1

    • staticObservableSet

      public static <E> IObservableSet<E> staticObservableSet(Realm realm, Set<E> set)
      Returns an observable set belonging to the given realm, backed by the given set.
      Type Parameters:
      E - the element type
      Parameters:
      realm - the realm of the returned set
      set - the set to wrap in an IObservableSet
      Returns:
      an observable set backed by the given unchanging set

    • staticObservableSet

      public static <E> IObservableSet<E> staticObservableSet(Realm realm, Set<E> set, Object elementType)
      Returns an observable set of the given element type and belonging to the given realm, backed by the given set.
      Type Parameters:
      E - the set element type
      Parameters:
      realm - the realm of the returned set
      set - the set to wrap in an IObservableSet
      elementType - the element type of the returned set
      Returns:
      an observable set backed by the given set
      Since:
      1.1

    • proxyObservableValue

      public static <T> IObservableValue<T> proxyObservableValue(IObservableValue<T> target)
      Returns an observable value that contains the same value as the given observable, and fires the same events as the given observable, but can be disposed of without disposing of the wrapped observable.
      Type Parameters:
      T - the value type
      Parameters:
      target - the observable value to wrap
      Returns:
      a disposable proxy for the given observable value.
      Since:
      1.2

    • proxyObservableSet

      public static <E> IObservableSet<E> proxyObservableSet(IObservableSet<E> target)
      Returns an observable set that contains the same elements as the given set, and fires the same events as the given set, but can be disposed of without disposing of the wrapped set.
      Type Parameters:
      E - the set element type
      Parameters:
      target - the set to wrap
      Returns:
      a disposable proxy for the given observable set

    • proxyObservableList

      public static <E> IObservableList<E> proxyObservableList(IObservableList<E> target)
      Returns an observable list that contains the same elements as the given list, and fires the same events as the given list, but can be disposed of without disposing of the wrapped list.
      Type Parameters:
      E - the list element type
      Parameters:
      target - the list to wrap
      Returns:
      a disposable proxy for the given observable list
      Since:
      1.1

    • proxyObservableMap

      public static <K, V> IObservableMap<K,V> proxyObservableMap(IObservableMap<K,V> target)
      Returns an observable map that contains the same entries as the given map, and fires the same events as the given map, but can be disposed of without disposing of the wrapped map.
      Type Parameters:
      K - the map key type
      V - the map value type
      Parameters:
      target - the map to wrap
      Returns:
      a disposable proxy for the given observable map
      Since:
      1.2

    • staticObservableList

      public static <E> IObservableList<E> staticObservableList(List<E> list)
      Returns an observable list backed by the given list.
      Type Parameters:
      E - the list element type
      Parameters:
      list - the list to wrap in an IObservableList
      Returns:
      an observable list backed by the given unchanging list

    • staticObservableList

      public static <E> IObservableList<E> staticObservableList(List<E> list, Object elementType)
      Returns an observable list of the given element type, backed by the given list.
      Type Parameters:
      E - the list element type
      Parameters:
      list - the list to wrap in an IObservableList
      elementType - the element type of the returned list
      Returns:
      an observable list backed by the given unchanging list
      Since:
      1.1

    • staticObservableList

      public static <E> IObservableList<E> staticObservableList(Realm realm, List<E> list)
      Returns an observable list belonging to the given realm, backed by the given list.
      Type Parameters:
      E - the list element type
      Parameters:
      realm - the realm of the returned list
      list - the list to wrap in an IObservableList
      Returns:
      an observable list backed by the given unchanging list

    • staticObservableList

      public static <E> IObservableList<E> staticObservableList(Realm realm, List<E> list, Object elementType)
      Returns an observable list of the given element type and belonging to the given realm, backed by the given list.
      Type Parameters:
      E - the list element type
      Parameters:
      realm - the realm of the returned list
      list - the list to wrap in an IObservableList
      elementType - the element type of the returned list
      Returns:
      an observable list backed by the given unchanging list
      Since:
      1.1

    • observeStale

      public static IObservableValue<Boolean> observeStale(IObservable observable)
      Returns an observable value of type Boolean.TYPE which tracks whether the given observable is stale.
      Parameters:
      observable - the observable to track
      Returns:
      an observable value which tracks whether the given observable is stale
      Since:
      1.1

    • observeMapEntry

      public static <K, V> IObservableValue<V> observeMapEntry(IObservableMap<K,V> map, K key)
      Returns an observable value that tracks changes to the value of an observable map's entry specified by its key.

      The state where the key does not exist in the map is equivalent to the state where the key exists and its value is null. The transition between these two states is not considered a value change and no event is fired.

      Type Parameters:
      K - the map key type
      V - the map value type
      Parameters:
      map - the observable map whose entry will be tracked.
      key - the key identifying the map entry to track.
      Returns:
      an observable value that tracks the value associated with the specified key in the given map
      Since:
      1.2

    • observeMapEntry

      public static <K, V> IObservableValue<V> observeMapEntry(IObservableMap<K,V> map, K key, Object valueType)
      Returns an observable value that tracks changes to the value of an observable map's entry specified by its key.

      The state where the key does not exist in the map is equivalent to the state where the key exists and its value is null. The transition between these two states is not considered a value change and no event is fired.

      Type Parameters:
      K - the map key type
      V - the map value type
      Parameters:
      map - the observable map whose entry will be tracked.
      key - the key identifying the map entry to track.
      valueType - the type of the value. May be null, meaning the value is untyped.
      Returns:
      an observable value that tracks the value associated with the specified key in the given map
      Since:
      1.1

    • mapEntryValueFactory

      public static <K, V> IObservableFactory<K,IObservableValue<V>> mapEntryValueFactory(IObservableMap<K,V> map, Object valueType)
      Returns a factory for creating observable values tracking the value of the observable map entry identified by a particular key.
      Type Parameters:
      K - the map key type
      V - the map value type
      Parameters:
      map - the observable map whose entry will be tracked.
      valueType - the type of the value. May be null, meaning the value is untyped.
      Returns:
      a factory for creating observable values tracking the value of the observable map entry identified by a particular key object.
      Since:
      1.1

    • observeDetailMapEntry

      public static <K, V> IObservableValue<V> observeDetailMapEntry(IObservableMap<K,V> map, IObservableValue<K> master, Object valueType)
      Helper method for MasterDetailObservables.detailValue(master, mapEntryValueFactory(map, valueType), valueType).
      Type Parameters:
      K - the map key type
      V - the map value type
      Parameters:
      map - the observable map whose entry will be tracked.
      master - the observable value that identifies which map entry to track.
      valueType - the type of the value. May be null, meaning the value is untyped.
      Returns:
      an observable value tracking the current value of the specified key in the given map an observable value that tracks the current value of the named property for the current value of the master observable value
      Since:
      1.1

    • pipe

      public static <T> void pipe(IObservableValue<T> source, IObservableValue<? super T> destination)
      Copies the current value of the source observable to the destination observable, and upon value change events fired by the source observable, updates the destination observable accordingly, until the source observable is disposed. This method assumes that both observables are on the same realm.
      Type Parameters:
      T - the value type
      Parameters:
      source - the source observable
      destination - the destination observable
      Since:
      1.2