001    //License: GPL. Copyright 2007 by Immanuel Scholz and others
002    package org.openstreetmap.josm.actions;
003    
004    import static org.openstreetmap.josm.tools.I18n.tr;
005    import static org.openstreetmap.josm.gui.help.HelpUtil.ht;
006    
007    import java.awt.event.ActionEvent;
008    import java.awt.event.KeyEvent;
009    import java.math.BigDecimal;
010    import java.math.MathContext;
011    import java.util.Collection;
012    import java.util.LinkedList;
013    import java.util.List;
014    
015    import javax.swing.JOptionPane;
016    
017    import org.openstreetmap.josm.Main;
018    import org.openstreetmap.josm.command.Command;
019    import org.openstreetmap.josm.command.MoveCommand;
020    import org.openstreetmap.josm.command.SequenceCommand;
021    import org.openstreetmap.josm.data.coor.EastNorth;
022    import org.openstreetmap.josm.data.osm.Node;
023    import org.openstreetmap.josm.data.osm.OsmPrimitive;
024    import org.openstreetmap.josm.data.osm.Way;
025    import org.openstreetmap.josm.tools.Geometry;
026    import org.openstreetmap.josm.tools.Shortcut;
027    
028    /**
029     * Aligns all selected nodes within a circle. (Useful for roundabouts)
030     *
031     * @author Matthew Newton
032     * @author Petr Dlouh??
033     * @author Teemu Koskinen
034     */
035    public final class AlignInCircleAction extends JosmAction {
036    
037        public AlignInCircleAction() {
038            super(tr("Align Nodes in Circle"), "aligncircle", tr("Move the selected nodes into a circle."),
039                    Shortcut.registerShortcut("tools:aligncircle", tr("Tool: {0}", tr("Align Nodes in Circle")),
040                            KeyEvent.VK_O, Shortcut.DIRECT), true);
041            putValue("help", ht("/Action/AlignInCircle"));
042        }
043    
044        public double distance(EastNorth n, EastNorth m) {
045            double easd, nord;
046            easd = n.east() - m.east();
047            nord = n.north() - m.north();
048            return Math.sqrt(easd * easd + nord * nord);
049        }
050    
051        public class PolarCoor {
052            double radius;
053            double angle;
054            EastNorth origin = new EastNorth(0, 0);
055            double azimuth = 0;
056    
057            PolarCoor(double radius, double angle) {
058                this(radius, angle, new EastNorth(0, 0), 0);
059            }
060    
061            PolarCoor(double radius, double angle, EastNorth origin, double azimuth) {
062                this.radius = radius;
063                this.angle = angle;
064                this.origin = origin;
065                this.azimuth = azimuth;
066            }
067    
068            PolarCoor(EastNorth en) {
069                this(en, new EastNorth(0, 0), 0);
070            }
071    
072            PolarCoor(EastNorth en, EastNorth origin, double azimuth) {
073                radius = distance(en, origin);
074                angle = Math.atan2(en.north() - origin.north(), en.east() - origin.east());
075                this.origin = origin;
076                this.azimuth = azimuth;
077            }
078    
079            public EastNorth toEastNorth() {
080                return new EastNorth(radius * Math.cos(angle - azimuth) + origin.east(), radius * Math.sin(angle - azimuth)
081                        + origin.north());
082            }
083        }
084    
085        public void actionPerformed(ActionEvent e) {
086            if (!isEnabled())
087                return;
088    
089            Collection<OsmPrimitive> sel = getCurrentDataSet().getSelected();
090            List<Node> nodes = new LinkedList<Node>();
091            List<Way> ways = new LinkedList<Way>();
092            EastNorth center = null;
093            double radius = 0;
094            boolean regular = false;
095    
096            for (OsmPrimitive osm : sel) {
097                if (osm instanceof Node) {
098                    nodes.add((Node) osm);
099                } else if (osm instanceof Way) {
100                    ways.add((Way) osm);
101                }
102            }
103    
104            // special case if no single nodes are selected and exactly one way is:
105            // then use the way's nodes
106            if ((nodes.size() <= 2) && (ways.size() == 1)) {
107                Way way = ways.get(0);
108    
109                // some more special combinations:
110                // When is selected node that is part of the way, then make a regular polygon, selected
111                // node doesn't move.
112                // I haven't got better idea, how to activate that function.
113                //
114                // When one way and one node is selected, set center to position of that node.
115                // When one more node, part of the way, is selected, set the radius equal to the
116                // distance between two nodes.
