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.marktr;
006import static org.openstreetmap.josm.tools.I18n.tr;
007import static org.openstreetmap.josm.tools.I18n.trn;
008
009import java.awt.BasicStroke;
010import java.awt.Color;
011import java.awt.Cursor;
012import java.awt.Graphics2D;
013import java.awt.Point;
014import java.awt.event.ActionEvent;
015import java.awt.event.KeyEvent;
016import java.awt.event.MouseEvent;
017import java.awt.event.MouseListener;
018import java.util.ArrayList;
019import java.util.Arrays;
020import java.util.Collection;
021import java.util.Collections;
022import java.util.Comparator;
023import java.util.HashMap;
024import java.util.HashSet;
025import java.util.Iterator;
026import java.util.LinkedList;
027import java.util.List;
028import java.util.Map;
029import java.util.Set;
030import java.util.stream.DoubleStream;
031
032import javax.swing.AbstractAction;
033import javax.swing.JCheckBoxMenuItem;
034import javax.swing.JMenuItem;
035import javax.swing.JOptionPane;
036import javax.swing.JPopupMenu;
037
038import org.openstreetmap.josm.Main;
039import org.openstreetmap.josm.actions.JosmAction;
040import org.openstreetmap.josm.command.AddCommand;
041import org.openstreetmap.josm.command.ChangeCommand;
042import org.openstreetmap.josm.command.Command;
043import org.openstreetmap.josm.command.SequenceCommand;
044import org.openstreetmap.josm.data.Bounds;
045import org.openstreetmap.josm.data.SelectionChangedListener;
046import org.openstreetmap.josm.data.coor.EastNorth;
047import org.openstreetmap.josm.data.coor.LatLon;
048import org.openstreetmap.josm.data.osm.DataSet;
049import org.openstreetmap.josm.data.osm.Node;
050import org.openstreetmap.josm.data.osm.OsmPrimitive;
051import org.openstreetmap.josm.data.osm.Way;
052import org.openstreetmap.josm.data.osm.WaySegment;
053import org.openstreetmap.josm.data.osm.visitor.paint.ArrowPaintHelper;
054import org.openstreetmap.josm.data.osm.visitor.paint.PaintColors;
055import org.openstreetmap.josm.data.preferences.AbstractToStringProperty;
056import org.openstreetmap.josm.data.preferences.BooleanProperty;
057import org.openstreetmap.josm.data.preferences.CachingProperty;
058import org.openstreetmap.josm.data.preferences.ColorProperty;
059import org.openstreetmap.josm.data.preferences.DoubleProperty;
060import org.openstreetmap.josm.data.preferences.StrokeProperty;
061import org.openstreetmap.josm.gui.MainMenu;
062import org.openstreetmap.josm.gui.MapFrame;
063import org.openstreetmap.josm.gui.MapView;
064import org.openstreetmap.josm.gui.MapViewState;
065import org.openstreetmap.josm.gui.MapViewState.MapViewPoint;
066import org.openstreetmap.josm.gui.NavigatableComponent;
067import org.openstreetmap.josm.gui.draw.MapPath2D;
068import org.openstreetmap.josm.gui.draw.MapViewPath;
069import org.openstreetmap.josm.gui.draw.SymbolShape;
070import org.openstreetmap.josm.gui.layer.Layer;
071import org.openstreetmap.josm.gui.layer.MapViewPaintable;
072import org.openstreetmap.josm.gui.layer.OsmDataLayer;
073import org.openstreetmap.josm.gui.util.KeyPressReleaseListener;
074import org.openstreetmap.josm.gui.util.ModifierListener;
075import org.openstreetmap.josm.gui.widgets.PopupMenuLauncher;
076import org.openstreetmap.josm.tools.Geometry;
077import org.openstreetmap.josm.tools.ImageProvider;
078import org.openstreetmap.josm.tools.Pair;
079import org.openstreetmap.josm.tools.Shortcut;
080import org.openstreetmap.josm.tools.Utils;
081
082/**
083 * Mapmode to add nodes, create and extend ways.
084 */
085public class DrawAction extends MapMode implements MapViewPaintable, SelectionChangedListener, KeyPressReleaseListener, ModifierListener {
086
087    private static final Color ORANGE_TRANSPARENT = new Color(Color.ORANGE.getRed(), Color.ORANGE.getGreen(), Color.ORANGE.getBlue(), 128);
088
089    private static final ArrowPaintHelper START_WAY_INDICATOR = new ArrowPaintHelper(Math.toRadians(90), 8);
090
091    private static final CachingProperty<Boolean> USE_REPEATED_SHORTCUT
092            = new BooleanProperty("draw.anglesnap.toggleOnRepeatedA", true).cached();
093    private static final CachingProperty<BasicStroke> RUBBER_LINE_STROKE
094            = new StrokeProperty("draw.stroke.helper-line", "3").cached();
095
096    private static final CachingProperty<BasicStroke> HIGHLIGHT_STROKE
097            = new StrokeProperty("draw.anglesnap.stroke.highlight", "10").cached();
098    private static final CachingProperty<BasicStroke> HELPER_STROKE
099            = new StrokeProperty("draw.anglesnap.stroke.helper", "1 4").cached();
100
101    private static final CachingProperty<Double> SNAP_ANGLE_TOLERANCE
102            = new DoubleProperty("draw.anglesnap.tolerance", 5.0).cached();
103    private static final CachingProperty<Boolean> DRAW_CONSTRUCTION_GEOMETRY
104            = new BooleanProperty("draw.anglesnap.drawConstructionGeometry", true).cached();
105    private static final CachingProperty<Boolean> SHOW_PROJECTED_POINT
106            = new BooleanProperty("draw.anglesnap.drawProjectedPoint", true).cached();
107    private static final CachingProperty<Boolean> SNAP_TO_PROJECTIONS
108            = new BooleanProperty("draw.anglesnap.projectionsnap", true).cached();
109
110    private static final CachingProperty<Boolean> SHOW_ANGLE
111            = new BooleanProperty("draw.anglesnap.showAngle", true).cached();
112
113    private static final CachingProperty<Color> SNAP_HELPER_COLOR
114            = new ColorProperty(marktr("draw angle snap"), Color.ORANGE).cached();
115
116    private static final CachingProperty<Color> HIGHLIGHT_COLOR
117            = new ColorProperty(marktr("draw angle snap highlight"), ORANGE_TRANSPARENT).cached();
118
119    private static final AbstractToStringProperty<Color> RUBBER_LINE_COLOR
120            = PaintColors.SELECTED.getProperty().getChildColor(marktr("helper line"));
121
122    private static final CachingProperty<Boolean> DRAW_HELPER_LINE
123            = new BooleanProperty("draw.helper-line", true).cached();
124    private static final CachingProperty<Boolean> DRAW_TARGET_HIGHLIGHT
125            = new BooleanProperty("draw.target-highlight", true).cached();
126    private static final CachingProperty<Double> SNAP_TO_INTERSECTION_THRESHOLD
127            = new DoubleProperty("edit.snap-intersection-threshold", 10).cached();
128
129    private final Cursor cursorJoinNode;
130    private final Cursor cursorJoinWay;
131
132    private transient Node lastUsedNode;
133    private double toleranceMultiplier;
134
135    private transient Node mouseOnExistingNode;
136    private transient Set<Way> mouseOnExistingWays = new HashSet<>();
137    // old highlights store which primitives are currently highlighted. This
138    // is true, even if target highlighting is disabled since the status bar
139    // derives its information from this list as well.
140    private transient Set<OsmPrimitive> oldHighlights = new HashSet<>();
141    // new highlights contains a list of primitives that should be highlighted
142    // but haven't been so far. The idea is to compare old and new and only
143    // repaint if there are changes.
144    private transient Set<OsmPrimitive> newHighlights = new HashSet<>();
145    private boolean wayIsFinished;
146    private Point mousePos;
147    private Point oldMousePos;
148
149    private transient Node currentBaseNode;
150    private transient Node previousNode;
151    private EastNorth currentMouseEastNorth;
152
153    private final transient SnapHelper snapHelper = new SnapHelper();
154
155    private final transient Shortcut backspaceShortcut;
156    private final BackSpaceAction backspaceAction;
157    private final transient Shortcut snappingShortcut;
158    private boolean ignoreNextKeyRelease;
159
160    private final SnapChangeAction snapChangeAction;
161    private final JCheckBoxMenuItem snapCheckboxMenuItem;
162    private static final BasicStroke BASIC_STROKE = new BasicStroke(1);
163
164    private Point rightClickPressPos;
165
166    /**
167     * Constructs a new {@code DrawAction}.
