Module javafx.base
Package javafx.collections

Class ObservableListBase<E>

java.lang.Object
java.util.AbstractCollection<E>
java.util.AbstractList<E>
javafx.collections.ObservableListBase<E>
Type Parameters:
E - the type of the elements contained in the List
All Implemented Interfaces:
Iterable<E>, Collection<E>, List<E>, Observable, ObservableList<E>
Direct Known Subclasses:
ModifiableObservableListBase, TransformationList
public abstract class ObservableListBase<E> extends AbstractList<E> implements ObservableList<E>
Abstract class that serves as a base class for ObservableList implementations. The base class provides two functionalities for the implementing classes. 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 AbstractList.listIterator(), AbstractList.iterator() methods and use them in AbstractList.get(int), AbstractCollection.size() and other methods accordingly.

Since:
JavaFX 8.0
See Also:

  • Constructor Details

    • ObservableListBase

      public ObservableListBase()
      Creates a default ObservableListBase.

  • Method Details

    • nextUpdate

      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 - the position in the list where the updated element resides.

    • nextSet

      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 - the index of the item that was set
      old - the old value at the idx position.

    • nextReplace

      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 - the index where the items were replaced
      to - the end index (exclusive) of the range where the new items reside
      removed - the list of items that were removed

    • nextRemove

      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 - the index where the items were removed
      removed - the list of items that were removed

    • nextRemove

      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 - the index where the item was removed
      removed - the item that was removed

    • nextPermutation

      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 - marks the beginning (inclusive) of the range that was permutated
      to - marks the end (exclusive) of the range that was permutated
      perm - 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)

    • nextAdd

      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 - marks the beginning (inclusive) of the range that was added
      to - marks the end (exclusive) of the range that was added

    • beginChange

      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 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:

    • addListener

      public final void addListener(InvalidationListener listener)
      Description copied from interface: Observable
      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.

      Specified by:
      addListener in interface Observable
      Parameters:
      listener - The listener to register
      See Also:

    • removeListener

      public final void removeListener(InvalidationListener listener)
      Description copied from interface: Observable
      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.

      Specified by:
      removeListener in interface Observable
      Parameters:
      listener - The listener to remove
      See Also:

    • addListener

      public final void addListener(ListChangeListener<? super E> listener)
      Description copied from interface: ObservableList
      Add a listener to this observable list.
      Specified by:
      addListener in interface ObservableList<E>
      Parameters:
      listener - the listener for listening to the list changes

    • removeListener

      public final void removeListener(ListChangeListener<? super E> listener)
      Description copied from interface: ObservableList
      Tries to remove a listener from this observable list. If the listener is not attached to this list, nothing happens.
      Specified by:
      removeListener in interface ObservableList<E>
      Parameters:
      listener - a listener to remove

    • fireChange

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

    • hasListeners

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

    • addAll

      public boolean addAll(E... elements)
      Description copied from interface: ObservableList
      A convenience method for var-arg addition of elements.
      Specified by:
      addAll in interface ObservableList<E>
      Parameters:
      elements - the elements to add
      Returns:
      true (as specified by Collection.add(E))

    • setAll

      public boolean setAll(E... elements)
      Description copied from interface: ObservableList
      Clears the ObservableList and adds all the elements passed as var-args.
      Specified by:
      setAll in interface ObservableList<E>
      Parameters:
      elements - the elements to set
      Returns:
      true (as specified by Collection.add(E))

    • setAll

      public boolean setAll(Collection<? extends E> col)
      Description copied from interface: ObservableList
      Clears the ObservableList and adds all elements from the collection.
      Specified by:
      setAll in interface ObservableList<E>
      Parameters:
      col - the collection with elements that will be added to this observableArrayList
      Returns:
      true (as specified by Collection.add(E))

    • removeAll

      public boolean removeAll(E... elements)
      Description copied from interface: ObservableList
      A convenience method for var-arg usage of the removeAll method.
      Specified by:
      removeAll in interface ObservableList<E>
      Parameters:
      elements - the elements to be removed
      Returns:
      true if list changed as a result of this call

    • retainAll

      public boolean retainAll(E... elements)
      Description copied from interface: ObservableList
      A convenience method for var-arg usage of the retainAll method.
      Specified by:
      retainAll in interface ObservableList<E>
      Parameters:
      elements - the elements to be retained
      Returns:
      true if list changed as a result of this call

    • remove

      public void remove(int from, int to)
      Description copied from interface: ObservableList
      A simplified way of calling sublist(from, to).clear(). As this is a common operation, ObservableList has this method for convenient usage.
      Specified by:
      remove in interface ObservableList<E>
      Parameters:
      from - the start of the range to remove (inclusive)
      to - the end of the range to remove (exclusive)