001// License: GPL. For details, see LICENSE file.
002package org.openstreetmap.josm.actions;
003
004import static org.openstreetmap.josm.tools.I18n.marktr;
005import static org.openstreetmap.josm.tools.I18n.tr;
006import static org.openstreetmap.josm.tools.I18n.trn;
007
008import java.awt.event.ActionEvent;
009import java.awt.event.KeyEvent;
010import java.util.ArrayList;
011import java.util.Collection;
012import java.util.Collections;
013import java.util.HashMap;
014import java.util.HashSet;
015import java.util.LinkedHashSet;
016import java.util.LinkedList;
017import java.util.List;
018import java.util.Map;
019import java.util.Objects;
020import java.util.Set;
021import java.util.TreeMap;
022
023import javax.swing.JOptionPane;
024
025import org.openstreetmap.josm.Main;
026import org.openstreetmap.josm.actions.ReverseWayAction.ReverseWayResult;
027import org.openstreetmap.josm.actions.SplitWayAction.SplitWayResult;
028import org.openstreetmap.josm.command.AddCommand;
029import org.openstreetmap.josm.command.ChangeCommand;
030import org.openstreetmap.josm.command.Command;
031import org.openstreetmap.josm.command.DeleteCommand;
032import org.openstreetmap.josm.command.SequenceCommand;
033import org.openstreetmap.josm.data.UndoRedoHandler;
034import org.openstreetmap.josm.data.coor.EastNorth;
035import org.openstreetmap.josm.data.osm.DataSet;
036import org.openstreetmap.josm.data.osm.Node;
037import org.openstreetmap.josm.data.osm.NodePositionComparator;
038import org.openstreetmap.josm.data.osm.OsmPrimitive;
039import org.openstreetmap.josm.data.osm.Relation;
040import org.openstreetmap.josm.data.osm.RelationMember;
041import org.openstreetmap.josm.data.osm.TagCollection;
042import org.openstreetmap.josm.data.osm.Way;
043import org.openstreetmap.josm.gui.Notification;
044import org.openstreetmap.josm.gui.conflict.tags.CombinePrimitiveResolverDialog;
045import org.openstreetmap.josm.tools.Geometry;
046import org.openstreetmap.josm.tools.Pair;
047import org.openstreetmap.josm.tools.Shortcut;
048import org.openstreetmap.josm.tools.UserCancelException;
049import org.openstreetmap.josm.tools.Utils;
050
051/**
052 * Join Areas (i.e. closed ways and multipolygons).
053 * @since 2575
054 */
055public class JoinAreasAction extends JosmAction {
056    // This will be used to commit commands and unite them into one large command sequence at the end
057    private final transient LinkedList<Command> cmds = new LinkedList<>();
058    private int cmdsCount;
059    private final transient List<Relation> addedRelations = new LinkedList<>();
060
061    /**
062     * This helper class describes join areas action result.
063     * @author viesturs
064     */
065    public static class JoinAreasResult {
066
067        public boolean hasChanges;
068
069        public List<Multipolygon> polygons;
070    }
071
072    public static class Multipolygon {
073        public Way outerWay;
074        public List<Way> innerWays;
075
076        public Multipolygon(Way way) {
077            outerWay = way;
078            innerWays = new ArrayList<>();
079        }
080    }
081
082    // HelperClass
083    // Saves a relation and a role an OsmPrimitve was part of until it was stripped from all relations
084    private static class RelationRole {
085        public final Relation rel;
086        public final String role;
087
088        RelationRole(Relation rel, String role) {
089            this.rel = rel;
090            this.role = role;
091        }
092
093        @Override
094        public int hashCode() {
095            return Objects.hash(rel, role);
096        }
097
098        @Override
099        public boolean equals(Object other) {
100            if (this == other) return true;
101            if (other == null || getClass() != other.getClass()) return false;
102            RelationRole that = (RelationRole) other;
103            return Objects.equals(rel, that.rel) &&
104                    Objects.equals(role, that.role);
105        }
106    }
107
108    /**
109     * HelperClass - saves a way and the "inside" side.
110     *
111     * insideToTheLeft: if true left side is "in", false -right side is "in".
112     * Left and right are determined along the orientation of way.
113     */
114    public static class WayInPolygon {
115        public final Way way;
116        public boolean insideToTheRight;
117
118        public WayInPolygon(Way way, boolean insideRight) {
119            this.way = way;
120            this.insideToTheRight = insideRight;
121        }
122
123        @Override
124        public int hashCode() {
125            return Objects.hash(way, insideToTheRight);
126        }
127
128        @Override
129        public boolean equals(Object other) {
130            if (this == other) return true;
131            if (other == null || getClass() != other.getClass()) return false;
132            WayInPolygon that = (WayInPolygon) other;
133            return insideToTheRight == that.insideToTheRight &&
134                    Objects.equals(way, that.way);
135        }
136    }
137
138    /**
139     * This helper class describes a polygon, assembled from several ways.
140     * @author viesturs
141     *
142     */
143    public static class AssembledPolygon {
144        public List<WayInPolygon> ways;
145
146        public AssembledPolygon(List<WayInPolygon> boundary) {
147            this.ways = boundary;
148        }
149
150        public List<Node> getNodes() {
151            List<Node> nodes = new ArrayList<>();
152            for (WayInPolygon way : this.ways) {
153                //do not add the last node as it will be repeated in the next way
154                if (way.insideToTheRight) {
155                    for (int pos = 0; pos < way.way.getNodesCount() - 1; pos++) {
156                        nodes.add(way.way.getNode(pos));
157                    }
158                } else {
159                    for (int pos = way.way.getNodesCount() - 1; pos > 0; pos--) {
160                        nodes.add(way.way.getNode(pos));
161                    }
162                }
163            }
164
165            return nodes;
166        }
167
168        /**
169         * Inverse inside and outside
170         */
171        public void reverse() {
172            for (WayInPolygon way: ways) {
173                way.insideToTheRight = !way.insideToTheRight;
174            }
175            Collections.reverse(ways);
176        }
177    }
178
179    public static class AssembledMultipolygon {
180        public AssembledPolygon outerWay;
181        public List<AssembledPolygon> innerWays;
182
183        public AssembledMultipolygon(AssembledPolygon way) {
184            outerWay = way;
185            innerWays = new ArrayList<>();
186        }
187    }
188
189    /**
190     * This hepler class implements algorithm traversing trough connected ways.
191     * Assumes you are going in clockwise orientation.
