JavaFX 24 · javafx.collections.ObservableListBase · APIdia, the JavaDoc alternative

Abstract class that serves as a base class for ObservableList implementations. The base class provides two functionalities for the implementing classes.

Listener handling by implementing addListener and removeListener methods. fireChange(javafx.collections.ListChangeListener.Change) method is provided for notifying the listeners with a Change object.
Methods for building up a ListChangeListener.Change object. There are various methods called next*, like nextAdd(int, int) for new items in the lists or nextRemove(int, java.lang.Object) for an item being removed from the list.
These methods must be always enclosed in beginChange() and endChange() block.
See the example below.

The following example shows how the Change build-up works:

 public void removeOddIndexes() {
     beginChange();
     try {
         for (int i = 1; i < size(); ++i) {
             remove(i);
         }
     } finally {
         endChange();
     }
 }

 public void remove(int i) {
     beginChange();
     try {
         E removed = ... //do some stuff that will actually remove the element at index i
         nextRemove(i, removed);
     } finally {
         endChange();
     }
 }

The try/finally blocks in the example are needed only if there's a possibility for an exception to occur inside a beginChange() / endChange() block

Note

If you want to create modifiable ObservableList implementation, consider using ModifiableObservableListBase as a superclass.

Note

In order to create list with sequential access, you should override listIterator(), iterator() methods and use them in get, size() and other methods accordingly.

Field Summary

Modifier and Type	Field and Description
private ListChangeBuilder<E>	changeBuilder
private ListListenerHelper<E>	listenerHelper

Inherited from java.util.AbstractList:: modCount

Constructor Summary

Access	Constructor and Description
public	ObservableListBase() Creates a default `ObservableListBase`.

Method Summary

Modifier and Type	Method and Description
public boolean	addAll(E... the elements to add elements) Implements javafx.collections.ObservableList.addAll. A convenience method for var-arg addition of elements.
public final void	addListener(InvalidationListener The listener to register listener) Implements javafx.beans.Observable.addListener. Adds an `InvalidationListener` which will be notified whenever the `Observable` becomes invalid.
public final void	addListener(ListChangeListener<? super E> the listener for listening to the list changes listener) Implements javafx.collections.ObservableList.addListener. Add a listener to this observable list.
protected final void	beginChange() Begins a change block.
protected final void	endChange() Ends the change block.
protected final void	fireChange(ListChangeListener.Change<? extends E> an object representing the change that was done change) Notifies all listeners of a change
private ListChangeBuilder<E>	getListChangeBuilder()
protected final boolean	Returns: true if there is a listener for this list hasListeners() Returns true if there are some listeners registered for this list.
protected final void	nextAdd(int marks the beginning (inclusive) of the range that was added from, int marks the end (exclusive) of the range that was added to) Adds a new add operation to the change.
protected final void	nextPermutation(int marks the beginning (inclusive) of the range that was permutated from, int marks the end (exclusive) of the range that was permutated to, int[] the permutation in that range. Even if `from != 0`, the array should contain the indexes of the list. Therefore, such permutation would not contain indexes of range `(0, from)` perm) Adds a new permutation operation to the change.
protected final void	nextRemove(int the index where the items were removed idx, List<? extends E> the list of items that were removed removed) Adds a new remove operation to the change with multiple items removed.
protected final void	nextRemove(int the index where the item was removed idx, E the item that was removed removed) Adds a new remove operation to the change with single item removed.
protected final void	nextReplace(int the index where the items were replaced from, int the end index (exclusive) of the range where the new items reside to, List<? extends E> the list of items that were removed removed) Adds a new replace operation to the change.
protected final void	nextSet(int the index of the item that was set idx, E the old value at the `idx` position. old) Adds a new set operation to the change.
protected final void	nextUpdate(int the position in the list where the updated element resides. pos) Adds a new update operation to the change.
public void	remove(int the start of the range to remove (inclusive) from, int the end of the range to remove (exclusive) to) Implements javafx.collections.ObservableList.remove. A simplified way of calling `sublist(from, to).clear()`.
public boolean	removeAll(E... the elements to be removed elements) Implements javafx.collections.ObservableList.removeAll. A convenience method for var-arg usage of the `removeAll` method.
public final void	removeListener(InvalidationListener The listener to remove listener) Implements javafx.beans.Observable.removeListener. Removes the given listener from the list of listeners, that are notified whenever the value of the `Observable` becomes invalid.
public final void	removeListener(ListChangeListener<? super E> a listener to remove listener) Implements javafx.collections.ObservableList.removeListener. Tries to remove a listener from this observable list.
public boolean	retainAll(E... the elements to be retained elements) Implements javafx.collections.ObservableList.retainAll. A convenience method for var-arg usage of the `retainAll` method.
public boolean	setAll(E... the elements to set elements) Implements javafx.collections.ObservableList.setAll. Clears the ObservableList and adds all the elements passed as var-args.
public boolean	setAll(Collection<? extends E> the collection with elements that will be added to this observableArrayList col) Implements javafx.collections.ObservableList.setAll. Clears the ObservableList and adds all elements from the collection.

