Package ca.odell.glazedlists

Class SeparatorList<E>

  • All Implemented Interfaces:
    ListEventListener<E>, EventList<E>, java.lang.Iterable<E>, java.util.Collection<E>, java.util.EventListener, java.util.List<E>
    public class SeparatorList<E>
extends TransformedList<E,​E>
    A list that adds separator objects before each group of elements.

    SeparatorList is writable, however, attempts to write over separators will always produce an IllegalArgumentException. For example, calling TransformedList.add(int, Object), TransformedList.set(int, Object) or TransformedList.remove(int) with a an index that actually corresponds to a separator in this list will produce an IllegalArgumentException. This is because there is no corresponding index for separators in the source list; separators are added by this SeparatorList. All index-based write operations must be performed on indexes known to correspond to non-separator elements.

    Warning: this class won't work very well with generics because separators are mixed in, which will be a different class than the other list elements.

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

    Developer Preview this class is still under heavy development and subject to API changes. It's also really slow at the moment and won't scale to lists of size larger than a hundred or so efficiently.

    Author:
    Jesse Wilson

    • Constructor Detail

      • SeparatorList

        public SeparatorList​(EventList<E> source,
                     java.util.Comparator<? super E> comparator,
                     int minimumSizeForSeparator,
                     int defaultLimit)
        Construct a SeparatorList overtop of the source list by using the given comparator to compute groups of similar source items. For each group a single separator will be present in this SeparatorList provided the group contains at least the minimumSizeForSeparator number of items (otherwise they are left without a separator). In addition this SeparatorList will never show more than the defaultLimit number of group elements from any given group.
        Parameters:
        source - the list containing the raw items to be grouped
        comparator - the Comparator which defines the grouping logic
        minimumSizeForSeparator - the number of elements which must exist in a group in order for a separator to be created
        defaultLimit - the maximum number of element to display for a group; extra elements are truncated

    • Method Detail

      • 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.

      • getSourceIndex

        protected int getSourceIndex​(int mutationIndex)
        Gets the index in the source EventList that corresponds to the specified index. More formally, returns the index such that
        this.get(i) == source.get(getSourceIndex(i)) for all legal values of i.
        Overrides:
        getSourceIndex in class TransformedList<E,​E>

      • isWritable

        protected boolean isWritable()
        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>

      • setComparator

        public void setComparator​(java.util.Comparator<E> comparator)
        Set the Comparator used to determine how elements are split into groups.

        Performance Note: sorting will take O(N * Log N) time.

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

      • 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