192     * @author viesturs
193     */
194    private static class WayTraverser {
195
196        /** Set of {@link WayInPolygon} to be joined by walk algorithm */
197        private final Set<WayInPolygon> availableWays;
198        /** Current state of walk algorithm */
199        private WayInPolygon lastWay;
200        /** Direction of current way */
201        private boolean lastWayReverse;
202
203        /** Constructor
204         * @param ways available ways
205         */
206        WayTraverser(Collection<WayInPolygon> ways) {
207            availableWays = new HashSet<>(ways);
208            lastWay = null;
209        }
210
211        /**
212         *  Remove ways from available ways
213         *  @param ways Collection of WayInPolygon
214         */
215        public void removeWays(Collection<WayInPolygon> ways) {
216            availableWays.removeAll(ways);
217        }
218
219        /**
220         * Remove a single way from available ways
221         * @param way WayInPolygon
222         */
223        public void removeWay(WayInPolygon way) {
224            availableWays.remove(way);
225        }
226
227        /**
228         * Reset walk algorithm to a new start point
229         * @param way New start point
230         */
231        public void setStartWay(WayInPolygon way) {
232            lastWay = way;
233            lastWayReverse = !way.insideToTheRight;
234        }
235
236        /**
237         * Reset walk algorithm to a new start point.
238         * @return The new start point or null if no available way remains
239         */
240        public WayInPolygon startNewWay() {
241            if (availableWays.isEmpty()) {
242                lastWay = null;
243            } else {
244                lastWay = availableWays.iterator().next();
245                lastWayReverse = !lastWay.insideToTheRight;
246            }
247
248            return lastWay;
249        }
250
251        /**
252         * Walking through {@link WayInPolygon} segments, head node is the current position
253         * @return Head node
254         */
255        private Node getHeadNode() {
256            return !lastWayReverse ? lastWay.way.lastNode() : lastWay.way.firstNode();
257        }
258
259        /**
260         * Node just before head node.
261         * @return Previous node
262         */
263        private Node getPrevNode() {
264            return !lastWayReverse ? lastWay.way.getNode(lastWay.way.getNodesCount() - 2) : lastWay.way.getNode(1);
265        }
266
267        /**
268         * Returns oriented angle (N1N2, N1N3) in range [0; 2*Math.PI[
269         * @param n1 first node
270         * @param n2 second node
271         * @param n3 third node
272         * @return oriented angle (N1N2, N1N3) in range [0; 2*Math.PI[
273         */
274        private static double getAngle(Node n1, Node n2, Node n3) {
275            EastNorth en1 = n1.getEastNorth();
276            EastNorth en2 = n2.getEastNorth();
277            EastNorth en3 = n3.getEastNorth();
278            double angle = Math.atan2(en3.getY() - en1.getY(), en3.getX() - en1.getX()) -
279                    Math.atan2(en2.getY() - en1.getY(), en2.getX() - en1.getX());
280            while (angle >= 2*Math.PI) {
281                angle -= 2*Math.PI;
282            }
283            while (angle < 0) {
284                angle += 2*Math.PI;
285            }
286            return angle;
287        }
288
289        /**
290         * Get the next way creating a clockwise path, ensure it is the most right way. #7959
291         * @return The next way.
292         */
293        public WayInPolygon walk() {
294            Node headNode = getHeadNode();
295            Node prevNode = getPrevNode();
296
297            double headAngle = Math.atan2(headNode.getEastNorth().east() - prevNode.getEastNorth().east(),
298                    headNode.getEastNorth().north() - prevNode.getEastNorth().north());
299            double bestAngle = 0;
300
301            //find best next way
302            WayInPolygon bestWay = null;
303            boolean bestWayReverse = false;
304
305            for (WayInPolygon way : availableWays) {
306                Node nextNode;
307
308                // Check for a connected way
309                if (way.way.firstNode().equals(headNode) && way.insideToTheRight) {
310                    nextNode = way.way.getNode(1);
311                } else if (way.way.lastNode().equals(headNode) && !way.insideToTheRight) {
312                    nextNode = way.way.getNode(way.way.getNodesCount() - 2);
313                } else {
314                    continue;
315                }
316
317                if (nextNode == prevNode) {
318                    // go back
319                    lastWay = way;
320                    lastWayReverse = !way.insideToTheRight;
321                    return lastWay;
322                }
323
324                double angle = Math.atan2(nextNode.getEastNorth().east() - headNode.getEastNorth().east(),
325                        nextNode.getEastNorth().north() - headNode.getEastNorth().north()) - headAngle;
326                if (angle > Math.PI)
327                    angle -= 2*Math.PI;
328                if (angle <= -Math.PI)
329                    angle += 2*Math.PI;
330
331                // Now we have a valid candidate way, is it better than the previous one ?
332                if (bestWay == null || angle > bestAngle) {
333                    //the new way is better
334                    bestWay = way;
335                    bestWayReverse = !way.insideToTheRight;
336                    bestAngle = angle;
337                }
338            }
339
340            lastWay = bestWay;
341            lastWayReverse = bestWayReverse;
342            return lastWay;
343        }
344
345        /**
346         * Search for an other way coming to the same head node at left side from last way. #9951
347         * @return left way or null if none found
348         */
349        public WayInPolygon leftComingWay() {
350            Node headNode = getHeadNode();
351            Node prevNode = getPrevNode();
352
353            WayInPolygon mostLeft = null; // most left way connected to head node
354            boolean comingToHead = false; // true if candidate come to head node
355            double angle = 2*Math.PI;
356
357            for (WayInPolygon candidateWay : availableWays) {
358                boolean candidateComingToHead;
359                Node candidatePrevNode;
360
361                if (candidateWay.way.firstNode().equals(headNode)) {
362                    candidateComingToHead = !candidateWay.insideToTheRight;
363                    candidatePrevNode = candidateWay.way.getNode(1);
364                } else if (candidateWay.way.lastNode().equals(headNode)) {
365                     candidateComingToHead = candidateWay.insideToTheRight;
366                     candidatePrevNode = candidateWay.way.getNode(candidateWay.way.getNodesCount() - 2);
367                } else
368                    continue;
369                if (candidateWay.equals(lastWay) && candidateComingToHead)
370                    continue;
371
372                double candidateAngle = getAngle(headNode, candidatePrevNode, prevNode);
373
374                if (mostLeft == null || candidateAngle < angle || (Utils.equalsEpsilon(candidateAngle, angle) && !candidateComingToHead)) {
375                    // Candidate is most left
376                    mostLeft = candidateWay;
377                    comingToHead = candidateComingToHead;
378                    angle = candidateAngle;
379                }
380            }
381
382            return comingToHead ? mostLeft : null;
383        }
384    }
385
386    /**
387     * Helper storage class for finding findOuterWays
388     * @author viesturs
389     */
390    static class PolygonLevel {
391        public final int level;
392        public final AssembledMultipolygon pol;
393
394        PolygonLevel(AssembledMultipolygon pol, int level) {
395            this.pol = pol;
396            this.level = level;
397        }
398    }
399
400    /**
401     * Constructs a new {@code JoinAreasAction}.
