001// License: GPL. For details, see LICENSE file.
002package org.openstreetmap.josm.actions;
003
004import static org.openstreetmap.josm.gui.help.HelpUtil.ht;
005import static org.openstreetmap.josm.tools.I18n.tr;
006
007import java.awt.event.ActionEvent;
008import java.awt.event.KeyEvent;
009import java.util.ArrayList;
010import java.util.Arrays;
011import java.util.Collection;
012import java.util.Collections;
013import java.util.HashMap;
014import java.util.HashSet;
015import java.util.Iterator;
016import java.util.LinkedList;
017import java.util.List;
018import java.util.Map;
019import java.util.Set;
020
021import javax.swing.JOptionPane;
022
023import org.openstreetmap.josm.Main;
024import org.openstreetmap.josm.command.Command;
025import org.openstreetmap.josm.command.MoveCommand;
026import org.openstreetmap.josm.command.SequenceCommand;
027import org.openstreetmap.josm.data.coor.EastNorth;
028import org.openstreetmap.josm.data.osm.Node;
029import org.openstreetmap.josm.data.osm.OsmPrimitive;
030import org.openstreetmap.josm.data.osm.Way;
031import org.openstreetmap.josm.gui.ConditionalOptionPaneUtil;
032import org.openstreetmap.josm.gui.Notification;
033import org.openstreetmap.josm.tools.JosmRuntimeException;
034import org.openstreetmap.josm.tools.Shortcut;
035
036/**
037 * Tools / Orthogonalize
038 *
039 * Align edges of a way so all angles are angles of 90 or 180 degrees.
040 * See USAGE String below.
041 */
042public final class OrthogonalizeAction extends JosmAction {
043    private static final String USAGE = tr(
044            "<h3>When one or more ways are selected, the shape is adjusted such, that all angles are 90 or 180 degrees.</h3>"+
045            "You can add two nodes to the selection. Then, the direction is fixed by these two reference nodes. "+
046            "(Afterwards, you can undo the movement for certain nodes:<br>"+
047            "Select them and press the shortcut for Orthogonalize / Undo. The default is Shift-Q.)");
048
049    private static final double EPSILON = 1E-6;
050
051    /**
052     * Constructs a new {@code OrthogonalizeAction}.
053     */
054    public OrthogonalizeAction() {
055        super(tr("Orthogonalize Shape"),
056                "ortho",
057                tr("Move nodes so all angles are 90 or 180 degrees"),
058                Shortcut.registerShortcut("tools:orthogonalize", tr("Tool: {0}", tr("Orthogonalize Shape")),
059                        KeyEvent.VK_Q,
060                        Shortcut.DIRECT), true);
061        putValue("help", ht("/Action/OrthogonalizeShape"));
062    }
063
064    /**
065     * excepted deviation from an angle of 0, 90, 180, 360 degrees
066     * maximum value: 45 degrees
067     *
068     * Current policy is to except just everything, no matter how strange the result would be.
069     */
070    private static final double TOLERANCE1 = Math.toRadians(45.);   // within a way
071    private static final double TOLERANCE2 = Math.toRadians(45.);   // ways relative to each other
072
073    /**
074     * Remember movements, so the user can later undo it for certain nodes
075     */
076    private static final Map<Node, EastNorth> rememberMovements = new HashMap<>();
077
078    /**
079     * Undo the previous orthogonalization for certain nodes.
080     *
081     * This is useful, if the way shares nodes that you don't like to change, e.g. imports or
082     * work of another user.
083     *
084     * This action can be triggered by shortcut only.