168     * @param mapFrame Map frame
169     */
170    public DrawAction(MapFrame mapFrame) {
171        super(tr("Draw"), "node/autonode", tr("Draw nodes"),
172                Shortcut.registerShortcut("mapmode:draw", tr("Mode: {0}", tr("Draw")), KeyEvent.VK_A, Shortcut.DIRECT),
173                mapFrame, ImageProvider.getCursor("crosshair", null));
174
175        snappingShortcut = Shortcut.registerShortcut("mapmode:drawanglesnapping",
176                tr("Mode: Draw Angle snapping"), KeyEvent.CHAR_UNDEFINED, Shortcut.NONE);
177        snapChangeAction = new SnapChangeAction();
178        snapCheckboxMenuItem = addMenuItem();
179        snapHelper.setMenuCheckBox(snapCheckboxMenuItem);
180        backspaceShortcut = Shortcut.registerShortcut("mapmode:backspace",
181                tr("Backspace in Add mode"), KeyEvent.VK_BACK_SPACE, Shortcut.DIRECT);
182        backspaceAction = new BackSpaceAction();
183        cursorJoinNode = ImageProvider.getCursor("crosshair", "joinnode");
184        cursorJoinWay = ImageProvider.getCursor("crosshair", "joinway");
185
186        snapHelper.init();
187    }
188
189    private JCheckBoxMenuItem addMenuItem() {
190        int n = Main.main.menu.editMenu.getItemCount();
191        for (int i = n-1; i > 0; i--) {
192            JMenuItem item = Main.main.menu.editMenu.getItem(i);
193            if (item != null && item.getAction() != null && item.getAction() instanceof SnapChangeAction) {
194                Main.main.menu.editMenu.remove(i);
195            }
196        }
197        return MainMenu.addWithCheckbox(Main.main.menu.editMenu, snapChangeAction, MainMenu.WINDOW_MENU_GROUP.VOLATILE);
198    }
199
200    /**
201     * Checks if a map redraw is required and does so if needed. Also updates the status bar.
202     * @return true if a repaint is needed
203     */
204    private boolean redrawIfRequired() {
205        updateStatusLine();
206        // repaint required if the helper line is active.
207        boolean needsRepaint = DRAW_HELPER_LINE.get() && !wayIsFinished;
208        if (DRAW_TARGET_HIGHLIGHT.get()) {
209            // move newHighlights to oldHighlights; only update changed primitives
210            for (OsmPrimitive x : newHighlights) {
211                if (oldHighlights.contains(x)) {
212                    continue;
213                }
214                x.setHighlighted(true);
215                needsRepaint = true;
216            }
217            oldHighlights.removeAll(newHighlights);
218            for (OsmPrimitive x : oldHighlights) {
219                x.setHighlighted(false);
220                needsRepaint = true;
221            }
222        }
223        // required in order to print correct help text
224        oldHighlights = newHighlights;
225
226        if (!needsRepaint && !DRAW_TARGET_HIGHLIGHT.get())
227            return false;
228
229        // update selection to reflect which way being modified
230        OsmDataLayer editLayer = getLayerManager().getEditLayer();
231        if (getCurrentBaseNode() != null && editLayer != null && !editLayer.data.selectionEmpty()) {
232            DataSet currentDataSet = editLayer.data;
233            Way continueFrom = getWayForNode(getCurrentBaseNode());
234            if (alt && continueFrom != null && (!getCurrentBaseNode().isSelected() || continueFrom.isSelected())) {
235                addRemoveSelection(currentDataSet, getCurrentBaseNode(), continueFrom);
236                needsRepaint = true;
237            } else if (!alt && continueFrom != null && !continueFrom.isSelected()) {
238                currentDataSet.addSelected(continueFrom);
239                needsRepaint = true;
240            }
241        }
242
243        if (needsRepaint && editLayer != null) {
244            editLayer.invalidate();
245        }
246        return needsRepaint;
247    }
248
249    private static void addRemoveSelection(DataSet ds, OsmPrimitive toAdd, OsmPrimitive toRemove) {
250        ds.beginUpdate(); // to prevent the selection listener to screw around with the state
251        ds.addSelected(toAdd);
252        ds.clearSelection(toRemove);
253        ds.endUpdate();
254    }
255
256    @Override
257    public void enterMode() {
258        if (!isEnabled())
259            return;
260        super.enterMode();
261        readPreferences();
262
263        // determine if selection is suitable to continue drawing. If it
264        // isn't, set wayIsFinished to true to avoid superfluous repaints.
265        determineCurrentBaseNodeAndPreviousNode(getLayerManager().getEditDataSet().getSelected());
266        wayIsFinished = getCurrentBaseNode() == null;
267
268        toleranceMultiplier = 0.01 * NavigatableComponent.PROP_SNAP_DISTANCE.get();
269
270        snapHelper.init();
271        snapCheckboxMenuItem.getAction().setEnabled(true);
272
273        Main.map.statusLine.getAnglePanel().addMouseListener(snapHelper.anglePopupListener);
274        Main.registerActionShortcut(backspaceAction, backspaceShortcut);
275
276        Main.map.mapView.addMouseListener(this);
277        Main.map.mapView.addMouseMotionListener(this);
278        Main.map.mapView.addTemporaryLayer(this);
279        DataSet.addSelectionListener(this);
280
281        Main.map.keyDetector.addKeyListener(this);
282        Main.map.keyDetector.addModifierListener(this);
283        ignoreNextKeyRelease = true;
284    }
285
286    @Override
287    public void exitMode() {
288        super.exitMode();
289        Main.map.mapView.removeMouseListener(this);
290        Main.map.mapView.removeMouseMotionListener(this);
291        Main.map.mapView.removeTemporaryLayer(this);
292        DataSet.removeSelectionListener(this);
293        Main.unregisterActionShortcut(backspaceAction, backspaceShortcut);
294        snapHelper.unsetFixedMode();
295        snapCheckboxMenuItem.getAction().setEnabled(false);
296
297        Main.map.statusLine.getAnglePanel().removeMouseListener(snapHelper.anglePopupListener);
298        Main.map.statusLine.activateAnglePanel(false);
299
300        removeHighlighting();
301        Main.map.keyDetector.removeKeyListener(this);
302        Main.map.keyDetector.removeModifierListener(this);
303
304        // when exiting we let everybody know about the currently selected
305        // primitives
306        //
307        DataSet ds = getLayerManager().getEditDataSet();
308        if (ds != null) {
309            ds.fireSelectionChanged();
310        }
311    }
312
313    /**
314     * redraw to (possibly) get rid of helper line if selection changes.
315     */
316    @Override
317    public void modifiersChanged(int modifiers) {
318        if (!Main.isDisplayingMapView() || !Main.map.mapView.isActiveLayerDrawable())
319            return;
320        updateKeyModifiers(modifiers);
321        computeHelperLine();
322        addHighlighting();
323    }
324
325    @Override
326    public void doKeyPressed(KeyEvent e) {
327        if (!snappingShortcut.isEvent(e) && !(USE_REPEATED_SHORTCUT.get() && getShortcut().isEvent(e)))
328            return;
329        snapHelper.setFixedMode();
330        computeHelperLine();
331        redrawIfRequired();
332    }
333
334    @Override
335    public void doKeyReleased(KeyEvent e) {
336        if (!snappingShortcut.isEvent(e) && !(USE_REPEATED_SHORTCUT.get() && getShortcut().isEvent(e)))
337            return;
338        if (ignoreNextKeyRelease) {
339            ignoreNextKeyRelease = false;
340            return;
341        }
342        snapHelper.unFixOrTurnOff();
343        computeHelperLine();
344        redrawIfRequired();
345    }
346
347    /**
348     * redraw to (possibly) get rid of helper line if selection changes.
349     */
350    @Override
351    public void selectionChanged(Collection<? extends OsmPrimitive> newSelection) {
352        if (!Main.map.mapView.isActiveLayerDrawable())
353            return;
354        computeHelperLine();
355        addHighlighting();
356    }
357
358    private void tryAgain(MouseEvent e) {
359        getLayerManager().getEditDataSet().setSelected();
360        mouseReleased(e);
361    }
362
363    /**
364     * This function should be called when the user wishes to finish his current draw action.
365     * If Potlatch Style is enabled, it will switch to select tool, otherwise simply disable
366     * the helper line until the user chooses to draw something else.
367     */
368    private void finishDrawing() {
369        // let everybody else know about the current selection
370        //
371        Main.getLayerManager().getEditDataSet().fireSelectionChanged();
372        lastUsedNode = null;
373        wayIsFinished = true;
374        Main.map.selectSelectTool(true);
375        snapHelper.noSnapNow();
376
377        // Redraw to remove the helper line stub
378        computeHelperLine();
379        removeHighlighting();
380    }
381
382    @Override
383    public void mousePressed(MouseEvent e) {
384        if (e.getButton() == MouseEvent.BUTTON3) {
385            rightClickPressPos = e.getPoint();
386        }
387    }
388
389    /**
390     * If user clicked with the left button, add a node at the current mouse
391     * position.
392     *
393     * If in nodeway mode, insert the node into the way.
