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package org.gvsig.fmap.dal.feature;

import java.util.List;

import org.gvsig.fmap.dal.DataSet;

import org.gvsig.fmap.dal.exception.DataException;

import org.gvsig.tools.dispose.DisposableIterator;

import org.gvsig.tools.dynobject.DynObject;

import org.gvsig.tools.dynobject.DynObjectSet;

import org.gvsig.tools.visitor.IndexedVisitable;

/**

 * A FeatureSet represents a set of {@link Feature}(s). These sets of features

 * are typically obtained directly from a {@link FeatureStore}, or through a

 * {@link FeatureQuery}.

 * 

 * A FeatureSet may contain subsets of {@link Feature}(s) of different

 * {@link FeatureType}(s). It allows iterating and editing the features.

 * 

 * FIXME: Actualizar javadoc

 * 

 * Si el store en el que esta basado el featureset es modificado, se realiza un

 * update, insert, delete o se modifican los featuretype de este, el FeatureSet

 * quedara invalidado, y cualquier acceso a el provocara que se lance una

 * excepcion de tiempo de ejecucion ConcurrentModificationException.

 * 

 * Habria que indicar que invocar al metodo accept del interface visitor

 * provocara la excepcion ConcurrentModificationException si el store a sido

 * modificado desde otro punto.

 * 

 * Indicar que los metodos insert/delete/update ademas de actuar sobre el set,

 * actuan sobre el store en el que este esta basado, pero que no invalidan el

 * set sobre el que se ejecutan. No se si esto deberia hacerse mencion en esos

 * metodos o en la doc general del featureset.

 * 

 */

public interface FeatureSet extends DataSet, IndexedVisitable {

        /**

         * Returns the default {@link FeatureType} of this FeatureSet.

         * 

         * @return default {@link FeatureType} in this FeatureSet.

         */

        public FeatureType getDefaultFeatureType();

        /**

         * Returns a list of the {@link FeatureType}(s) in this FeatureSet.

         * 

         * @return list of the {@link FeatureType}(s) in this FeatureSet.

         */

        public List getFeatureTypes();

        /**

         * Returns the number of {@link Feature}(s) contained in this FeatureSet.

         * 

         * The value returned by this method won't be accurate when

         * the FeatureStore is being edited and this set's features

         * are modified, added or deleted.

         *  

         * @return number of {@link Feature}(s) contained in this FeatureSet.

         * 

         * @throws DataException

         */

    public long getSize() throws DataException;

        /**

         * Returns an iterator over the elements in this collection, in the order

         * (if any) defined when the collection was obtained.

         * 

         * The iterator starts at the specified position in this collection. The

         * specified index indicates the first element that would be returned by an

         * initial call to the <tt>next</tt> method. An initial call to the

         * <tt>previous</tt> method would return the element with the specified

         * index minus one.

         * 

         * <p>

         * <em>

         * <strong>NOTE:</strong> if you use this method to get the iterator, you

         * must get sure the iterator is disposed (@see

         * {@link DisposableIterator#dispose()}) in any case, even if an error occurs

         * while getting the data. It is recommended to use the <code>accept</code>

         * methods instead, which handle everything for you. 

         * Take into account the accept methods may use a fast iterator to 

         * get the features.

         * </em>

         * </p>

         * 

         * @see #accept(org.gvsig.tools.visitor.Visitor)

         * @see #accept(org.gvsig.tools.visitor.Visitor, long)

         * 

         * @param index

         *            index of first element to be returned from the iterator (by a

         *            call to the <tt>next</tt> method).

         * @return an iterator of the elements in this collection (in proper

         *         sequence), starting at the specified position in the collection.

         * @throws DataException

         *             if the index is out of range (index < 0 || index >

         *             size()).

         */

        DisposableIterator iterator(long index) throws DataException;

        /**

         * Returns an iterator over the elements in this collection, in the order

         * (if any) defined when the collection was obtained.

         * 

         * <p>

         * <em>

         * <strong>NOTE:</strong> if you use this method to get the iterator, you

         * must get sure the iterator is disposed (@see

         * {@link DisposableIterator#dispose()}) in any case, even if an error occurs

         * while getting the data. It is recommended to use the <code>accept</code>

         * methods instead, which handle everything for you. 

