| 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.ArrayList;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import java.util.Map.Entry;

import org.gvsig.fmap.dal.DataStoreNotification;

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

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

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

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

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

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

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

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

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

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

import org.gvsig.tools.ToolsLocator;

import org.gvsig.tools.dynobject.DynClass;

import org.gvsig.tools.dynobject.DynObjectManager;

import org.gvsig.tools.exception.BaseException;

import org.gvsig.tools.persistence.PersistenceException;

import org.gvsig.tools.persistence.PersistentState;

import org.gvsig.tools.visitor.Visitor;

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);

        }

        /**

         * Creates a new Selection with the total size of Features from which the

         * selection will be performed.

         *

         * @param featureStore

         *            the FeatureStore of the selected FeatureReferences

         * @param helper

         *            to get some information of the Store

         * @throws DataException

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

         *             Features of the Store.

         */

        public DefaultFeatureSelection(FeatureStore featureStore,

                        FeatureSelectionHelper helper) throws DataException {

                super(featureStore, helper);

        }

         /**

     * Constructor used by the persistence manager. Don't use directly.

     * After to invoke this method, the persistence manager calls 

     * the the method {@link #loadFromState(PersistentState)} to set 

     * the values of the internal attributes that this class needs to work.

     */

        public DefaultFeatureSelection() {

                super();

        }

        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()) {

                        removeFeatureTypeCount(feature.getType());

                } else {

                        addFeatureTypeCount(feature.getType());

                }

                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;

                boolean inComplex = false;

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

                                && !getCommands().inComplex()) {

                        inComplex = getCommands().inComplex();

                        getCommands().startComplex("_selectionSelectFeatureSet");

                }

                disableNotifications();

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

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

                }

                enableNotifications();

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

                        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()) {

                        addFeatureTypeCount(feature.getType());

                } else {

                        removeFeatureTypeCount(feature.getType());

                }

                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 (DisposableIterator 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 (java.util.Iterator iterator = featureTypeCounts.entrySet()

                                .iterator(); iterator

                                .hasNext();) {

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

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

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

                        if (count.longValue() > 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 DisposableIterator 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 DisposableIterator 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 DisposableIterator 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 DisposableIterator fastIterator(long index) {

                return iterator(index, true);

        }

        protected void clearFeatureReferences() {

                super.clearFeatureReferences();

                featureTypeCounts.clear();

        }

        /**

         * Creates an iterator for the Selection.

         */

        private DisposableIterator iterator(long index, boolean fastIterator) {

                if (isReversed()) {

                        DisposableIterator 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

                        java.util.Iterator iter = referenceIterator();

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

                                iter.next();

                        }

                        return new FeatureIteratorFacade(iter, getFeatureStore());

                }

        }

        private Long removeFeatureTypeCount(FeatureType featureType) {

                Long count = (Long) featureTypeCounts.get(featureType);

                if (count == null) {

                        count = new Long(-1);

                } else {

                        count = new Long(count.longValue() - 1);

                }

                featureTypeCounts.put(featureType, count);

                return count;

        }

        private Long addFeatureTypeCount(FeatureType featureType) {

                Long count = (Long) featureTypeCounts.get(featureType);

                if (count == null) {

                        count = new Long(1);

                } else {

                        count = new Long(count.longValue() + 1);

                }

                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 DisposableIterator {

                final Logger logger = LoggerFactory

                .getLogger(FeatureIteratorFacade.class);

                private java.util.Iterator refIterator;

                private FeatureStore featureStore;

                public FeatureIteratorFacade(java.util.Iterator iter,

                                FeatureStore featureStore) {

                        this.refIterator = iter;

                        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();

                }

                public void dispose() {

                        if (refIterator instanceof DisposableIterator) {

                                ((DisposableIterator) refIterator).dispose();

                        }

                        refIterator = null;

                        featureStore = null;

                }

        }

        /**

         * 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 DisposableIterator {

                private SelectionData selectionData;

                private DisposableIterator iterator;

                private Feature nextFeature = null;

                private FeatureSet featureSet;

                public ReversedFeatureIteratorFacade(SelectionData selectionData,

                                FeatureStore featureStore, boolean fastIterator) {

                        this.selectionData = selectionData;

                        // Load a Set with all the store features

                        try {

                                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;

                }

                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;

                                }

                        }

                }

                public void dispose() {

                        this.featureSet.dispose();

                        this.iterator.dispose();

                        this.selectionData = null;

                        this.nextFeature = null;

                }

        }

        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();

        }

        /*

         * (non-Javadoc)

         *

         * @seeorg.gvsig.fmap.dal.feature.impl.DefaultFeatureReferenceSelection#

         * loadFromState(org.gvsig.tools.persistence.PersistentState)

         */

        public void loadFromState(PersistentState state)

        throws PersistenceException {

                super.loadFromState(state);

        }

        public void accept(Visitor visitor) throws BaseException {

                accept(visitor, 0);

        }

        public void accept(Visitor visitor, long firstValueIndex)

        throws BaseException {

                DisposableIterator iterator = fastIterator(firstValueIndex);

                if (iterator != null) {

                        try {

                                while (iterator.hasNext()) {

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

                                        visitor.visit(feature);

                                }

                        } finally {

                                iterator.dispose();

                        }

                }

        }

        public static void registerPersistent() {

                DynObjectManager dynMan = ToolsLocator.getDynObjectManager();

                DynClass dynClass = dynMan.add(

                                "DefaultFeatureSelection_Persistent",

                "DefaultFeatureSelection Persistent definition");

                dynClass

                .extend(DefaultFeatureReferenceSelection.DYNCLASS_PERSISTENT_NAME);

                dynClass.addDynFieldMap("featureTypeCounts").setMandatory(true);

                ToolsLocator.getPersistenceManager().registerClass(

                                DefaultFeatureSelection.class, dynClass);

        }

}