Package org.eclipse.core.databinding

Class DataBindingContext

java.lang.Object
org.eclipse.core.databinding.DataBindingContext
public class DataBindingContext extends Object
A DataBindingContext is the point of contact for the creation and management of bindings, and aggregates validation statuses of its bindings, or more generally, its validation status providers.

A DataBindingContext provides the following abilities:

  • Ability to create bindings between observable values.
  • Ability to create bindings between observable lists.
  • Access to the bindings created by the instance.
  • Access to the list of validation status providers (this includes all bindings).

Multiple contexts can be used at any point in time. One strategy for the management of contexts is the aggregation of validation statuses. For example an IWizardPage could use a single context and the statuses could be aggregated to set the page status and fulfillment. Each page in the IWizard would have its own context instance.

Default converters

If the model and target types do not match and no converter is set on the update strategy object then an attempt is made to find a default converter between them. IObservableValue.getValueType() or IObservableCollection.getElementType() is used for this.

There are default converters available between the following types:

  • Strings to/from numeric types, including BigInteger and BigDecimal.
  • String to/from boolean, using constant names provided the internal messages file.
  • String to/from Date, using the pattern in the internal messages file.
  • IStatus to string, using the status message.
  • Object to string, using Object.toString().

More default converters might be added in a future version. This might cause the types that now use the object-to-string converter to instead use a more specific converter.

The internal messages file is located at org.eclipse.core.databinding/src/org/eclipse/core/internal/databinding/messages.properties.

Since:
1.0

  • Constructor Details

    • DataBindingContext

      public DataBindingContext()
      Creates a data binding context, using the current default realm for the validation observables.
      See Also:

    • DataBindingContext

      public DataBindingContext(Realm validationRealm)
      Creates a data binding context using the given realm for the validation observables.
      Parameters:
      validationRealm - the realm to be used for the validation observables
      See Also:

  • Method Details

    • bindValue

      public final <T, M> Binding bindValue(IObservableValue<T> targetObservableValue, IObservableValue<M> modelObservableValue)
      Creates a Binding to synchronize the values of two observable values. This method is an alias for bindValue(targetObservableValue, modelObservableValue, null, null).
      Parameters:
      targetObservableValue - target value, commonly a UI widget
      modelObservableValue - model value
      Returns:
      created binding
      Since:
      1.2

    • bindValue

      public final <T, M> Binding bindValue(IObservableValue<T> targetObservableValue, IObservableValue<M> modelObservableValue, UpdateValueStrategy<? super T,? extends M> targetToModel, UpdateValueStrategy<? super M,? extends T> modelToTarget)
      Creates a Binding to synchronize the values of two observable values. During synchronization validation and conversion can be employed to customize the process. For specifics on the customization of the process see UpdateValueStrategy.
      Parameters:
      targetObservableValue - target value, commonly a UI widget
      modelObservableValue - model value
      targetToModel - strategy to employ when the target is the source of the change and the model is the destination
      modelToTarget - strategy to employ when the model is the source of the change and the target is the destination
      Returns:
      created binding
      See Also:

    • createModelToTargetUpdateValueStrategy

      protected <M, T> UpdateValueStrategy<M,T> createModelToTargetUpdateValueStrategy(IObservableValue<M> fromValue, IObservableValue<T> toValue)
      Returns an update value strategy to be used for copying values from the from value to the to value. Clients may override.
      Parameters:
      fromValue - from model value
      toValue - to target value
      Returns:
      a update value strategy

    • createTargetToModelUpdateValueStrategy

      protected <T, M> UpdateValueStrategy<T,M> createTargetToModelUpdateValueStrategy(IObservableValue<T> fromValue, IObservableValue<M> toValue)
      Returns an update value strategy to be used for copying values from the from value to the to value. Clients may override.
      Parameters:
      fromValue - from target value
      toValue - to model value
      Returns:
      a update value strategy

    • bindList

      public final <T, M> Binding bindList(IObservableList<T> targetObservableList, IObservableList<M> modelObservableList)
      Creates a Binding to synchronize the values of two observable lists. This method is an alias for bindList(targetObservableList, modelObservableList, null, null).
      Parameters:
      targetObservableList - target list, commonly a list representing a list in the UI
      modelObservableList - model list
      Returns:
      created binding
      Since:
      1.2
      See Also:

    • bindList

      public final <T, M> Binding bindList(IObservableList<T> targetObservableList, IObservableList<M> modelObservableList, UpdateListStrategy<? super T,? extends M> targetToModel, UpdateListStrategy<? super M,? extends T> modelToTarget)
      Creates a Binding to synchronize the values of two observable lists. During synchronization validation and conversion can be employed to customize the process. For specifics on the customization of the process see UpdateListStrategy.
      Parameters:
      targetObservableList - target list, commonly a list representing a list in the UI
      modelObservableList - model list
      targetToModel - strategy to employ when the target is the source of the change and the model is the destination
      modelToTarget - strategy to employ when the model is the source of the change and the target is the destination
      Returns:
      created binding
      See Also:

    • createModelToTargetUpdateListStrategy

      protected <M, T> UpdateListStrategy<M,T> createModelToTargetUpdateListStrategy(IObservableList<M> modelObservableList, IObservableList<T> targetObservableList)
      Returns an update value strategy to be used for copying value list from the model list to the target list. Clients may override.
      Parameters:
      modelObservableList - from model list
      targetObservableList - to target list
      Returns:
      an update list strategy

    • createTargetToModelUpdateListStrategy

      protected <T, M> UpdateListStrategy<T,M> createTargetToModelUpdateListStrategy(IObservableList<T> targetObservableList, IObservableList<M> modelObservableList)
      Returns an update value strategy to be used for copying value list from the target list to the model list. Clients may override.
      Parameters:
      targetObservableList - from target list
      modelObservableList - to model list
      Returns:
      an update list strategy

    • bindSet

      public final <T, M> Binding bindSet(IObservableSet<T> targetObservableSet, IObservableSet<M> modelObservableSet)
      Creates a Binding to synchronize the values of two observable sets. This method is an alias for bindSet(targetObservableValue, modelObservableValue, null, null).
      Parameters:
      targetObservableSet - target set, commonly a set representing a set in the UI
      modelObservableSet - model set
      Returns:
      created binding
      Since:
      1.2

    • bindSet

      public final <T, M> Binding bindSet(IObservableSet<T> targetObservableSet, IObservableSet<M> modelObservableSet, UpdateSetStrategy<? super T,? extends M> targetToModel, UpdateSetStrategy<? super M,? extends T> modelToTarget)
      Creates a Binding to synchronize the values of two observable sets. During synchronization validation and conversion can be employed to customize the process. For specifics on the customization of the process see UpdateSetStrategy.
      Parameters:
      targetObservableSet - target set, commonly a set representing a set in the UI
      modelObservableSet - model set
      targetToModel - strategy to employ when the target is the source of the change and the model is the destination
      modelToTarget - strategy to employ when the model is the source of the change and the target is the destination
      Returns:
      created binding
      Since:
      1.1

    • createTargetToModelUpdateSetStrategy

      protected <T, M> UpdateSetStrategy<T,M> createTargetToModelUpdateSetStrategy(IObservableSet<T> targetObservableSet, IObservableSet<M> modelObservableSet)
      Returns an update value strategy to be used for copying value set from the target set to the model set. Clients may override.
      Parameters:
      targetObservableSet - from target set
      modelObservableSet - to model set
      Returns:
      a default set update strategy
      Since:
      1.1

    • createModelToTargetUpdateSetStrategy

      protected <M, T> UpdateSetStrategy<M,T> createModelToTargetUpdateSetStrategy(IObservableSet<M> modelObservableSet, IObservableSet<T> targetObservableSet)
      Returns an update value strategy to be used for copying value set from the model set to the target set. Clients may override.
      Parameters:
      modelObservableSet - from model set
      targetObservableSet - to target set
      Returns:
      a default set update strategy
      Since:
      1.1

    • dispose

      public final void dispose()
      Disposes of this data binding context and all bindings and validation status providers that were added to this context. This method must be called in the validation realm.

    • getBindings

      public final IObservableList<Binding> getBindings()
      Returns an unmodifiable IObservableList of all bindings in order by time of addition.
      Returns:
      an unmodifiable IObservableList of all bindings

    • getValidationStatusProviders

      public final IObservableList<ValidationStatusProvider> getValidationStatusProviders()
      Returns an unmodifiable IObservableList of all validation status providers in order by time of addition.
      Returns:
      an unmodifiable IObservableList of all validation status providers
      Since:
      1.1

    • getValidationStatusMap

      @Deprecated public final IObservableMap<Binding,IStatus> getValidationStatusMap()
      Deprecated.
      as of 1.1, please use getValidationStatusProviders()
      Returns an IObservableMap mapping from bindings to current validation statuses. The keys of the map are the bindings returned by getBindings(), and the values are the current IStatus objects for each binding.
      Returns:
      the observable map from bindings to status objects.

    • addBinding

      public void addBinding(Binding binding)
      Adds the given binding to this data binding context. This will also add the given binding to the list of validation status providers.
      Parameters:
      binding - The binding to add.
      See Also:

    • addValidationStatusProvider

      public void addValidationStatusProvider(ValidationStatusProvider validationStatusProvider)
      Adds the given validation status provider to this data binding context.
      Parameters:
      validationStatusProvider - The validation status provider to add.
      Since:
      1.1

    • updateModels

      public final void updateModels()
      Updates all model observable objects to reflect the current state of the target observable objects.

    • updateTargets

      public final void updateTargets()
      Updates all target observable objects to reflect the current state of the model observable objects.

    • removeBinding

      public boolean removeBinding(Binding binding)
      Removes the given binding.
      Parameters:
      binding - The binding to remove.
      Returns:
      true if was associated with the context, false if not

    • removeValidationStatusProvider

      public boolean removeValidationStatusProvider(ValidationStatusProvider validationStatusProvider)
      Removes the validation status provider.
      Parameters:
      validationStatusProvider - The validation status provider to remove.
      Returns:
      true if was associated with the context, false if not
      Since:
      1.1

    • getValidationRealm

      public final Realm getValidationRealm()
      Returns the validation realm.
      Returns:
      the realm for the validation observables
      See Also: