001// License: GPL. For details, see LICENSE file. 002package org.openstreetmap.josm.actions; 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.event.ActionEvent; 009import java.awt.event.KeyEvent; 010import java.util.ArrayList; 011import java.util.Arrays; 012import java.util.Collection; 013import java.util.Collections; 014import java.util.HashSet; 015import java.util.LinkedList; 016import java.util.List; 017import java.util.Set; 018import java.util.stream.Collectors; 019 020import javax.swing.JOptionPane; 021import javax.swing.SwingUtilities; 022 023import org.openstreetmap.josm.command.ChangeCommand; 024import org.openstreetmap.josm.command.Command; 025import org.openstreetmap.josm.command.DeleteCommand; 026import org.openstreetmap.josm.command.SequenceCommand; 027import org.openstreetmap.josm.data.UndoRedoHandler; 028import org.openstreetmap.josm.data.osm.DataSet; 029import org.openstreetmap.josm.data.osm.Node; 030import org.openstreetmap.josm.data.osm.OsmPrimitive; 031import org.openstreetmap.josm.data.osm.Way; 032import org.openstreetmap.josm.data.projection.Ellipsoid; 033import org.openstreetmap.josm.gui.HelpAwareOptionPane; 034import org.openstreetmap.josm.gui.HelpAwareOptionPane.ButtonSpec; 035import org.openstreetmap.josm.gui.MainApplication; 036import org.openstreetmap.josm.gui.Notification; 037import org.openstreetmap.josm.spi.preferences.Config; 038import org.openstreetmap.josm.tools.ImageProvider; 039import org.openstreetmap.josm.tools.Shortcut; 040 041/** 042 * Delete unnecessary nodes from a way 043 * @since 2575 044 */ 045public class SimplifyWayAction extends JosmAction { 046 047 /** 048 * Constructs a new {@code SimplifyWayAction}. 049 */ 050 public SimplifyWayAction() { 051 super(tr("Simplify Way"), "simplify", tr("Delete unnecessary nodes from a way."), 052 Shortcut.registerShortcut("tools:simplify", tr("Tool: {0}", tr("Simplify Way")), KeyEvent.VK_Y, Shortcut.SHIFT), true); 053 setHelpId(ht("/Action/SimplifyWay")); 054 } 055 056 protected boolean confirmWayWithNodesOutsideBoundingBox(List<? extends OsmPrimitive> primitives) { 057 return DeleteAction.checkAndConfirmOutlyingDelete(primitives, null); 058 } 059 060 protected void alertSelectAtLeastOneWay() { 061 SwingUtilities.invokeLater(() -> 062 new Notification( 063 tr("Please select at least one way to simplify.")) 064 .setIcon(JOptionPane.WARNING_MESSAGE) 065 .setDuration(Notification.TIME_SHORT) 066 .setHelpTopic(ht("/Action/SimplifyWay#SelectAWayToSimplify")) 067 .show() 068 ); 069 } 070 071 protected boolean confirmSimplifyManyWays(int numWays) { 072 ButtonSpec[] options = new ButtonSpec[] { 073 new ButtonSpec( 074 tr("Yes"), 075 new ImageProvider("ok"), 076 tr("Simplify all selected ways"), 077 null), 078 new ButtonSpec( 079 tr("Cancel"), 080 new ImageProvider("cancel"), 081 tr("Cancel operation"), 082 null) 083 }; 084 return 0 == HelpAwareOptionPane.showOptionDialog( 085 MainApplication.getMainFrame(), 086 tr("The selection contains {0} ways. Are you sure you want to simplify them all?", numWays), 087 tr("Simplify ways?"), 088 JOptionPane.WARNING_MESSAGE, 089 null, // no special icon 090 options, 091 options[0], 092 ht("/Action/SimplifyWay#ConfirmSimplifyAll") 093 ); 094 } 095 096 @Override 097 public void actionPerformed(ActionEvent e) { 098 DataSet ds = getLayerManager().getEditDataSet(); 099 ds.beginUpdate(); 100 try { 101 List<Way> ways = ds.getSelectedWays().stream() 102 .filter(p -> !p.isIncomplete()) 103 .collect(Collectors.toList()); 104 if (ways.isEmpty()) { 