| gvSIG desktop 1

/* gvSIG. Geographic Information System of the Valencian Government

 *

 * Copyright (C) 2007-2008 Infrastructures and Transports Department

 * of the Valencian Gobernment (CIT)

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 2

 * of the License, or (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,

 * MA  02110-1301, USA.

 *

 */

/*

 * AUTHORS (In addition to CIT):

 * 2008 {DiSiD Technologies}  {Implement data selection}

 */

package org.gvsig.fmap.dal.feature.impl;

import java.util.*;

import java.util.Map.Entry;

import org.gvsig.fmap.dal.DataStoreNotification;

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

import org.gvsig.fmap.dal.feature.*;

import org.gvsig.fmap.dal.feature.exception.ReversedSelectionIteratorException;

import org.gvsig.tools.persistence.PersistenceException;

import org.gvsig.tools.persistence.PersistentState;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

/**

 * Default implementation of the FeatureSelection interface. Internally, only

 * FeatureReference values are stored.

 *

 * This implementation performs better if used with the selection related

 * methods: select, deselect and isSelected ones.

 *

 * @author <a href="mailto:cordin@disid.com">C?sar Ordi?ana</a>

 */

public class DefaultFeatureSelection extends DefaultFeatureReferenceSelection

        implements FeatureSelection {

    private static final Logger LOGGER = LoggerFactory

            .getLogger(DefaultFeatureSelection.class);

    private Map featureTypeCounts = new HashMap(1);

    /**

     * Creates a DefaultFeatureSelection, with a FeatureStore.

     *

     * @param featureStore

     *            the FeatureStore to load Features from

     * @throws DataException

     *             if there is an error while getting the total number of

     *             Features of the Store.

     * @see AbstractSetBasedDataSelection#DefaultSelection(int)

     */

    public DefaultFeatureSelection(DefaultFeatureStore featureStore)

            throws DataException {

        super(featureStore);

    }

    public boolean select(Feature feature) {

        return select(feature, true);

    }

    /**

     * @see #select(Feature)

     * @param undoable

     *            if the action must be undoable

     */

    public boolean select(Feature feature, boolean undoable) {

        // TODO: should we check if the feature is from the same FeatureStore??

        if (feature == null) {

            return false;

        }

//        LOGGER.debug("Selected feature: {}", feature);

        if (isReversed()) {

            getFeatureTypeCount(feature.getType()).remove();

        } else {

            getFeatureTypeCount(feature.getType()).add();

        }

        return select(feature.getReference(), undoable);

    }

    public boolean select(FeatureSet features) throws DataException {

        return select(features, true);

    }

    /**

     * @see #select(FeatureSet)

     * @param undoable

     *            if the action must be undoable

     */

    public boolean select(FeatureSet features, boolean undoable)

            throws DataException {

        boolean change = false;

        if (undoable && getFeatureStore().isEditing()) {

            getCommands().startComplex("_selectionSelectFeatureSet");

        }

        disableNotifications();

        for (Iterator iter = features.fastIterator(); iter.hasNext();) {

            change |= select((Feature) iter.next(), undoable);

        }

        enableNotifications();

        if (undoable && getFeatureStore().isEditing()) {

            getCommands().endComplex();

        }

        if (change) {

            notifyObservers(DataStoreNotification.SELECTION_CHANGE);

        }

        return change;

    }

    public boolean deselect(Feature feature) {

        return deselect(feature, true);

    }

    /**

     * @see #deselect(Feature)

     * @param undoable

     *            if the action must be undoable

     */

    public boolean deselect(Feature feature, boolean undoable) {

        if (feature == null) {

            return false;

        }

        LOGGER.debug("Deselected feature: {}", feature);

        if (isReversed()) {

            getFeatureTypeCount(feature.getType()).add();

        } else {

            getFeatureTypeCount(feature.getType()).remove();

        }

        return deselect(feature.getReference(), undoable);

    }

    public boolean deselect(FeatureSet features) throws DataException {

        return deselect(features, true);