402     */
403    public JoinAreasAction() {
404        super(tr("Join overlapping Areas"), "joinareas", tr("Joins areas that overlap each other"),
405        Shortcut.registerShortcut("tools:joinareas", tr("Tool: {0}", tr("Join overlapping Areas")),
406            KeyEvent.VK_J, Shortcut.SHIFT), true);
407    }
408
409    /**
410     * Gets called whenever the shortcut is pressed or the menu entry is selected.
411     * Checks whether the selected objects are suitable to join and joins them if so.
412     */
413    @Override
414    public void actionPerformed(ActionEvent e) {
415        join(Main.getLayerManager().getEditDataSet().getSelectedWays());
416    }
417
418    /**
419     * Joins the given ways.
420     * @param ways Ways to join
421     * @since 7534
422     */
423    public void join(Collection<Way> ways) {
424        addedRelations.clear();
425
426        if (ways.isEmpty()) {
427            new Notification(
428                    tr("Please select at least one closed way that should be joined."))
429                    .setIcon(JOptionPane.INFORMATION_MESSAGE)
430                    .show();
431            return;
432        }
433
434        List<Node> allNodes = new ArrayList<>();
435        for (Way way : ways) {
436            if (!way.isClosed()) {
437                new Notification(
438                        tr("One of the selected ways is not closed and therefore cannot be joined."))
439                        .setIcon(JOptionPane.INFORMATION_MESSAGE)
440                        .show();
441                return;
442            }
443
444            allNodes.addAll(way.getNodes());
445        }
446
447        // TODO: Only display this warning when nodes outside dataSourceArea are deleted
448        boolean ok = Command.checkAndConfirmOutlyingOperation("joinarea", tr("Join area confirmation"),
449                trn("The selected way has nodes outside of the downloaded data region.",
450                    "The selected ways have nodes outside of the downloaded data region.",
451                    ways.size()) + "<br/>"
452                    + tr("This can lead to nodes being deleted accidentally.") + "<br/>"
453                    + tr("Are you really sure to continue?")
454                    + tr("Please abort if you are not sure"),
455                tr("The selected area is incomplete. Continue?"),
456                allNodes, null);
457        if (!ok) return;
458
459        //analyze multipolygon relations and collect all areas
460        List<Multipolygon> areas = collectMultipolygons(ways);
461
462        if (areas == null)
463            //too complex multipolygon relations found
464            return;
465
466        if (!testJoin(areas)) {
467            new Notification(
468                    tr("No intersection found. Nothing was changed."))
469                    .setIcon(JOptionPane.INFORMATION_MESSAGE)
470                    .show();
471            return;
472        }
473
474        if (!resolveTagConflicts(areas))
475            return;
476        //user canceled, do nothing.
477
478        try {
479            // see #11026 - Because <ways> is a dynamic filtered (on ways) of a filtered (on selected objects) collection,
480            // retrieve effective dataset before joining the ways (which affects the selection, thus, the <ways> collection)
481            // Dataset retrieving allows to call this code without relying on Main.getCurrentDataSet(), thus, on a mapview instance
482            DataSet ds = ways.iterator().next().getDataSet();
483
484            // Do the job of joining areas
485            JoinAreasResult result = joinAreas(areas);
486
487            if (result.hasChanges) {
488                // move tags from ways to newly created relations
489                // TODO: do we need to also move tags for the modified relations?
490                for (Relation r: addedRelations) {
491                    cmds.addAll(CreateMultipolygonAction.removeTagsFromWaysIfNeeded(r));
492                }
493                commitCommands(tr("Move tags from ways to relations"));
494
495                List<Way> allWays = new ArrayList<>();
496                for (Multipolygon pol : result.polygons) {
497                    allWays.add(pol.outerWay);
498                    allWays.addAll(pol.innerWays);
499                }
500                if (ds != null) {
501                    ds.setSelected(allWays);
502                }
503            } else {
504                new Notification(
505                        tr("No intersection found. Nothing was changed."))
506                        .setIcon(JOptionPane.INFORMATION_MESSAGE)
507                        .show();
508            }
509        } catch (UserCancelException exception) {
510            Main.trace(exception);
511            //revert changes
512            //FIXME: this is dirty hack
513            makeCommitsOneAction(tr("Reverting changes"));
514            Main.main.undoRedo.undo();
515            Main.main.undoRedo.redoCommands.clear();
516        }
517    }
518
519    /**
520     * Tests if the areas have some intersections to join.
521     * @param areas Areas to test
522     * @return {@code true} if areas are joinable
523     */
524    private boolean testJoin(List<Multipolygon> areas) {
525        List<Way> allStartingWays = new ArrayList<>();
526
527        for (Multipolygon area : areas) {
528            allStartingWays.add(area.outerWay);
529            allStartingWays.addAll(area.innerWays);
530        }
531
532        //find intersection points
533        Set<Node> nodes = Geometry.addIntersections(allStartingWays, true, cmds);
534        return !nodes.isEmpty();
535    }
536
537    /**
538     * Will join two or more overlapping areas
539     * @param areas list of areas to join
540     * @return new area formed.
541     * @throws UserCancelException if user cancels the operation
542     */
543    private JoinAreasResult joinAreas(List<Multipolygon> areas) throws UserCancelException {
544
545        JoinAreasResult result = new JoinAreasResult();
546        result.hasChanges = false;
547
548        List<Way> allStartingWays = new ArrayList<>();
549        List<Way> innerStartingWays = new ArrayList<>();
550        List<Way> outerStartingWays = new ArrayList<>();
551
552        for (Multipolygon area : areas) {
553            outerStartingWays.add(area.outerWay);
554            innerStartingWays.addAll(area.innerWays);
555        }
556
557        allStartingWays.addAll(innerStartingWays);
558        allStartingWays.addAll(outerStartingWays);
559
560        //first remove nodes in the same coordinate
561        boolean removedDuplicates = false;
562        removedDuplicates |= removeDuplicateNodes(allStartingWays);
563
564        if (removedDuplicates) {
565            result.hasChanges = true;
566            commitCommands(marktr("Removed duplicate nodes"));
567        }
568
569        //find intersection points
570        Set<Node> nodes = Geometry.addIntersections(allStartingWays, false, cmds);
571
572        //no intersections, return.
573        if (nodes.isEmpty())
574            return result;
575        commitCommands(marktr("Added node on all intersections"));
576
577        List<RelationRole> relations = new ArrayList<>();
578
579        // Remove ways from all relations so ways can be combined/split quietly
580        for (Way way : allStartingWays) {
581            relations.addAll(removeFromAllRelations(way));
582        }
583
584        // Don't warn now, because it will really look corrupted
585        boolean warnAboutRelations = !relations.isEmpty() && allStartingWays.size() > 1;
586
587        List<WayInPolygon> preparedWays = new ArrayList<>();
588
589        for (Way way : outerStartingWays) {
590            List<Way> splitWays = splitWayOnNodes(way, nodes);
591            preparedWays.addAll(markWayInsideSide(splitWays, false));
592        }
593
594        for (Way way : innerStartingWays) {
595            List<Way> splitWays = splitWayOnNodes(way, nodes);
596            preparedWays.addAll(markWayInsideSide(splitWays, true));
597        }
598
599        // Find boundary ways
600        List<Way> discardedWays = new ArrayList<>();
601        List<AssembledPolygon> boundaries = findBoundaryPolygons(preparedWays, discardedWays);
602
603        //find polygons
604        List<AssembledMultipolygon> preparedPolygons = findPolygons(boundaries);
605
606        //assemble final polygons
607        List<Multipolygon> polygons = new ArrayList<>();
608        Set<Relation> relationsToDelete = new LinkedHashSet<>();
609
610        for (AssembledMultipolygon pol : preparedPolygons) {
611
612            //create the new ways
613            Multipolygon resultPol = joinPolygon(pol);
614
615            //create multipolygon relation, if necessary.
