001// License: GPL. For details, see LICENSE file.
002package org.openstreetmap.josm.actions.mapmode;
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.BasicStroke;
009import java.awt.Color;
010import java.awt.Cursor;
011import java.awt.Graphics2D;
012import java.awt.Point;
013import java.awt.event.KeyEvent;
014import java.awt.event.MouseEvent;
015import java.util.ArrayList;
016import java.util.Collection;
017import java.util.Collections;
018import java.util.HashSet;
019import java.util.LinkedList;
020import java.util.List;
021import java.util.Set;
022
023import javax.swing.JOptionPane;
024
025import org.openstreetmap.josm.command.AddCommand;
026import org.openstreetmap.josm.command.ChangeNodesCommand;
027import org.openstreetmap.josm.command.Command;
028import org.openstreetmap.josm.command.DeleteCommand;
029import org.openstreetmap.josm.command.MoveCommand;
030import org.openstreetmap.josm.command.SequenceCommand;
031import org.openstreetmap.josm.data.Bounds;
032import org.openstreetmap.josm.data.UndoRedoHandler;
033import org.openstreetmap.josm.data.coor.EastNorth;
034import org.openstreetmap.josm.data.osm.DataSelectionListener;
035import org.openstreetmap.josm.data.osm.DataSet;
036import org.openstreetmap.josm.data.osm.Node;
037import org.openstreetmap.josm.data.osm.OsmPrimitive;
038import org.openstreetmap.josm.data.osm.Way;
039import org.openstreetmap.josm.data.osm.WaySegment;
040import org.openstreetmap.josm.data.osm.event.AbstractDatasetChangedEvent;
041import org.openstreetmap.josm.data.osm.event.DataChangedEvent;
042import org.openstreetmap.josm.data.osm.event.DataSetListener;
043import org.openstreetmap.josm.data.osm.event.DatasetEventManager;
044import org.openstreetmap.josm.data.osm.event.DatasetEventManager.FireMode;
045import org.openstreetmap.josm.data.osm.event.NodeMovedEvent;
046import org.openstreetmap.josm.data.osm.event.PrimitivesAddedEvent;
047import org.openstreetmap.josm.data.osm.event.PrimitivesRemovedEvent;
048import org.openstreetmap.josm.data.osm.event.RelationMembersChangedEvent;
049import org.openstreetmap.josm.data.osm.event.SelectionEventManager;
050import org.openstreetmap.josm.data.osm.event.TagsChangedEvent;
051import org.openstreetmap.josm.data.osm.event.WayNodesChangedEvent;
052import org.openstreetmap.josm.data.preferences.CachingProperty;
053import org.openstreetmap.josm.data.preferences.IntegerProperty;
054import org.openstreetmap.josm.data.preferences.NamedColorProperty;
055import org.openstreetmap.josm.data.preferences.StrokeProperty;
056import org.openstreetmap.josm.gui.MainApplication;
057import org.openstreetmap.josm.gui.MapFrame;
058import org.openstreetmap.josm.gui.MapView;
059import org.openstreetmap.josm.gui.draw.MapViewPath;
060import org.openstreetmap.josm.gui.draw.SymbolShape;
061import org.openstreetmap.josm.gui.layer.AbstractMapViewPaintable;
062import org.openstreetmap.josm.gui.layer.Layer;
063import org.openstreetmap.josm.gui.util.ModifierExListener;
064import org.openstreetmap.josm.tools.ImageProvider;
065import org.openstreetmap.josm.tools.Logging;
066import org.openstreetmap.josm.tools.Pair;
067import org.openstreetmap.josm.tools.Shortcut;
068
069/**
070 * A special map mode that is optimized for improving way geometry.
071 * (by efficiently moving, adding and deleting way-nodes)
072 *
073 * @author Alexander Kachkaev <alexander@kachkaev.ru>, 2011
074 */
075public class ImproveWayAccuracyAction extends MapMode implements DataSelectionListener, DataSetListener, ModifierExListener {
076
077    private static final String CROSSHAIR = /* ICON(cursor/)*/ "crosshair";
078
079    enum State {
080        SELECTING, IMPROVING
081    }
082
083    private State state;
084
085    private MapView mv;
086
087    private static final long serialVersionUID = 42L;
088
089    private transient Way targetWay;
090    private transient Node candidateNode;
091    private transient WaySegment candidateSegment;
092
093    private Point mousePos;
094    private boolean dragging;
095
096    private final Cursor cursorSelect = ImageProvider.getCursor(/* ICON(cursor/)*/ "normal", /* ICON(cursor/modifier/)*/ "mode");
097    private final Cursor cursorSelectHover = ImageProvider.getCursor(/* ICON(cursor/)*/ "hand", /* ICON(cursor/modifier/)*/ "mode");
098    private final Cursor cursorImprove = ImageProvider.getCursor(CROSSHAIR, null);
099    private final Cursor cursorImproveAdd = ImageProvider.getCursor(CROSSHAIR, /* ICON(cursor/modifier/)*/ "addnode");
100    private final Cursor cursorImproveDelete = ImageProvider.getCursor(CROSSHAIR, /* ICON(cursor/modifier/)*/ "delete_node");
101    private final Cursor cursorImproveAddLock = ImageProvider.getCursor(CROSSHAIR, /* ICON(cursor/modifier/)*/ "add_node_lock");
102    private final Cursor cursorImproveLock = ImageProvider.getCursor(CROSSHAIR, /* ICON(cursor/modifier/)*/ "lock");
103
104    private Color guideColor;
105
106    private static final CachingProperty<BasicStroke> SELECT_TARGET_WAY_STROKE
107            = new StrokeProperty("improvewayaccuracy.stroke.select-target", "2").cached();
108    private static final CachingProperty<BasicStroke> MOVE_NODE_STROKE
109            = new StrokeProperty("improvewayaccuracy.stroke.move-node", "1 6").cached();
110    private static final CachingProperty<BasicStroke> MOVE_NODE_INTERSECTING_STROKE
111            = new StrokeProperty("improvewayaccuracy.stroke.move-node-intersecting", "1 2 6").cached();
112    private static final CachingProperty<BasicStroke> ADD_NODE_STROKE
113            = new StrokeProperty("improvewayaccuracy.stroke.add-node", "1").cached();
114    private static final CachingProperty<BasicStroke> DELETE_NODE_STROKE
115            = new StrokeProperty("improvewayaccuracy.stroke.delete-node", "1").cached();
116    private static final CachingProperty<Integer> DOT_SIZE
117            = new IntegerProperty("improvewayaccuracy.dot-size", 6).cached();
118
119    private boolean selectionChangedBlocked;
120
121    protected String oldModeHelpText;
122
123    private final transient AbstractMapViewPaintable temporaryLayer = new AbstractMapViewPaintable() {
124        @Override
125        public void paint(Graphics2D g, MapView mv, Bounds bbox) {
126            ImproveWayAccuracyAction.this.paint(g, mv, bbox);
127        }
128    };
129
130    /**
131     * Constructs a new {@code ImproveWayAccuracyAction}.
132     * @since 11713
133     */
134    public ImproveWayAccuracyAction() {
135        super(tr("Improve Way Accuracy"), "improvewayaccuracy",
136                tr("Improve Way Accuracy mode"),
137                Shortcut.registerShortcut("mapmode:ImproveWayAccuracy",
138                tr("Mode: {0}", tr("Improve Way Accuracy")),
139                KeyEvent.VK_W, Shortcut.DIRECT), Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
140
141        readPreferences();
142    }
143
144    // -------------------------------------------------------------------------
145    // Mode methods
146    // -------------------------------------------------------------------------
147    @Override
148    public void enterMode() {
149        if (!isEnabled()) {
150            return;
151        }
152        super.enterMode();
153        readPreferences();
154
155        MapFrame map = MainApplication.getMap();
156        mv = map.mapView;
157        mousePos = null;
158        oldModeHelpText = "";
159
160        if (getLayerManager().getEditDataSet() == null) {
161            return;
162        }
163
164        updateStateByCurrentSelection();
165
166        map.mapView.addMouseListener(this);
167        map.mapView.addMouseMotionListener(this);
168        map.mapView.addTemporaryLayer(temporaryLayer);
169        SelectionEventManager.getInstance().addSelectionListener(this);
170        DatasetEventManager.getInstance().addDatasetListener(this, FireMode.IMMEDIATELY);
171
172        map.keyDetector.addModifierExListener(this);
173    }
174
175    @Override
176    protected void readPreferences() {
177        guideColor = new NamedColorProperty(marktr("improve way accuracy helper line"), Color.RED).get();
178    }
179
180    @Override
181    public void exitMode() {
182        super.exitMode();
183
184        MapFrame map = MainApplication.getMap();
185        map.mapView.removeMouseListener(this);
186        map.mapView.removeMouseMotionListener(this);
187        map.mapView.removeTemporaryLayer(temporaryLayer);
188        SelectionEventManager.getInstance().removeSelectionListener(this);
189        DatasetEventManager.getInstance().removeDatasetListener(this);
190
191        map.keyDetector.removeModifierExListener(this);
192        temporaryLayer.invalidate();
193        targetWay = null;
194        candidateNode = null;
195        candidateSegment = null;
196    }
197
198    @Override
199    protected void updateStatusLine() {
200        String newModeHelpText = getModeHelpText();
201        if (!newModeHelpText.equals(oldModeHelpText)) {
202            oldModeHelpText = newModeHelpText;
203            MapFrame map = MainApplication.getMap();
204            map.statusLine.setHelpText(newModeHelpText);
205            map.statusLine.repaint();
206        }
207    }
208
209    @Override
210    public String getModeHelpText() {
211        if (state == State.SELECTING) {
212            if (targetWay != null) {
213                return tr("Click on the way to start improving its shape.");
214            } else {
215                return tr("Select a way that you want to make more accurate.");
216            }
217        } else {
218            if (ctrl) {
219                return tr("Click to add a new node. Release Ctrl to move existing nodes or hold Alt to delete.");
220            } else if (alt) {
221                return tr("Click to delete the highlighted node. Release Alt to move existing nodes or hold Ctrl to add new nodes.");
222            } else {
223                return tr("Click to move the highlighted node. Hold Ctrl to add new nodes, or Alt to delete.");
224            }
225        }
226    }
227
228    @Override
229    public boolean layerIsSupported(Layer l) {
230        return isEditableDataLayer(l);
231    }
232
233    @Override
234    protected void updateEnabledState() {
235        setEnabled(getLayerManager().getEditLayer() != null);
236    }
237
238    // -------------------------------------------------------------------------
239    // MapViewPaintable methods
240    // -------------------------------------------------------------------------
241    /**
242     * Redraws temporary layer. Highlights targetWay in select mode. Draws
243     * preview lines in improve mode and highlights the candidateNode
244     * @param g The graphics
245     * @param mv The map view
246     * @param bbox The bounding box
247     */
248    public void paint(Graphics2D g, MapView mv, Bounds bbox) {
249        if (mousePos == null || (candidateNode != null && candidateNode.getDataSet() == null)) {
250            return;
251        }
252
253        g.setColor(guideColor);
254
255        if (state == State.SELECTING && targetWay != null) {
256            // Highlighting the targetWay in Selecting state
257            // Non-native highlighting is used, because sometimes highlighted
258            // segments are covered with others, which is bad.
259            BasicStroke stroke = SELECT_TARGET_WAY_STROKE.get();
260            g.setStroke(stroke);
261
262            List<Node> nodes = targetWay.getNodes();
263
264            g.draw(new MapViewPath(mv).append(nodes, false).computeClippedLine(stroke));
265
266        } else if (state == State.IMPROVING) {
267            // Drawing preview lines and highlighting the node
268            // that is going to be moved.
269            // Non-native highlighting is used here as well.
270
271            // Finding endpoints
272            Node p1 = null;
273            Node p2 = null;
274            if (ctrl && candidateSegment != null) {
275                g.setStroke(ADD_NODE_STROKE.get());
276                try {
277                    p1 = candidateSegment.getFirstNode();
278                    p2 = candidateSegment.getSecondNode();
279                } catch (ArrayIndexOutOfBoundsException e) {
280                    Logging.error(e);
281                }
282            } else if (!alt && !ctrl && candidateNode != null) {
283                g.setStroke(MOVE_NODE_STROKE.get());
284                List<Pair<Node, Node>> wpps = targetWay.getNodePairs(false);
285                for (Pair<Node, Node> wpp : wpps) {
286                    if (wpp.a == candidateNode) {
287                        p1 = wpp.b;
288                    }
289                    if (wpp.b == candidateNode) {
290                        p2 = wpp.a;
291                    }
292                    if (p1 != null && p2 != null) {
293                        break;
294                    }
295                }
296            } else if (alt && !ctrl && candidateNode != null) {
297                g.setStroke(DELETE_NODE_STROKE.get());
298                List<Node> nodes = targetWay.getNodes();
299                int index = nodes.indexOf(candidateNode);
300
301                // Only draw line if node is not first and/or last
302                if (index > 0 && index < (nodes.size() - 1)) {
303                    p1 = nodes.get(index - 1);
304                    p2 = nodes.get(index + 1);
305                } else if (targetWay.isClosed()) {
306                    p1 = targetWay.getNode(1);
307                    p2 = targetWay.getNode(nodes.size() - 2);
308                }
309                // TODO: indicate what part that will be deleted? (for end nodes)
310            }
311
312
313            // Drawing preview lines
314            MapViewPath b = new MapViewPath(mv);
315            if (alt && !ctrl) {
316                // In delete mode
317                if (p1 != null && p2 != null) {
318                    b.moveTo(p1);
319                    b.lineTo(p2);
320                }
321            } else {
322                // In add or move mode
323                if (p1 != null) {
324                    b.moveTo(mousePos.x, mousePos.y);
325                    b.lineTo(p1);
326                }
327                if (p2 != null) {
328                    b.moveTo(mousePos.x, mousePos.y);
329                    b.lineTo(p2);
330                }
331            }
332            g.draw(b.computeClippedLine(g.getStroke()));
333
334            // Highlighting candidateNode
335            if (candidateNode != null) {
336                p1 = candidateNode;
337                g.fill(new MapViewPath(mv).shapeAround(p1, SymbolShape.SQUARE, DOT_SIZE.get()));
338            }
339
340            if (!alt && !ctrl && candidateNode != null) {
341                b.reset();
342                drawIntersectingWayHelperLines(mv, b);
343                g.setStroke(MOVE_NODE_INTERSECTING_STROKE.get());
344                g.draw(b.computeClippedLine(g.getStroke()));
345            }
346
347        }
348    }
349
350    protected void drawIntersectingWayHelperLines(MapView mv, MapViewPath b) {
351        for (final OsmPrimitive referrer : candidateNode.getReferrers()) {
352            if (!(referrer instanceof Way) || targetWay.equals(referrer)) {
353                continue;
354            }
355            final List<Node> nodes = ((Way) referrer).getNodes();
356            for (int i = 0; i < nodes.size(); i++) {
357                if (!candidateNode.equals(nodes.get(i))) {
358                    continue;
359                }
360                if (i > 0) {
361                    b.moveTo(mousePos.x, mousePos.y);
362                    b.lineTo(nodes.get(i - 1));
363                }
364                if (i < nodes.size() - 1) {
365                    b.moveTo(mousePos.x, mousePos.y);
366                    b.lineTo(nodes.get(i + 1));
367                }
368            }
369        }
370    }
371
372    // -------------------------------------------------------------------------
373    // Event handlers
374    // -------------------------------------------------------------------------
375    @Override
376    public void modifiersExChanged(int modifiers) {
377        if (!MainApplication.isDisplayingMapView() || !MainApplication.getMap().mapView.isActiveLayerDrawable()) {
378            return;
379        }
380        updateKeyModifiersEx(modifiers);
381        updateCursorDependentObjectsIfNeeded();
382        updateCursor();
383        updateStatusLine();
384        temporaryLayer.invalidate();
385    }
386
387    @Override
388    public void selectionChanged(SelectionChangeEvent event) {
389        if (selectionChangedBlocked) {
390            return;
391        }
392        updateStateByCurrentSelection();
393    }
394
395    @Override
396    public void mouseDragged(MouseEvent e) {
397        dragging = true;
398        mouseMoved(e);
399    }
400
401    @Override
402    public void mouseMoved(MouseEvent e) {
403        if (!isEnabled()) {
404            return;
405        }
406
407        mousePos = e.getPoint();
408
409        updateKeyModifiers(e);
410        updateCursorDependentObjectsIfNeeded();
411        updateCursor();
412        updateStatusLine();
413        temporaryLayer.invalidate();
414    }
415
416    @Override
417    public void mouseReleased(MouseEvent e) {
418        dragging = false;
419        if (!isEnabled() || e.getButton() != MouseEvent.BUTTON1) {
420            return;
421        }
422
423        DataSet ds = getLayerManager().getEditDataSet();
424        updateKeyModifiers(e);
425        mousePos = e.getPoint();
426
427        if (state == State.SELECTING) {
428            if (targetWay != null) {
429                ds.setSelected(targetWay.getPrimitiveId());
430                updateStateByCurrentSelection();
431            }
432        } else if (state == State.IMPROVING) {
433            // Checking if the new coordinate is outside of the world
434            if (new Node(mv.getEastNorth(mousePos.x, mousePos.y)).isOutSideWorld()) {
435                JOptionPane.showMessageDialog(MainApplication.getMainFrame(),
436                        tr("Cannot add a node outside of the world."),
437                        tr("Warning"), JOptionPane.WARNING_MESSAGE);
438                return;
439            }
440
441            if (ctrl && !alt && candidateSegment != null) {
442                // Add a new node to the highlighted segment.
443                Collection<WaySegment> virtualSegments = new LinkedList<>();
444
445                // Check if other ways have the same segment.
446                // We have to make sure that we add the new node to all of them.
447                Set<Way> commonParentWays = new HashSet<>(candidateSegment.getFirstNode().getParentWays());
448                commonParentWays.retainAll(candidateSegment.getSecondNode().getParentWays());
449                for (Way w : commonParentWays) {
450                    for (int i = 0; i < w.getNodesCount() - 1; i++) {
451                        WaySegment testWS = new WaySegment(w, i);
452                        if (testWS.isSimilar(candidateSegment)) {
453                            virtualSegments.add(testWS);
454                        }
455                    }
456                }
457
458                Collection<Command> virtualCmds = new LinkedList<>();
459                // Create the new node
460                Node virtualNode = new Node(mv.getEastNorth(mousePos.x, mousePos.y));
461                virtualCmds.add(new AddCommand(ds, virtualNode));
462
463                // Adding the node to all segments found
464                for (WaySegment virtualSegment : virtualSegments) {
465                    Way w = virtualSegment.getWay();
466                    List<Node> modNodes = w.getNodes();
467                    modNodes.add(virtualSegment.getUpperIndex(), virtualNode);
468                    virtualCmds.add(new ChangeNodesCommand(w, modNodes));
469                }
470
471                // Finishing the sequence command
472                String text = trn("Add a new node to way",
473                        "Add a new node to {0} ways",
474                        virtualSegments.size(), virtualSegments.size());
475
476                UndoRedoHandler.getInstance().add(new SequenceCommand(text, virtualCmds));
477
478            } else if (alt && !ctrl && candidateNode != null) {
479                // Deleting the highlighted node
480
481                //check to see if node is in use by more than one object
482                long referrersCount = candidateNode.referrers(OsmPrimitive.class).count();
483                long referrerWayCount = candidateNode.referrers(Way.class).count();
484                if (referrersCount != 1 || referrerWayCount != 1) {
485                    // detach node from way
486                    final List<Node> nodes = targetWay.getNodes();
487                    nodes.remove(candidateNode);
488                    if (nodes.size() < 2) {
489                        final Command deleteCmd = DeleteCommand.delete(Collections.singleton(targetWay), true);
490                        if (deleteCmd != null) {
491                            UndoRedoHandler.getInstance().add(deleteCmd);
492                        }
493                    } else {
494                        UndoRedoHandler.getInstance().add(new ChangeNodesCommand(targetWay, nodes));
495                    }
496                } else if (candidateNode.isTagged()) {
497                    JOptionPane.showMessageDialog(MainApplication.getMainFrame(),
498                            tr("Cannot delete node that has tags"),
499                            tr("Error"), JOptionPane.ERROR_MESSAGE);
500                } else {
501                    final Command deleteCmd = DeleteCommand.delete(Collections.singleton(candidateNode), true);
502                    if (deleteCmd != null) {
503                        UndoRedoHandler.getInstance().add(deleteCmd);
504                    }
505                }
506
507            } else if (candidateNode != null) {
508                // Moving the highlighted node
509                EastNorth nodeEN = candidateNode.getEastNorth();
510                EastNorth cursorEN = mv.getEastNorth(mousePos.x, mousePos.y);
511
512                UndoRedoHandler.getInstance().add(
513                        new MoveCommand(candidateNode, cursorEN.east() - nodeEN.east(), cursorEN.north() - nodeEN.north()));
514
515                SelectAction.checkCommandForLargeDistance(UndoRedoHandler.getInstance().getLastCommand());
516            }
517        }
518
519        mousePos = null;
520        updateCursor();
521        updateStatusLine();
522        temporaryLayer.invalidate();
523    }
524
525    @Override
526    public void mouseExited(MouseEvent e) {
527        if (!isEnabled()) {
528            return;
529        }
530
531        if (!dragging) {
532            mousePos = null;
533        }
534        temporaryLayer.invalidate();
535    }
536
537    // -------------------------------------------------------------------------
538    // Custom methods
539    // -------------------------------------------------------------------------
540    /**
541     * Sets new cursor depending on state, mouse position
542     */
543    private void updateCursor() {
544        if (!isEnabled()) {
545            mv.setNewCursor(null, this);
546            return;
547        }
548
549        if (state == State.SELECTING) {
550            mv.setNewCursor(targetWay == null ? cursorSelect
551                    : cursorSelectHover, this);
552        } else if (state == State.IMPROVING) {
553            if (alt && !ctrl) {
554                mv.setNewCursor(cursorImproveDelete, this);
555            } else if (shift || dragging) {
556                if (ctrl) {
557                    mv.setNewCursor(cursorImproveAddLock, this);
558                } else {
559                    mv.setNewCursor(cursorImproveLock, this);
560                }
561            } else if (ctrl && !alt) {
562                mv.setNewCursor(cursorImproveAdd, this);
563            } else {
564                mv.setNewCursor(cursorImprove, this);
565            }
566        }
567    }
568
569    /**
570     * Updates these objects under cursor: targetWay, candidateNode,
571     * candidateSegment
572     */
573    public void updateCursorDependentObjectsIfNeeded() {
574        if (state == State.IMPROVING && (shift || dragging)
575                && !(candidateNode == null && candidateSegment == null)) {
576            return;
577        }
578
579        if (mousePos == null) {
580            candidateNode = null;
581            candidateSegment = null;
582            return;
583        }
584
585        if (state == State.SELECTING) {
586            targetWay = ImproveWayAccuracyHelper.findWay(mv, mousePos);
587        } else if (state == State.IMPROVING) {
588            if (ctrl && !alt) {
589                candidateSegment = ImproveWayAccuracyHelper.findCandidateSegment(mv,
590                        targetWay, mousePos);
591                candidateNode = null;
592            } else {
593                candidateNode = ImproveWayAccuracyHelper.findCandidateNode(mv,
594                        targetWay, mousePos);
595                candidateSegment = null;
596            }
597        }
598    }
599
600    /**
601     * Switches to Selecting state
602     */
603    public void startSelecting() {
604        state = State.SELECTING;
605
606        targetWay = null;
607
608        temporaryLayer.invalidate();
609        updateStatusLine();
610    }
611
612    /**
613     * Switches to Improving state
614     *
615     * @param targetWay Way that is going to be improved
616     */
617    public void startImproving(Way targetWay) {
618        state = State.IMPROVING;
619
620        DataSet ds = getLayerManager().getEditDataSet();
621        Collection<OsmPrimitive> currentSelection = ds.getSelected();
622        if (currentSelection.size() != 1
623                || !currentSelection.iterator().next().equals(targetWay)) {
624            selectionChangedBlocked = true;
625            ds.clearSelection();
626            ds.setSelected(targetWay.getPrimitiveId());
627            selectionChangedBlocked = false;
628        }
629
630        this.targetWay = targetWay;
631        this.candidateNode = null;
632        this.candidateSegment = null;
633
634        temporaryLayer.invalidate();
635        updateStatusLine();
636    }
637
638    /**
639     * Updates the state according to the current selection. Goes to Improve
640     * state if a single way or node is selected. Extracts a way by a node in
641     * the second case.
642     */
643    private void updateStateByCurrentSelection() {
644        final List<Node> nodeList = new ArrayList<>();
645        final List<Way> wayList = new ArrayList<>();
646        final DataSet ds = getLayerManager().getEditDataSet();
647        if (ds != null) {
648            final Collection<OsmPrimitive> sel = ds.getSelected();
649
650            // Collecting nodes and ways from the selection
651            for (OsmPrimitive p : sel) {
652                if (p instanceof Way) {
653                    wayList.add((Way) p);
654                }
655                if (p instanceof Node) {
656                    nodeList.add((Node) p);
657                }
658            }
659
660            if (wayList.size() == 1) {
661                // Starting improving the single selected way
662                startImproving(wayList.get(0));
663                return;
664            } else if (nodeList.size() == 1) {
665                // Starting improving the only way of the single selected node
666                List<OsmPrimitive> r = nodeList.get(0).getReferrers();
667                if (r.size() == 1 && (r.get(0) instanceof Way)) {
668                    startImproving((Way) r.get(0));
669                    return;
670                }
671            }
672        }
673
674        // Starting selecting by default
675        startSelecting();
676    }
677
678    @Override
679    public void primitivesRemoved(PrimitivesRemovedEvent event) {
680        if (event.getPrimitives().contains(candidateNode) || event.getPrimitives().contains(targetWay)) {
681            updateCursorDependentObjectsIfNeeded();
682        }
683    }
684
685    @Override
686    public void primitivesAdded(PrimitivesAddedEvent event) {
687        // Do nothing
688    }
689
690    @Override
691    public void tagsChanged(TagsChangedEvent event) {
692        // Do nothing
693    }
694
695    @Override
696    public void nodeMoved(NodeMovedEvent event) {
697        // Do nothing
698    }
699
700    @Override
701    public void wayNodesChanged(WayNodesChangedEvent event) {
702        // Do nothing
703    }
704
705    @Override
706    public void relationMembersChanged(RelationMembersChangedEvent event) {
707        // Do nothing
708    }
709
710    @Override
711    public void otherDatasetChange(AbstractDatasetChangedEvent event) {
712        // Do nothing
713    }
714
715    @Override
716    public void dataChanged(DataChangedEvent event) {
717        // Do nothing
718    }
719}