    }

    /**

     * @see #deselect(FeatureSet)

     * @param undoable

     *            if the action must be undoable

     */

    public boolean deselect(FeatureSet features, boolean undoable)

            throws DataException {

        boolean change = false;

        if (undoable && getFeatureStore().isEditing()) {

            getCommands().startComplex("_selectionDeselectFeatureSet");

        }

        disableNotifications();

        for (Iterator iter = features.fastIterator(); iter.hasNext();) {

            change |= deselect((Feature) iter.next(), undoable);

        }

        enableNotifications();

        if (undoable && getFeatureStore().isEditing()) {

            getCommands().endComplex();

        }

        if (change) {

            notifyObservers(DataStoreNotification.SELECTION_CHANGE);

        }

        return change;

    }

    public boolean isSelected(Feature feature) {

        if (feature == null) {

            return false;

        }

        return isSelected(feature.getReference());

    }

    public FeatureType getDefaultFeatureType() {

        try {

            return getFeatureStore().getDefaultFeatureType();

        } catch (DataException ex) {

            LOGGER.error("Error getting the default feature type "

                    + "of the FeatureStore: " + getFeatureStore(), ex);

        }

        return null;

    }

    public List getFeatureTypes() {

        // Go through the map of FeatureTypes, and return only the ones that

        // have at least a Feature.

        List types = new ArrayList();

        for (Iterator iterator = featureTypeCounts.entrySet().iterator(); iterator

                .hasNext();) {

            Map.Entry entry = (Entry) iterator.next();

            FeatureType type = (FeatureType) entry.getKey();

            FeatureTypeCount count = (FeatureTypeCount) entry.getValue();

            if (count.getCount() > 0) {

                types.add(type);

            }

        }

        return types;

    }

    public long getSize() throws DataException {

        return getSelectedCount();

    }

    public boolean isEmpty() throws DataException {

        return getSelectedCount() == 0;

    }

    /**

     * Returns the list of selected values, or the deselected ones if the

     * selection has been reversed.

     */

    public Iterator iterator() {

        return iterator(0);

    }

    /**

     * Returns the list of selected values, or the deselected ones if the

     * selection has been reversed.

     *

     * WARN: not very good performance implementation.

     */

    public Iterator iterator(long index) {

        return iterator(index, false);

    }

    /**

     * Returns the list of selected values, or the deselected ones if the

     * selection has been reversed.

     *

     * WARN: not really a fast implementation.

     */

    public Iterator fastIterator() {

        return fastIterator(0);

    }

    /**

     * Returns the list of selected values, or the deselected ones if the

     * selection has been reversed.

     *

     * WARN: not really a fast implementation.

     */

    public Iterator fastIterator(long index) {

        return iterator(index, true);

    }

    public void loadState(PersistentState state) throws PersistenceException {

        super.loadState(state);

        for (Iterator iterator = fastIterator(); iterator.hasNext();) {

            Feature feature = (Feature) iterator.next();

            getFeatureTypeCount(feature.getType()).add();

        }

    }

    protected void clearFeatureReferences() {

        super.clearFeatureReferences();

        featureTypeCounts.clear();

    }

    /**

     * Creates an iterator for the Selection.

     */

    private Iterator iterator(long index, boolean fastIterator) {

        if (isReversed()) {

            Iterator iter = new ReversedFeatureIteratorFacade(getData(),

                    getFeatureStore(), fastIterator);

            for (long l = 0; l < index && iter.hasNext(); l++) {

                iter.next();

            }

            return iter;

        } else {

            // TODO: maybe we could add a new referenceIterator(int index)

            // method that could be implemented in a more performant way

            Iterator iter = referenceIterator();

            for (long l = 0; l < index && iter.hasNext(); l++) {

                iter.next();

            }

            return new FeatureIteratorFacade(iter, getFeatureStore());

        }

    }

    private FeatureTypeCount getFeatureTypeCount(FeatureType featureType) {

        FeatureTypeCount count = (FeatureTypeCount) featureTypeCounts

                .get(featureType);

        if (count == null) {

            count = new FeatureTypeCount();

            featureTypeCounts.put(featureType, count);

        }

        return count;

    }

    /**

     * Facade over a Iterator of FeatureReferences, to return Features instead.

