001// License: GPL. For details, see LICENSE file.
002package org.openstreetmap.josm.actions.mapmode;
003
004import static org.openstreetmap.josm.gui.help.HelpUtil.ht;
005import static org.openstreetmap.josm.tools.I18n.tr;
006import static org.openstreetmap.josm.tools.I18n.trn;
007
008import java.awt.Cursor;
009import java.awt.Point;
010import java.awt.Rectangle;
011import java.awt.event.KeyEvent;
012import java.awt.event.MouseEvent;
013import java.awt.geom.Point2D;
014import java.util.Collection;
015import java.util.Collections;
016import java.util.HashSet;
017import java.util.Iterator;
018import java.util.LinkedList;
019import java.util.Set;
020
021import javax.swing.JOptionPane;
022
023import org.openstreetmap.josm.Main;
024import org.openstreetmap.josm.actions.MergeNodesAction;
025import org.openstreetmap.josm.command.AddCommand;
026import org.openstreetmap.josm.command.ChangeCommand;
027import org.openstreetmap.josm.command.Command;
028import org.openstreetmap.josm.command.MoveCommand;
029import org.openstreetmap.josm.command.RotateCommand;
030import org.openstreetmap.josm.command.ScaleCommand;
031import org.openstreetmap.josm.command.SequenceCommand;
032import org.openstreetmap.josm.data.coor.EastNorth;
033import org.openstreetmap.josm.data.coor.LatLon;
034import org.openstreetmap.josm.data.osm.DataSet;
035import org.openstreetmap.josm.data.osm.Node;
036import org.openstreetmap.josm.data.osm.OsmPrimitive;
037import org.openstreetmap.josm.data.osm.Way;
038import org.openstreetmap.josm.data.osm.WaySegment;
039import org.openstreetmap.josm.data.osm.visitor.AllNodesVisitor;
040import org.openstreetmap.josm.data.osm.visitor.paint.WireframeMapRenderer;
041import org.openstreetmap.josm.gui.ExtendedDialog;
042import org.openstreetmap.josm.gui.MapFrame;
043import org.openstreetmap.josm.gui.MapView;
044import org.openstreetmap.josm.gui.MapViewState.MapViewPoint;
045import org.openstreetmap.josm.gui.SelectionManager;
046import org.openstreetmap.josm.gui.SelectionManager.SelectionEnded;
047import org.openstreetmap.josm.gui.layer.Layer;
048import org.openstreetmap.josm.gui.layer.OsmDataLayer;
049import org.openstreetmap.josm.gui.util.GuiHelper;
050import org.openstreetmap.josm.gui.util.KeyPressReleaseListener;
051import org.openstreetmap.josm.gui.util.ModifierListener;
052import org.openstreetmap.josm.tools.ImageProvider;
053import org.openstreetmap.josm.tools.Pair;
054import org.openstreetmap.josm.tools.Shortcut;
055import org.openstreetmap.josm.tools.Utils;
056
057/**
058 * Move is an action that can move all kind of OsmPrimitives (except keys for now).
059 *
060 * If an selected object is under the mouse when dragging, move all selected objects.
061 * If an unselected object is under the mouse when dragging, it becomes selected
062 * and will be moved.
063 * If no object is under the mouse, move all selected objects (if any)
064 *
065 * On Mac OS X, Ctrl + mouse button 1 simulates right click (map move), so the
066 * feature "selection remove" is disabled on this platform.
067 */
068public class SelectAction extends MapMode implements ModifierListener, KeyPressReleaseListener, SelectionEnded {
069
070    /**
071     * Select action mode.
072     * @since 7543
073     */
074    public enum Mode {
075        /** "MOVE" means either dragging or select if no mouse movement occurs (i.e. just clicking) */
076        MOVE,
077        /** "ROTATE" allows to apply a rotation transformation on the selected object (see {@link RotateCommand}) */
078        ROTATE,
079        /** "SCALE" allows to apply a scaling transformation on the selected object (see {@link ScaleCommand}) */
080        SCALE,
081        /** "SELECT" means the selection rectangle */
082        SELECT
083    }
084
085    // contains all possible cases the cursor can be in the SelectAction
086    private enum SelectActionCursor {
087        rect("normal", /* ICON(cursor/modifier/) */ "selection"),
088        rect_add("normal", /* ICON(cursor/modifier/) */ "select_add"),
089        rect_rm("normal", /* ICON(cursor/modifier/) */ "select_remove"),
090        way("normal", /* ICON(cursor/modifier/) */ "select_way"),
091        way_add("normal", /* ICON(cursor/modifier/) */ "select_way_add"),
092        way_rm("normal", /* ICON(cursor/modifier/) */ "select_way_remove"),
093        node("normal", /* ICON(cursor/modifier/) */ "select_node"),
094        node_add("normal", /* ICON(cursor/modifier/) */ "select_node_add"),
095        node_rm("normal", /* ICON(cursor/modifier/) */ "select_node_remove"),
096        virtual_node("normal", /* ICON(cursor/modifier/) */ "addnode"),
097        scale(/* ICON(cursor/) */ "scale", null),
098        rotate(/* ICON(cursor/) */ "rotate", null),
099        merge(/* ICON(cursor/) */ "crosshair", null),
100        lasso("normal", /* ICON(cursor/modifier/) */ "rope"),
101        merge_to_node("crosshair", /* ICON(cursor/modifier/) */ "joinnode"),
102        move(Cursor.MOVE_CURSOR);
103
104        private final Cursor c;
105        SelectActionCursor(String main, String sub) {
106            c = ImageProvider.getCursor(main, sub);
107        }
108
109        SelectActionCursor(int systemCursor) {
110            c = Cursor.getPredefinedCursor(systemCursor);
111        }
112
113        public Cursor cursor() {
114            return c;
115        }
116    }
117
118    private boolean lassoMode;
119    public boolean repeatedKeySwitchLassoOption;
120
121    // Cache previous mouse event (needed when only the modifier keys are
122    // pressed but the mouse isn't moved)
123    private MouseEvent oldEvent;
124
125    private Mode mode;
126    private final transient SelectionManager selectionManager;
127    private boolean cancelDrawMode;
128    private boolean drawTargetHighlight;
129    private boolean didMouseDrag;
130    /**
131     * The component this SelectAction is associated with.
132     */
133    private final MapView mv;
134    /**
135     * The old cursor before the user pressed the mouse button.
136     */
137    private Point startingDraggingPos;
138    /**
139     * point where user pressed the mouse to start movement
140     */
141    private EastNorth startEN;
142    /**
143     * The last known position of the mouse.
144     */
145    private Point lastMousePos;
146    /**
147     * The time of the user mouse down event.
148     */
149    private long mouseDownTime;
150    /**
151     * The pressed button of the user mouse down event.
152     */
153    private int mouseDownButton;
154    /**
155     * The time of the user mouse down event.
156     */
157    private long mouseReleaseTime;
158    /**
159     * The time which needs to pass between click and release before something
160     * counts as a move, in milliseconds
161     */
162    private int initialMoveDelay;
163    /**
164     * The screen distance which needs to be travelled before something
165     * counts as a move, in pixels
166     */
167    private int initialMoveThreshold;
168    private boolean initialMoveThresholdExceeded;
169
170    /**
171     * elements that have been highlighted in the previous iteration. Used
172     * to remove the highlight from them again as otherwise the whole data
173     * set would have to be checked.
174     */
175    private transient Set<OsmPrimitive> oldHighlights = new HashSet<>();
176
177    /**
178     * Create a new SelectAction
179     * @param mapFrame The MapFrame this action belongs to.
180     */
181    public SelectAction(MapFrame mapFrame) {
182        super(tr("Select"), "move/move", tr("Select, move, scale and rotate objects"),
183                Shortcut.registerShortcut("mapmode:select", tr("Mode: {0}", tr("Select")), KeyEvent.VK_S, Shortcut.DIRECT),
184                mapFrame,
185                ImageProvider.getCursor("normal", "selection"));
186        mv = mapFrame.mapView;
187        putValue("help", ht("/Action/Select"));
188        selectionManager = new SelectionManager(this, false, mv);
189    }
190
191    @Override
192    public void enterMode() {
193        super.enterMode();
194        mv.addMouseListener(this);
195        mv.addMouseMotionListener(this);
196        mv.setVirtualNodesEnabled(Main.pref.getInteger("mappaint.node.virtual-size", 8) != 0);
197        drawTargetHighlight = Main.pref.getBoolean("draw.target-highlight", true);
198        initialMoveDelay = Main.pref.getInteger("edit.initial-move-delay", 200);
199        initialMoveThreshold = Main.pref.getInteger("edit.initial-move-threshold", 5);
200        repeatedKeySwitchLassoOption = Main.pref.getBoolean("mappaint.select.toggle-lasso-on-repeated-S", true);
201        cycleManager.init();
202        virtualManager.init();
203        // This is required to update the cursors when ctrl/shift/alt is pressed
204        Main.map.keyDetector.addModifierListener(this);
205        Main.map.keyDetector.addKeyListener(this);
206    }
207
208    @Override
209    public void exitMode() {
210        super.exitMode();
211        selectionManager.unregister(mv);
212        mv.removeMouseListener(this);
213        mv.removeMouseMotionListener(this);
214        mv.setVirtualNodesEnabled(false);
215        Main.map.keyDetector.removeModifierListener(this);
216        Main.map.keyDetector.removeKeyListener(this);
217        removeHighlighting();
218    }
219
220    @Override
221    public void modifiersChanged(int modifiers) {
222        if (!Main.isDisplayingMapView() || oldEvent == null) return;
223        if (giveUserFeedback(oldEvent, modifiers)) {
224            mv.repaint();
225        }
226    }
227
228    /**
229     * handles adding highlights and updating the cursor for the given mouse event.
230     * Please note that the highlighting for merging while moving is handled via mouseDragged.
231     * @param e {@code MouseEvent} which should be used as base for the feedback
232     * @return {@code true} if repaint is required
233     */
234    private boolean giveUserFeedback(MouseEvent e) {
235        return giveUserFeedback(e, e.getModifiers());
236    }
237
238    /**
239     * handles adding highlights and updating the cursor for the given mouse event.
240     * Please note that the highlighting for merging while moving is handled via mouseDragged.
241     * @param e {@code MouseEvent} which should be used as base for the feedback
242     * @param modifiers define custom keyboard modifiers if the ones from MouseEvent are outdated or similar
243     * @return {@code true} if repaint is required
244     */
245    private boolean giveUserFeedback(MouseEvent e, int modifiers) {
246        Collection<OsmPrimitive> c = asColl(
247                mv.getNearestNodeOrWay(e.getPoint(), mv.isSelectablePredicate, true));
248
249        updateKeyModifiers(modifiers);
250        determineMapMode(!c.isEmpty());
251
252        Set<OsmPrimitive> newHighlights = new HashSet<>();
253
254        virtualManager.clear();
255        if (mode == Mode.MOVE) {
256            if (!dragInProgress() && virtualManager.activateVirtualNodeNearPoint(e.getPoint())) {
257                DataSet ds = getLayerManager().getEditDataSet();
258                if (ds != null && drawTargetHighlight) {
259                    ds.setHighlightedVirtualNodes(virtualManager.virtualWays);
260                }
261                mv.setNewCursor(SelectActionCursor.virtual_node.cursor(), this);
262                // don't highlight anything else if a virtual node will be
263                return repaintIfRequired(newHighlights);
264            }
265        }
266
267        mv.setNewCursor(getCursor(c), this);
268
269        // return early if there can't be any highlights
270        if (!drawTargetHighlight || mode != Mode.MOVE || c.isEmpty())
271            return repaintIfRequired(newHighlights);
272
273        // CTRL toggles selection, but if while dragging CTRL means merge
274        final boolean isToggleMode = ctrl && !dragInProgress();
275        for (OsmPrimitive x : c) {
276            // only highlight primitives that will change the selection
277            // when clicked. I.e. don't highlight selected elements unless
278            // we are in toggle mode.
279            if (isToggleMode || !x.isSelected()) {
280                newHighlights.add(x);
281            }
282        }
283        return repaintIfRequired(newHighlights);
284    }
285
286    /**
287     * works out which cursor should be displayed for most of SelectAction's
288     * features. The only exception is the "move" cursor when actually dragging
289     * primitives.
290     * @param nearbyStuff  primitives near the cursor
291     * @return the cursor that should be displayed
292     */
293    private Cursor getCursor(Collection<OsmPrimitive> nearbyStuff) {
294        String c = "rect";
295        switch(mode) {
296        case MOVE:
297            if (virtualManager.hasVirtualNode()) {
298                c = "virtual_node";
299                break;
300            }
301            final Iterator<OsmPrimitive> it = nearbyStuff.iterator();
302            final OsmPrimitive osm = it.hasNext() ? it.next() : null;
303
304            if (dragInProgress()) {
305                // only consider merge if ctrl is pressed and there are nodes in
306                // the selection that could be merged
307                if (!ctrl || getLayerManager().getEditDataSet().getSelectedNodes().isEmpty()) {
308                    c = "move";
309                    break;
310                }
311                // only show merge to node cursor if nearby node and that node is currently
312                // not being dragged
313                final boolean hasTarget = osm instanceof Node && !osm.isSelected();
314                c = hasTarget ? "merge_to_node" : "merge";
315                break;
316            }
317
318            c = (osm instanceof Node) ? "node" : c;
319            c = (osm instanceof Way) ? "way" : c;
320            if (shift) {
321                c += "_add";
322            } else if (ctrl) {
323                c += osm == null || osm.isSelected() ? "_rm" : "_add";
324            }
325            break;
326        case ROTATE:
327            c = "rotate";
328            break;
329        case SCALE:
330            c = "scale";
331            break;
332        case SELECT:
333            if (lassoMode) {
334                c = "lasso";
335            } else {
336                c = "rect" + (shift ? "_add" : (ctrl && !Main.isPlatformOsx() ? "_rm" : ""));
337            }
338            break;
339        }
340        return SelectActionCursor.valueOf(c).cursor();
341    }
342
343    /**
344     * Removes all existing highlights.
345     * @return true if a repaint is required
346     */
347    private boolean removeHighlighting() {
348        boolean needsRepaint = false;
349        DataSet ds = getLayerManager().getEditDataSet();
350        if (ds != null && !ds.getHighlightedVirtualNodes().isEmpty()) {
351            needsRepaint = true;
352            ds.clearHighlightedVirtualNodes();
353        }
354        if (oldHighlights.isEmpty())
355            return needsRepaint;
356
357        for (OsmPrimitive prim : oldHighlights) {
358            prim.setHighlighted(false);
359        }
360        oldHighlights = new HashSet<>();
361        return true;
362    }
363
364    private boolean repaintIfRequired(Set<OsmPrimitive> newHighlights) {
365        if (!drawTargetHighlight)
366            return false;
367
368        boolean needsRepaint = false;
369        for (OsmPrimitive x : newHighlights) {
370            if (oldHighlights.contains(x)) {
371                continue;
372            }
373            needsRepaint = true;
374            x.setHighlighted(true);
375        }
376        oldHighlights.removeAll(newHighlights);
377        for (OsmPrimitive x : oldHighlights) {
378            x.setHighlighted(false);
379            needsRepaint = true;
380        }
381        oldHighlights = newHighlights;
382        return needsRepaint;
383    }
384
385    /**
386     * Look, whether any object is selected. If not, select the nearest node.
387     * If there are no nodes in the dataset, do nothing.
388     *
389     * If the user did not press the left mouse button, do nothing.
390     *
391     * Also remember the starting position of the movement and change the mouse
392     * cursor to movement.
393     */
394    @Override
395    public void mousePressed(MouseEvent e) {
396        mouseDownButton = e.getButton();
397        // return early
398        if (!mv.isActiveLayerVisible() || !(Boolean) this.getValue("active") || mouseDownButton != MouseEvent.BUTTON1)
399            return;
400
401        // left-button mouse click only is processed here
402
403        // request focus in order to enable the expected keyboard shortcuts
404        mv.requestFocus();
405
406        // update which modifiers are pressed (shift, alt, ctrl)
407        updateKeyModifiers(e);
408
409        // We don't want to change to draw tool if the user tries to (de)select
410        // stuff but accidentally clicks in an empty area when selection is empty
411        cancelDrawMode = shift || ctrl;
412        didMouseDrag = false;
413        initialMoveThresholdExceeded = false;
414        mouseDownTime = System.currentTimeMillis();
415        lastMousePos = e.getPoint();
416        startEN = mv.getEastNorth(lastMousePos.x, lastMousePos.y);
417
418        // primitives under cursor are stored in c collection
419
420        OsmPrimitive nearestPrimitive = mv.getNearestNodeOrWay(e.getPoint(), mv.isSelectablePredicate, true);
421
422        determineMapMode(nearestPrimitive != null);
423
424        switch(mode) {
425        case ROTATE:
426        case SCALE:
427            //  if nothing was selected, select primitive under cursor for scaling or rotating
428            DataSet ds = getLayerManager().getEditDataSet();
429            if (ds.selectionEmpty()) {
430                ds.setSelected(asColl(nearestPrimitive));
431            }
432
433            // Mode.select redraws when selectPrims is called
434            // Mode.move   redraws when mouseDragged is called
435            // Mode.rotate redraws here
436            // Mode.scale redraws here
437            break;
438        case MOVE:
439            // also include case when some primitive is under cursor and no shift+ctrl / alt+ctrl is pressed
440            // so this is not movement, but selection on primitive under cursor
441            if (!cancelDrawMode && nearestPrimitive instanceof Way) {
442                virtualManager.activateVirtualNodeNearPoint(e.getPoint());
443            }
444            OsmPrimitive toSelect = cycleManager.cycleSetup(nearestPrimitive, e.getPoint());
445            selectPrims(asColl(toSelect), false, false);
446            useLastMoveCommandIfPossible();
447            // Schedule a timer to update status line "initialMoveDelay+1" ms in the future
448            GuiHelper.scheduleTimer(initialMoveDelay+1, evt -> updateStatusLine(), false);
449            break;
450        case SELECT:
451        default:
452            if (!(ctrl && Main.isPlatformOsx())) {
453                // start working with rectangle or lasso
454                selectionManager.register(mv, lassoMode);
455                selectionManager.mousePressed(e);
456                break;
457            }
458        }
459        if (giveUserFeedback(e)) {
460            mv.repaint();
461        }
462        updateStatusLine();
463    }
464
465    @Override
466    public void mouseMoved(MouseEvent e) {
467        // Mac OSX simulates with ctrl + mouse 1 the second mouse button hence no dragging events get fired.
468        if (Main.isPlatformOsx() && (mode == Mode.ROTATE || mode == Mode.SCALE)) {
469            mouseDragged(e);
470            return;
471        }
472        oldEvent = e;
473        if (giveUserFeedback(e)) {
474            mv.repaint();
475        }
476    }
477
478    /**
479     * If the left mouse button is pressed, move all currently selected
480     * objects (if one of them is under the mouse) or the current one under the
481     * mouse (which will become selected).
482     */
483    @Override
484    public void mouseDragged(MouseEvent e) {
485        if (!mv.isActiveLayerVisible())
486            return;
487
488        // Swing sends random mouseDragged events when closing dialogs by double-clicking their top-left icon on Windows
489        // Ignore such false events to prevent issues like #7078
490        if (mouseDownButton == MouseEvent.BUTTON1 && mouseReleaseTime > mouseDownTime)
491            return;
492
493        cancelDrawMode = true;
494        if (mode == Mode.SELECT) {
495            // Unregisters selectionManager if ctrl has been pressed after mouse click on Mac OS X in order to move the map
496            if (ctrl && Main.isPlatformOsx()) {
497                selectionManager.unregister(mv);
498                // Make sure correct cursor is displayed
499                mv.setNewCursor(Cursor.MOVE_CURSOR, this);
500            }
501            return;
502        }
503
504        // do not count anything as a move if it lasts less than 100 milliseconds.
505        if ((mode == Mode.MOVE) && (System.currentTimeMillis() - mouseDownTime < initialMoveDelay))
506            return;
507
508        if (mode != Mode.ROTATE && mode != Mode.SCALE && (e.getModifiersEx() & MouseEvent.BUTTON1_DOWN_MASK) == 0) {
509            // button is pressed in rotate mode
510            return;
511        }
512
513        if (mode == Mode.MOVE) {
514            // If ctrl is pressed we are in merge mode. Look for a nearby node,
515            // highlight it and adjust the cursor accordingly.
516            final boolean canMerge = ctrl && !getLayerManager().getEditDataSet().getSelectedNodes().isEmpty();
517            final OsmPrimitive p = canMerge ? findNodeToMergeTo(e.getPoint()) : null;
518            boolean needsRepaint = removeHighlighting();
519            if (p != null) {
520                p.setHighlighted(true);
521                oldHighlights.add(p);
522                needsRepaint = true;
523            }
524            mv.setNewCursor(getCursor(asColl(p)), this);
525            // also update the stored mouse event, so we can display the correct cursor
526            // when dragging a node onto another one and then press CTRL to merge
527            oldEvent = e;
528            if (needsRepaint) {
529                mv.repaint();
530            }
531        }
532
533        if (startingDraggingPos == null) {
534            startingDraggingPos = new Point(e.getX(), e.getY());
535        }
536
537        if (lastMousePos == null) {
538            lastMousePos = e.getPoint();
539            return;
540        }
541
542        if (!initialMoveThresholdExceeded) {
543            int dp = (int) lastMousePos.distance(e.getX(), e.getY());
544            if (dp < initialMoveThreshold)
545                return; // ignore small drags
546            initialMoveThresholdExceeded = true; //no more ingnoring uintil nex mouse press
547        }
548        if (e.getPoint().equals(lastMousePos))
549            return;
550
551        EastNorth currentEN = mv.getEastNorth(e.getX(), e.getY());
552
553        if (virtualManager.hasVirtualWaysToBeConstructed()) {
554            virtualManager.createMiddleNodeFromVirtual(currentEN);
555        } else {
556            if (!updateCommandWhileDragging(currentEN)) return;
557        }
558
559        mv.repaint();
560        if (mode != Mode.SCALE) {
561            lastMousePos = e.getPoint();
562        }
563
564        didMouseDrag = true;
565    }
566
567    @Override
568    public void mouseExited(MouseEvent e) {
569        if (removeHighlighting()) {
570            mv.repaint();
571        }
572    }
573
574    @Override
575    public void mouseReleased(MouseEvent e) {
576        if (!mv.isActiveLayerVisible())
577            return;
578
579        startingDraggingPos = null;
580        mouseReleaseTime = System.currentTimeMillis();
581
582        if (mode == Mode.SELECT) {
583            if (e.getButton() != MouseEvent.BUTTON1) {
584                return;
585            }
586            selectionManager.endSelecting(e);
587            selectionManager.unregister(mv);
588
589            // Select Draw Tool if no selection has been made
590            if (getLayerManager().getEditDataSet().selectionEmpty() && !cancelDrawMode) {
591                Main.map.selectDrawTool(true);
592                updateStatusLine();
593                return;
594            }
595        }
596
597        if (mode == Mode.MOVE && e.getButton() == MouseEvent.BUTTON1) {
598            if (!didMouseDrag) {
599                // only built in move mode
600                virtualManager.clear();
601                // do nothing if the click was to short too be recognized as a drag,
602                // but the release position is farther than 10px away from the press position
603                if (lastMousePos == null || lastMousePos.distanceSq(e.getPoint()) < 100) {
604                    updateKeyModifiers(e);
605                    selectPrims(cycleManager.cyclePrims(), true, false);
606
607                    // If the user double-clicked a node, change to draw mode
608                    Collection<OsmPrimitive> c = getLayerManager().getEditDataSet().getSelected();
609                    if (e.getClickCount() >= 2 && c.size() == 1 && c.iterator().next() instanceof Node) {
610                        // We need to do it like this as otherwise drawAction will see a double
611                        // click and switch back to SelectMode
612                        Main.worker.execute(() -> Main.map.selectDrawTool(true));
613                        return;
614                    }
615                }
616            } else {
617                confirmOrUndoMovement(e);
618            }
619        }
620
621        mode = null;
622
623        // simply remove any highlights if the middle click popup is active because
624        // the highlights don't depend on the cursor position there. If something was
625        // selected beforehand this would put us into move mode as well, which breaks
626        // the cycling through primitives on top of each other (see #6739).
627        if (e.getButton() == MouseEvent.BUTTON2) {
628            removeHighlighting();
629        } else {
630            giveUserFeedback(e);
631        }
632        updateStatusLine();
633    }
634
635    @Override
636    public void selectionEnded(Rectangle r, MouseEvent e) {
637        updateKeyModifiers(e);
638        selectPrims(selectionManager.getSelectedObjects(alt), true, true);
639    }
640
641    @Override
642    public void doKeyPressed(KeyEvent e) {
643        if (!Main.isDisplayingMapView() ||
644                !repeatedKeySwitchLassoOption || !getShortcut().isEvent(e)) return;
645        if (Main.isDebugEnabled()) {
646            Main.debug(getClass().getName()+" consuming event "+e);
647        }
648        e.consume();
649        if (!lassoMode) {
650            Main.map.selectMapMode(Main.map.mapModeSelectLasso);
651        } else {
652            Main.map.selectMapMode(Main.map.mapModeSelect);
653        }
654    }
655
656    @Override
657    public void doKeyReleased(KeyEvent e) {
658        // Do nothing
659    }
660
661    /**
662     * sets the mapmode according to key modifiers and if there are any
663     * selectables nearby. Everything has to be pre-determined for this
664     * function; its main purpose is to centralize what the modifiers do.
665     * @param hasSelectionNearby {@code true} if some primitves are selectable nearby
666     */
667    private void determineMapMode(boolean hasSelectionNearby) {
668        if (shift && ctrl) {
669            mode = Mode.ROTATE;
670        } else if (alt && ctrl) {
671            mode = Mode.SCALE;
672        } else if (hasSelectionNearby || dragInProgress()) {
673            mode = Mode.MOVE;
674        } else {
675            mode = Mode.SELECT;
676        }
677    }
678
679    /**
680     * Determines whenever elements have been grabbed and moved (i.e. the initial
681     * thresholds have been exceeded) and is still in progress (i.e. mouse button still pressed)
682     * @return true if a drag is in progress
683     */
684    private boolean dragInProgress() {
685        return didMouseDrag && startingDraggingPos != null;
686    }
687
688    /**
689     * Create or update data modification command while dragging mouse - implementation of
690     * continuous moving, scaling and rotation
691     * @param currentEN - mouse position
692     * @return status of action (<code>true</code> when action was performed)
693     */
694    private boolean updateCommandWhileDragging(EastNorth currentEN) {
695        // Currently we support only transformations which do not affect relations.
696        // So don't add them in the first place to make handling easier
697        DataSet ds = getLayerManager().getEditDataSet();
698        Collection<OsmPrimitive> selection = ds.getSelectedNodesAndWays();
699        if (selection.isEmpty()) { // if nothing was selected to drag, just select nearest node/way to the cursor
700            OsmPrimitive nearestPrimitive = mv.getNearestNodeOrWay(mv.getPoint(startEN), mv.isSelectablePredicate, true);
701            ds.setSelected(nearestPrimitive);
702        }
703
704        Collection<Node> affectedNodes = AllNodesVisitor.getAllNodes(selection);
705        // for these transformations, having only one node makes no sense - quit silently
706        if (affectedNodes.size() < 2 && (mode == Mode.ROTATE || mode == Mode.SCALE)) {
707            return false;
708        }
709        Command c = getLastCommand();
710        if (mode == Mode.MOVE) {
711            if (startEN == null) return false; // fix #8128
712            ds.beginUpdate();
713            if (c instanceof MoveCommand && affectedNodes.equals(((MoveCommand) c).getParticipatingPrimitives())) {
714                ((MoveCommand) c).saveCheckpoint();
715                ((MoveCommand) c).applyVectorTo(currentEN);
716            } else {
717                c = new MoveCommand(selection, startEN, currentEN);
718                Main.main.undoRedo.add(c);
719            }
720            for (Node n : affectedNodes) {
721                LatLon ll = n.getCoor();
722                if (ll != null && ll.isOutSideWorld()) {
723                    // Revert move
724                    ((MoveCommand) c).resetToCheckpoint();
725                    ds.endUpdate();
726                    JOptionPane.showMessageDialog(
727                            Main.parent,
728                            tr("Cannot move objects outside of the world."),
729                            tr("Warning"),
730                            JOptionPane.WARNING_MESSAGE);
731                    mv.setNewCursor(cursor, this);
732                    return false;
733                }
734            }
735        } else {
736            startEN = currentEN; // drag can continue after scaling/rotation
737
738            if (mode != Mode.ROTATE && mode != Mode.SCALE) {
739                return false;
740            }
741
742            ds.beginUpdate();
743
744            if (mode == Mode.ROTATE) {
745                if (c instanceof RotateCommand && affectedNodes.equals(((RotateCommand) c).getTransformedNodes())) {
746                    ((RotateCommand) c).handleEvent(currentEN);
747                } else {
748                    Main.main.undoRedo.add(new RotateCommand(selection, currentEN));
749                }
750            } else if (mode == Mode.SCALE) {
751                if (c instanceof ScaleCommand && affectedNodes.equals(((ScaleCommand) c).getTransformedNodes())) {
752                    ((ScaleCommand) c).handleEvent(currentEN);
753                } else {
754                    Main.main.undoRedo.add(new ScaleCommand(selection, currentEN));
755                }
756            }
757
758            Collection<Way> ways = ds.getSelectedWays();
759            if (doesImpactStatusLine(affectedNodes, ways)) {
760                Main.map.statusLine.setDist(ways);
761            }
762        }
763        ds.endUpdate();
764        return true;
765    }
766
767    private static boolean doesImpactStatusLine(Collection<Node> affectedNodes, Collection<Way> selectedWays) {
768        for (Way w : selectedWays) {
769            for (Node n : w.getNodes()) {
770                if (affectedNodes.contains(n)) {
771                    return true;
772                }
773            }
774        }
775        return false;
776    }
777
778    /**
779     * Adapt last move command (if it is suitable) to work with next drag, started at point startEN
780     */
781    private void useLastMoveCommandIfPossible() {
782        Command c = getLastCommand();
783        Collection<Node> affectedNodes = AllNodesVisitor.getAllNodes(getLayerManager().getEditDataSet().getSelected());
784        if (c instanceof MoveCommand && affectedNodes.equals(((MoveCommand) c).getParticipatingPrimitives())) {
785            // old command was created with different base point of movement, we need to recalculate it
786            ((MoveCommand) c).changeStartPoint(startEN);
787        }
788    }
789
790    /**
791     * Obtain command in undoRedo stack to "continue" when dragging
792     * @return last command
793     */
794    private static Command getLastCommand() {
795        Command c = !Main.main.undoRedo.commands.isEmpty()
796                ? Main.main.undoRedo.commands.getLast() : null;
797        if (c instanceof SequenceCommand) {
798            c = ((SequenceCommand) c).getLastCommand();
799        }
800        return c;
801    }
802
803    /**
804     * Present warning in the following cases and undo unwanted movements: <ul>
805     * <li>large and possibly unwanted movements</li>
806     * <li>movement of node with attached ways that are hidden by filters</li>
807     * </ul>
808     *
809     * @param e the mouse event causing the action (mouse released)
810     */
811    private void confirmOrUndoMovement(MouseEvent e) {
812        if (movesHiddenWay()) {
813            final ExtendedDialog ed = new ConfirmMoveDialog();
814            ed.setContent(tr("Are you sure that you want to move elements with attached ways that are hidden by filters?"));
815            ed.toggleEnable("movedHiddenElements");
816            ed.showDialog();
817            if (ed.getValue() != 1) {
818                Main.main.undoRedo.undo();
819            }
820        }
821        int max = Main.pref.getInteger("warn.move.maxelements", 20), limit = max;
822        for (OsmPrimitive osm : getLayerManager().getEditDataSet().getSelected()) {
823            if (osm instanceof Way) {
824                limit -= ((Way) osm).getNodes().size();
825            }
826            if (--limit < 0) {
827                break;
828            }
829        }
830        if (limit < 0) {
831            final ExtendedDialog ed = new ConfirmMoveDialog();
832            ed.setContent(
833                    /* for correct i18n of plural forms - see #9110 */
834                    trn("You moved more than {0} element. " + "Moving a large number of elements is often an error.\n" + "Really move them?",
835                        "You moved more than {0} elements. " + "Moving a large number of elements is often an error.\n" + "Really move them?",
836                        max, max));
837            ed.toggleEnable("movedManyElements");
838            ed.showDialog();
839
840            if (ed.getValue() != 1) {
841                Main.main.undoRedo.undo();
842            }
843        } else {
844            // if small number of elements were moved,
845            updateKeyModifiers(e);
846            if (ctrl) mergePrims(e.getPoint());
847        }
848        getLayerManager().getEditDataSet().fireSelectionChanged();
849    }
850
851    static class ConfirmMoveDialog extends ExtendedDialog {
852        ConfirmMoveDialog() {
853            super(Main.parent,
854                    tr("Move elements"),
855                    new String[]{tr("Move them"), tr("Undo move")});
856            setButtonIcons(new String[]{"reorder", "cancel"});
857            setCancelButton(2);
858        }
859    }
860
861    private boolean movesHiddenWay() {
862        DataSet ds = getLayerManager().getEditDataSet();
863        final Collection<OsmPrimitive> elementsToTest = new HashSet<>(ds.getSelected());
864        for (Way osm : Utils.filteredCollection(ds.getSelected(), Way.class)) {
865            elementsToTest.addAll(osm.getNodes());
866        }
867        for (OsmPrimitive node : Utils.filteredCollection(elementsToTest, Node.class)) {
868            for (Way ref : Utils.filteredCollection(node.getReferrers(), Way.class)) {
869                if (ref.isDisabledAndHidden()) {
870                    return true;
871                }
872            }
873        }
874        return false;
875    }
876
877    /**
878     * Merges the selected nodes to the one closest to the given mouse position if the control
879     * key is pressed. If there is no such node, no action will be done and no error will be
880     * reported. If there is, it will execute the merge and add it to the undo buffer.
881     * @param p mouse position
882     */
883    private void mergePrims(Point p) {
884        DataSet ds = getLayerManager().getEditDataSet();
885        Collection<Node> selNodes = ds.getSelectedNodes();
886        if (selNodes.isEmpty())
887            return;
888
889        Node target = findNodeToMergeTo(p);
890        if (target == null)
891            return;
892
893        if (selNodes.size() == 1) {
894            // Move all selected primitive to preserve shape #10748
895            Collection<OsmPrimitive> selection = ds.getSelectedNodesAndWays();
896            Collection<Node> affectedNodes = AllNodesVisitor.getAllNodes(selection);
897            Command c = getLastCommand();
898            ds.beginUpdate();
899            if (c instanceof MoveCommand
900                && affectedNodes.equals(((MoveCommand) c).getParticipatingPrimitives())) {
901                Node selectedNode = selNodes.iterator().next();
902                EastNorth selectedEN = selectedNode.getEastNorth();
903                EastNorth targetEN = target.getEastNorth();
904                ((MoveCommand) c).moveAgain(targetEN.getX() - selectedEN.getX(),
905                                            targetEN.getY() - selectedEN.getY());
906            }
907            ds.endUpdate();
908        }
909
910        Collection<Node> nodesToMerge = new LinkedList<>(selNodes);
911        nodesToMerge.add(target);
912        mergeNodes(Main.getLayerManager().getEditLayer(), nodesToMerge, target);
913    }
914
915    /**
916     * Merge nodes using {@code MergeNodesAction}.
917     * Can be overridden for testing purpose.
918     * @param layer layer the reference data layer. Must not be null
919     * @param nodes the collection of nodes. Ignored if null
920     * @param targetLocationNode this node's location will be used for the target node
921     */
922    public void mergeNodes(OsmDataLayer layer, Collection<Node> nodes,
923                           Node targetLocationNode) {
924        MergeNodesAction.doMergeNodes(layer, nodes, targetLocationNode);
925    }
926
927    /**
928     * Tries to find a node to merge to when in move-merge mode for the current mouse
929     * position. Either returns the node or null, if no suitable one is nearby.
930     * @param p mouse position
931     * @return node to merge to, or null
932     */
933    private Node findNodeToMergeTo(Point p) {
934        Collection<Node> target = mv.getNearestNodes(p,
935                getLayerManager().getEditDataSet().getSelectedNodes(),
936                mv.isSelectablePredicate);
937        return target.isEmpty() ? null : target.iterator().next();
938    }
939
940    private void selectPrims(Collection<OsmPrimitive> prims, boolean released, boolean area) {
941        DataSet ds = getLayerManager().getEditDataSet();
942
943        // not allowed together: do not change dataset selection, return early
944        // Virtual Ways: if non-empty the cursor is above a virtual node. So don't highlight
945        // anything if about to drag the virtual node (i.e. !released) but continue if the
946        // cursor is only released above a virtual node by accident (i.e. released). See #7018
947        if (ds == null || (shift && ctrl) || (ctrl && !released) || (virtualManager.hasVirtualWaysToBeConstructed() && !released))
948            return;
949
950        if (!released) {
951            // Don't replace the selection if the user clicked on a
952            // selected object (it breaks moving of selected groups).
953            // Do it later, on mouse release.
954            shift |= ds.getSelected().containsAll(prims);
955        }
956
957        if (ctrl) {
958            // Ctrl on an item toggles its selection status,
959            // but Ctrl on an *area* just clears those items
960            // out of the selection.
961            if (area) {
962                ds.clearSelection(prims);
963            } else {
964                ds.toggleSelected(prims);
965            }
966        } else if (shift) {
967            // add prims to an existing selection
968            ds.addSelected(prims);
969        } else {
970            // clear selection, then select the prims clicked
971            ds.setSelected(prims);
972        }
973    }
974
975    /**
976     * Returns the current select mode.
977     * @return the select mode
978     * @since 7543
979     */
980    public final Mode getMode() {
981        return mode;
982    }
983
984    @Override
985    public String getModeHelpText() {
986        if (mouseDownButton == MouseEvent.BUTTON1 && mouseReleaseTime < mouseDownTime) {
987            if (mode == Mode.SELECT)
988                return tr("Release the mouse button to select the objects in the rectangle.");
989            else if (mode == Mode.MOVE && (System.currentTimeMillis() - mouseDownTime >= initialMoveDelay)) {
990                final DataSet ds = getLayerManager().getEditDataSet();
991                final boolean canMerge = ds != null && !ds.getSelectedNodes().isEmpty();
992                final String mergeHelp = canMerge ? (' ' + tr("Ctrl to merge with nearest node.")) : "";
993                return tr("Release the mouse button to stop moving.") + mergeHelp;
994            } else if (mode == Mode.ROTATE)
995                return tr("Release the mouse button to stop rotating.");
996            else if (mode == Mode.SCALE)
997                return tr("Release the mouse button to stop scaling.");
998        }
999        return tr("Move objects by dragging; Shift to add to selection (Ctrl to toggle); Shift-Ctrl to rotate selected; " +
1000                  "Alt-Ctrl to scale selected; or change selection");
1001    }
1002
1003    @Override
1004    public boolean layerIsSupported(Layer l) {
1005        return l instanceof OsmDataLayer;
1006    }
1007
1008    /**
1009     * Enable or diable the lasso mode
1010     * @param lassoMode true to enable the lasso mode, false otherwise
1011     */
1012    public void setLassoMode(boolean lassoMode) {
1013        this.selectionManager.setLassoMode(lassoMode);
1014        this.lassoMode = lassoMode;
1015    }
1016
1017    private final transient CycleManager cycleManager = new CycleManager();
1018    private final transient VirtualManager virtualManager = new VirtualManager();
1019
1020    private class CycleManager {
1021
1022        private Collection<OsmPrimitive> cycleList = Collections.emptyList();
1023        private boolean cyclePrims;
1024        private OsmPrimitive cycleStart;
1025        private boolean waitForMouseUpParameter;
1026        private boolean multipleMatchesParameter;
1027        /**
1028         * read preferences
1029         */
1030        private void init() {
1031            waitForMouseUpParameter = Main.pref.getBoolean("mappaint.select.waits-for-mouse-up", false);
1032            multipleMatchesParameter = Main.pref.getBoolean("selectaction.cycles.multiple.matches", false);
1033        }
1034
1035        /**
1036         * Determine primitive to be selected and build cycleList
1037         * @param nearest primitive found by simple method
1038         * @param p point where user clicked
1039         * @return OsmPrimitive to be selected
1040         */
1041        private OsmPrimitive cycleSetup(OsmPrimitive nearest, Point p) {
1042            OsmPrimitive osm = null;
1043
1044            if (nearest != null) {
1045                osm = nearest;
1046
1047                if (!(alt || multipleMatchesParameter)) {
1048                    // no real cycling, just one element in cycle list
1049                    cycleList = asColl(osm);
1050
1051                    if (waitForMouseUpParameter) {
1052                        // prefer a selected nearest node or way, if possible
1053                        osm = mv.getNearestNodeOrWay(p, mv.isSelectablePredicate, true);
1054                    }
1055                } else {
1056                    // Alt + left mouse button pressed: we need to build cycle list
1057                    cycleList = mv.getAllNearest(p, mv.isSelectablePredicate);
1058
1059                    if (cycleList.size() > 1) {
1060                        cyclePrims = false;
1061
1062                        // find first already selected element in cycle list
1063                        OsmPrimitive old = osm;
1064                        for (OsmPrimitive o : cycleList) {
1065                            if (o.isSelected()) {
1066                                cyclePrims = true;
1067                                osm = o;
1068                                break;
1069                            }
1070                        }
1071
1072                        // special case:  for cycle groups of 2, we can toggle to the
1073                        // true nearest primitive on mousePressed right away
1074                        if (cycleList.size() == 2 && !waitForMouseUpParameter) {
1075                            if (!(osm.equals(old) || osm.isNew() || ctrl)) {
1076                                cyclePrims = false;
1077                                osm = old;
1078                            } // else defer toggling to mouseRelease time in those cases:
1079                            /*
1080                             * osm == old -- the true nearest node is the
1081                             * selected one osm is a new node -- do not break
1082                             * unglue ways in ALT mode ctrl is pressed -- ctrl
1083                             * generally works on mouseReleased
1084                             */
1085                        }
1086                    }
1087                }
1088            }
1089            return osm;
1090        }
1091
1092        /**
1093         * Modifies current selection state and returns the next element in a
1094         * selection cycle given by
1095         * <code>cycleList</code> field
1096         * @return the next element of cycle list
1097         */
1098        private Collection<OsmPrimitive> cyclePrims() {
1099            if (cycleList.size() <= 1) {
1100                // no real cycling, just return one-element collection with nearest primitive in it
1101                return cycleList;
1102            }
1103            // updateKeyModifiers() already called before!
1104
1105            DataSet ds = getLayerManager().getEditDataSet();
1106            OsmPrimitive first = cycleList.iterator().next(), foundInDS = null;
1107            OsmPrimitive nxt = first;
1108
1109            if (cyclePrims && shift) {
1110                for (Iterator<OsmPrimitive> i = cycleList.iterator(); i.hasNext();) {
1111                    nxt = i.next();
1112                    if (!nxt.isSelected()) {
1113                        break; // take first primitive in cycleList not in sel
1114                    }
1115                }
1116                // if primitives 1,2,3 are under cursor, [Alt-press] [Shift-release] gives 1 -> 12 -> 123
1117            } else {
1118                for (Iterator<OsmPrimitive> i = cycleList.iterator(); i.hasNext();) {
1119                    nxt = i.next();
1120                    if (nxt.isSelected()) {
1121                        foundInDS = nxt;
1122                        // first selected primitive in cycleList is found
1123                        if (cyclePrims || ctrl) {
1124                            ds.clearSelection(foundInDS); // deselect it
1125                            nxt = i.hasNext() ? i.next() : first;
1126                            // return next one in cycle list (last->first)
1127                        }
1128                        break; // take next primitive in cycleList
1129                    }
1130                }
1131            }
1132
1133            // if "no-alt-cycling" is enabled, Ctrl-Click arrives here.
1134            if (ctrl) {
1135                // a member of cycleList was found in the current dataset selection
1136                if (foundInDS != null) {
1137                    // mouse was moved to a different selection group w/ a previous sel
1138                    if (!cycleList.contains(cycleStart)) {
1139                        ds.clearSelection(cycleList);
1140                        cycleStart = foundInDS;
1141                    } else if (cycleStart.equals(nxt)) {
1142                        // loop detected, insert deselect step
1143                        ds.addSelected(nxt);
1144                    }
1145                } else {
1146                    // setup for iterating a sel group again or a new, different one..
1147                    nxt = cycleList.contains(cycleStart) ? cycleStart : first;
1148                    cycleStart = nxt;
1149                }
1150            } else {
1151                cycleStart = null;
1152            }
1153            // return one-element collection with one element to be selected (or added  to selection)
1154            return asColl(nxt);
1155        }
1156    }
1157
1158    private class VirtualManager {
1159
1160        private Node virtualNode;
1161        private Collection<WaySegment> virtualWays = new LinkedList<>();
1162        private int nodeVirtualSize;
1163        private int virtualSnapDistSq2;
1164        private int virtualSpace;
1165
1166        private void init() {
1167            nodeVirtualSize = Main.pref.getInteger("mappaint.node.virtual-size", 8);
1168            int virtualSnapDistSq = Main.pref.getInteger("mappaint.node.virtual-snap-distance", 8);
1169            virtualSnapDistSq2 = virtualSnapDistSq*virtualSnapDistSq;
1170            virtualSpace = Main.pref.getInteger("mappaint.node.virtual-space", 70);
1171        }
1172
1173        /**
1174         * Calculate a virtual node if there is enough visual space to draw a
1175         * crosshair node and the middle of a way segment is clicked. If the
1176         * user drags the crosshair node, it will be added to all ways in
1177         * <code>virtualWays</code>.
1178         *
1179         * @param p the point clicked
1180         * @return whether
1181         * <code>virtualNode</code> and
1182         * <code>virtualWays</code> were setup.
1183         */
1184        private boolean activateVirtualNodeNearPoint(Point p) {
1185            if (nodeVirtualSize > 0) {
1186
1187                Collection<WaySegment> selVirtualWays = new LinkedList<>();
1188                Pair<Node, Node> vnp = null, wnp = new Pair<>(null, null);
1189
1190                for (WaySegment ws : mv.getNearestWaySegments(p, mv.isSelectablePredicate)) {
1191                    Way w = ws.way;
1192
1193                    wnp.a = w.getNode(ws.lowerIndex);
1194                    wnp.b = w.getNode(ws.lowerIndex + 1);
1195                    MapViewPoint p1 = mv.getState().getPointFor(wnp.a);
1196                    MapViewPoint p2 = mv.getState().getPointFor(wnp.b);
1197                    if (WireframeMapRenderer.isLargeSegment(p1, p2, virtualSpace)) {
1198                        Point2D pc = new Point2D.Double((p1.getInViewX() + p2.getInViewX()) / 2, (p1.getInViewY() + p2.getInViewY()) / 2);
1199                        if (p.distanceSq(pc) < virtualSnapDistSq2) {
1200                            // Check that only segments on top of each other get added to the
1201                            // virtual ways list. Otherwise ways that coincidentally have their
1202                            // virtual node at the same spot will be joined which is likely unwanted
1203                            Pair.sort(wnp);
1204                            if (vnp == null) {
1205                                vnp = new Pair<>(wnp.a, wnp.b);
1206                                virtualNode = new Node(mv.getLatLon(pc.getX(), pc.getY()));
1207                            }
1208                            if (vnp.equals(wnp)) {
1209                                // if mutiple line segments have the same points,
1210                                // add all segments to be splitted to virtualWays list
1211                                // if some lines are selected, only their segments will go to virtualWays
1212                                (w.isSelected() ? selVirtualWays : virtualWays).add(ws);
1213                            }
1214                        }
1215                    }
1216                }
1217
1218                if (!selVirtualWays.isEmpty()) {
1219                    virtualWays = selVirtualWays;
1220                }
1221            }
1222
1223            return !virtualWays.isEmpty();
1224        }
1225
1226        private void createMiddleNodeFromVirtual(EastNorth currentEN) {
1227            Collection<Command> virtualCmds = new LinkedList<>();
1228            virtualCmds.add(new AddCommand(virtualNode));
1229            for (WaySegment virtualWay : virtualWays) {
1230                Way w = virtualWay.way;
1231                Way wnew = new Way(w);
1232                wnew.addNode(virtualWay.lowerIndex + 1, virtualNode);
1233                virtualCmds.add(new ChangeCommand(w, wnew));
1234            }
1235            virtualCmds.add(new MoveCommand(virtualNode, startEN, currentEN));
1236            String text = trn("Add and move a virtual new node to way",
1237                    "Add and move a virtual new node to {0} ways", virtualWays.size(),
1238                    virtualWays.size());
1239            Main.main.undoRedo.add(new SequenceCommand(text, virtualCmds));
1240            getLayerManager().getEditDataSet().setSelected(Collections.singleton((OsmPrimitive) virtualNode));
1241            clear();
1242        }
1243
1244        private void clear() {
1245            virtualWays.clear();
1246            virtualNode = null;
1247        }
1248
1249        private boolean hasVirtualNode() {
1250            return virtualNode != null;
1251        }
1252
1253        private boolean hasVirtualWaysToBeConstructed() {
1254            return !virtualWays.isEmpty();
1255        }
1256    }
1257
1258    /**
1259     * Returns {@code o} as collection of {@code o}'s type.
1260     * @param <T> object type
1261     * @param o any object
1262     * @return {@code o} as collection of {@code o}'s type.
1263     */
1264    protected static <T> Collection<T> asColl(T o) {
1265        if (o == null)
1266            return Collections.emptySet();
1267        return Collections.singleton(o);
1268    }
1269}