616            RelationRole ownMultipolygonRelation = addOwnMultipolygonRelation(resultPol.innerWays);
617
618            //add back the original relations, merged with our new multipolygon relation
619            fixRelations(relations, resultPol.outerWay, ownMultipolygonRelation, relationsToDelete);
620
621            //strip tags from inner ways
622            //TODO: preserve tags on existing inner ways
623            stripTags(resultPol.innerWays);
624
625            polygons.add(resultPol);
626        }
627
628        commitCommands(marktr("Assemble new polygons"));
629
630        for (Relation rel: relationsToDelete) {
631            cmds.add(new DeleteCommand(rel));
632        }
633
634        commitCommands(marktr("Delete relations"));
635
636        // Delete the discarded inner ways
637        if (!discardedWays.isEmpty()) {
638            Command deleteCmd = DeleteCommand.delete(Main.getLayerManager().getEditLayer(), discardedWays, true);
639            if (deleteCmd != null) {
640                cmds.add(deleteCmd);
641                commitCommands(marktr("Delete Ways that are not part of an inner multipolygon"));
642            }
643        }
644
645        makeCommitsOneAction(marktr("Joined overlapping areas"));
646
647        if (warnAboutRelations) {
648            new Notification(
649                    tr("Some of the ways were part of relations that have been modified.<br>Please verify no errors have been introduced."))
650                    .setIcon(JOptionPane.INFORMATION_MESSAGE)
651                    .setDuration(Notification.TIME_LONG)
652                    .show();
653        }
654
655        result.hasChanges = true;
656        result.polygons = polygons;
657        return result;
658    }
659
660    /**
661     * Checks if tags of two given ways differ, and presents the user a dialog to solve conflicts
662     * @param polygons ways to check
663     * @return {@code true} if all conflicts are resolved, {@code false} if conflicts remain.
664     */
665    private boolean resolveTagConflicts(List<Multipolygon> polygons) {
666
667        List<Way> ways = new ArrayList<>();
668
669        for (Multipolygon pol : polygons) {
670            ways.add(pol.outerWay);
671            ways.addAll(pol.innerWays);
672        }
673
674        if (ways.size() < 2) {
675            return true;
676        }
677
678        TagCollection wayTags = TagCollection.unionOfAllPrimitives(ways);
679        try {
680            cmds.addAll(CombinePrimitiveResolverDialog.launchIfNecessary(wayTags, ways, ways));
681            commitCommands(marktr("Fix tag conflicts"));
682            return true;
683        } catch (UserCancelException ex) {
684            Main.trace(ex);
685            return false;
686        }
687    }
688
689    /**
690     * This method removes duplicate points (if any) from the input way.
691     * @param ways the ways to process
692     * @return {@code true} if any changes where made
693     */
694    private boolean removeDuplicateNodes(List<Way> ways) {
695        //TODO: maybe join nodes with JoinNodesAction, rather than reconnect the ways.
696
697        Map<Node, Node> nodeMap = new TreeMap<>(new NodePositionComparator());
698        int totalNodesRemoved = 0;
699
700        for (Way way : ways) {
701            if (way.getNodes().size() < 2) {
702                continue;
703            }
704
705            int nodesRemoved = 0;
706            List<Node> newNodes = new ArrayList<>();
707            Node prevNode = null;
708
709            for (Node node : way.getNodes()) {
710                if (!nodeMap.containsKey(node)) {
711                    //new node
712                    nodeMap.put(node, node);
713
714                    //avoid duplicate nodes
715                    if (prevNode != node) {
716                        newNodes.add(node);
717                    } else {
718                        nodesRemoved++;
719                    }
720                } else {
721                    //node with same coordinates already exists, substitute with existing node
722                    Node representator = nodeMap.get(node);
723
724                    if (representator != node) {
725                        nodesRemoved++;
726                    }
727
728                    //avoid duplicate node
729                    if (prevNode != representator) {
730                        newNodes.add(representator);
731                    }
732                }
733                prevNode = node;
734            }
735
736            if (nodesRemoved > 0) {
737
738                if (newNodes.size() == 1) { //all nodes in the same coordinate - add one more node, to have closed way.
739                    newNodes.add(newNodes.get(0));
740                }
741
742                Way newWay = new Way(way);
743                newWay.setNodes(newNodes);
744                cmds.add(new ChangeCommand(way, newWay));
745                totalNodesRemoved += nodesRemoved;
746            }
747        }
748
749        return totalNodesRemoved > 0;
750    }
751
752    /**
753     * Commits the command list with a description
754     * @param description The description of what the commands do
755     */
756    private void commitCommands(String description) {
757        switch(cmds.size()) {
758        case 0:
759            return;
760        case 1:
761            Main.main.undoRedo.add(cmds.getFirst());
762            break;
763        default:
764            Command c = new SequenceCommand(tr(description), cmds);
765            Main.main.undoRedo.add(c);
766            break;
767        }
768
769        cmds.clear();
770        cmdsCount++;
771    }
772
773    /**
774     * This method analyzes the way and assigns each part what direction polygon "inside" is.
775     * @param parts the split parts of the way
776     * @param isInner - if true, reverts the direction (for multipolygon islands)
777     * @return list of parts, marked with the inside orientation.
778     * @throws IllegalArgumentException if parts is empty or not circular
779     */
780    private static List<WayInPolygon> markWayInsideSide(List<Way> parts, boolean isInner) {
781
782        //prepare next map
783        Map<Way, Way> nextWayMap = new HashMap<>();
784
785        for (int pos = 0; pos < parts.size(); pos++) {
786
787            if (!parts.get(pos).lastNode().equals(parts.get((pos + 1) % parts.size()).firstNode()))
788                throw new IllegalArgumentException("Way not circular");
789
790            nextWayMap.put(parts.get(pos), parts.get((pos + 1) % parts.size()));
791        }
792
793        //find the node with minimum y - it's guaranteed to be outer. (What about the south pole?)
