001// License: GPL. For details, see LICENSE file.
002package org.openstreetmap.josm.actions;
003
004import static org.openstreetmap.josm.tools.I18n.tr;
005
006import java.awt.Component;
007import java.awt.event.ActionEvent;
008import java.lang.ref.WeakReference;
009import java.util.ArrayList;
010import java.util.Iterator;
011import java.util.List;
012
013import org.openstreetmap.josm.Main;
014
015/**
016 * This action toggles the Expert mode.
017 * @since 4840
018 */
019public class ExpertToggleAction extends ToggleAction {
020
021    public interface ExpertModeChangeListener {
022        void expertChanged(boolean isExpert);
023    }
024
025    private static final List<WeakReference<ExpertModeChangeListener>> listeners = new ArrayList<>();
026    private static final List<WeakReference<Component>> visibilityToggleListeners = new ArrayList<>();
027
028    private static final ExpertToggleAction INSTANCE = new ExpertToggleAction();
029
030    private static synchronized void fireExpertModeChanged(boolean isExpert) {
031        Iterator<WeakReference<ExpertModeChangeListener>> it1 = listeners.iterator();
032        while (it1.hasNext()) {
033            WeakReference<ExpertModeChangeListener> wr = it1.next();
034            ExpertModeChangeListener listener = wr.get();
035            if (listener == null) {
036                it1.remove();
037                continue;
038            }
039            listener.expertChanged(isExpert);
040        }
041        Iterator<WeakReference<Component>> it2 = visibilityToggleListeners.iterator();
042        while (it2.hasNext()) {
043            WeakReference<Component> wr = it2.next();
044            Component c = wr.get();
045            if (c == null) {
046                it2.remove();
047                continue;
048            }
049            c.setVisible(isExpert);
050        }
051    }
052
053    /**
054     * Register a expert mode change listener
055     *
056     * @param listener the listener. Ignored if null.
057     */
058    public static void addExpertModeChangeListener(ExpertModeChangeListener listener) {
059        addExpertModeChangeListener(listener, false);
060    }
061
062    public static synchronized void addExpertModeChangeListener(ExpertModeChangeListener listener, boolean fireWhenAdding) {
063        if (listener == null) return;
064        for (WeakReference<ExpertModeChangeListener> wr : listeners) {
065            // already registered ? => abort
066            if (wr.get() == listener) return;
067        }
068        listeners.add(new WeakReference<>(listener));
069        if (fireWhenAdding) {
070            listener.expertChanged(isExpert());
071        }
072    }
073
074    /**
075     * Removes a expert mode change listener
076     *
077     * @param listener the listener. Ignored if null.
078     */
079    public static synchronized void removeExpertModeChangeListener(ExpertModeChangeListener listener) {
080        if (listener == null) return;
081        Iterator<WeakReference<ExpertModeChangeListener>> it = listeners.iterator();
082        while (it.hasNext()) {
083            WeakReference<ExpertModeChangeListener> wr = it.next();
084            // remove the listener - and any other listener which god garbage
085            // collected in the meantime
086            if (wr.get() == null || wr.get() == listener) {
087                it.remove();
088            }
089        }
090    }
091
092    public static synchronized void addVisibilitySwitcher(Component c) {
093        if (c == null) return;
094        for (WeakReference<Component> wr : visibilityToggleListeners) {
095            // already registered ? => abort
096            if (wr.get() == c) return;
097        }
098        visibilityToggleListeners.add(new WeakReference<>(c));
099        c.setVisible(isExpert());
100    }
101
102    public static synchronized void removeVisibilitySwitcher(Component c) {
103        if (c == null) return;
104        Iterator<WeakReference<Component>> it = visibilityToggleListeners.iterator();
105        while (it.hasNext()) {
106            WeakReference<Component> wr = it.next();
107            // remove the listener - and any other listener which god garbage
108            // collected in the meantime
109            if (wr.get() == null || wr.get() == c) {
110                it.remove();
111            }
112        }
113    }
114
115    /**
116     * Constructs a new {@code ExpertToggleAction}.
117     */
118    public ExpertToggleAction() {
119        super(tr("Expert Mode"),
120              "expert",
121              tr("Enable/disable expert mode"),
122              null,
123              false /* register toolbar */
124        );
125        putValue("toolbar", "expertmode");
126        if (Main.toolbar != null) {
127            Main.toolbar.register(this);
128        }
129        setSelected(Main.pref.getBoolean("expert", false));
130        notifySelectedState();
131    }
132
133    @Override
134    protected final void notifySelectedState() {
135        super.notifySelectedState();
136        fireExpertModeChanged(isSelected());
137    }
138
139    @Override
140    public void actionPerformed(ActionEvent e) {
141        toggleSelectedState(e);
142        Main.pref.put("expert", isSelected());
143        notifySelectedState();
144    }
145
146    /**
147     * Replies the unique instance of this action.
148     * @return The unique instance of this action
149     */
150    public static ExpertToggleAction getInstance() {
151        return INSTANCE;
152    }
153
154    /**
155     * Determines if expert mode is enabled.
156     * @return {@code true} if expert mode is enabled, {@code false} otherwise.
157     */
158    public static boolean isExpert() {
159        return INSTANCE.isSelected();
160    }
161}