394     */
395    @Override
396    public void mouseReleased(MouseEvent e) {
397        if (e.getButton() == MouseEvent.BUTTON3) {
398            Point curMousePos = e.getPoint();
399            if (curMousePos.equals(rightClickPressPos)) {
400                tryToSetBaseSegmentForAngleSnap();
401            }
402            return;
403        }
404        if (e.getButton() != MouseEvent.BUTTON1)
405            return;
406        if (!Main.map.mapView.isActiveLayerDrawable())
407            return;
408        // request focus in order to enable the expected keyboard shortcuts
409        //
410        Main.map.mapView.requestFocus();
411
412        if (e.getClickCount() > 1 && mousePos != null && mousePos.equals(oldMousePos)) {
413            // A double click equals "user clicked last node again, finish way"
414            // Change draw tool only if mouse position is nearly the same, as
415            // otherwise fast clicks will count as a double click
416            finishDrawing();
417            return;
418        }
419        oldMousePos = mousePos;
420
421        // we copy ctrl/alt/shift from the event just in case our global
422        // keyDetector didn't make it through the security manager. Unclear
423        // if that can ever happen but better be safe.
424        updateKeyModifiers(e);
425        mousePos = e.getPoint();
426
427        DataSet ds = getLayerManager().getEditDataSet();
428        Collection<OsmPrimitive> selection = new ArrayList<>(ds.getSelected());
429
430        boolean newNode = false;
431        Node n = Main.map.mapView.getNearestNode(mousePos, OsmPrimitive::isSelectable);
432        if (ctrl) {
433            Iterator<Way> it = ds.getSelectedWays().iterator();
434            if (it.hasNext()) {
435                // ctrl-click on node of selected way = reuse node despite of ctrl
436                if (!it.next().containsNode(n)) n = null;
437            } else {
438                n = null; // ctrl-click + no selected way = new node
439            }
440        }
441
442        if (n != null && !snapHelper.isActive()) {
443            // user clicked on node
444            if (selection.isEmpty() || wayIsFinished) {
445                // select the clicked node and do nothing else
446                // (this is just a convenience option so that people don't
447                // have to switch modes)
448
449                ds.setSelected(n);
450                // If we extend/continue an existing way, select it already now to make it obvious
451                Way continueFrom = getWayForNode(n);
452                if (continueFrom != null) {
453                    ds.addSelected(continueFrom);
454                }
455
456                // The user explicitly selected a node, so let him continue drawing
457                wayIsFinished = false;
458                return;
459            }
460        } else {
461            EastNorth newEN;
462            if (n != null) {
463                EastNorth foundPoint = n.getEastNorth();
464                // project found node to snapping line
465                newEN = snapHelper.getSnapPoint(foundPoint);
466                // do not add new node if there is some node within snapping distance
467                double tolerance = Main.map.mapView.getDist100Pixel() * toleranceMultiplier;
468                if (foundPoint.distance(newEN) > tolerance) {
469                    n = new Node(newEN); // point != projected, so we create new node
470                    newNode = true;
471                }
472            } else { // n==null, no node found in clicked area
473                EastNorth mouseEN = Main.map.mapView.getEastNorth(e.getX(), e.getY());
474                newEN = snapHelper.isSnapOn() ? snapHelper.getSnapPoint(mouseEN) : mouseEN;
475                n = new Node(newEN); //create node at clicked point
476                newNode = true;
477            }
478            snapHelper.unsetFixedMode();
479        }
480
481        Collection<Command> cmds = new LinkedList<>();
482        Collection<OsmPrimitive> newSelection = new LinkedList<>(ds.getSelected());
483        List<Way> reuseWays = new ArrayList<>();
484        List<Way> replacedWays = new ArrayList<>();
485
486        if (newNode) {
487            if (n.getCoor().isOutSideWorld()) {
488                JOptionPane.showMessageDialog(
489                        Main.parent,
490                        tr("Cannot add a node outside of the world."),
491                        tr("Warning"),
492                        JOptionPane.WARNING_MESSAGE
493                        );
494                return;
495            }
496            cmds.add(new AddCommand(n));
497
498            if (!ctrl) {
499                // Insert the node into all the nearby way segments
500                List<WaySegment> wss = Main.map.mapView.getNearestWaySegments(
501                        Main.map.mapView.getPoint(n), OsmPrimitive::isSelectable);
502                if (snapHelper.isActive()) {
503                    tryToMoveNodeOnIntersection(wss, n);
504                }
505                insertNodeIntoAllNearbySegments(wss, n, newSelection, cmds, replacedWays, reuseWays);
506            }
507        }
508        // now "n" is newly created or reused node that shoud be added to some way
509
510        // This part decides whether or not a "segment" (i.e. a connection) is made to an existing node.
511
512        // For a connection to be made, the user must either have a node selected (connection
513        // is made to that node), or he must have a way selected *and* one of the endpoints
514        // of that way must be the last used node (connection is made to last used node), or
515        // he must have a way and a node selected (connection is made to the selected node).
516
517        // If the above does not apply, the selection is cleared and a new try is started
518
519        boolean extendedWay = false;
520        boolean wayIsFinishedTemp = wayIsFinished;
521        wayIsFinished = false;
522
523        // don't draw lines if shift is held
524        if (!selection.isEmpty() && !shift) {
525            Node selectedNode = null;
526            Way selectedWay = null;
527
528            for (OsmPrimitive p : selection) {
529                if (p instanceof Node) {
530                    if (selectedNode != null) {
531                        // Too many nodes selected to do something useful
532                        tryAgain(e);
533                        return;
534                    }
535                    selectedNode = (Node) p;
536                } else if (p instanceof Way) {
537                    if (selectedWay != null) {
538                        // Too many ways selected to do something useful
539                        tryAgain(e);
540                        return;
541                    }
542                    selectedWay = (Way) p;
543                }
544            }
545
546            // the node from which we make a connection
547            Node n0 = findNodeToContinueFrom(selectedNode, selectedWay);
548            // We have a selection but it isn't suitable. Try again.
549            if (n0 == null) {
550                tryAgain(e);
551                return;
552            }
553            if (!wayIsFinishedTemp) {
554                if (isSelfContainedWay(selectedWay, n0, n))
555                    return;
556
557                // User clicked last node again, finish way
558                if (n0 == n) {
559                    finishDrawing();
560                    return;
561                }
562
563                // Ok we know now that we'll insert a line segment, but will it connect to an
564                // existing way or make a new way of its own? The "alt" modifier means that the
565                // user wants a new way.
566                Way way = alt ? null : (selectedWay != null ? selectedWay : getWayForNode(n0));
567                Way wayToSelect;
568
569                // Don't allow creation of self-overlapping ways
570                if (way != null) {
571                    int nodeCount = 0;
572                    for (Node p : way.getNodes()) {
573                        if (p.equals(n0)) {
574                            nodeCount++;
575                        }
576                    }
577                    if (nodeCount > 1) {
578                        way = null;
579                    }
580                }
581
582                if (way == null) {
583                    way = new Way();
584                    way.addNode(n0);
585                    cmds.add(new AddCommand(way));
586                    wayToSelect = way;
587                } else {
588                    int i;
589                    if ((i = replacedWays.indexOf(way)) != -1) {
590                        way = reuseWays.get(i);
591                        wayToSelect = way;
592                    } else {
593                        wayToSelect = way;
594                        Way wnew = new Way(way);
595                        cmds.add(new ChangeCommand(way, wnew));
596                        way = wnew;
597                    }
598                }
599
600                // Connected to a node that's already in the way
601                if (way.containsNode(n)) {
602                    wayIsFinished = true;
603                    selection.clear();
604                }
605
606                // Add new node to way
607                if (way.getNode(way.getNodesCount() - 1) == n0) {
608                    way.addNode(n);
609                } else {
610                    way.addNode(0, n);
611                }
612
613                extendedWay = true;
614                newSelection.clear();
615                newSelection.add(wayToSelect);
616            }
617        }
618        if (!extendedWay && !newNode) {
619            return; // We didn't do anything.
620        }
621
622        String title = getTitle(newNode, n, newSelection, reuseWays, extendedWay);
623
624        Command c = new SequenceCommand(title, cmds);
625
626        Main.main.undoRedo.add(c);
627        if (!wayIsFinished) {
628            lastUsedNode = n;
629        }
630
631        ds.setSelected(newSelection);
632
633        // "viewport following" mode for tracing long features
634        // from aerial imagery or GPS tracks.