794        Way topWay = null;
795        Node topNode = null;
796        int topIndex = 0;
797        double minY = Double.POSITIVE_INFINITY;
798
799        for (Way way : parts) {
800            for (int pos = 0; pos < way.getNodesCount(); pos++) {
801                Node node = way.getNode(pos);
802
803                if (node.getEastNorth().getY() < minY) {
804                    minY = node.getEastNorth().getY();
805                    topWay = way;
806                    topNode = node;
807                    topIndex = pos;
808                }
809            }
810        }
811
812        if (topWay == null || topNode == null) {
813            throw new IllegalArgumentException();
814        }
815
816        //get the upper way and it's orientation.
817
818        boolean wayClockwise; // orientation of the top way.
819
820        if (topNode.equals(topWay.firstNode()) || topNode.equals(topWay.lastNode())) {
821            Node headNode; // the node at junction
822            Node prevNode; // last node from previous path
823
824            //node is in split point - find the outermost way from this point
825
826            headNode = topNode;
827            //make a fake node that is downwards from head node (smaller Y). It will be a division point between paths.
828            prevNode = new Node(new EastNorth(headNode.getEastNorth().getX(), headNode.getEastNorth().getY() - 1e5));
829
830            topWay = null;
831            wayClockwise = false;
832            Node bestWayNextNode = null;
833
834            for (Way way : parts) {
835                if (way.firstNode().equals(headNode)) {
836                    Node nextNode = way.getNode(1);
837
838                    if (topWay == null || !Geometry.isToTheRightSideOfLine(prevNode, headNode, bestWayNextNode, nextNode)) {
839                        //the new way is better
840                        topWay = way;
841                        wayClockwise = true;
842                        bestWayNextNode = nextNode;
843                    }
844                }
845
846                if (way.lastNode().equals(headNode)) {
847                    //end adjacent to headNode
848                    Node nextNode = way.getNode(way.getNodesCount() - 2);
849
850                    if (topWay == null || !Geometry.isToTheRightSideOfLine(prevNode, headNode, bestWayNextNode, nextNode)) {
851                        //the new way is better
852                        topWay = way;
853                        wayClockwise = false;
854                        bestWayNextNode = nextNode;
855                    }
856                }
857            }
858        } else {
859            //node is inside way - pick the clockwise going end.
860            Node prev = topWay.getNode(topIndex - 1);
861            Node next = topWay.getNode(topIndex + 1);
862
863            //there will be no parallel segments in the middle of way, so all fine.
864            wayClockwise = Geometry.angleIsClockwise(prev, topNode, next);
865        }
866
867        Way curWay = topWay;
868        boolean curWayInsideToTheRight = wayClockwise ^ isInner;
869        List<WayInPolygon> result = new ArrayList<>();
870
871        //iterate till full circle is reached
872        while (curWay != null) {
873
874            //add cur way
875            WayInPolygon resultWay = new WayInPolygon(curWay, curWayInsideToTheRight);
876            result.add(resultWay);
877
878            //process next way
879            Way nextWay = nextWayMap.get(curWay);
880            Node prevNode = curWay.getNode(curWay.getNodesCount() - 2);
881            Node headNode = curWay.lastNode();
882            Node nextNode = nextWay.getNode(1);
883
884            if (nextWay == topWay) {
885                //full loop traversed - all done.
886                break;
887            }
888
889            //find intersecting segments
890            // the intersections will look like this:
891            //
892            //                       ^
893            //                       |
894            //                       X wayBNode
895            //                       |
896            //                  wayB |
897            //                       |
898            //             curWay    |       nextWay
899            //----X----------------->X----------------------X---->
900            //    prevNode           ^headNode              nextNode
901            //                       |
902            //                       |
903            //                  wayA |
904            //                       |
905            //                       X wayANode
906            //                       |
907
908            int intersectionCount = 0;
909
910            for (Way wayA : parts) {
911
912                if (wayA == curWay) {
913                    continue;
914                }
915
916                if (wayA.lastNode().equals(headNode)) {
917
918                    Way wayB = nextWayMap.get(wayA);
919
920                    //test if wayA is opposite wayB relative to curWay and nextWay
921
922                    Node wayANode = wayA.getNode(wayA.getNodesCount() - 2);
923                    Node wayBNode = wayB.getNode(1);
924
925                    boolean wayAToTheRight = Geometry.isToTheRightSideOfLine(prevNode, headNode, nextNode, wayANode);
926                    boolean wayBToTheRight = Geometry.isToTheRightSideOfLine(prevNode, headNode, nextNode, wayBNode);
927
928                    if (wayAToTheRight != wayBToTheRight) {
929                        intersectionCount++;
930                    }
931                }
932            }
933
934            //if odd number of crossings, invert orientation
935            if (intersectionCount % 2 != 0) {
936                curWayInsideToTheRight = !curWayInsideToTheRight;
937            }
938
939            curWay = nextWay;
940        }
941
942        return result;
943    }
944
945    /**
946     * This is a method that splits way into smaller parts, using the prepared nodes list as split points.
947     * Uses {@link SplitWayAction#splitWay} for the heavy lifting.
948     * @param way way to split
949     * @param nodes split points
950     * @return list of split ways (or original ways if no splitting is done).
951     */
952    private List<Way> splitWayOnNodes(Way way, Set<Node> nodes) {
953
954        List<Way> result = new ArrayList<>();
955        List<List<Node>> chunks = buildNodeChunks(way, nodes);
956
957        if (chunks.size() > 1) {
958            SplitWayResult split = SplitWayAction.splitWay(getLayerManager().getEditLayer(), way, chunks,
959                    Collections.<OsmPrimitive>emptyList(), SplitWayAction.Strategy.keepFirstChunk());
960
961            if (split != null) {
962                //execute the command, we need the results
963                cmds.add(split.getCommand());
964                commitCommands(marktr("Split ways into fragments"));
965
966                result.add(split.getOriginalWay());
967                result.addAll(split.getNewWays());
968            }
969        }
970        if (result.isEmpty()) {
971            //nothing to split
972            result.add(way);
973        }
974
975        return result;
976    }
977
978    /**
979     * Simple chunking version. Does not care about circular ways and result being
980     * proper, we will glue it all back together later on.
981     * @param way the way to chunk
982     * @param splitNodes the places where to cut.
983     * @return list of node paths to produce.
984     */
985    private static List<List<Node>> buildNodeChunks(Way way, Collection<Node> splitNodes) {
986        List<List<Node>> result = new ArrayList<>();
987        List<Node> curList = new ArrayList<>();
988
989        for (Node node : way.getNodes()) {
990            curList.add(node);
991            if (curList.size() > 1 && splitNodes.contains(node)) {
992                result.add(curList);
993                curList = new ArrayList<>();
994                curList.add(node);
995            }
996        }
997
998        if (curList.size() > 1) {
999            result.add(curList);
1000        }
1001
1002        return result;
1003    }
1004
1005    /**
1006     * This method finds which ways are outer and which are inner.
