Package ca.odell.glazedlists

Class SequenceList<E>

  • All Implemented Interfaces:
    ListEventListener<E>, EventList<E>, java.lang.Iterable<E>, java.util.Collection<E>, java.util.EventListener, java.util.List<E>, java.util.RandomAccess
    public final class SequenceList<E>
extends TransformedList<E,​E>
implements java.util.RandomAccess
    A SequenceList contains values in adjacent indices which occur at predictable intervals from each other. A simple SequenceList could be: 
     {-10, -5, 0, 5, 10, 15}
    while a more sophisticated example could be: 
     {Jun 1, Jul 1, Aug 1, Sep 1, Oct 1}
    As long as the values can be ordered via a Comparator and a SequenceList.Sequencer can be implemented to reliably produce the next or previous value in a sequence using only some value from the source list.

    SequenceList is a readonly list; calling any write method on this list will produce an UnsupportedOperationException.

    The start and end values of the sequence are the smallest sequence values which maintain the invariant that: sequence start <= each value in the source list <= sequence end

    Warning: This class is thread ready but not thread safe. See EventList for an example of thread safe code.

    EventList Overview
    Writable:no
    Concurrency:thread ready, not thread safe
    Performance:reads: O(1)
    Memory:O(N)
    Unit Tests:SequenceListTest
    Issues:N/A
    Author:
    James Lemieux

    • Constructor Detail

      • SequenceList

        public SequenceList​(EventList<E> source,
                    SequenceList.Sequencer<E> sequencer)
        Constructs a SequenceList containing a sequence of values produced by the sequencer which cover the range of values contained within the source.
        Parameters:
        source - the raw values to build a sequence around
        sequencer - the logic to produce sequence values relative to a value

      • SequenceList

        public SequenceList​(EventList<E> source,
                    SequenceList.Sequencer<E> sequencer,
                    java.util.Comparator<? super E> comparator)
        Constructs a SequenceList containing a sequence of values produced by the sequencer which cover the range of values contained within the source. The given comparator determines the order of the sequence values.
        Parameters:
        source - the raw values to build a sequence around
        sequencer - the logic to produce sequence values relative to a value
        comparator - determines the order of the sequence values

    • Method Detail

      • isWritable

        protected boolean isWritable()
        Description copied from class: TransformedList
        Gets whether the source EventList is writable via this API.

        Extending classes must override this method in order to make themselves writable.

        Specified by:
        isWritable in class TransformedList<E,​E>
        Returns:
        false; SequenceList is readonly

      • size

        public int size()
        Returns the number of elements in this list. If this list contains more than Integer.MAX_VALUE elements, returns Integer.MAX_VALUE.
        Specified by:
        size in interface java.util.Collection<E>
        Specified by:
        size in interface java.util.List<E>
        Overrides:
        size in class TransformedList<E,​E>
        Returns:
        the number of elements in this list.

      • get

        public E get​(int index)
        Returns the element at the specified position in this list.
        Specified by:
        get in interface java.util.List<E>
        Overrides:
        get in class TransformedList<E,​E>
        Parameters:
        index - index of element to return.
        Returns:
        the element at the specified position in this list.

      • getPreviousSequenceValue

        public E getPreviousSequenceValue​(E value)
        Returns the previous value in the sequence defined by this list or value itself if it is a sequence value.
        Parameters:
        value - the value relative to which the previous sequence value is returned
        Returns:
        the previous sequence value relative to the given value

      • getNextSequenceValue

        public E getNextSequenceValue​(E value)
        Returns the next value in the sequence defined by this list or value itself if it is a sequence value.
        Parameters:
        value - the value relative to which the next sequence value is returned
        Returns:
        the next sequence value relative to the given value

      • listChanged

        public void listChanged​(ListEvent<E> listChanges)
        When the underlying list changes, this notification allows the object to repaint itself or update itself as necessary.

        It is mandatory that the calling thread has obtained the write lock on the source list. This is because the calling thread will have written to the source list to cause this event. This condition guarantees that no writes can occur while the listener is handling this event. It is an error to write to the source list while processing an event.

        Specified by:
        listChanged in interface ListEventListener<E>
        Specified by:
        listChanged in class TransformedList<E,​E>
        Parameters:
        listChanges - a ListEvent describing the changes to the list