Inherited from java.util.AbstractList:: add add addAll clear equals get hashCode indexOf iterator lastIndexOf listIterator listIterator remove removeRange set subList

Field Detail

changeBuilder	back to summary
private ListChangeBuilder<E> changeBuilder

listenerHelper	back to summary
private ListListenerHelper<E> listenerHelper

Constructor Detail

ObservableListBase	back to summary
public ObservableListBase() Creates a default `ObservableListBase`.

Method Detail

addAll	back to summary
public boolean addAll(E... elements) Implements javafx.collections.ObservableList.addAll. Doc from javafx.collections.ObservableList.addAll. A convenience method for var-arg addition of elements. Parameters elements:E[] the elements to add Returns:boolean true (as specified by Collection.add(E)) Annotations @Override

addAll

back to summary

public boolean addAll(E... elements)

Implements javafx.collections.ObservableList.addAll.

Doc from javafx.collections.ObservableList.addAll.

A convenience method for var-arg addition of elements.

Parameters

elements:E[]: the elements to add

Returns:boolean

true (as specified by Collection.add(E))

Annotations

@Override

addListener back to summary

addListener	back to summary
public final void addListener(InvalidationListener listener) Implements javafx.beans.Observable.addListener. Doc from javafx.beans.Observable.addListener. Adds an `InvalidationListener` which will be notified whenever the `Observable` becomes invalid. If the same listener is added more than once, then it will be notified more than once. That is, no check is made to ensure uniqueness. Note that the same actual `InvalidationListener` instance may be safely registered for different `Observables`. The `Observable` stores a strong reference to the listener which will prevent the listener from being garbage collected and may result in a memory leak. It is recommended to either unregister a listener by calling `removeListener` after use or to use an instance of `WeakInvalidationListener` avoid this situation. Parameters listener:InvalidationListener The listener to register Annotations @Override

public final void addListener(InvalidationListener listener)

Implements javafx.beans.Observable.addListener.

Doc from javafx.beans.Observable.addListener.

Adds an InvalidationListener which will be notified whenever the Observable becomes invalid. If the same listener is added more than once, then it will be notified more than once. That is, no check is made to ensure uniqueness.

Note that the same actual InvalidationListener instance may be safely registered for different Observables.

The Observable stores a strong reference to the listener which will prevent the listener from being garbage collected and may result in a memory leak. It is recommended to either unregister a listener by calling removeListener after use or to use an instance of WeakInvalidationListener avoid this situation.

Parameters

listener:InvalidationListener: The listener to register

Annotations

@Override

addListener	back to summary
public final void addListener(ListChangeListener<? super E> listener) Implements javafx.collections.ObservableList.addListener. Doc from javafx.collections.ObservableList.addListener. Add a listener to this observable list. Parameters listener:ListChangeListener<? super E> the listener for listening to the list changes Annotations @Override

addListener

back to summary

public final void addListener(ListChangeListener<? super E> listener)

Implements javafx.collections.ObservableList.addListener.

Doc from javafx.collections.ObservableList.addListener.

Add a listener to this observable list.