635        if (Main.map.mapView.viewportFollowing) {
636            Main.map.mapView.smoothScrollTo(n.getEastNorth());
637        }
638        computeHelperLine();
639        removeHighlighting();
640    }
641
642    private static String getTitle(boolean newNode, Node n, Collection<OsmPrimitive> newSelection, List<Way> reuseWays,
643            boolean extendedWay) {
644        String title;
645        if (!extendedWay) {
646            if (reuseWays.isEmpty()) {
647                title = tr("Add node");
648            } else {
649                title = tr("Add node into way");
650                for (Way w : reuseWays) {
651                    newSelection.remove(w);
652                }
653            }
654            newSelection.clear();
655            newSelection.add(n);
656        } else if (!newNode) {
657            title = tr("Connect existing way to node");
658        } else if (reuseWays.isEmpty()) {
659            title = tr("Add a new node to an existing way");
660        } else {
661            title = tr("Add node into way and connect");
662        }
663        return title;
664    }
665
666    private void insertNodeIntoAllNearbySegments(List<WaySegment> wss, Node n, Collection<OsmPrimitive> newSelection,
667            Collection<Command> cmds, List<Way> replacedWays, List<Way> reuseWays) {
668        Map<Way, List<Integer>> insertPoints = new HashMap<>();
669        for (WaySegment ws : wss) {
670            List<Integer> is;
671            if (insertPoints.containsKey(ws.way)) {
672                is = insertPoints.get(ws.way);
673            } else {
674                is = new ArrayList<>();
675                insertPoints.put(ws.way, is);
676            }
677
678            is.add(ws.lowerIndex);
679        }
680
681        Set<Pair<Node, Node>> segSet = new HashSet<>();
682
683        for (Map.Entry<Way, List<Integer>> insertPoint : insertPoints.entrySet()) {
684            Way w = insertPoint.getKey();
685            List<Integer> is = insertPoint.getValue();
686
687            Way wnew = new Way(w);
688
689            pruneSuccsAndReverse(is);
690            for (int i : is) {
691                segSet.add(Pair.sort(new Pair<>(w.getNode(i), w.getNode(i+1))));
692                wnew.addNode(i + 1, n);
693            }
694
695            // If ALT is pressed, a new way should be created and that new way should get
696            // selected. This works everytime unless the ways the nodes get inserted into
697            // are already selected. This is the case when creating a self-overlapping way
698            // but pressing ALT prevents this. Therefore we must de-select the way manually
699            // here so /only/ the new way will be selected after this method finishes.
700            if (alt) {
701                newSelection.add(insertPoint.getKey());
702            }
703
704            cmds.add(new ChangeCommand(insertPoint.getKey(), wnew));
705            replacedWays.add(insertPoint.getKey());
706            reuseWays.add(wnew);
707        }
708
709        adjustNode(segSet, n);
710    }
711
712    /**
713     * Prevent creation of ways that look like this: &lt;----&gt;
714     * This happens if users want to draw a no-exit-sideway from the main way like this:
715     * ^
716     * |&lt;----&gt;
717     * |
718     * The solution isn't ideal because the main way will end in the side way, which is bad for
719     * navigation software ("drive straight on") but at least easier to fix. Maybe users will fix
720     * it on their own, too. At least it's better than producing an error.
721     *
722     * @param selectedWay the way to check
723     * @param currentNode the current node (i.e. the one the connection will be made from)
724     * @param targetNode the target node (i.e. the one the connection will be made to)
725     * @return {@code true} if this would create a selfcontaining way, {@code false} otherwise.
726     */
727    private boolean isSelfContainedWay(Way selectedWay, Node currentNode, Node targetNode) {
728        if (selectedWay != null) {
729            int posn0 = selectedWay.getNodes().indexOf(currentNode);
730            // CHECKSTYLE.OFF: SingleSpaceSeparator
731            if ((posn0 != -1 && // n0 is part of way
732                (posn0 >= 1                            && targetNode.equals(selectedWay.getNode(posn0-1)))) || // previous node
733                (posn0 < selectedWay.getNodesCount()-1 && targetNode.equals(selectedWay.getNode(posn0+1)))) {  // next node
734                getLayerManager().getEditDataSet().setSelected(targetNode);
735                lastUsedNode = targetNode;
736                return true;
737            }
738            // CHECKSTYLE.ON: SingleSpaceSeparator
739        }
740
741        return false;
742    }
743
744    /**
745     * Finds a node to continue drawing from. Decision is based upon given node and way.
746     * @param selectedNode Currently selected node, may be null
747     * @param selectedWay Currently selected way, may be null
748     * @return Node if a suitable node is found, null otherwise
749     */
750    private Node findNodeToContinueFrom(Node selectedNode, Way selectedWay) {
751        // No nodes or ways have been selected, this occurs when a relation
752        // has been selected or the selection is empty
753        if (selectedNode == null && selectedWay == null)
754            return null;
755
756        if (selectedNode == null) {
757            if (selectedWay.isFirstLastNode(lastUsedNode))
758                return lastUsedNode;
759
760            // We have a way selected, but no suitable node to continue from. Start anew.
761            return null;
762        }
763
764        if (selectedWay == null)
765            return selectedNode;
766
767        if (selectedWay.isFirstLastNode(selectedNode))
768            return selectedNode;
769
770        // We have a way and node selected, but it's not at the start/end of the way. Start anew.
771        return null;
772    }
773
774    @Override
775    public void mouseDragged(MouseEvent e) {
776        mouseMoved(e);
777    }
778
779    @Override
780    public void mouseMoved(MouseEvent e) {
781        if (!Main.map.mapView.isActiveLayerDrawable())
782            return;
783
784        // we copy ctrl/alt/shift from the event just in case our global
785        // keyDetector didn't make it through the security manager. Unclear
786        // if that can ever happen but better be safe.
787        updateKeyModifiers(e);
788        mousePos = e.getPoint();
789        if (snapHelper.isSnapOn() && ctrl)
790            tryToSetBaseSegmentForAngleSnap();
791
792        computeHelperLine();
793        addHighlighting();
794    }
795
796    /**
797     * This method is used to detect segment under mouse and use it as reference for angle snapping
798     */
799    private void tryToSetBaseSegmentForAngleSnap() {
800        WaySegment seg = Main.map.mapView.getNearestWaySegment(mousePos, OsmPrimitive::isSelectable);
801        if (seg != null) {
802            snapHelper.setBaseSegment(seg);
803        }
804    }
805
806    /**
807     * This method prepares data required for painting the "helper line" from
808     * the last used position to the mouse cursor. It duplicates some code from
809     * mouseReleased() (FIXME).
810     */
811    private void computeHelperLine() {
812        if (mousePos == null) {
813            // Don't draw the line.
814            currentMouseEastNorth = null;
815            currentBaseNode = null;
816            return;
817        }
818
819        Collection<OsmPrimitive> selection = getLayerManager().getEditDataSet().getSelected();
820
821        MapView mv = Main.map.mapView;
822        Node currentMouseNode = null;
823        mouseOnExistingNode = null;
824        mouseOnExistingWays = new HashSet<>();
825
826        showStatusInfo(-1, -1, -1, snapHelper.isSnapOn());
827
828        if (!ctrl && mousePos != null) {
829            currentMouseNode = mv.getNearestNode(mousePos, OsmPrimitive::isSelectable);
830        }
831
832        // We need this for highlighting and we'll only do so if we actually want to re-use
833        // *and* there is no node nearby (because nodes beat ways when re-using)
834        if (!ctrl && currentMouseNode == null) {
835            List<WaySegment> wss = mv.getNearestWaySegments(mousePos, OsmPrimitive::isSelectable);
836            for (WaySegment ws : wss) {
837                mouseOnExistingWays.add(ws.way);
838            }
839        }
840
841        if (currentMouseNode != null) {
842            // user clicked on node
843            if (selection.isEmpty()) return;
844            currentMouseEastNorth = currentMouseNode.getEastNorth();
845            mouseOnExistingNode = currentMouseNode;
846        } else {
847            // no node found in clicked area
848            currentMouseEastNorth = mv.getEastNorth(mousePos.x, mousePos.y);
849        }
850
851        determineCurrentBaseNodeAndPreviousNode(selection);
852        if (previousNode == null) {
853            snapHelper.noSnapNow();
854        }
855
856        if (getCurrentBaseNode() == null || getCurrentBaseNode() == currentMouseNode)
857            return; // Don't create zero length way segments.
858
859
860        double curHdg = Math.toDegrees(getCurrentBaseNode().getEastNorth()
861                .heading(currentMouseEastNorth));
862        double baseHdg = -1;
863        if (previousNode != null) {
864            EastNorth en = previousNode.getEastNorth();
865            if (en != null) {
866                baseHdg = Math.toDegrees(en.heading(getCurrentBaseNode().getEastNorth()));
867            }
868        }
869
870        snapHelper.checkAngleSnapping(currentMouseEastNorth, baseHdg, curHdg);
871
872        // status bar was filled by snapHelper
873    }
874
875    private static void showStatusInfo(double angle, double hdg, double distance, boolean activeFlag) {
876        Main.map.statusLine.setAngle(angle);
877        Main.map.statusLine.activateAnglePanel(activeFlag);
878        Main.map.statusLine.setHeading(hdg);
879        Main.map.statusLine.setDist(distance);
880    }
881
882    /**
883     * Helper function that sets fields currentBaseNode and previousNode
884     * @param selection
885     * uses also lastUsedNode field
886     */
887    private void determineCurrentBaseNodeAndPreviousNode(Collection<OsmPrimitive> selection) {
888        Node selectedNode = null;
889        Way selectedWay = null;
890        for (OsmPrimitive p : selection) {
891            if (p instanceof Node) {
892                if (selectedNode != null)
893                    return;
894                selectedNode = (Node) p;
895            } else if (p instanceof Way) {
896                if (selectedWay != null)
897                    return;
898                selectedWay = (Way) p;
899            }
900        }
901        // we are here, if not more than 1 way or node is selected,
902
903        // the node from which we make a connection
904        currentBaseNode = null;
905        previousNode = null;
906
907        // Try to find an open way to measure angle from it. The way is not to be continued!
908        // warning: may result in changes of currentBaseNode and previousNode
909        // please remove if bugs arise
910        if (selectedWay == null && selectedNode != null) {
911            for (OsmPrimitive p: selectedNode.getReferrers()) {
912                if (p.isUsable() && p instanceof Way && ((Way) p).isFirstLastNode(selectedNode)) {
913                    if (selectedWay != null) { // two uncontinued ways, nothing to take as reference
914                        selectedWay = null;
915                        break;
916                    } else {
917                        // set us ~continue this way (measure angle from it)
918                        selectedWay = (Way) p;
919                    }
920                }
921            }
922        }
923
924        if (selectedNode == null) {
925            if (selectedWay == null)
926                return;
927            continueWayFromNode(selectedWay, lastUsedNode);
928        } else if (selectedWay == null) {
929            currentBaseNode = selectedNode;
930        } else if (!selectedWay.isDeleted()) { // fix #7118
931            continueWayFromNode(selectedWay, selectedNode);
932        }
933    }
934
935    /**
936     * if one of the ends of {@code way} is given {@code node},
937     * then set currentBaseNode = node and previousNode = adjacent node of way
938     * @param way way to continue
939     * @param node starting node
940     */
941    private void continueWayFromNode(Way way, Node node) {
942        int n = way.getNodesCount();
943        if (node == way.firstNode()) {
944            currentBaseNode = node;
945            if (n > 1) previousNode = way.getNode(1);
946        } else if (node == way.lastNode()) {
947            currentBaseNode = node;
948            if (n > 1) previousNode = way.getNode(n-2);
949        }
950    }
951
952    /**
953     * Repaint on mouse exit so that the helper line goes away.
954     */
955    @Override
956    public void mouseExited(MouseEvent e) {
957        OsmDataLayer editLayer = Main.getLayerManager().getEditLayer();
958        if (editLayer == null)
959            return;
960        mousePos = e.getPoint();
961        snapHelper.noSnapNow();
962        boolean repaintIssued = removeHighlighting();
963        // force repaint in case snapHelper needs one. If removeHighlighting
964        // caused one already, don't do it again.
965        if (!repaintIssued) {
966            editLayer.invalidate();
967        }
968    }
969
970    /**
971     * @param n node
972     * @return If the node is the end of exactly one way, return this.
973     *  <code>null</code> otherwise.
974     */
975    public static Way getWayForNode(Node n) {
976        Way way = null;
977        for (Way w : Utils.filteredCollection(n.getReferrers(), Way.class)) {
978            if (!w.isUsable() || w.getNodesCount() < 1) {
979                continue;
980            }
981            Node firstNode = w.getNode(0);
982            Node lastNode = w.getNode(w.getNodesCount() - 1);
983            if ((firstNode == n || lastNode == n) && (firstNode != lastNode)) {
984                if (way != null)
985                    return null;
986                way = w;
987            }
988        }
989        return way;
990    }
991
992    /**
993     * Replies the current base node, after having checked it is still usable (see #11105).
994     * @return the current base node (can be null). If not-null, it's guaranteed the node is usable
995     */
996    public Node getCurrentBaseNode() {
997        if (currentBaseNode != null && (currentBaseNode.getDataSet() == null || !currentBaseNode.isUsable())) {
998            currentBaseNode = null;
999        }
1000        return currentBaseNode;
1001    }
1002
1003    private static void pruneSuccsAndReverse(List<Integer> is) {
1004        Set<Integer> is2 = new HashSet<>();
1005        for (int i : is) {
1006            if (!is2.contains(i - 1) && !is2.contains(i + 1)) {
1007                is2.add(i);
1008            }
1009        }
1010        is.clear();
1011        is.addAll(is2);
1012        Collections.sort(is);
1013        Collections.reverse(is);
1014    }
1015
1016    /**
1017     * Adjusts the position of a node to lie on a segment (or a segment
1018     * intersection).
1019     *
1020     * If one or more than two segments are passed, the node is adjusted
1021     * to lie on the first segment that is passed.
1022     *
1023     * If two segments are passed, the node is adjusted to be at their
1024     * intersection.
1025     *
1026     * No action is taken if no segments are passed.
1027     *
1028     * @param segs the segments to use as a reference when adjusting
1029     * @param n the node to adjust
1030     */
1031    private static void adjustNode(Collection<Pair<Node, Node>> segs, Node n) {
1032
1033        switch (segs.size()) {
1034        case 0:
1035            return;
1036        case 2:
1037            // This computes the intersection between the two segments and adjusts the node position.
1038            Iterator<Pair<Node, Node>> i = segs.iterator();
1039            Pair<Node, Node> seg = i.next();
1040            EastNorth pA = seg.a.getEastNorth();
1041            EastNorth pB = seg.b.getEastNorth();
1042            seg = i.next();
1043            EastNorth pC = seg.a.getEastNorth();
1044            EastNorth pD = seg.b.getEastNorth();
1045
1046            double u = det(pB.east() - pA.east(), pB.north() - pA.north(), pC.east() - pD.east(), pC.north() - pD.north());
1047
1048            // Check for parallel segments and do nothing if they are
1049            // In practice this will probably only happen when a way has been duplicated
1050
1051            if (u == 0)
1052                return;
1053
1054            // q is a number between 0 and 1
1055            // It is the point in the segment where the intersection occurs
1056            // if the segment is scaled to lenght 1
1057
1058            double q = det(pB.north() - pC.north(), pB.east() - pC.east(), pD.north() - pC.north(), pD.east() - pC.east()) / u;
1059            EastNorth intersection = new EastNorth(
1060                    pB.east() + q * (pA.east() - pB.east()),
1061                    pB.north() + q * (pA.north() - pB.north()));
1062
1063
1064            // only adjust to intersection if within snapToIntersectionThreshold pixel of mouse click; otherwise
1065            // fall through to default action.
1066            // (for semi-parallel lines, intersection might be miles away!)
1067            if (Main.map.mapView.getPoint2D(n).distance(Main.map.mapView.getPoint2D(intersection)) < SNAP_TO_INTERSECTION_THRESHOLD.get()) {
1068                n.setEastNorth(intersection);
1069                return;
1070            }
1071        default:
1072            EastNorth p = n.getEastNorth();
1073            seg = segs.iterator().next();
1074            pA = seg.a.getEastNorth();
1075            pB = seg.b.getEastNorth();
1076            double a = p.distanceSq(pB);
1077            double b = p.distanceSq(pA);
1078            double c = pA.distanceSq(pB);
1079            q = (a - b + c) / (2*c);
1080            n.setEastNorth(new EastNorth(pB.east() + q * (pA.east() - pB.east()), pB.north() + q * (pA.north() - pB.north())));
1081        }
1082    }
1083
1084    // helper for adjustNode
1085    static double det(double a, double b, double c, double d) {
1086        return a * d - b * c;
1087    }
1088
1089    private void tryToMoveNodeOnIntersection(List<WaySegment> wss, Node n) {
1090        if (wss.isEmpty())
1091            return;
1092        WaySegment ws = wss.get(0);
1093        EastNorth p1 = ws.getFirstNode().getEastNorth();
1094        EastNorth p2 = ws.getSecondNode().getEastNorth();
1095        if (snapHelper.dir2 != null && getCurrentBaseNode() != null) {
1096            EastNorth xPoint = Geometry.getSegmentSegmentIntersection(p1, p2, snapHelper.dir2,
1097                    getCurrentBaseNode().getEastNorth());
1098            if (xPoint != null) {
1099                n.setEastNorth(xPoint);
1100            }
1101        }
1102    }
1103
1104    /**
1105     * Takes the data from computeHelperLine to determine which ways/nodes should be highlighted
1106     * (if feature enabled). Also sets the target cursor if appropriate. It adds the to-be-
1107     * highlighted primitives to newHighlights but does not actually highlight them. This work is
1108     * done in redrawIfRequired. This means, calling addHighlighting() without redrawIfRequired()
1109     * will leave the data in an inconsistent state.
1110     *
1111     * The status bar derives its information from oldHighlights, so in order to update the status
1112     * bar both addHighlighting() and repaintIfRequired() are needed, since former fills newHighlights
1113     * and latter processes them into oldHighlights.
1114     */
1115    private void addHighlighting() {
1116        newHighlights = new HashSet<>();
1117
1118        // if ctrl key is held ("no join"), don't highlight anything
1119        if (ctrl) {
1120            Main.map.mapView.setNewCursor(cursor, this);
1121            redrawIfRequired();
1122            return;
1123        }
1124
1125        // This happens when nothing is selected, but we still want to highlight the "target node"
1126        if (mouseOnExistingNode == null && getLayerManager().getEditDataSet().selectionEmpty() && mousePos != null) {
1127            mouseOnExistingNode = Main.map.mapView.getNearestNode(mousePos, OsmPrimitive::isSelectable);
1128        }
1129
1130        if (mouseOnExistingNode != null) {
1131            Main.map.mapView.setNewCursor(cursorJoinNode, this);
1132            newHighlights.add(mouseOnExistingNode);
1133            redrawIfRequired();
1134            return;
1135        }
1136
1137        // Insert the node into all the nearby way segments
1138        if (mouseOnExistingWays.isEmpty()) {
1139            Main.map.mapView.setNewCursor(cursor, this);
1140            redrawIfRequired();
1141            return;
1142        }
1143
1144        Main.map.mapView.setNewCursor(cursorJoinWay, this);
1145        newHighlights.addAll(mouseOnExistingWays);
1146        redrawIfRequired();
1147    }
1148
1149    /**
1150     * Removes target highlighting from primitives. Issues repaint if required.
1151     * @return true if a repaint has been issued.
1152     */
1153    private boolean removeHighlighting() {
1154        newHighlights = new HashSet<>();
1155        return redrawIfRequired();
1156    }
1157
1158    @Override
1159    public void paint(Graphics2D g, MapView mv, Bounds box) {
1160        // sanity checks
1161        if (Main.map.mapView == null || mousePos == null
1162                // don't draw line if we don't know where from or where to
1163                || getCurrentBaseNode() == null || currentMouseEastNorth == null
1164                // don't draw line if mouse is outside window
1165                || !Main.map.mapView.getBounds().contains(mousePos))
1166            return;
1167
1168        Graphics2D g2 = g;
1169        snapHelper.drawIfNeeded(g2, mv.getState());
1170        if (!DRAW_HELPER_LINE.get() || wayIsFinished || shift)
1171            return;
1172
1173        if (!snapHelper.isActive()) {
1174            g2.setColor(RUBBER_LINE_COLOR.get());
1175            g2.setStroke(RUBBER_LINE_STROKE.get());
1176            paintConstructionGeometry(mv, g2);
1177        } else if (DRAW_CONSTRUCTION_GEOMETRY.get()) {
1178            // else use color and stoke from  snapHelper.draw
1179            paintConstructionGeometry(mv, g2);
1180        }
1181    }
1182
1183    private void paintConstructionGeometry(MapView mv, Graphics2D g2) {
1184        MapPath2D b = new MapPath2D();
1185        MapViewPoint p1 = mv.getState().getPointFor(getCurrentBaseNode());
1186        MapViewPoint p2 = mv.getState().getPointFor(currentMouseEastNorth);
1187
1188        b.moveTo(p1);
1189        b.lineTo(p2);
1190
1191        // if alt key is held ("start new way"), draw a little perpendicular line
1192        if (alt) {
1193            START_WAY_INDICATOR.paintArrowAt(b, p1, p2);
1194        }
1195
1196        g2.draw(b);
1197        g2.setStroke(BASIC_STROKE);
1198    }
1199
1200    @Override
1201    public String getModeHelpText() {
1202        StringBuilder rv;
1203        /*
1204         *  No modifiers: all (Connect, Node Re-Use, Auto-Weld)
1205         *  CTRL: disables node re-use, auto-weld
1206         *  Shift: do not make connection
1207         *  ALT: make connection but start new way in doing so
1208         */
1209
1210        /*
1211         * Status line text generation is split into two parts to keep it maintainable.
1212         * First part looks at what will happen to the new node inserted on click and
1213         * the second part will look if a connection is made or not.
1214         *
1215         * Note that this help text is not absolutely accurate as it doesn't catch any special
1216         * cases (e.g. when preventing <---> ways). The only special that it catches is when
1217         * a way is about to be finished.
1218         *
1219         * First check what happens to the new node.
1220         */
1221
1222        // oldHighlights stores the current highlights. If this
1223        // list is empty we can assume that we won't do any joins
1224        if (ctrl || oldHighlights.isEmpty()) {
1225            rv = new StringBuilder(tr("Create new node."));
1226        } else {
1227            // oldHighlights may store a node or way, check if it's a node
1228            OsmPrimitive x = oldHighlights.iterator().next();
1229            if (x instanceof Node) {
1230                rv = new StringBuilder(tr("Select node under cursor."));
1231            } else {
1232                rv = new StringBuilder(trn("Insert new node into way.", "Insert new node into {0} ways.",
1233                        oldHighlights.size(), oldHighlights.size()));
1234            }
1235        }
1236
1237        /*
1238         * Check whether a connection will be made
1239         */
1240        if (getCurrentBaseNode() != null && !wayIsFinished) {
1241            if (alt) {
1242                rv.append(' ').append(tr("Start new way from last node."));
1243            } else {
1244                rv.append(' ').append(tr("Continue way from last node."));
1245            }
1246            if (snapHelper.isSnapOn()) {
1247                rv.append(' ').append(tr("Angle snapping active."));
1248            }
1249        }
1250
1251        Node n = mouseOnExistingNode;
1252        DataSet ds = getLayerManager().getEditDataSet();
1253        /*
1254         * Handle special case: Highlighted node == selected node => finish drawing
1255         */
1256        if (n != null && ds != null && ds.getSelectedNodes().contains(n)) {
1257            if (wayIsFinished) {
1258                rv = new StringBuilder(tr("Select node under cursor."));
1259            } else {
1260                rv = new StringBuilder(tr("Finish drawing."));
1261            }
1262        }
1263
1264        /*
1265         * Handle special case: Self-Overlapping or closing way
1266         */
1267        if (ds != null && !ds.getSelectedWays().isEmpty() && !wayIsFinished && !alt) {
1268            Way w = ds.getSelectedWays().iterator().next();
1269            for (Node m : w.getNodes()) {
1270                if (m.equals(mouseOnExistingNode) || mouseOnExistingWays.contains(w)) {
1271                    rv.append(' ').append(tr("Finish drawing."));
1272                    break;
1273                }
1274            }
1275        }
1276        return rv.toString();
1277    }
1278
1279    /**
1280     * Get selected primitives, while draw action is in progress.
1281     *
1282     * While drawing a way, technically the last node is selected.
1283     * This is inconvenient when the user tries to add/edit tags to the way.
1284     * For this case, this method returns the current way as selection,
1285     * to work around this issue.
1286     * Otherwise the normal selection of the current data layer is returned.