105 alertSelectAtLeastOneWay(); 106 return; 107 } else if (!confirmWayWithNodesOutsideBoundingBox(ways) || (ways.size() > 10 && !confirmSimplifyManyWays(ways.size()))) { 108 return; 109 } 110 111 Collection<Command> allCommands = new LinkedList<>(); 112 for (Way way: ways) { 113 SequenceCommand simplifyCommand = simplifyWay(way); 114 if (simplifyCommand == null) { 115 continue; 116 } 117 allCommands.add(simplifyCommand); 118 } 119 if (allCommands.isEmpty()) return; 120 SequenceCommand rootCommand = new SequenceCommand( 121 trn("Simplify {0} way", "Simplify {0} ways", allCommands.size(), allCommands.size()), 122 allCommands 123 ); 124 UndoRedoHandler.getInstance().add(rootCommand); 125 } finally { 126 ds.endUpdate(); 127 } 128 } 129 130 /** 131 * Replies true if <code>node</code> is a required node which can't be removed 132 * in order to simplify the way. 133 * 134 * @param way the way to be simplified 135 * @param node the node to check 136 * @return true if <code>node</code> is a required node which can't be removed 137 * in order to simplify the way. 138 */ 139 protected static boolean isRequiredNode(Way way, Node node) { 140 boolean isRequired = node.isTagged(); 141 if (!isRequired) { 142 int frequency = Collections.frequency(way.getNodes(), node); 143 if ((way.getNode(0) == node) && (way.getNode(way.getNodesCount()-1) == node)) { 144 frequency = frequency - 1; // closed way closing node counted only once 145 } 146 isRequired = frequency > 1; 147 } 148 if (!isRequired) { 149 List<OsmPrimitive> parents = new LinkedList<>(); 150 parents.addAll(node.getReferrers()); 151 parents.remove(way); 152 isRequired = !parents.isEmpty(); 153 } 154 return isRequired; 155 } 156 157 /** 158 * Simplifies a way with default threshold (read from preferences). 159 * 160 * @param w the way to simplify 161 * @return The sequence of commands to run 162 * @since 6411 163 */ 164 public final SequenceCommand simplifyWay(Way w) { 165 return simplifyWay(w, Config.getPref().getDouble("simplify-way.max-error", 3.0)); 166 } 167 168 /** 169 * Simplifies a way with a given threshold. 170 * 171 * @param w the way to simplify 172 * @param threshold the max error threshold 173 * @return The sequence of commands to run 174 * @since 6411 175 */ 176 public static SequenceCommand simplifyWay(Way w, double threshold) { 177 int lower = 0; 178 int i = 0; 179 List<Node> newNodes = new ArrayList<>(w.getNodesCount()); 180 while (i < w.getNodesCount()) { 181 if (isRequiredNode(w, w.getNode(i))) { 182 // copy a required node to the list of new nodes. Simplify not possible 183 newNodes.add(w.getNode(i)); 184 i++; 185 lower++; 186 continue; 187 } 188 i++; 189 // find the longest sequence of not required nodes ... 190 while (i < w.getNodesCount() && !isRequiredNode(w, w.getNode(i))) { 191 i++; 192 } 193 // ... and simplify them 194 buildSimplifiedNodeList(w.getNodes(), lower, Math.min(w.getNodesCount()-1, i), threshold, newNodes); 195 lower = i; 196 i++; 197 } 198 199 // Closed way, check if the first node could also be simplified ... 