085     */
086    public static class Undo extends JosmAction {
087        /**
088         * Constructor
089         */
090        public Undo() {
091            super(tr("Orthogonalize Shape / Undo"), "ortho",
092                    tr("Undo orthogonalization for certain nodes"),
093                    Shortcut.registerShortcut("tools:orthogonalizeUndo", tr("Tool: {0}", tr("Orthogonalize Shape / Undo")),
094                            KeyEvent.VK_Q,
095                            Shortcut.SHIFT),
096                    true, "action/orthogonalize/undo", true);
097        }
098
099        @Override
100        public void actionPerformed(ActionEvent e) {
101            if (!isEnabled())
102                return;
103            final Collection<Command> commands = new LinkedList<>();
104            final Collection<OsmPrimitive> sel = getLayerManager().getEditDataSet().getSelected();
105            try {
106                for (OsmPrimitive p : sel) {
107                    if (!(p instanceof Node)) throw new InvalidUserInputException("selected object is not a node");
108                    Node n = (Node) p;
109                    if (rememberMovements.containsKey(n)) {
110                        EastNorth tmp = rememberMovements.get(n);
111                        commands.add(new MoveCommand(n, -tmp.east(), -tmp.north()));
112                        rememberMovements.remove(n);
113                    }
114                }
115                if (!commands.isEmpty()) {
116                    Main.main.undoRedo.add(new SequenceCommand(tr("Orthogonalize / Undo"), commands));
117                } else {
118                    throw new InvalidUserInputException("Commands are empty");
119                }
120            } catch (InvalidUserInputException ex) {
121                Main.debug(ex);
122                new Notification(
123                        tr("Orthogonalize Shape / Undo<br>"+
124                        "Please select nodes that were moved by the previous Orthogonalize Shape action!"))
125                        .setIcon(JOptionPane.INFORMATION_MESSAGE)
126                        .show();
127            }
128        }
129
130        @Override
131        protected void updateEnabledState() {
132            updateEnabledStateOnCurrentSelection();
133        }
134
135        @Override
136        protected void updateEnabledState(Collection<? extends OsmPrimitive> selection) {
137            setEnabled(selection != null && !selection.isEmpty());
138        }
139    }
140
141    @Override
142    public void actionPerformed(ActionEvent e) {
143        if (!isEnabled())
144            return;
145        if ("EPSG:4326".equals(Main.getProjection().toString())) {
146            String msg = tr("<html>You are using the EPSG:4326 projection which might lead<br>" +
147                    "to undesirable results when doing rectangular alignments.<br>" +
148                    "Change your projection to get rid of this warning.<br>" +
149            "Do you want to continue?</html>");
150            if (!ConditionalOptionPaneUtil.showConfirmationDialog(
151                    "align_rectangular_4326",
152                    Main.parent,
153                    msg,
154                    tr("Warning"),
155                    JOptionPane.YES_NO_OPTION,
156                    JOptionPane.QUESTION_MESSAGE,
157                    JOptionPane.YES_OPTION))
158                return;
159        }
160
161        final Collection<OsmPrimitive> sel = getLayerManager().getEditDataSet().getSelected();
162
163        try {
164            final SequenceCommand command = orthogonalize(sel);
165            Main.main.undoRedo.add(new SequenceCommand(tr("Orthogonalize"), command));
166        } catch (InvalidUserInputException ex) {
167            Main.debug(ex);
168            String msg;
169            if ("usage".equals(ex.getMessage())) {
170                msg = "<h2>" + tr("Usage") + "</h2>" + USAGE;
171            } else {
172                msg = ex.getMessage() + "<br><hr><h2>" + tr("Usage") + "</h2>" + USAGE;
173            }
174            new Notification(msg)
175                    .setIcon(JOptionPane.INFORMATION_MESSAGE)
176                    .setDuration(Notification.TIME_DEFAULT)
177                    .show();
178        }
179    }
180
181    /**
182     * Rectifies the selection
183     * @param selection the selection which should be rectified
184     * @return a rectifying command
185     * @throws InvalidUserInputException if the selection is invalid
186     */
187    static SequenceCommand orthogonalize(Iterable<OsmPrimitive> selection) throws InvalidUserInputException {
188        final List<Node> nodeList = new ArrayList<>();
189        final List<WayData> wayDataList = new ArrayList<>();
190        // collect nodes and ways from the selection
191        for (OsmPrimitive p : selection) {
192            if (p instanceof Node) {
193                nodeList.add((Node) p);
194            } else if (p instanceof Way) {
195                wayDataList.add(new WayData(((Way) p).getNodes()));
196            } else {
197                throw new InvalidUserInputException(tr("Selection must consist only of ways and nodes."));
198            }
199        }
200        if (wayDataList.isEmpty() && nodeList.size() > 2) {
201            final WayData data = new WayData(nodeList);
202            final Collection<Command> commands = orthogonalize(Collections.singletonList(data), Collections.<Node>emptyList());
203            return new SequenceCommand(tr("Orthogonalize"), commands);
204        } else if (wayDataList.isEmpty()) {
205            throw new InvalidUserInputException("usage");
206        } else {
207            if (nodeList.size() == 2 || nodeList.isEmpty()) {
208                OrthogonalizeAction.rememberMovements.clear();
209                final Collection<Command> commands = new LinkedList<>();
210
211                if (nodeList.size() == 2) {  // fixed direction
212                    commands.addAll(orthogonalize(wayDataList, nodeList));
213                } else if (nodeList.isEmpty()) {
214                    List<List<WayData>> groups = buildGroups(wayDataList);
215                    for (List<WayData> g: groups) {
216                        commands.addAll(orthogonalize(g, nodeList));
217                    }
218                } else {
219                    throw new IllegalStateException();
220                }
221
222                return new SequenceCommand(tr("Orthogonalize"), commands);
223
224            } else {
225                throw new InvalidUserInputException("usage");
226            }
227        }
228    }
229
230    /**
231     * Collect groups of ways with common nodes in order to orthogonalize each group separately.
