001package jmri.jmrit.logix;
002
003import java.beans.PropertyChangeEvent;
004import java.beans.PropertyChangeListener;
005import java.beans.PropertyChangeSupport;
006
007import java.util.*;
008
009import javax.annotation.Nonnull;
010import javax.annotation.OverridingMethodsMustInvokeSuper;
011
012/**
013 * Basic implementation of a PortalManager.
014 * <p>
015 * Note that this does not enforce any particular system naming convention.
016 * <p>
017 * Note this is an 'after thought' manager. Portals have been in use since 2009.
018 * Their use has now expanded well beyond what was expected. A Portal factory is
019 * needed for development to continue.
020 *
021 * Portal system names will be numbers and they will not be shown to users. The
022 * UI will treat Portal names as it does now as user names.
023 *
024 * <hr>
025 * This file is part of JMRI.
026 * <p>
027 * JMRI is free software; you can redistribute it and/or modify it under the
028 * terms of version 2 of the GNU General Public License as published by the Free
029 * Software Foundation. See the "COPYING" file for a copy of this license.
030 * <p>
031 * JMRI is distributed in the hope that it will be useful, but WITHOUT ANY
032 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
033 * A PARTICULAR PURPOSE. See the GNU General Public License for more details.
034 *
035 * @author Pete Cressman Copyright (C) 2014
036 */
037public class PortalManager implements jmri.InstanceManagerAutoDefault, PropertyChangeListener {
038
039    private final PropertyChangeSupport pcs = new PropertyChangeSupport(this);
040    private final ArrayList<Portal> _nameList = new ArrayList<>();          // stores Portal in loaded order
041    private final HashMap<String, Portal> _portalMap = new HashMap<>(); // stores portal by current name
042
043    /**
044     * String constant for the property num portals.
045     */
046    public static final String PROPERTY_NUM_PORTALS = "numPortals";
047
048    public PortalManager() {
049        // no setup currently required
050    }
051
052    public int getPortalCount() {
053        return _nameList.size();
054    }
055
056    public Portal getPortal(int idx) {
057        return _nameList.get(idx);
058    }
059
060    public int getIndexOf(Portal portal) {
061        return _nameList.indexOf(portal);
062    }
063
064    public Portal getPortal(String name) {
065        return _portalMap.get(name);
066    }
067
068    public Collection<Portal> getPortalSet() {
069        return Collections.unmodifiableCollection(_nameList);
070    }
071
072    /*
073     * Create a new Portal with a given user name.
074     *
075     * @return null if a Portal with the same userName already exists,
076     * or if an empty userName was requested
077     */
078    public Portal createNewPortal(@Nonnull String userName) {
079        java.util.Objects.requireNonNull(userName, "Name cannot be null");
080        // Check that Portal does not already exist
081        Portal portal;
082        if (userName.trim().length() > 0) {
083            portal = _portalMap.get(userName);
084            if (portal != null) {
085                return null;
086            }
087        } else {  // must have a user name for backward compatibility
088            return null;
089        }
090        // Portal does not exist, create a new Portal
091        portal = new Portal(userName);
092        // save in the maps
093        _nameList.add(portal);
094        _portalMap.put(userName, portal);
095        pcs.firePropertyChange(PROPERTY_NUM_PORTALS, null, _nameList.size());
096        // listen for name and state changes to forward
097        portal.addPropertyChangeListener(this);
098        return portal;
099    }
100
101    public Portal providePortal(String name) {
102        if (name == null || name.trim().length() == 0) {
103            return null;
104        }
105        Portal portal = getPortal(name);
106        if (portal == null) {
107            portal = createNewPortal(name);
108        }
109        return portal;
110    }
111
112    private synchronized void deletePortal(Portal portal) {
113        String name = portal.getName();
114        _nameList.remove(portal);
115        _portalMap.remove(name);
116        pcs.firePropertyChange(PROPERTY_NUM_PORTALS, portal, _nameList.size());
117    }
118
119    @OverridingMethodsMustInvokeSuper
120    public synchronized void addPropertyChangeListener(PropertyChangeListener l) {
121        pcs.addPropertyChangeListener(l);
122    }
123
124    @OverridingMethodsMustInvokeSuper
125    public synchronized void removePropertyChangeListener(PropertyChangeListener l) {
126        pcs.removePropertyChangeListener(l);
127    }
128
129    @Override
130    public void propertyChange(PropertyChangeEvent e) {
131        if (!(e.getSource() instanceof Portal)) {
132            return;
133        }
134        Portal portal = (Portal)e.getSource();
135        String propertyName = e.getPropertyName();
136        log.debug("property = {}", propertyName);
137        if (Portal.PROPERTY_PORTAL_DELETE.equals(propertyName)) {
138            deletePortal(portal);
139        }
140    }
141
142    private static final org.slf4j.Logger log = org.slf4j.LoggerFactory.getLogger(PortalManager.class);
143
144}