200 if (newNodes.size() > 3 && newNodes.get(0) == newNodes.get(newNodes.size() - 1) && !isRequiredNode(w, newNodes.get(0))) { 201 final List<Node> l1 = Arrays.asList(newNodes.get(newNodes.size() - 2), newNodes.get(0), newNodes.get(1)); 202 final List<Node> l2 = new ArrayList<>(3); 203 buildSimplifiedNodeList(l1, 0, 2, threshold, l2); 204 if (!l2.contains(newNodes.get(0))) { 205 newNodes.remove(0); 206 newNodes.set(newNodes.size() - 1, newNodes.get(0)); // close the way 207 } 208 } 209 210 if (newNodes.size() == w.getNodesCount()) return null; 211 212 Set<Node> delNodes = new HashSet<>(); 213 delNodes.addAll(w.getNodes()); 214 delNodes.removeAll(newNodes); 215 216 if (delNodes.isEmpty()) return null; 217 218 Collection<Command> cmds = new LinkedList<>(); 219 Way newWay = new Way(w); 220 newWay.setNodes(newNodes); 221 cmds.add(new ChangeCommand(w, newWay)); 222 cmds.add(new DeleteCommand(w.getDataSet(), delNodes)); 223 w.getDataSet().clearSelection(delNodes); 224 return new SequenceCommand( 225 trn("Simplify Way (remove {0} node)", "Simplify Way (remove {0} nodes)", delNodes.size(), delNodes.size()), cmds); 226 } 227 228 /** 229 * Builds the simplified list of nodes for a way segment given by a lower index <code>from</code> 230 * and an upper index <code>to</code> 231 * 232 * @param wnew the way to simplify 233 * @param from the lower index 234 * @param to the upper index 235 * @param threshold the max error threshold 236 * @param simplifiedNodes list that will contain resulting nodes 237 */ 238 protected static void buildSimplifiedNodeList(List<Node> wnew, int from, int to, double threshold, List<Node> simplifiedNodes) { 239 240 Node fromN = wnew.get(from); 241 Node toN = wnew.get(to); 242 243 // Get max xte 244 int imax = -1; 245 double xtemax = 0; 246 for (int i = from + 1; i < to; i++) { 247 Node n = wnew.get(i); 248 // CHECKSTYLE.OFF: SingleSpaceSeparator 249 double xte = Math.abs(Ellipsoid.WGS84.a 250 * xtd(fromN.lat() * Math.PI / 180, fromN.lon() * Math.PI / 180, toN.lat() * Math.PI / 180, 251 toN.lon() * Math.PI / 180, n.lat() * Math.PI / 180, n.lon() * Math.PI / 180)); 252 // CHECKSTYLE.ON: SingleSpaceSeparator 253 if (xte > xtemax) { 254 xtemax = xte; 255 imax = i; 256 } 257 } 258 259 if (imax != -1 && xtemax >= threshold) { 260 // Segment cannot be simplified - try shorter segments 261 buildSimplifiedNodeList(wnew, from, imax, threshold, simplifiedNodes); 262 buildSimplifiedNodeList(wnew, imax, to, threshold, simplifiedNodes); 263 } else { 264 // Simplify segment 265 if (simplifiedNodes.isEmpty() || simplifiedNodes.get(simplifiedNodes.size()-1) != fromN) { 266 simplifiedNodes.add(fromN); 267 } 268 if (fromN != toN) { 269 simplifiedNodes.add(toN); 270 } 271 } 272 } 273 274 /* From Aviaton Formulary v1.3 275 * http://williams.best.vwh.net/avform.htm 276 */ 277 private static double dist(double lat1, double lon1, double lat2, double lon2) { 278 return 2 * Math.asin(Math.sqrt(Math.pow(Math.sin((lat1 - lat2) / 2), 2) + Math.cos(lat1) * Math.cos(lat2) 279 * Math.pow(Math.sin((lon1 - lon2) / 2), 2))); 280 } 281 282 private static double course(double lat1, double lon1, double lat2, double lon2) { 283 return Math.atan2(Math.sin(lon1 - lon2) * Math.cos(lat2), Math.cos(lat1) * Math.sin(lat2) - Math.sin(lat1) 284 * Math.cos(lat2) * Math.cos(lon1 - lon2)) 285 % (2 * Math.PI); 286 } 287 288 private static double xtd(double lat1, double lon1, double lat2, double lon2, double lat3, double lon3) { 289 double distAD = dist(lat1, lon1, lat3, lon3); 290 double crsAD = course(lat1, lon1, lat3, lon3); 291 double crsAB = course(lat1, lon1, lat2, lon2); 292 return Math.asin(Math.sin(distAD) * Math.sin(crsAD - crsAB)); 293 } 294 295 @Override 296 protected void updateEnabledState() { 297 updateEnabledStateOnCurrentSelection(); 298 } 299 300 @Override 301 protected void updateEnabledState(Collection<? extends OsmPrimitive> selection) { 302 updateEnabledStateOnModifiableSelection(selection); 303 } 304}