         * Take into account the accept methods may use a fast iterator to 

         * get the features.

         * </em>

         * </p>

         * 

         * @see #accept(org.gvsig.tools.visitor.Visitor)

         * @see #accept(org.gvsig.tools.visitor.Visitor, long)

         * 

         * @return an iterator of the elements in this collection (in proper

         *         sequence).

         * 

         * @throws DataException

         */

        DisposableIterator iterator() throws DataException;

        /**

         * Returns a fast iterator over this set.

         * 

         * <p>

         * <em>

         * <strong>NOTE:</strong> if you use this method to get the iterator, you

         * must get sure the iterator is disposed (@see

         * {@link DisposableIterator#dispose()}) in any case, even if an error occurs

         * while getting the data. It is recommended to use the <code>accept</code>

         * methods instead, which handle everything for you. 

         * Take into account the accept methods may use a fast iterator to 

         * get the features.

         * </em>

         * </p>

         * 

         * @see #accept(org.gvsig.tools.visitor.Visitor)

         * @see #accept(org.gvsig.tools.visitor.Visitor, long)

         * 

         * @return an iterator over this set.

         * 

         * @throws DataException

         */

        public DisposableIterator fastIterator() throws DataException;

        /**

         * Returns a fast iterator over this set, starting from the given index.

         * 

         * <p>

         * <em>

         * <strong>NOTE:</strong> if you use this method to get the iterator, you

         * must get sure the iterator is disposed (@see

         * {@link DisposableIterator#dispose()}) in any case, even if an error occurs

         * while getting the data. It is recommended to use the <code>accept</code>

         * methods instead, which handle everything for you. 

         * Take into account the accept methods may use a fast iterator to 

         * get the features.

         * </em>

         * </p>

         * 

         * @see #accept(org.gvsig.tools.visitor.Visitor)

         * @see #accept(org.gvsig.tools.visitor.Visitor, long)

         * 

         * @param index

         *            position in which the iterator is initially located.

         * 

         * @return an iterator initially located at the position indicated by the

         *         given index

         * 

         * @throws DataException

         */

        public DisposableIterator fastIterator(long index) throws DataException;

        /**

         * Indicates whether this FeatureSet contains zero features.

         * 

         * The value returned by this method won't be accurate when

         * the FeatureStore is being edited and this set's features

         * are modified, added or deleted.

         *  

         * @return true if this FeatureSet is empty, false otherwise.

         * 

         * @throws DataException

         */

        boolean isEmpty() throws DataException;

        /**

         * Updates a {@link Feature} with the given {@link EditableFeature}.<br>

         * 

         * Any {@link DisposableIterator} from this store that was still in use can will not

         * reflect this change.

         * 

         * @param feature

         *            an instance of {@link EditableFeature} with which to update

         *            the associated {@link Feature}.

         * 

         * @throws DataException

         */

        public void update(EditableFeature feature) throws DataException;

        /**

         * Deletes a {@link Feature} from this FeatureSet.<br>

         * 

         * Any {@link DisposableIterator} from this store that was still in use will be

         * <i>unsafe</i>. Use {@link DisposableIterator#remove()} instead.

         * 

         * @param feature

         *            the {@link Feature} to delete.

         * 

         * @throws DataException

         */

        public void delete(Feature feature) throws DataException;

        /**

         * Inserts a new feature in this set. It needs to be an instance of

         * {@link EditableFeature} as it has not been stored yet.<br>

         * 

         * Any {@link DisposableIterator} from this store that was still in use can will not

         * reflect this change.

         * 

         * @param feature

         *            the {@link EditableFeature} to insert.

         * 

         * @throws DataException

         */

        public void insert(EditableFeature feature) throws DataException;

    /**

     * Returns a {@link DynObjectSet} of the contents of this set.

     * Defaults to fast iteration.

     * 

     * @return a {@link DynObjectSet}

     */

    public DynObjectSet getDynObjectSet();

    /**

     * Returns a {@link DynObjectSet} of the contents of this set.

     * 

     * @param fast

     *            if the set will be able to be iterated in a fast way, by

     *            reusing the {@link DynObject} instance for each

     *            {@link Feature} instance.

     * @return a {@link DynObjectSet}

     */

    public DynObjectSet getDynObjectSet(boolean fast);

}