org.reactfx.collection.ListModificationLike Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of richtextfx Show documentation

FX-Text-Area for formatted text and other special effects.

There is a newer version: 1.11

package org.reactfx.collection;

import java.util.List;

import javafx.collections.ObservableList;

/**
 * Describes an elementary modification made to a list. Elementary modification
 * is represented by the position in the list where the change occurred
 * ({@link #getFrom()}), a list of elements removed by the modification
 * ({@link #getRemoved()}), and the number of added elements replacing the
 * removed elements ({@link #getAddedSize()}).
 *
 * Subtypes of this interface differ in how they refer to the added elements:
 *   

 *     {@link ListModification} holds a reference to the observable list
 *     in which the modification occurred and the
 *     {@link ListModification#getAddedSubList()} method returns a sublist view
 *     of the original observable list. Such sublist is valid only until the
 *     next list modification.
 *     
{@link MaterializedListModification} has its own copy of added
 *     elements ({@link MaterializedListModification#getAdded()}), thus the
 *     validity of the list of added elements returned from {@code getAdded()}
 *     is not restricted.
 *     
{@link QuasiListModification} does not provide a way to get the
 *     added elements directly, but has to be combined with the observable list
 *     to obtain {@linkplain ListModification}
 *     ({@link QuasiListModification#instantiate(QuasiListModification, ObservableList)})
 *     or {@linkplain MaterializedListModification}
 *     ({@link QuasiListModification#materialize(QuasiListModification, ObservableList)}).
 *   
 *
 * @param  type of list elements.
 */
interface ListModificationLike {
    /**
     * Returns the position in the list where this change occurred.
     */
    int getFrom();

    /**
     * Returns the number of items removed by this change.
     */
    default int getRemovedSize() { return getRemoved().size(); }

    /**
     * Returns the number of items added by this change.
     */
    int getAddedSize();

    /**
     * Returns the end position of the change in the modified list.
     * The returned value is equal to {@code getFrom() + getAddedSize()}.
     */
    default int getTo() { return getFrom() + getAddedSize(); }

    /**
     * Returns an immutable list of elements removed by this change.
     * Before the change occurred, the first element of the returned list
     * was at index {@link #getFrom()} in the original list.
     * If no elements were removed by this change, returns an empty list.
     * The size of the returned list is equal to the value returned by
     * {@link #getRemovedSize()}.
     */
    List getRemoved();
}