1007     * @param boundaries list of joined boundaries to search in
1008     * @return outer ways
1009     */
1010    private List<AssembledMultipolygon> findPolygons(Collection<AssembledPolygon> boundaries) {
1011
1012        List<PolygonLevel> list = findOuterWaysImpl(0, boundaries);
1013        List<AssembledMultipolygon> result = new ArrayList<>();
1014
1015        //take every other level
1016        for (PolygonLevel pol : list) {
1017            if (pol.level % 2 == 0) {
1018                result.add(pol.pol);
1019            }
1020        }
1021
1022        return result;
1023    }
1024
1025    /**
1026     * Collects outer way and corresponding inner ways from all boundaries.
1027     * @param level depth level
1028     * @param boundaryWays list of joined boundaries to search in
1029     * @return the outermost Way.
1030     */
1031    private static List<PolygonLevel> findOuterWaysImpl(int level, Collection<AssembledPolygon> boundaryWays) {
1032
1033        //TODO: bad performance for deep nestings...
1034        List<PolygonLevel> result = new ArrayList<>();
1035
1036        for (AssembledPolygon outerWay : boundaryWays) {
1037
1038            boolean outerGood = true;
1039            List<AssembledPolygon> innerCandidates = new ArrayList<>();
1040
1041            for (AssembledPolygon innerWay : boundaryWays) {
1042                if (innerWay == outerWay) {
1043                    continue;
1044                }
1045
1046                if (wayInsideWay(outerWay, innerWay)) {
1047                    outerGood = false;
1048                    break;
1049                } else if (wayInsideWay(innerWay, outerWay)) {
1050                    innerCandidates.add(innerWay);
1051                }
1052            }
1053
1054            if (!outerGood) {
1055                continue;
1056            }
1057
1058            //add new outer polygon
1059            AssembledMultipolygon pol = new AssembledMultipolygon(outerWay);
1060            PolygonLevel polLev = new PolygonLevel(pol, level);
1061
1062            //process inner ways
1063            if (!innerCandidates.isEmpty()) {
1064                List<PolygonLevel> innerList = findOuterWaysImpl(level + 1, innerCandidates);
1065                result.addAll(innerList);
1066
1067                for (PolygonLevel pl : innerList) {
1068                    if (pl.level == level + 1) {
1069                        pol.innerWays.add(pl.pol.outerWay);
1070                    }
1071                }
1072            }
1073
1074            result.add(polLev);
1075        }
1076
1077        return result;
1078    }
1079
1080    /**
1081     * Finds all ways that form inner or outer boundaries.
1082     * @param multigonWays A list of (splitted) ways that form a multigon and share common end nodes on intersections.
1083     * @param discardedResult this list is filled with ways that are to be discarded
1084     * @return A list of ways that form the outer and inner boundaries of the multigon.
1085     */
1086    public static List<AssembledPolygon> findBoundaryPolygons(Collection<WayInPolygon> multigonWays,
1087            List<Way> discardedResult) {
1088        //first find all discardable ways, by getting outer shells.
1089        //this will produce incorrect boundaries in some cases, but second pass will fix it.
1090        List<WayInPolygon> discardedWays = new ArrayList<>();
1091
1092        // In multigonWays collection, some way are just a point (i.e. way like nodeA-nodeA)
1093        // This seems to appear when is apply over invalid way like #9911 test-case
1094        // Remove all of these way to make the next work.
1095        List<WayInPolygon> cleanMultigonWays = new ArrayList<>();
1096        for (WayInPolygon way: multigonWays) {
1097            if (way.way.getNodesCount() == 2 && way.way.isClosed())
1098                discardedWays.add(way);
1099            else
1100                cleanMultigonWays.add(way);
1101        }
1102
1103        WayTraverser traverser = new WayTraverser(cleanMultigonWays);
1104        List<AssembledPolygon> result = new ArrayList<>();
1105
1106        WayInPolygon startWay;
1107        while ((startWay = traverser.startNewWay()) != null) {
1108            List<WayInPolygon> path = new ArrayList<>();
1109            List<WayInPolygon> startWays = new ArrayList<>();
1110            path.add(startWay);
1111            while (true) {
1112                WayInPolygon leftComing;
1113                while ((leftComing = traverser.leftComingWay()) != null) {
1114                    if (startWays.contains(leftComing))
1115                        break;
1116                    // Need restart traverser walk
1117                    path.clear();
1118                    path.add(leftComing);
1119                    traverser.setStartWay(leftComing);
1120                    startWays.add(leftComing);
1121                    break;
1122                }
1123                WayInPolygon nextWay = traverser.walk();
1124                if (nextWay == null)
1125                    throw new RuntimeException("Join areas internal error.");
1126                if (path.get(0) == nextWay) {
1127                    // path is closed -> stop here
1128                    AssembledPolygon ring = new AssembledPolygon(path);
1129                    if (ring.getNodes().size() <= 2) {
1130                        // Invalid ring (2 nodes) -> remove
1131                        traverser.removeWays(path);
1132                        for (WayInPolygon way: path) {
1133                            discardedResult.add(way.way);
1134                        }
1135                    } else {
1136                        // Close ring -> add
1137                        result.add(ring);
1138                        traverser.removeWays(path);
1139                    }
1140                    break;
1141                }
1142                if (path.contains(nextWay)) {
1143                    // Inner loop -> remove
1144                    int index = path.indexOf(nextWay);
1145                    while (path.size() > index) {
1146                        WayInPolygon currentWay = path.get(index);
1147                        discardedResult.add(currentWay.way);
1148                        traverser.removeWay(currentWay);
1149                        path.remove(index);
1150                    }
1151                    traverser.setStartWay(path.get(index-1));
1152                } else {
1153                    path.add(nextWay);
1154                }
1155            }
1156        }
1157
1158        return fixTouchingPolygons(result);
1159    }
1160
1161    /**
1162     * This method checks if polygons have several touching parts and splits them in several polygons.
1163     * @param polygons the polygons to process.
1164     * @return the resulting list of polygons
1165     */
1166    public static List<AssembledPolygon> fixTouchingPolygons(List<AssembledPolygon> polygons) {
1167        List<AssembledPolygon> newPolygons = new ArrayList<>();
1168
1169        for (AssembledPolygon ring : polygons) {
1170            ring.reverse();
1171            WayTraverser traverser = new WayTraverser(ring.ways);
1172            WayInPolygon startWay;
1173
1174            while ((startWay = traverser.startNewWay()) != null) {
1175                List<WayInPolygon> simpleRingWays = new ArrayList<>();
1176                simpleRingWays.add(startWay);
1177                WayInPolygon nextWay;
1178                while ((nextWay = traverser.walk()) != startWay) {
1179                    if (nextWay == null)
1180                        throw new RuntimeException("Join areas internal error.");
1181                    simpleRingWays.add(nextWay);
1182                }
1183                traverser.removeWays(simpleRingWays);
1184                AssembledPolygon simpleRing = new AssembledPolygon(simpleRingWays);
1185                simpleRing.reverse();
1186                newPolygons.add(simpleRing);
1187            }
1188        }
1189
1190        return newPolygons;
1191    }
1192
1193    /**
1194     * Tests if way is inside other way
1195     * @param outside outer polygon description
1196     * @param inside inner polygon description
1197     * @return {@code true} if inner is inside outer
1198     */
1199    public static boolean wayInsideWay(AssembledPolygon inside, AssembledPolygon outside) {
1200        Set<Node> outsideNodes = new HashSet<>(outside.getNodes());
1201        List<Node> insideNodes = inside.getNodes();
1202
1203        for (Node insideNode : insideNodes) {
1204
1205            if (!outsideNodes.contains(insideNode))
1206                //simply test the one node
1207                return Geometry.nodeInsidePolygon(insideNode, outside.getNodes());
1208        }
1209
1210        //all nodes shared.