117                if (nodes.size() > 0) {
118                    if (nodes.size() == 1 && way.containsNode(nodes.get(0))) {
119                        regular = true;
120                    } else {
121    
122                        center = nodes.get(way.containsNode(nodes.get(0)) ? 1 : 0).getEastNorth();
123                        if (nodes.size() == 2) {
124                            radius = distance(nodes.get(0).getEastNorth(), nodes.get(1).getEastNorth());
125                        }
126                    }
127                    nodes = new LinkedList<Node>();
128                }
129    
130                for (Node n : way.getNodes()) {
131                    if (!nodes.contains(n)) {
132                        nodes.add(n);
133                    }
134                }
135            }
136    
137            if (nodes.size() < 4) {
138                JOptionPane.showMessageDialog(
139                        Main.parent,
140                        tr("Please select at least four nodes."),
141                        tr("Information"),
142                        JOptionPane.INFORMATION_MESSAGE
143                );
144                return;
145            }
146    
147            // Reorder the nodes if they didn't come from a single way
148            if (ways.size() != 1) {
149                // First calculate the average point
150    
151                BigDecimal east = new BigDecimal(0);
152                BigDecimal north = new BigDecimal(0);
153    
154                for (Node n : nodes) {
155                    BigDecimal x = new BigDecimal(n.getEastNorth().east());
156                    BigDecimal y = new BigDecimal(n.getEastNorth().north());
157                    east = east.add(x, MathContext.DECIMAL128);
158                    north = north.add(y, MathContext.DECIMAL128);
159                }
160                BigDecimal nodesSize = new BigDecimal(nodes.size());
161                east = east.divide(nodesSize, MathContext.DECIMAL128);
162                north = north.divide(nodesSize, MathContext.DECIMAL128);
163    
164                EastNorth average = new EastNorth(east.doubleValue(), north.doubleValue());
165                List<Node> newNodes = new LinkedList<Node>();
166    
167                // Then reorder them based on heading from the average point
168                while (!nodes.isEmpty()) {
169                    double maxHeading = -1.0;
170                    Node maxNode = null;
171                    for (Node n : nodes) {
172                        double heading = average.heading(n.getEastNorth());
173                        if (heading > maxHeading) {
174                            maxHeading = heading;
175                            maxNode = n;
176                        }
177                    }
178                    newNodes.add(maxNode);
179                    nodes.remove(maxNode);
180                }
181    
182                nodes = newNodes;
183            }
184    
185            if (center == null) {
186                // Compute the centroid of nodes
187                center = Geometry.getCentroid(nodes);
188            }
189            // Node "center" now is central to all selected nodes.
190    
191            // Now calculate the average distance to each node from the
192            // centre. This method is ok as long as distances are short
193            // relative to the distance from the N or S poles.
194            if (radius == 0) {
195                for (Node n : nodes) {
196                    radius += distance(center, n.getEastNorth());
197                }
198                radius = radius / nodes.size();
199            }
200    
201            Collection<Command> cmds = new LinkedList<Command>();
202    
203            PolarCoor pc;
204    
205            if (regular) { // Make a regular polygon
206                double angle = Math.PI * 2 / nodes.size();
207                pc = new PolarCoor(nodes.get(0).getEastNorth(), center, 0);
208    
209                if (pc.angle > (new PolarCoor(nodes.get(1).getEastNorth(), center, 0).angle)) {
210                    angle *= -1;
211                }
212    
213                pc.radius = radius;
214                for (Node n : nodes) {
215                    EastNorth no = pc.toEastNorth();
216                    cmds.add(new MoveCommand(n, no.east() - n.getEastNorth().east(), no.north() - n.getEastNorth().north()));
217                    pc.angle += angle;
218                }
219            } else { // Move each node to that distance from the centre.
220                for (Node n : nodes) {
221                    pc = new PolarCoor(n.getEastNorth(), center, 0);
222                    pc.radius = radius;
223                    EastNorth no = pc.toEastNorth();
224                    cmds.add(new MoveCommand(n, no.east() - n.getEastNorth().east(), no.north() - n.getEastNorth().north()));
225                }
226            }
227    
228            Main.main.undoRedo.add(new SequenceCommand(tr("Align Nodes in Circle"), cmds));
229            Main.map.repaint();
230        }
231    
232        @Override
233        protected void updateEnabledState() {
234            setEnabled(getCurrentDataSet() != null && !getCurrentDataSet().getSelected().isEmpty());
235        }
236    
237        @Override
238        protected void updateEnabledState(Collection<? extends OsmPrimitive> selection) {
239            setEnabled(selection != null && !selection.isEmpty());
240        }
241    }