232     * @param wayDataList list of ways
233     * @return groups of ways with common nodes
234     */
235    private static List<List<WayData>> buildGroups(List<WayData> wayDataList) {
236        List<List<WayData>> groups = new ArrayList<>();
237        Set<WayData> remaining = new HashSet<>(wayDataList);
238        while (!remaining.isEmpty()) {
239            List<WayData> group = new ArrayList<>();
240            groups.add(group);
241            Iterator<WayData> it = remaining.iterator();
242            WayData next = it.next();
243            it.remove();
244            extendGroupRec(group, next, new ArrayList<>(remaining));
245            remaining.removeAll(group);
246        }
247        return groups;
248    }
249
250    private static void extendGroupRec(List<WayData> group, WayData newGroupMember, List<WayData> remaining) {
251        group.add(newGroupMember);
252        for (int i = 0; i < remaining.size(); ++i) {
253            WayData candidate = remaining.get(i);
254            if (candidate == null) continue;
255            if (!Collections.disjoint(candidate.wayNodes, newGroupMember.wayNodes)) {
256                remaining.set(i, null);
257                extendGroupRec(group, candidate, remaining);
258            }
259        }
260    }
261
262    /**
263     *
264     *  Outline:
265     *  1. Find direction of all segments
266     *      - direction = 0..3 (right,up,left,down)
267     *      - right is not really right, you may have to turn your screen
268     *  2. Find average heading of all segments
269     *      - heading = angle of a vector in polar coordinates
270     *      - sum up horizontal segments (those with direction 0 or 2)
271     *      - sum up vertical segments
272     *      - turn the vertical sum by 90 degrees and add it to the horizontal sum
273     *      - get the average heading from this total sum
274     *  3. Rotate all nodes by the average heading so that right is really right
275     *      and all segments are approximately NS or EW.
276     *  4. If nodes are connected by a horizontal segment: Replace their y-Coordinate by
277     *      the mean value of their y-Coordinates.
278     *      - The same for vertical segments.
279     *  5. Rotate back.
280     * @param wayDataList list of ways
281     * @param headingNodes list of heading nodes
282     * @return list of commands to perform
283     * @throws InvalidUserInputException if selected ways have an angle different from 90 or 180 degrees
284     **/
285    private static Collection<Command> orthogonalize(List<WayData> wayDataList, List<Node> headingNodes) throws InvalidUserInputException {
286        // find average heading
287        double headingAll;
288        try {
289            if (headingNodes.isEmpty()) {
290                // find directions of the segments and make them consistent between different ways
291                wayDataList.get(0).calcDirections(Direction.RIGHT);
292                double refHeading = wayDataList.get(0).heading;
293                EastNorth totSum = new EastNorth(0., 0.);
294                for (WayData w : wayDataList) {
295                    w.calcDirections(Direction.RIGHT);
296                    int directionOffset = angleToDirectionChange(w.heading - refHeading, TOLERANCE2);
297                    w.calcDirections(Direction.RIGHT.changeBy(directionOffset));
298                    if (angleToDirectionChange(refHeading - w.heading, TOLERANCE2) != 0)
299                        throw new JosmRuntimeException("orthogonalize error");
300                    totSum = EN.sum(totSum, w.segSum);
301                }
302                headingAll = EN.polar(new EastNorth(0., 0.), totSum);
303            } else {
304                headingAll = EN.polar(headingNodes.get(0).getEastNorth(), headingNodes.get(1).getEastNorth());
305                for (WayData w : wayDataList) {
306                    w.calcDirections(Direction.RIGHT);
307                    int directionOffset = angleToDirectionChange(w.heading - headingAll, TOLERANCE2);
308                    w.calcDirections(Direction.RIGHT.changeBy(directionOffset));
309                }
310            }
311        } catch (RejectedAngleException ex) {