Parameters

listener:ListChangeListener<? super E>: the listener for listening to the list changes

Annotations

@Override

beginChange back to summary

beginChange	back to summary
protected final void beginChange() Begins a change block. Must be called before any of the `next*` methods is called. For every `beginChange()`, there must be a corresponding `endChange()` call. `beginChange()` calls can be nested in a `beginChange()`/`endChange()` block. See Also `endChange()`

protected final void beginChange()

Begins a change block. Must be called before any of the next* methods is called. For every beginChange(), there must be a corresponding endChange() call.

beginChange() calls can be nested in a beginChange()/endChange() block.

See Also: endChange()

endChange back to summary

endChange	back to summary
protected final void endChange() Ends the change block. If the block is the outer-most block for the `ObservableList`, the `Change` is constructed and all listeners are notified. Ending a nested block doesn't fire a notification. See Also `beginChange()`

protected final void endChange()

Ends the change block. If the block is the outer-most block for the ObservableList, the Change is constructed and all listeners are notified.

Ending a nested block doesn't fire a notification.

See Also: beginChange()

fireChange	back to summary
protected final void fireChange(ListChangeListener.Change<? extends E> change) Notifies all listeners of a change Parameters change:ListChangeListener.Change<? extends E> an object representing the change that was done

fireChange

back to summary

protected final void fireChange(ListChangeListener.Change<? extends E> change)

Notifies all listeners of a change

Parameters

change:ListChangeListener.Change<? extends E>: an object representing the change that was done

getListChangeBuilder	back to summary
private ListChangeBuilder<E> getListChangeBuilder()

hasListeners	back to summary
protected final boolean hasListeners() Returns true if there are some listeners registered for this list. Returns:boolean true if there is a listener for this list

hasListeners

back to summary

protected final boolean hasListeners()

Returns true if there are some listeners registered for this list.

Returns:boolean: true if there is a listener for this list

nextAdd back to summary

nextAdd	back to summary
protected final void nextAdd(int from, int to) Adds a new add operation to the change. There's no need to provide the list of added items as they can be found directly in the list under the specified indexes. Note needs to be called inside `beginChange()` / `endChange()` block. Note needs to reflect the current state of the list. Parameters from:int marks the beginning (inclusive) of the range that was added to:int marks the end (exclusive) of the range that was added

protected final void nextAdd(int from, int to)

Adds a new add operation to the change. There's no need to provide the list of added items as they can be found directly in the list under the specified indexes.

Note

needs to be called inside beginChange() / endChange() block.

Note

needs to reflect the current state of the list.

Parameters

from:int: marks the beginning (inclusive) of the range that was added
to:int: marks the end (exclusive) of the range that was added

nextPermutation back to summary

nextPermutation	back to summary
protected final void nextPermutation(int from, int to, int[] perm) Adds a new permutation operation to the change. The permutation on index `"i"` contains the index, where the item from the index `"i"` was moved. It's not necessary to provide the smallest permutation possible. It's correct to always call this method with `nextPermutation(0, size(), permutation);` Note needs to be called inside `beginChange()` / `endChange()` block. Note needs to reflect the current state of the list. Parameters from:int marks the beginning (inclusive) of the range that was permutated to:int marks the end (exclusive) of the range that was permutated perm:int[] the permutation in that range. Even if `from != 0`, the array should contain the indexes of the list. Therefore, such permutation would not contain indexes of range `(0, from)`

protected final void nextPermutation(int from, int to, int[] perm)

Adds a new permutation operation to the change. The permutation on index "i" contains the index, where the item from the index "i" was moved.

It's not necessary to provide the smallest permutation possible. It's correct to always call this method with nextPermutation(0, size(), permutation);

Note

needs to be called inside beginChange() / endChange() block.

Note

needs to reflect the current state of the list.

Parameters

from:int: marks the beginning (inclusive) of the range that was permutated
to:int: marks the end (exclusive) of the range that was permutated
perm:int[]: the permutation in that range. Even if from != 0, the array should contain the indexes of the list. Therefore, such permutation would not contain indexes of range (0, from)

nextRemove back to summary

nextRemove	back to summary
protected final void nextRemove(int idx, List<? extends E> removed) Adds a new remove operation to the change with multiple items removed. Note needs to be called inside `beginChange()` / `endChange()` block. Note needs to reflect the current state of the list. Parameters idx:int the index where the items were removed removed:List<? extends E> the list of items that were removed

protected final void nextRemove(int idx, List<? extends E> removed)

Adds a new remove operation to the change with multiple items removed.