     *

     * @author <a href="mailto:cordin@disid.com">C?sar Ordi?ana</a>

     */

    private class FeatureIteratorFacade implements Iterator {

        final Logger logger = LoggerFactory

                .getLogger(FeatureIteratorFacade.class);

        private Iterator refIterator;

        private DefaultFeatureStore featureStore;

        public FeatureIteratorFacade(Iterator refIterator,

                DefaultFeatureStore featureStore) {

            this.refIterator = refIterator;

            this.featureStore = featureStore;

        }

        public boolean hasNext() {

            return refIterator.hasNext();

        }

        public Object next() {

            FeatureReference ref = nextFeatureReference();

            try {

                return featureStore.getFeatureByReference(ref);

            } catch (DataException ex) {

                logger.error(

                        "Error loading the Feature with FeatureReference: "

                                + ref, ex);

                return null;

            }

        }

        /**

         * Returns the next FeatureReference.

         *

         * @return the next FeatureReference

         */

        public FeatureReference nextFeatureReference() {

            return (FeatureReference) refIterator.next();

        }

        public void remove() {

            refIterator.remove();

        }

        /**

         * Returns a Feature for the FeatureReference.

         */

        protected Feature getFeature(FeatureReference ref) throws DataException {

            return ref.getFeature();

        }

    }

    /**

     * Facade over a Iterator of FeatureReferences, to return Features instead,

     * when the Selection is reversed

     *

     * @author <a href="mailto:cordin@disid.com">C?sar Ordi?ana</a>

     */

    private class ReversedFeatureIteratorFacade implements Iterator {

        final Logger logger = LoggerFactory

                .getLogger(ReversedFeatureIteratorFacade.class);

        private Iterator refIterator;

        private SelectionData selectionData;

        private Iterator iterator;

        private Feature nextFeature = null;

        public ReversedFeatureIteratorFacade(SelectionData selectionData,

                DefaultFeatureStore featureStore, boolean fastIterator) {

            this.selectionData = selectionData;

            // Load a Set with all the store features

            try {

                FeatureSet featureSet = featureStore.getFeatureSet();

                if (fastIterator) {

                    iterator = featureSet.fastIterator();

                } else {

                    iterator = featureSet.iterator();

                }

            } catch (DataException ex) {

                throw new ReversedSelectionIteratorException(ex);

            }

            // Filter the features not selected and position in the next

            // selected feature

            positionInNextElement();

        }

        public boolean hasNext() {

            return nextFeature != null;

        }

        public Object next() {

            Feature tmp = nextFeature;

            positionInNextElement();

            return tmp;

        }

        /**

         * Returns the next FeatureReference.

         *

         * @return the next FeatureReference

         */

        public FeatureReference nextFeatureReference() {

            return (FeatureReference) refIterator.next();

        }

        public void remove() {

            iterator.remove();

        }

        private void positionInNextElement() {

            nextFeature = null;

            while (iterator.hasNext()) {

                nextFeature = (Feature) iterator.next();

                if (selectionData.contains(nextFeature.getReference())) {

                    nextFeature = null;

                } else {

                    break;

                }

            }

        }

    }

    private class FeatureTypeCount {

        private long count = 0;

        public void add() {

            count++;

        }

        public void remove() {

            count--;

        }

        public long getCount() {

            return count;

        }

    }

    public void delete(Feature feature) throws DataException {

        throw new UnsupportedOperationException();

    }

    public void insert(EditableFeature feature) throws DataException {

        throw new UnsupportedOperationException();

    }

    public void update(EditableFeature feature) throws DataException {

        throw new UnsupportedOperationException();

    }

}