312            throw new InvalidUserInputException(
313                    tr("<html>Please make sure all selected ways head in a similar direction<br>"+
314                    "or orthogonalize them one by one.</html>"), ex);
315        }
316
317        // put the nodes of all ways in a set
318        final Set<Node> allNodes = new HashSet<>();
319        for (WayData w : wayDataList) {
320            allNodes.addAll(w.wayNodes);
321        }
322
323        // the new x and y value for each node
324        final Map<Node, Double> nX = new HashMap<>();
325        final Map<Node, Double> nY = new HashMap<>();
326
327        // calculate the centroid of all nodes
328        // it is used as rotation center
329        EastNorth pivot = new EastNorth(0., 0.);
330        for (Node n : allNodes) {
331            pivot = EN.sum(pivot, n.getEastNorth());
332        }
333        pivot = new EastNorth(pivot.east() / allNodes.size(), pivot.north() / allNodes.size());
334
335        // rotate
336        for (Node n: allNodes) {
337            EastNorth tmp = EN.rotateCC(pivot, n.getEastNorth(), -headingAll);
338            nX.put(n, tmp.east());
339            nY.put(n, tmp.north());
340        }
341
342        // orthogonalize
343        final Direction[] horizontal = {Direction.RIGHT, Direction.LEFT};
344        final Direction[] vertical = {Direction.UP, Direction.DOWN};
345        final Direction[][] orientations = {horizontal, vertical};
346        for (Direction[] orientation : orientations) {
347            final Set<Node> s = new HashSet<>(allNodes);
348            int size = s.size();
349            for (int dummy = 0; dummy < size; ++dummy) {
350                if (s.isEmpty()) {
351                    break;
352                }
353                final Node dummyN = s.iterator().next();     // pick arbitrary element of s
354
355                final Set<Node> cs = new HashSet<>(); // will contain each node that can be reached from dummyN
356                cs.add(dummyN);                      // walking only on horizontal / vertical segments
357
358                boolean somethingHappened = true;
359                while (somethingHappened) {
360                    somethingHappened = false;
361                    for (WayData w : wayDataList) {
362                        for (int i = 0; i < w.nSeg; ++i) {
363                            Node n1 = w.wayNodes.get(i);
364                            Node n2 = w.wayNodes.get(i+1);
365                            if (Arrays.asList(orientation).contains(w.segDirections[i])) {
366                                if (cs.contains(n1) && !cs.contains(n2)) {
367                                    cs.add(n2);
368                                    somethingHappened = true;
369                                }
370                                if (cs.contains(n2) && !cs.contains(n1)) {
371                                    cs.add(n1);
372                                    somethingHappened = true;
373                                }
374                            }
375                        }
376                    }
377                }
378
379                final Map<Node, Double> nC = (orientation == horizontal) ? nY : nX;
380
381                double average = 0;
382                for (Node n : cs) {
383                    s.remove(n);
384                    average += nC.get(n).doubleValue();
385                }
386                average = average / cs.size();
387
388                // if one of the nodes is a heading node, forget about the average and use its value
389                for (Node fn : headingNodes) {
390                    if (cs.contains(fn)) {
391                        average = nC.get(fn);
392                    }
393                }
394
395                // At this point, the two heading nodes (if any) are horizontally aligned, i.e. they
396                // have the same y coordinate. So in general we shouldn't find them in a vertical string
397                // of segments. This can still happen in some pathological cases (see #7889). To avoid
398                // both heading nodes collapsing to one point, we simply skip this segment string and
399                // don't touch the node coordinates.
