Top Description Fields Constructors Methods

com.dlsc.gemsfx.binding

public Class AggregatedListBinding<T, S, R>

Class Inheritance

extends ObjectBinding<R>

java.lang.Object
javafx.beans.binding.ObjectExpression
javafx.beans.binding.ObjectBinding
com.dlsc.gemsfx.binding.AggregatedListBinding

Type Parameters

<T>: the type of the elements in the source list
<S>: the type of the elements in the nested lists
<R>: the type of the result computed from the stream of elements in the nested lists

Imports

javafx.beans.binding.ObjectBinding, javafx.beans.property.ObjectProperty, .SimpleListProperty, javafx.collections.ListChangeListener, .ObservableList, .WeakListChangeListener, java.util.List, .Objects, java.util.function.Function, java.util.stream.Stream

Binds an ObservableList of items to a computed value based on the elements of their associated nested ObservableLists. This binding listens for changes not only in the top-level list but also in the nested lists of each item. It aggregates or computes values dynamically as the lists change, making it ideal for applications where the data model is highly dynamic.

This class is designed to be used with a consistent source of ObservableLists provided by the itemToListFunction. The function must return the same ObservableList instance for any given item throughout its lifecycle to ensure correct behavior and prevent memory leaks.

Important Considerations:

Stable List References: The itemToListFunction should not return different instances of ObservableList over time for the same item. If the lists are stored in properties such as ObjectProperty or SimpleListProperty, ensure that these properties are not reassigned new lists during the lifecycle of an item, as this can lead to erratic behavior and potential memory leaks if listeners are not removed from old lists.
Managing Listeners: If using properties to store the lists, manage listeners carefully. Ensure that any list set on a property has listeners appropriately added or removed to prevent memory leaks. This may require overriding property setters or using property change listeners to add/remove list listeners when the property's value changes.

Field Summary

Modifier and Type	Field and Description
private final Function<Stream<S>, R>	aggregationFunction
private final Function<T, ObservableList<S>>	itemToListFunction
private final ListChangeListener<Object>	nestedListChangeListener
private final ObservableList<T>	source
private final ListChangeListener<T>	sourceListChangeListener
private final WeakListChangeListener<Object>	weakNestedListChangeListener
private final WeakListChangeListener<T>	weakSourceListChangeListener

Constructor Summary

Access	Constructor and Description
public	AggregatedListBinding(ObservableList<T> the observable list of source items that should be stable (not dynamically replaced). source, final Function<T, ObservableList<S>> a function to retrieve an observable list from each source item, which must consistently return the same observable list instance for any given item throughout its lifecycle. itemToListFunction, Function<Stream<S>, R> a function to compute a result from all elements in the nested lists, based on current data in those lists. aggregationFunction) Constructs a new AggregatedListBinding.

Access

Constructor and Description

public

AggregatedListBinding(ObservableList<T>

the observable list of source items that should be stable (not dynamically replaced).

source, final Function<T, ObservableList<S>>

a function to retrieve an observable list from each source item, which must consistently return the same observable list instance for any given item throughout its lifecycle.

itemToListFunction, Function<Stream<S>, R>

a function to compute a result from all elements in the nested lists, based on current data in those lists.

aggregationFunction)

Constructs a new AggregatedListBinding.

Method Summary

Modifier and Type	Method and Description
protected R	computeValue() Implements abstract javafx.beans.binding.ObjectBinding.computeValue. Calculates the current value of this binding.
private void	convertToListAndSafeAddListener(T item)
private void	convertToListAndSafeRemoveListener(T item)
public void	dispose() Overrides javafx.beans.binding.ObjectBinding.dispose. Implements javafx.beans.binding.Binding.dispose. A default implementation of `dispose()` that is empty.
private void	safeAddListener(ObservableList<S> list)
private void	safeRemoveListener(ObservableList<S> list)

Inherited from javafx.beans.binding.ObjectBinding:: addListener addListener allowValidation bind get getDependencies invalidate isObserved isValid onInvalidating removeListener removeListener toString unbind

Field Detail

aggregationFunction	back to summary
private final Function<Stream<S>, R> aggregationFunction

itemToListFunction	back to summary
private final Function<T, ObservableList<S>> itemToListFunction

nestedListChangeListener	back to summary
private final ListChangeListener<Object> nestedListChangeListener

source	back to summary
private final ObservableList<T> source

sourceListChangeListener	back to summary
private final ListChangeListener<T> sourceListChangeListener

weakNestedListChangeListener	back to summary
private final WeakListChangeListener<Object> weakNestedListChangeListener

weakSourceListChangeListener	back to summary
private final WeakListChangeListener<T> weakSourceListChangeListener

Constructor Detail

AggregatedListBinding	back to summary
public AggregatedListBinding(ObservableList<T> source, final Function<T, ObservableList<S>> itemToListFunction, Function<Stream<S>, R> aggregationFunction) Constructs a new AggregatedListBinding. Parameters source:ObservableList<T> the observable list of source items that should be stable (not dynamically replaced). itemToListFunction:Function<T, ObservableList<S>> a function to retrieve an observable list from each source item, which must consistently return the same observable list instance for any given item throughout its lifecycle. aggregationFunction:Function<Stream<S>, R> a function to compute a result from all elements in the nested lists, based on current data in those lists.

AggregatedListBinding

back to summary

public AggregatedListBinding(ObservableList<T> source, final Function<T, ObservableList<S>> itemToListFunction, Function<Stream<S>, R> aggregationFunction)

Constructs a new AggregatedListBinding.

Parameters

source:ObservableList<T>: the observable list of source items that should be stable (not dynamically replaced).
itemToListFunction:Function<T, ObservableList<S>>: a function to retrieve an observable list from each source item, which must consistently return the same observable list instance for any given item throughout its lifecycle.
aggregationFunction:Function<Stream<S>, R>: a function to compute a result from all elements in the nested lists, based on current data in those lists.

Method Detail

computeValue back to summary

computeValue	back to summary
protected R computeValue() Implements abstract javafx.beans.binding.ObjectBinding.computeValue. Doc from javafx.beans.binding.ObjectBinding.computeValue. Calculates the current value of this binding. Classes extending `ObjectBinding` have to provide an implementation of `computeValue`. Annotations @Override

protected R computeValue()

Implements abstract javafx.beans.binding.ObjectBinding.computeValue.

Doc from javafx.beans.binding.ObjectBinding.computeValue.

Calculates the current value of this binding.

Classes extending ObjectBinding have to provide an implementation of computeValue.

Annotations

@Override

convertToListAndSafeAddListener	back to summary
private void convertToListAndSafeAddListener(T item)

convertToListAndSafeRemoveListener	back to summary
private void convertToListAndSafeRemoveListener(T item)

dispose back to summary

dispose	back to summary
public void dispose() Overrides javafx.beans.binding.ObjectBinding.dispose. Implements javafx.beans.binding.Binding.dispose. Doc from javafx.beans.binding.ObjectBinding.dispose. A default implementation of `dispose()` that is empty. Annotations @Override

public void dispose()

Overrides javafx.beans.binding.ObjectBinding.dispose.

Implements javafx.beans.binding.Binding.dispose.

Doc from javafx.beans.binding.ObjectBinding.dispose.

A default implementation of dispose() that is empty.

Annotations

@Override

safeAddListener	back to summary
private void safeAddListener(ObservableList<S> list)

safeRemoveListener	back to summary
private void safeRemoveListener(ObservableList<S> list)