1287     * @return selected primitives, while draw action is in progress
1288     */
1289    public Collection<OsmPrimitive> getInProgressSelection() {
1290        DataSet ds = getLayerManager().getEditDataSet();
1291        if (ds == null) return null;
1292        if (getCurrentBaseNode() != null && !ds.selectionEmpty()) {
1293            Way continueFrom = getWayForNode(getCurrentBaseNode());
1294            if (continueFrom != null)
1295                return Collections.<OsmPrimitive>singleton(continueFrom);
1296        }
1297        return ds.getSelected();
1298    }
1299
1300    @Override
1301    public boolean layerIsSupported(Layer l) {
1302        return l instanceof OsmDataLayer;
1303    }
1304
1305    @Override
1306    protected void updateEnabledState() {
1307        setEnabled(getLayerManager().getEditLayer() != null);
1308    }
1309
1310    @Override
1311    public void destroy() {
1312        super.destroy();
1313        snapChangeAction.destroy();
1314    }
1315
1316    public class BackSpaceAction extends AbstractAction {
1317
1318        @Override
1319        public void actionPerformed(ActionEvent e) {
1320            Main.main.undoRedo.undo();
1321            Command lastCmd = Main.main.undoRedo.commands.peekLast();
1322            if (lastCmd == null) return;
1323            Node n = null;
1324            for (OsmPrimitive p: lastCmd.getParticipatingPrimitives()) {
1325                if (p instanceof Node) {
1326                    if (n == null) {
1327                        n = (Node) p; // found one node
1328                        wayIsFinished = false;
1329                    } else {
1330                        // if more than 1 node were affected by previous command,
1331                        // we have no way to continue, so we forget about found node
1332                        n = null;
1333                        break;
1334                    }
1335                }
1336            }
1337            // select last added node - maybe we will continue drawing from it
1338            if (n != null) {
1339                getLayerManager().getEditDataSet().addSelected(n);
1340            }
1341        }
1342    }
1343
1344    private class SnapHelper {
1345        private static final String DRAW_ANGLESNAP_ANGLES = "draw.anglesnap.angles";
1346
1347        private final class AnglePopupMenu extends JPopupMenu {
1348
1349            private final JCheckBoxMenuItem repeatedCb = new JCheckBoxMenuItem(
1350                    new AbstractAction(tr("Toggle snapping by {0}", getShortcut().getKeyText())) {
1351                @Override
1352                public void actionPerformed(ActionEvent e) {
1353                    boolean sel = ((JCheckBoxMenuItem) e.getSource()).getState();
1354                    USE_REPEATED_SHORTCUT.put(sel);
1355                }
1356            });
1357
1358            private final JCheckBoxMenuItem helperCb = new JCheckBoxMenuItem(
1359                    new AbstractAction(tr("Show helper geometry")) {
1360                @Override
1361                public void actionPerformed(ActionEvent e) {
1362                    boolean sel = ((JCheckBoxMenuItem) e.getSource()).getState();
1363                    DRAW_CONSTRUCTION_GEOMETRY.put(sel);
1364                    SHOW_PROJECTED_POINT.put(sel);
1365                    SHOW_ANGLE.put(sel);
1366                    enableSnapping();
1367                }
1368            });
1369
1370            private final JCheckBoxMenuItem projectionCb = new JCheckBoxMenuItem(
1371                    new AbstractAction(tr("Snap to node projections")) {
1372                @Override
1373                public void actionPerformed(ActionEvent e) {
1374                    boolean sel = ((JCheckBoxMenuItem) e.getSource()).getState();
1375                    SNAP_TO_PROJECTIONS.put(sel);
1376                    enableSnapping();
1377                }
1378            });
1379
1380            private AnglePopupMenu() {
1381                helperCb.setState(DRAW_CONSTRUCTION_GEOMETRY.get());
1382                projectionCb.setState(SNAP_TO_PROJECTIONS.get());
1383                repeatedCb.setState(USE_REPEATED_SHORTCUT.get());
1384                add(repeatedCb);
1385                add(helperCb);
1386                add(projectionCb);
1387                add(new AbstractAction(tr("Disable")) {
1388                    @Override public void actionPerformed(ActionEvent e) {
1389                        saveAngles("180");
1390                        init();
1391                        enableSnapping();
1392                    }
1393                });
1394                add(new AbstractAction(tr("0,90,...")) {
1395                    @Override public void actionPerformed(ActionEvent e) {
1396                        saveAngles("0", "90", "180");
1397                        init();
1398                        enableSnapping();
1399                    }
1400                });
1401                add(new AbstractAction(tr("0,45,90,...")) {
1402                    @Override public void actionPerformed(ActionEvent e) {
1403                        saveAngles("0", "45", "90", "135", "180");
1404                        init();
1405                        enableSnapping();
1406                    }
1407                });
1408                add(new AbstractAction(tr("0,30,45,60,90,...")) {
1409                    @Override public void actionPerformed(ActionEvent e) {
1410                        saveAngles("0", "30", "45", "60", "90", "120", "135", "150", "180");
1411                        init();
1412                        enableSnapping();
1413                    }
1414                });
1415            }
1416        }
1417
1418        private boolean snapOn; // snapping is turned on
1419
1420        private boolean active; // snapping is active for current mouse position
1421        private boolean fixed; // snap angle is fixed
1422        private boolean absoluteFix; // snap angle is absolute
1423
1424        private EastNorth dir2;
1425        private EastNorth projected;
1426        private String labelText;
1427        private double lastAngle;
1428
1429        private double customBaseHeading = -1; // angle of base line, if not last segment)
1430        private EastNorth segmentPoint1; // remembered first point of base segment
1431        private EastNorth segmentPoint2; // remembered second point of base segment
1432        private EastNorth projectionSource; // point that we are projecting to the line
1433
1434        private double[] snapAngles;
1435
1436        private double pe, pn; // (pe, pn) - direction of snapping line
1437        private double e0, n0; // (e0, n0) - origin of snapping line
1438
1439        private final String fixFmt = "%d "+tr("FIX");
1440
1441        private JCheckBoxMenuItem checkBox;
1442
1443        private final MouseListener anglePopupListener = new PopupMenuLauncher(new AnglePopupMenu()) {
1444            @Override
1445            public void mouseClicked(MouseEvent e) {
1446                super.mouseClicked(e);
1447                if (e.getButton() == MouseEvent.BUTTON1) {
1448                    toggleSnapping();
1449                    updateStatusLine();
1450                }
1451            }
1452        };
1453
1454        /**
1455         * Set the initial state
1456         */
1457        public void init() {
1458            snapOn = false;
1459            checkBox.setState(snapOn);
1460            fixed = false;
1461            absoluteFix = false;
1462
1463            computeSnapAngles();
1464            Main.pref.addWeakKeyPreferenceChangeListener(DRAW_ANGLESNAP_ANGLES, e -> this.computeSnapAngles());
1465        }
1466
1467        private void computeSnapAngles() {
1468            snapAngles = Main.pref.getCollection(DRAW_ANGLESNAP_ANGLES,
1469                    Arrays.asList("0", "30", "45", "60", "90", "120", "135", "150", "180"))
1470                    .stream()
1471                    .mapToDouble(this::parseSnapAngle)
1472                    .flatMap(s -> DoubleStream.of(s, 360-s))
1473                    .toArray();
1474        }
1475
1476        private double parseSnapAngle(String string) {
1477            try {
1478                return Double.parseDouble(string);
1479            } catch (NumberFormatException e) {
1480                Main.warn("Incorrect number in draw.anglesnap.angles preferences: {0}", string);
1481                return 0;
1482            }
1483        }
1484
1485        /**
1486         * Save the snap angles
1487         * @param angles The angles
1488         */
1489        public void saveAngles(String ... angles) {
1490            Main.pref.putCollection(DRAW_ANGLESNAP_ANGLES, Arrays.asList(angles));
1491        }
1492
1493        public void setMenuCheckBox(JCheckBoxMenuItem checkBox) {
1494            this.checkBox = checkBox;
1495        }
1496
1497        /**
1498         * Draw the snap hint line.
1499         * @param g2 graphics
1500         * @param mv MapView state
1501         * @since 10874
1502         */
1503        public void drawIfNeeded(Graphics2D g2, MapViewState mv) {
1504            if (!snapOn || !active)
1505                return;
1506            MapViewPoint p1 = mv.getPointFor(getCurrentBaseNode());
1507            MapViewPoint p2 = mv.getPointFor(dir2);
1508            MapViewPoint p3 = mv.getPointFor(projected);
1509            if (DRAW_CONSTRUCTION_GEOMETRY.get()) {
1510                g2.setColor(SNAP_HELPER_COLOR.get());
1511                g2.setStroke(HELPER_STROKE.get());
1512
1513                MapViewPath b = new MapViewPath(mv);
1514                b.moveTo(p2);
1515                if (absoluteFix) {
1516                    b.lineTo(p2.interpolate(p1, 2)); // bi-directional line
1517                } else {
1518                    b.lineTo(p3);
1519                }
1520                g2.draw(b);
1521            }
1522            if (projectionSource != null) {
1523                g2.setColor(SNAP_HELPER_COLOR.get());
1524                g2.setStroke(HELPER_STROKE.get());
1525                MapViewPath b = new MapViewPath(mv);
1526                b.moveTo(p3);
1527                b.lineTo(projectionSource);
1528                g2.draw(b);
1529            }
1530
1531            if (customBaseHeading >= 0) {
1532                g2.setColor(HIGHLIGHT_COLOR.get());
1533                g2.setStroke(HIGHLIGHT_STROKE.get());
1534                MapViewPath b = new MapViewPath(mv);
1535                b.moveTo(segmentPoint1);
1536                b.lineTo(segmentPoint2);
1537                g2.draw(b);
1538            }
1539
1540            g2.setColor(RUBBER_LINE_COLOR.get());
1541            g2.setStroke(RUBBER_LINE_STROKE.get());
1542            MapViewPath b = new MapViewPath(mv);