400                if (orientation == vertical && headingNodes.size() == 2 && cs.containsAll(headingNodes)) {
401                    continue;
402                }
403
404                for (Node n : cs) {
405                    nC.put(n, average);
406                }
407            }
408            if (!s.isEmpty()) throw new JosmRuntimeException("orthogonalize error");
409        }
410
411        // rotate back and log the change
412        final Collection<Command> commands = new LinkedList<>();
413        for (Node n: allNodes) {
414            EastNorth tmp = new EastNorth(nX.get(n), nY.get(n));
415            tmp = EN.rotateCC(pivot, tmp, headingAll);
416            final double dx = tmp.east() - n.getEastNorth().east();
417            final double dy = tmp.north() - n.getEastNorth().north();
418            if (headingNodes.contains(n)) { // The heading nodes should not have changed
419                if (Math.abs(dx) > Math.abs(EPSILON * tmp.east()) ||
420                    Math.abs(dy) > Math.abs(EPSILON * tmp.east()))
421                    throw new AssertionError("heading node has changed");
422            } else {
423                OrthogonalizeAction.rememberMovements.put(n, new EastNorth(dx, dy));
424                commands.add(new MoveCommand(n, dx, dy));
425            }
426        }
427        return commands;
428    }
429
430    /**
431     * Class contains everything we need to know about a single way.
432     */
433    private static class WayData {
434        public final List<Node> wayNodes;       // The assigned way
435        public final int nSeg;                  // Number of Segments of the Way
436        public final int nNode;                 // Number of Nodes of the Way
437        public final Direction[] segDirections; // Direction of the segments
438        // segment i goes from node i to node (i+1)
439        public EastNorth segSum;          // (Vector-)sum of all horizontal segments plus the sum of all vertical
440        // segments turned by 90 degrees
441        public double heading;            // heading of segSum == approximate heading of the way
442
443        WayData(List<Node> wayNodes) {
444            this.wayNodes = wayNodes;
445            this.nNode = wayNodes.size();
446            this.nSeg = nNode - 1;
447            this.segDirections = new Direction[nSeg];
448        }
449
450        /**
451         * Estimate the direction of the segments, given the first segment points in the
452         * direction <code>pInitialDirection</code>.
453         * Then sum up all horizontal / vertical segments to have a good guess for the
454         * heading of the entire way.
455         * @param pInitialDirection initial direction
456         * @throws InvalidUserInputException if selected ways have an angle different from 90 or 180 degrees
457         */
458        public void calcDirections(Direction pInitialDirection) throws InvalidUserInputException {
459            final EastNorth[] en = new EastNorth[nNode]; // alias: wayNodes.get(i).getEastNorth() ---> en[i]
460            for (int i = 0; i < nNode; i++) {
461                en[i] = wayNodes.get(i).getEastNorth();
462            }
463            Direction direction = pInitialDirection;
464            segDirections[0] = direction;
465            for (int i = 0; i < nSeg - 1; i++) {
466                double h1 = EN.polar(en[i], en[i+1]);
467                double h2 = EN.polar(en[i+1], en[i+2]);
468                try {
469                    direction = direction.changeBy(angleToDirectionChange(h2 - h1, TOLERANCE1));
470                } catch (RejectedAngleException ex) {
471                    throw new InvalidUserInputException(tr("Please select ways with angles of approximately 90 or 180 degrees."), ex);
472                }
473                segDirections[i+1] = direction;
474            }
475
476            // sum up segments
477            EastNorth h = new EastNorth(0., 0.);
478            EastNorth v = new EastNorth(0., 0.);
479            for (int i = 0; i < nSeg; ++i) {
480                EastNorth segment = EN.diff(en[i+1], en[i]);
481                if (segDirections[i] == Direction.RIGHT) {
482                    h = EN.sum(h, segment);
483                } else if (segDirections[i] == Direction.UP) {
484                    v = EN.sum(v, segment);
485                } else if (segDirections[i] == Direction.LEFT) {
486                    h = EN.diff(h, segment);
487                } else if (segDirections[i] == Direction.DOWN) {
488                    v = EN.diff(v, segment);
489                } else throw new IllegalStateException();
490            }
491            // rotate the vertical vector by 90 degrees (clockwise) and add it to the horizontal vector
492            segSum = EN.sum(h, new EastNorth(v.north(), -v.east()));
493            this.heading = EN.polar(new EastNorth(0., 0.), segSum);
494        }
495    }
496
497    private enum Direction {
498        RIGHT, UP, LEFT, DOWN;
499        public Direction changeBy(int directionChange) {
500            int tmp = (this.ordinal() + directionChange) % 4;
501            if (tmp < 0) {
502                tmp += 4;          // the % operator can return negative value
503            }
504            return Direction.values()[tmp];
505        }
506    }
507
508    /**
509     * Make sure angle (up to 2*Pi) is in interval [ 0, 2*Pi ).