Note

needs to be called inside beginChange() / endChange() block.

Note

needs to reflect the current state of the list.

Parameters

idx:int: the index where the items were removed
removed:List<? extends E>: the list of items that were removed

nextRemove back to summary

nextRemove	back to summary
protected final void nextRemove(int idx, E removed) Adds a new remove operation to the change with single item removed. Note needs to be called inside `beginChange()` / `endChange()` block. Note needs to reflect the current state of the list. Parameters idx:int the index where the item was removed removed:E the item that was removed

protected final void nextRemove(int idx, E removed)

Adds a new remove operation to the change with single item removed.

Note

needs to be called inside beginChange() / endChange() block.

Note

needs to reflect the current state of the list.

Parameters

idx:int: the index where the item was removed
removed:E: the item that was removed

nextReplace back to summary

nextReplace	back to summary
protected final void nextReplace(int from, int to, List<? extends E> removed) Adds a new replace operation to the change. Equivalent to `nextRemove(from, removed); nextAdd(from, to);` Note needs to be called inside `beginChange()` / `endChange()` block. Note needs to reflect the current state of the list. Parameters from:int the index where the items were replaced to:int the end index (exclusive) of the range where the new items reside removed:List<? extends E> the list of items that were removed

protected final void nextReplace(int from, int to, List<? extends E> removed)

Adds a new replace operation to the change. Equivalent to nextRemove(from, removed); nextAdd(from, to);

Note

needs to be called inside beginChange() / endChange() block.

Note

needs to reflect the current state of the list.

Parameters

from:int: the index where the items were replaced
to:int: the end index (exclusive) of the range where the new items reside
removed:List<? extends E>: the list of items that were removed

nextSet back to summary

nextSet	back to summary
protected final void nextSet(int idx, E old) Adds a new set operation to the change. Equivalent to `nextRemove(idx); nextAdd(idx, idx + 1);` . Note needs to be called inside `beginChange()` / `endChange()` block. Note needs to reflect the current state of the list. Parameters idx:int the index of the item that was set old:E the old value at the `idx` position.

protected final void nextSet(int idx, E old)

Adds a new set operation to the change. Equivalent to nextRemove(idx); nextAdd(idx, idx + 1); .

Note

needs to be called inside beginChange() / endChange() block.

Note

needs to reflect the current state of the list.

Parameters

idx:int: the index of the item that was set
old:E: the old value at the idx position.

nextUpdate back to summary

nextUpdate	back to summary
protected final void nextUpdate(int pos) Adds a new update operation to the change. Note needs to be called inside `beginChange()` / `endChange()` block. Note needs to reflect the current state of the list. Parameters pos:int the position in the list where the updated element resides.

protected final void nextUpdate(int pos)

Adds a new update operation to the change.

Note

needs to be called inside beginChange() / endChange() block.

Note

needs to reflect the current state of the list.

Parameters

pos:int: the position in the list where the updated element resides.

remove back to summary

remove	back to summary
public void remove(int from, int to) Implements javafx.collections.ObservableList.remove. Doc from javafx.collections.ObservableList.remove. A simplified way of calling `sublist(from, to).clear()`. As this is a common operation, ObservableList has this method for convenient usage. Parameters from:int the start of the range to remove (inclusive) to:int the end of the range to remove (exclusive) Annotations @Override

public void remove(int from, int to)

Implements javafx.collections.ObservableList.remove.

Doc from javafx.collections.ObservableList.remove.

A simplified way of calling sublist(from, to).clear(). As this is a common operation, ObservableList has this method for convenient usage.

Parameters

from:int: the start of the range to remove (inclusive)
to:int: the end of the range to remove (exclusive)

Annotations

@Override

removeAll back to summary

removeAll	back to summary
public boolean removeAll(E... elements) Implements javafx.collections.ObservableList.removeAll. Doc from javafx.collections.ObservableList.removeAll. A convenience method for var-arg usage of the `removeAll` method. Parameters elements:E[] the elements to be removed Returns:boolean true if list changed as a result of this call Annotations @Override

public boolean removeAll(E... elements)

Implements javafx.collections.ObservableList.removeAll.