1543            b.moveTo(p1);
1544            b.lineTo(p3);
1545            g2.draw(b);
1546
1547            g2.drawString(labelText, (int) p3.getInViewX()-5, (int) p3.getInViewY()+20);
1548            if (SHOW_PROJECTED_POINT.get()) {
1549                g2.setStroke(RUBBER_LINE_STROKE.get());
1550                g2.draw(new MapViewPath(mv).shapeAround(p3, SymbolShape.CIRCLE, 10)); // projected point
1551            }
1552
1553            g2.setColor(SNAP_HELPER_COLOR.get());
1554            g2.setStroke(HELPER_STROKE.get());
1555        }
1556
1557        /**
1558         * If mouse position is close to line at 15-30-45-... angle, remembers this direction
1559         * @param currentEN Current position
1560         * @param baseHeading The heading
1561         * @param curHeading The current mouse heading
1562         */
1563        public void checkAngleSnapping(EastNorth currentEN, double baseHeading, double curHeading) {
1564            EastNorth p0 = getCurrentBaseNode().getEastNorth();
1565            EastNorth snapPoint = currentEN;
1566            double angle = -1;
1567
1568            double activeBaseHeading = (customBaseHeading >= 0) ? customBaseHeading : baseHeading;
1569
1570            if (snapOn && (activeBaseHeading >= 0)) {
1571                angle = curHeading - activeBaseHeading;
1572                if (angle < 0) {
1573                    angle += 360;
1574                }
1575                if (angle > 360) {
1576                    angle = 0;
1577                }
1578
1579                double nearestAngle;
1580                if (fixed) {
1581                    nearestAngle = lastAngle; // if direction is fixed use previous angle
1582                    active = true;
1583                } else {
1584                    nearestAngle = getNearestAngle(angle);
1585                    if (getAngleDelta(nearestAngle, angle) < SNAP_ANGLE_TOLERANCE.get()) {
1586                        active = customBaseHeading >= 0 || Math.abs(nearestAngle - 180) > 1e-3;
1587                        // if angle is to previous segment, exclude 180 degrees
1588                        lastAngle = nearestAngle;
1589                    } else {
1590                        active = false;
1591                    }
1592                }
1593
1594                if (active) {
1595                    double phi;
1596                    e0 = p0.east();
1597                    n0 = p0.north();
1598                    buildLabelText((nearestAngle <= 180) ? nearestAngle : (nearestAngle-360));
1599
1600                    phi = (nearestAngle + activeBaseHeading) * Math.PI / 180;
1601                    // (pe,pn) - direction of snapping line
1602                    pe = Math.sin(phi);
1603                    pn = Math.cos(phi);
1604                    double scale = 20 * Main.map.mapView.getDist100Pixel();
1605                    dir2 = new EastNorth(e0 + scale * pe, n0 + scale * pn);
1606                    snapPoint = getSnapPoint(currentEN);
1607                } else {
1608                    noSnapNow();
1609                }
1610            }
1611
1612            // find out the distance, in metres, between the base point and projected point
1613            LatLon mouseLatLon = Main.map.mapView.getProjection().eastNorth2latlon(snapPoint);
1614            double distance = getCurrentBaseNode().getCoor().greatCircleDistance(mouseLatLon);
1615            double hdg = Math.toDegrees(p0.heading(snapPoint));
1616            // heading of segment from current to calculated point, not to mouse position
1617
1618            if (baseHeading >= 0) { // there is previous line segment with some heading
1619                angle = hdg - baseHeading;
1620                if (angle < 0) {
1621                    angle += 360;
1622                }
1623                if (angle > 360) {
1624                    angle = 0;
1625                }
1626            }
1627            showStatusInfo(angle, hdg, distance, isSnapOn());
1628        }
1629
1630        private void buildLabelText(double nearestAngle) {
1631            if (SHOW_ANGLE.get()) {
1632                if (fixed) {
1633                    if (absoluteFix) {
1634                        labelText = "=";
1635                    } else {
1636                        labelText = String.format(fixFmt, (int) nearestAngle);
1637                    }
1638                } else {
1639                    labelText = String.format("%d", (int) nearestAngle);
1640                }
1641            } else {
1642                if (fixed) {
1643                    if (absoluteFix) {
1644                        labelText = "=";
1645                    } else {
1646                        labelText = String.format(tr("FIX"), 0);
1647                    }
1648                } else {
1649                    labelText = "";
1650                }
1651            }
1652        }
1653
1654        /**
1655         * Gets a snap point close to p. Stores the result for display.
1656         * @param p The point
1657         * @return The snap point close to p.
1658         */
1659        public EastNorth getSnapPoint(EastNorth p) {
1660            if (!active)
1661                return p;
1662            double de = p.east()-e0;
1663            double dn = p.north()-n0;
1664            double l = de*pe+dn*pn;
1665            double delta = Main.map.mapView.getDist100Pixel()/20;
1666            if (!absoluteFix && l < delta) {
1667                active = false;
1668                return p;
1669            } //  do not go backward!
1670
1671            projectionSource = null;
1672            if (SNAP_TO_PROJECTIONS.get()) {
1673                DataSet ds = getLayerManager().getEditDataSet();
1674                Collection<Way> selectedWays = ds.getSelectedWays();
1675                if (selectedWays.size() == 1) {
1676                    Way w = selectedWays.iterator().next();
1677                    Collection<EastNorth> pointsToProject = new ArrayList<>();
1678                    if (w.getNodesCount() < 1000) {
1679                        for (Node n: w.getNodes()) {
1680                            pointsToProject.add(n.getEastNorth());
1681                        }
1682                    }
1683                    if (customBaseHeading >= 0) {
1684                        pointsToProject.add(segmentPoint1);
1685                        pointsToProject.add(segmentPoint2);
1686                    }
1687                    EastNorth enOpt = null;
1688                    double dOpt = 1e5;
1689                    for (EastNorth en: pointsToProject) { // searching for besht projection
1690                        double l1 = (en.east()-e0)*pe+(en.north()-n0)*pn;
1691                        double d1 = Math.abs(l1-l);
1692                        if (d1 < delta && d1 < dOpt) {
1693                            l = l1;
1694                            enOpt = en;
1695                            dOpt = d1;
1696                        }
1697                    }
1698                    if (enOpt != null) {
1699                        projectionSource = enOpt;
1700                    }
1701                }
1702            }
1703            projected = new EastNorth(e0+l*pe, n0+l*pn);
1704            return projected;
1705        }
1706
1707        /**
1708         * Disables snapping
1709         */
1710        public void noSnapNow() {
1711            active = false;
1712            dir2 = null;
1713            projected = null;
1714            labelText = null;
1715        }
1716
1717        public void setBaseSegment(WaySegment seg) {
1718            if (seg == null) return;
1719            segmentPoint1 = seg.getFirstNode().getEastNorth();
1720            segmentPoint2 = seg.getSecondNode().getEastNorth();
1721
1722            double hdg = segmentPoint1.heading(segmentPoint2);
1723            hdg = Math.toDegrees(hdg);
1724            if (hdg < 0) {
1725                hdg += 360;
1726            }
1727            if (hdg > 360) {
1728                hdg -= 360;
1729            }
1730            customBaseHeading = hdg;
1731        }
1732
1733        /**
1734         * Enable snapping.
1735         */
1736        private void enableSnapping() {
1737            snapOn = true;
1738            checkBox.setState(snapOn);
1739            customBaseHeading = -1;
1740            unsetFixedMode();
1741        }
1742
1743        private void toggleSnapping() {
1744            snapOn = !snapOn;
1745            checkBox.setState(snapOn);
1746            customBaseHeading = -1;
1747            unsetFixedMode();
1748        }
1749
1750        public void setFixedMode() {
1751            if (active) {
1752                fixed = true;
1753            }
1754        }
1755
1756        public void unsetFixedMode() {
1757            fixed = false;
1758            absoluteFix = false;
1759            lastAngle = 0;
1760            active = false;
1761        }
1762
1763        public boolean isActive() {
1764            return active;
1765        }
1766
1767        public boolean isSnapOn() {
1768            return snapOn;
1769        }
1770
1771        private double getNearestAngle(double angle) {
1772            double bestAngle = DoubleStream.of(snapAngles).boxed()
1773                    .min(Comparator.comparing(snapAngle -> getAngleDelta(angle, snapAngle))).orElse(0.0);
1774            if (Math.abs(bestAngle-360) < 1e-3) {
1775                bestAngle = 0;
1776            }
1777            return bestAngle;
1778        }
1779
1780        private double getAngleDelta(double a, double b) {
1781            double delta = Math.abs(a-b);
1782            if (delta > 180)
1783                return 360-delta;
1784            else
1785                return delta;
1786        }
1787
1788        private void unFixOrTurnOff() {
1789            if (absoluteFix) {
1790                unsetFixedMode();
1791            } else {
1792                toggleSnapping();
1793            }
1794        }
1795    }
1796
1797    private class SnapChangeAction extends JosmAction {
1798        /**
1799         * Constructs a new {@code SnapChangeAction}.
1800         */
1801        SnapChangeAction() {
1802            super(tr("Angle snapping"), /* ICON() */ "anglesnap",
1803                    tr("Switch angle snapping mode while drawing"), null, false);
1804            putValue("help", ht("/Action/Draw/AngleSnap"));
1805        }
1806
1807        @Override
1808        public void actionPerformed(ActionEvent e) {
1809            if (snapHelper != null) {
1810                snapHelper.toggleSnapping();
1811            }
1812        }
1813
1814        @Override
1815        protected void updateEnabledState() {
1816            setEnabled(Main.map != null && Main.map.mapMode instanceof DrawAction);
1817        }
1818    }
1819}