510     * @param a angle
511     * @return correct angle
512     */
513    private static double standardAngle0to2PI(double a) {
514        while (a >= 2 * Math.PI) {
515            a -= 2 * Math.PI;
516        }
517        while (a < 0) {
518            a += 2 * Math.PI;
519        }
520        return a;
521    }
522
523    /**
524     * Make sure angle (up to 2*Pi) is in interval ( -Pi, Pi ].
525     * @param a angle
526     * @return correct angle
527     */
528    private static double standardAngleMPItoPI(double a) {
529        while (a > Math.PI) {
530            a -= 2 * Math.PI;
531        }
532        while (a <= -Math.PI) {
533            a += 2 * Math.PI;
534        }
535        return a;
536    }
537
538    /**
539     * Class contains some auxiliary functions
540     */
541    private static final class EN {
542        private EN() {
543            // Hide implicit public constructor for utility class
544        }
545
546        /**
547         * Rotate counter-clock-wise.
548         * @param pivot pivot
549         * @param en original east/north
550         * @param angle angle, in radians
551         * @return new east/north
552         */
553        public static EastNorth rotateCC(EastNorth pivot, EastNorth en, double angle) {
554            double cosPhi = Math.cos(angle);
555            double sinPhi = Math.sin(angle);
556            double x = en.east() - pivot.east();
557            double y = en.north() - pivot.north();
558            double nx = cosPhi * x - sinPhi * y + pivot.east();
559            double ny = sinPhi * x + cosPhi * y + pivot.north();
560            return new EastNorth(nx, ny);
561        }
562
563        public static EastNorth sum(EastNorth en1, EastNorth en2) {
564            return new EastNorth(en1.east() + en2.east(), en1.north() + en2.north());
565        }
566
567        public static EastNorth diff(EastNorth en1, EastNorth en2) {
568            return new EastNorth(en1.east() - en2.east(), en1.north() - en2.north());
569        }
570
571        public static double polar(EastNorth en1, EastNorth en2) {
572            return Math.atan2(en2.north() - en1.north(), en2.east() - en1.east());
573        }
574    }
575
576    /**
577     * Recognize angle to be approximately 0, 90, 180 or 270 degrees.
578     * returns an integral value, corresponding to a counter clockwise turn.
579     * @param a angle, in radians
580     * @param deltaMax maximum tolerance, in radians
581     * @return an integral value, corresponding to a counter clockwise turn
582     * @throws RejectedAngleException in case of invalid angle
583     */
584    private static int angleToDirectionChange(double a, double deltaMax) throws RejectedAngleException {
585        a = standardAngleMPItoPI(a);
586        double d0 = Math.abs(a);
587        double d90 = Math.abs(a - Math.PI / 2);
588        double dm90 = Math.abs(a + Math.PI / 2);
589        int dirChange;
590        if (d0 < deltaMax) {
591            dirChange = 0;
592        } else if (d90 < deltaMax) {
593            dirChange = 1;
594        } else if (dm90 < deltaMax) {
595            dirChange = -1;
596        } else {
597            a = standardAngle0to2PI(a);
598            double d180 = Math.abs(a - Math.PI);
599            if (d180 < deltaMax) {
600                dirChange = 2;
601            } else
602                throw new RejectedAngleException();
603        }
604        return dirChange;
605    }
606
607    /**
608     * Exception: unsuited user input
609     */
610    protected static class InvalidUserInputException extends Exception {
611        InvalidUserInputException(String message) {
612            super(message);
613        }
614
615        InvalidUserInputException(String message, Throwable cause) {
616            super(message, cause);
617        }
618    }
619
620    /**
621     * Exception: angle cannot be recognized as 0, 90, 180 or 270 degrees
622     */
623    protected static class RejectedAngleException extends Exception {
624        RejectedAngleException() {
625            super();
626        }
627    }
628
629    @Override
630    protected void updateEnabledState() {
631        updateEnabledStateOnCurrentSelection();
632    }
633
634    @Override
635    protected void updateEnabledState(Collection<? extends OsmPrimitive> selection) {
636        setEnabled(selection != null && !selection.isEmpty());
637    }
638}