Doc from javafx.collections.ObservableList.removeAll.

A convenience method for var-arg usage of the removeAll method.

Parameters

elements:E[]: the elements to be removed

Returns:boolean

true if list changed as a result of this call

Annotations

@Override

removeListener back to summary

removeListener	back to summary
public final void removeListener(InvalidationListener listener) Implements javafx.beans.Observable.removeListener. Doc from javafx.beans.Observable.removeListener. Removes the given listener from the list of listeners, that are notified whenever the value of the `Observable` becomes invalid. If the given listener has not been previously registered (i.e. it was never added) then this method call is a no-op. If it had been previously added then it will be removed. If it had been added more than once, then only the first occurrence will be removed. Parameters listener:InvalidationListener The listener to remove Annotations @Override

public final void removeListener(InvalidationListener listener)

Implements javafx.beans.Observable.removeListener.

Doc from javafx.beans.Observable.removeListener.

Removes the given listener from the list of listeners, that are notified whenever the value of the Observable becomes invalid.

If the given listener has not been previously registered (i.e. it was never added) then this method call is a no-op. If it had been previously added then it will be removed. If it had been added more than once, then only the first occurrence will be removed.

Parameters

listener:InvalidationListener: The listener to remove

Annotations

@Override

removeListener	back to summary
public final void removeListener(ListChangeListener<? super E> listener) Implements javafx.collections.ObservableList.removeListener. Doc from javafx.collections.ObservableList.removeListener. Tries to remove a listener from this observable list. If the listener is not attached to this list, nothing happens. Parameters listener:ListChangeListener<? super E> a listener to remove Annotations @Override

removeListener

back to summary

public final void removeListener(ListChangeListener<? super E> listener)

Implements javafx.collections.ObservableList.removeListener.

Doc from javafx.collections.ObservableList.removeListener.

Tries to remove a listener from this observable list. If the listener is not attached to this list, nothing happens.

Parameters

listener:ListChangeListener<? super E>: a listener to remove

Annotations

@Override

retainAll back to summary

retainAll	back to summary
public boolean retainAll(E... elements) Implements javafx.collections.ObservableList.retainAll. Doc from javafx.collections.ObservableList.retainAll. A convenience method for var-arg usage of the `retainAll` method. Parameters elements:E[] the elements to be retained Returns:boolean true if list changed as a result of this call Annotations @Override

public boolean retainAll(E... elements)

Implements javafx.collections.ObservableList.retainAll.

Doc from javafx.collections.ObservableList.retainAll.

A convenience method for var-arg usage of the retainAll method.

Parameters

elements:E[]: the elements to be retained

Returns:boolean

true if list changed as a result of this call

Annotations

@Override

setAll	back to summary
public boolean setAll(E... elements) Implements javafx.collections.ObservableList.setAll. Doc from javafx.collections.ObservableList.setAll. Clears the ObservableList and adds all the elements passed as var-args. Parameters elements:E[] the elements to set Returns:boolean true (as specified by Collection.add(E)) Annotations @Override

setAll

back to summary

public boolean setAll(E... elements)

Implements javafx.collections.ObservableList.setAll.

Doc from javafx.collections.ObservableList.setAll.

Clears the ObservableList and adds all the elements passed as var-args.

Parameters

elements:E[]: the elements to set

Returns:boolean

true (as specified by Collection.add(E))

Annotations

@Override

setAll	back to summary
public boolean setAll(Collection<? extends E> col) Implements javafx.collections.ObservableList.setAll. Doc from javafx.collections.ObservableList.setAll. Clears the ObservableList and adds all elements from the collection. Parameters col:Collection<? extends E> the collection with elements that will be added to this observableArrayList Returns:boolean true (as specified by Collection.add(E)) Annotations @Override

setAll

back to summary

public boolean setAll(Collection<? extends E> col)

Implements javafx.collections.ObservableList.setAll.

Doc from javafx.collections.ObservableList.setAll.

Clears the ObservableList and adds all elements from the collection.

Parameters