// Copyright 2009 Google Inc. All Rights Reserved.
package org.waveprotocol.wave.model.util;
/**
* A list of elements. This offers a subset of JDK list functionality.
*
* The list is a factory for new elements, created with {@link #add(Object)}.
* The motivating scenario for this interface is a list of domain objects
* represented in a Wave document. Documents have the constraint that you
* can not create structures then attach them later; you have to create them in
* place. Hence element initialisation occurs within the {@code add()} method,
* rather than initialising an element before adding it.
*
*
* @param <T> type of the elements
* @param <I> type of initialisation data for new elements
*
*
*/
public interface ElementList<T, I> {
/**
* @return the values in this list
*/
Iterable<T> getValues();
/**
* Removes a value from this set.
*
* @param element value to remove
*/
boolean remove(T element);
/**
* Adds an element as the last element of this list and returns it.
*
* @param initialState describes initial state for the created element
* @return the created and added element
*/
T add(I initialState);
/**
* Adds an element at the specified location. The location must be between 0
* and {@link #size()}.
*
* @param index location where the element is added
* @param initialState describes initial state for the created element
* @return the newly added element
* @throws IndexOutOfBoundsException if the location is out of bounds
*/
T add(int index, I initialState);
/**
* @param element the element to be located in this list
* @return the location of the element on this list, or -1 if not present
*/
int indexOf(T element);
/**
* @param index the location of the desired element
* @return the element at the given index
*/
T get(int index);
/**
* @return the number of elements in this list
*/
int size();
/**
* Removes all elements from this list.
*/
void clear();
}