1211        return false;
1212    }
1213
1214    /**
1215     * Joins the lists of ways.
1216     * @param polygon The list of outer ways that belong to that multigon.
1217     * @return The newly created outer way
1218     * @throws UserCancelException if user cancels the operation
1219     */
1220    private Multipolygon joinPolygon(AssembledMultipolygon polygon) throws UserCancelException {
1221        Multipolygon result = new Multipolygon(joinWays(polygon.outerWay.ways));
1222
1223        for (AssembledPolygon pol : polygon.innerWays) {
1224            result.innerWays.add(joinWays(pol.ways));
1225        }
1226
1227        return result;
1228    }
1229
1230    /**
1231     * Joins the outer ways and deletes all short ways that can't be part of a multipolygon anyway.
1232     * @param ways The list of outer ways that belong to that multigon.
1233     * @return The newly created outer way
1234     * @throws UserCancelException if user cancels the operation
1235     */
1236    private Way joinWays(List<WayInPolygon> ways) throws UserCancelException {
1237
1238        //leave original orientation, if all paths are reverse.
1239        boolean allReverse = true;
1240        for (WayInPolygon way : ways) {
1241            allReverse &= !way.insideToTheRight;
1242        }
1243
1244        if (allReverse) {
1245            for (WayInPolygon way : ways) {
1246                way.insideToTheRight = !way.insideToTheRight;
1247            }
1248        }
1249
1250        Way joinedWay = joinOrientedWays(ways);
1251
1252        //should not happen
1253        if (joinedWay == null || !joinedWay.isClosed())
1254            throw new RuntimeException("Join areas internal error.");
1255
1256        return joinedWay;
1257    }
1258
1259    /**
1260     * Joins a list of ways (using CombineWayAction and ReverseWayAction as specified in WayInPath)
1261     * @param ways The list of ways to join and reverse
1262     * @return The newly created way
1263     * @throws UserCancelException if user cancels the operation
1264     */
1265    private Way joinOrientedWays(List<WayInPolygon> ways) throws UserCancelException {
1266        if (ways.size() < 2)
1267            return ways.get(0).way;
1268
1269        // This will turn ways so all of them point in the same direction and CombineAction won't bug
1270        // the user about this.
1271
1272        //TODO: ReverseWay and Combine way are really slow and we use them a lot here. This slows down large joins.
1273        List<Way> actionWays = new ArrayList<>(ways.size());
1274
1275        for (WayInPolygon way : ways) {
1276            actionWays.add(way.way);
1277
1278            if (!way.insideToTheRight) {
1279                ReverseWayResult res = ReverseWayAction.reverseWay(way.way);
1280                Main.main.undoRedo.add(res.getReverseCommand());
1281                cmdsCount++;
1282            }
1283        }
1284
1285        Pair<Way, Command> result = CombineWayAction.combineWaysWorker(actionWays);
1286
1287        Main.main.undoRedo.add(result.b);
1288        cmdsCount++;
1289
1290        return result.a;
1291    }
1292
1293    /**
1294     * This method analyzes multipolygon relationships of given ways and collects addition inner ways to consider.
1295     * @param selectedWays the selected ways
1296     * @return list of polygons, or null if too complex relation encountered.
1297     */
1298    private static List<Multipolygon> collectMultipolygons(Collection<Way> selectedWays) {
1299
1300        List<Multipolygon> result = new ArrayList<>();
1301
1302        //prepare the lists, to minimize memory allocation.
1303        List<Way> outerWays = new ArrayList<>();
1304        List<Way> innerWays = new ArrayList<>();
1305
1306        Set<Way> processedOuterWays = new LinkedHashSet<>();
1307        Set<Way> processedInnerWays = new LinkedHashSet<>();
1308
1309        for (Relation r : OsmPrimitive.getParentRelations(selectedWays)) {
1310            if (r.isDeleted() || !r.isMultipolygon()) {
1311                continue;
1312            }
1313
1314            boolean hasKnownOuter = false;
1315            outerWays.clear();
1316            innerWays.clear();
1317
1318            for (RelationMember rm : r.getMembers()) {
1319                if ("outer".equalsIgnoreCase(rm.getRole())) {
1320                    outerWays.add(rm.getWay());
1321                    hasKnownOuter |= selectedWays.contains(rm.getWay());
1322                } else if ("inner".equalsIgnoreCase(rm.getRole())) {
1323                    innerWays.add(rm.getWay());
1324                }
1325            }
1326
1327            if (!hasKnownOuter) {
1328                continue;
1329            }
1330
1331            if (outerWays.size() > 1) {
1332                new Notification(
1333                        tr("Sorry. Cannot handle multipolygon relations with multiple outer ways."))
1334                        .setIcon(JOptionPane.INFORMATION_MESSAGE)
1335                        .show();
1336                return null;
1337            }
1338
1339            Way outerWay = outerWays.get(0);
1340
1341            //retain only selected inner ways
1342            innerWays.retainAll(selectedWays);
1343
1344            if (processedOuterWays.contains(outerWay)) {
1345                new Notification(
1346                        tr("Sorry. Cannot handle way that is outer in multiple multipolygon relations."))
1347                        .setIcon(JOptionPane.INFORMATION_MESSAGE)
1348                        .show();
1349                return null;
1350            }
1351
1352            if (processedInnerWays.contains(outerWay)) {
1353                new Notification(
1354                        tr("Sorry. Cannot handle way that is both inner and outer in multipolygon relations."))
1355                        .setIcon(JOptionPane.INFORMATION_MESSAGE)
1356                        .show();
1357                return null;
1358            }
1359
1360            for (Way way :innerWays) {
1361                if (processedOuterWays.contains(way)) {
1362                    new Notification(
1363                            tr("Sorry. Cannot handle way that is both inner and outer in multipolygon relations."))
1364                            .setIcon(JOptionPane.INFORMATION_MESSAGE)
1365                            .show();
1366                    return null;
1367                }
1368
1369                if (processedInnerWays.contains(way)) {
1370                    new Notification(
1371                            tr("Sorry. Cannot handle way that is inner in multiple multipolygon relations."))
