Module com.iamsoft.util.ui

Package com.iamsoft.util.ui.javafx.collections

Class LazyObservableList<K,V>

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractList<E>

javafx.collections.ObservableListBase<E>

javafx.collections.transformation.TransformationList<javafx.concurrent.Task<V>,K>

com.iamsoft.util.ui.javafx.collections.LazyObservableList<K,V>

Type Parameters:

K - Key type.

V - Value type.

All Implemented Interfaces:

Iterable<javafx.concurrent.Task<V>>, Collection<javafx.concurrent.Task<V>>, List<javafx.concurrent.Task<V>>, javafx.beans.Observable, javafx.collections.ObservableList<javafx.concurrent.Task<V>>

public class LazyObservableList<K,V>
extends javafx.collections.transformation.TransformationList<javafx.concurrent.Task<V>,K>

Observable list that fetches values from potentially slow resource. A 'viewport' defines the range of values that should be retrieved. When values exit viewport, they are immediately discarded and associated tasks are canceled. Thus, LazyObservableList typically contains mostly nulls with a narrow band of 'task' objects. Values are expected to be immutable. If change occurs, base ObservableList should simply replace object. To simulate mutation, use a decorator on top of LazyObservableList.

See Also:

• ViewportRange

Property Summary

Properties

Type	Property	Description
final javafx.beans.property.ReadOnlyBooleanProperty	viewportChange

Field Summary

Fields inherited from class java.util.AbstractList

modCount

Constructor Summary

Constructors

Constructor	Description
LazyObservableList(javafx.collections.ObservableList<K> pKeys, javafx.beans.value.ObservableValue<com.google.common.collect.Range<Integer>> pViewportRange, Function<com.google.common.collect.Range<Integer>,Map<K,javafx.concurrent.Task<V>>> pFetchFunction, Consumer<K> pUnsubscribeFunction)

Method Summary

Modifier and Type	Method	Description
javafx.concurrent.Task<V>	get(int pIdx)
static int	getFrom(com.google.common.collect.Range<Integer> pRange)	Get lower endpoint (inclusive).
int	getSourceIndex(int pIdx)
static int	getTo(com.google.common.collect.Range<Integer> pRange)	Get upper endpoint (exclusive).
int	getViewIndex(int pIdx)
final boolean	isViewportChange()	Can be used to determine whether a list change occurs due to viewport change.
void	refresh()	Clears old values and re-fetches viewport values.
protected void	runLater(Runnable pRunnable)
int	size()
protected void	sourceChanged(javafx.collections.ListChangeListener.Change<? extends K> pChg)
final javafx.beans.property.ReadOnlyBooleanProperty	viewportChangeProperty()

Methods inherited from class javafx.collections.transformation.TransformationList

getSource, getSourceIndexFor, isInTransformationChain

Methods inherited from class javafx.collections.ObservableListBase

addAll, addListener, addListener, beginChange, endChange, fireChange, hasListeners, nextAdd, nextPermutation, nextRemove, nextRemove, nextReplace, nextSet, nextUpdate, remove, removeAll, removeListener, removeListener, retainAll, setAll, setAll

Methods inherited from class java.util.AbstractList

add, add, addAll, clear, equals, hashCode, indexOf, iterator, lastIndexOf, listIterator, listIterator, remove, removeRange, set, subList

Methods inherited from class java.util.AbstractCollection

addAll, contains, containsAll, isEmpty, remove, removeAll, retainAll, toArray, toArray, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Collection

parallelStream, removeIf, stream, toArray

Methods inherited from interface java.lang.Iterable

forEach

Methods inherited from interface java.util.List

add, add, addAll, addAll, clear, contains, containsAll, equals, hashCode, indexOf, isEmpty, iterator, lastIndexOf, listIterator, listIterator, remove, remove, removeAll, replaceAll, retainAll, set, sort, spliterator, subList, toArray, toArray

Methods inherited from interface javafx.collections.ObservableList

filtered, sorted, sorted

Property Details

viewportChange

public final javafx.beans.property.ReadOnlyBooleanProperty viewportChangeProperty

See Also:

• isViewportChange()

Constructor Details

LazyObservableList

public LazyObservableList(javafx.collections.ObservableList<K> pKeys,
 javafx.beans.value.ObservableValue<com.google.common.collect.Range<Integer>> pViewportRange,
 Function<com.google.common.collect.Range<Integer>,Map<K,javafx.concurrent.Task<V>>> pFetchFunction,
 Consumer<K> pUnsubscribeFunction)

Parameters:

pKeys - List of unique item identifiers.

pViewportRange - Range (offset to length) within which data should be fetched and actively monitored. Range is allowed to extend beyond key list size.

pFetchFunction - Function for retrieving actively-monitored remote data. Function is responsible for starting tasks. Where possible, it is encouraged to request all data with a single 'parent' request upon which child tasks depend. In this case, canceling all child tasks should cancel parent.

pUnsubscribeFunction - Function to cease active monitoring of a value.

Method Details

viewportChangeProperty

public final javafx.beans.property.ReadOnlyBooleanProperty viewportChangeProperty()

See Also:

• isViewportChange()

isViewportChange

public final boolean isViewportChange()

Can be used to determine whether a list change occurs due to viewport change.

get

public javafx.concurrent.Task<V> get(int pIdx)

Specified by:

get in interface List<K>

Specified by:

get in class AbstractList<javafx.concurrent.Task<V>>

size

public int size()

Specified by:

size in interface Collection<K>

Specified by:

size in interface List<K>

Specified by:

size in class AbstractCollection<javafx.concurrent.Task<V>>

refresh

public void refresh()

Clears old values and re-fetches viewport values.

runLater

protected void runLater(Runnable pRunnable)

sourceChanged

protected void sourceChanged(javafx.collections.ListChangeListener.Change<? extends K> pChg)

Specified by:

sourceChanged in class javafx.collections.transformation.TransformationList<javafx.concurrent.Task<V>,K>

getSourceIndex

public int getSourceIndex(int pIdx)

Specified by:

getSourceIndex in class javafx.collections.transformation.TransformationList<javafx.concurrent.Task<V>,K>

getViewIndex

public int getViewIndex(int pIdx)

Specified by:

getViewIndex in class javafx.collections.transformation.TransformationList<javafx.concurrent.Task<V>,K>

getFrom

public static int getFrom(com.google.common.collect.Range<Integer> pRange)

Get lower endpoint (inclusive).

getTo

public static int getTo(com.google.common.collect.Range<Integer> pRange)

Get upper endpoint (exclusive).