1372                            .setIcon(JOptionPane.INFORMATION_MESSAGE)
1373                            .show();
1374                    return null;
1375                }
1376            }
1377
1378            processedOuterWays.add(outerWay);
1379            processedInnerWays.addAll(innerWays);
1380
1381            Multipolygon pol = new Multipolygon(outerWay);
1382            pol.innerWays.addAll(innerWays);
1383
1384            result.add(pol);
1385        }
1386
1387        //add remaining ways, not in relations
1388        for (Way way : selectedWays) {
1389            if (processedOuterWays.contains(way) || processedInnerWays.contains(way)) {
1390                continue;
1391            }
1392
1393            result.add(new Multipolygon(way));
1394        }
1395
1396        return result;
1397    }
1398
1399    /**
1400     * Will add own multipolygon relation to the "previously existing" relations. Fixup is done by fixRelations
1401     * @param inner List of already closed inner ways
1402     * @return The list of relation with roles to add own relation to
1403     */
1404    private RelationRole addOwnMultipolygonRelation(Collection<Way> inner) {
1405        if (inner.isEmpty()) return null;
1406        // Create new multipolygon relation and add all inner ways to it
1407        Relation newRel = new Relation();
1408        newRel.put("type", "multipolygon");
1409        for (Way w : inner) {
1410            newRel.addMember(new RelationMember("inner", w));
1411        }
1412        cmds.add(new AddCommand(newRel));
1413        addedRelations.add(newRel);
1414
1415        // We don't add outer to the relation because it will be handed to fixRelations()
1416        // which will then do the remaining work.
1417        return new RelationRole(newRel, "outer");
1418    }
1419
1420    /**
1421     * Removes a given OsmPrimitive from all relations.
1422     * @param osm Element to remove from all relations
1423     * @return List of relations with roles the primitives was part of
1424     */
1425    private List<RelationRole> removeFromAllRelations(OsmPrimitive osm) {
1426        List<RelationRole> result = new ArrayList<>();
1427
1428        for (Relation r : Main.getLayerManager().getEditDataSet().getRelations()) {
1429            if (r.isDeleted()) {
1430                continue;
1431            }
1432            for (RelationMember rm : r.getMembers()) {
1433                if (rm.getMember() != osm) {
1434                    continue;
1435                }
1436
1437                Relation newRel = new Relation(r);
1438                List<RelationMember> members = newRel.getMembers();
1439                members.remove(rm);
1440                newRel.setMembers(members);
1441
1442                cmds.add(new ChangeCommand(r, newRel));
1443                RelationRole saverel = new RelationRole(r, rm.getRole());
1444                if (!result.contains(saverel)) {
1445                    result.add(saverel);
1446                }
1447                break;
1448            }
1449        }
1450
1451        commitCommands(marktr("Removed Element from Relations"));
1452        return result;
1453    }
1454
1455    /**
1456     * Adds the previously removed relations again to the outer way. If there are multiple multipolygon
1457     * relations where the joined areas were in "outer" role a new relation is created instead with all
1458     * members of both. This function depends on multigon relations to be valid already, it won't fix them.
1459     * @param rels List of relations with roles the (original) ways were part of
1460     * @param outer The newly created outer area/way
1461     * @param ownMultipol elements to directly add as outer
1462     * @param relationsToDelete set of relations to delete.
1463     */
1464    private void fixRelations(List<RelationRole> rels, Way outer, RelationRole ownMultipol, Set<Relation> relationsToDelete) {
1465        List<RelationRole> multiouters = new ArrayList<>();
1466
1467        if (ownMultipol != null) {
1468            multiouters.add(ownMultipol);
1469        }
1470
1471        for (RelationRole r : rels) {
1472            if (r.rel.isMultipolygon() && "outer".equalsIgnoreCase(r.role)) {
1473                multiouters.add(r);
1474                continue;
1475            }
1476            // Add it back!
1477            Relation newRel = new Relation(r.rel);
1478            newRel.addMember(new RelationMember(r.role, outer));
1479            cmds.add(new ChangeCommand(r.rel, newRel));
1480        }
1481
1482        Relation newRel;
1483        switch (multiouters.size()) {
1484        case 0:
1485            return;
1486        case 1:
1487            // Found only one to be part of a multipolygon relation, so just add it back as well
1488            newRel = new Relation(multiouters.get(0).rel);
1489            newRel.addMember(new RelationMember(multiouters.get(0).role, outer));
1490            cmds.add(new ChangeCommand(multiouters.get(0).rel, newRel));
1491            return;
1492        default:
1493            // Create a new relation with all previous members and (Way)outer as outer.
1494            newRel = new Relation();
1495            for (RelationRole r : multiouters) {
1496                // Add members
1497                for (RelationMember rm : r.rel.getMembers()) {
1498                    if (!newRel.getMembers().contains(rm)) {
1499                        newRel.addMember(rm);
1500                    }
1501                }
1502                // Add tags
1503                for (String key : r.rel.keySet()) {
1504                    newRel.put(key, r.rel.get(key));
1505                }
1506                // Delete old relation
1507                relationsToDelete.add(r.rel);
1508            }
1509            newRel.addMember(new RelationMember("outer", outer));
1510            cmds.add(new AddCommand(newRel));
1511        }
1512    }
1513
1514    /**
1515     * Remove all tags from the all the way
1516     * @param ways The List of Ways to remove all tags from
1517     */
1518    private void stripTags(Collection<Way> ways) {
1519        for (Way w : ways) {
1520            final Way wayWithoutTags = new Way(w);
1521            wayWithoutTags.removeAll();
1522            cmds.add(new ChangeCommand(w, wayWithoutTags));
1523        }
1524        /* I18N: current action printed in status display */
1525        commitCommands(marktr("Remove tags from inner ways"));
1526    }
1527
1528    /**
1529     * Takes the last cmdsCount actions back and combines them into a single action
1530     * (for when the user wants to undo the join action)
1531     * @param message The commit message to display
1532     */
1533    private void makeCommitsOneAction(String message) {
1534        UndoRedoHandler ur = Main.main.undoRedo;
1535        cmds.clear();
1536        int i = Math.max(ur.commands.size() - cmdsCount, 0);
1537        for (; i < ur.commands.size(); i++) {
1538            cmds.add(ur.commands.get(i));
1539        }
1540
1541        for (i = 0; i < cmds.size(); i++) {
1542            ur.undo();
1543        }
1544
1545        commitCommands(message == null ? marktr("Join Areas Function") : message);
1546        cmdsCount = 0;
1547    }
1548
1549    @Override
1550    protected void updateEnabledState() {
1551        updateEnabledStateOnCurrentSelection();
1552    }
1553
1554    @Override
1555    protected void updateEnabledState(Collection<? extends OsmPrimitive> selection) {
1556        setEnabled(selection != null && !selection.isEmpty());
1557    }
1558}