// License: GPL. For details, see LICENSE file.
package org.openstreetmap.josm.actions;
import static org.openstreetmap.josm.tools.I18n.tr;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;
import java.util.Set;
import org.openstreetmap.josm.Main;
import org.openstreetmap.josm.actions.mapmode.DrawAction;
import org.openstreetmap.josm.command.ChangeCommand;
import org.openstreetmap.josm.command.SelectCommand;
import org.openstreetmap.josm.command.SequenceCommand;
import org.openstreetmap.josm.data.osm.Node;
import org.openstreetmap.josm.data.osm.OsmPrimitive;
import org.openstreetmap.josm.data.osm.Way;
import org.openstreetmap.josm.gui.layer.OsmDataLayer;
import org.openstreetmap.josm.tools.Shortcut;
import org.openstreetmap.josm.tools.Utils;
/**
* Follow line action - Makes easier to draw a line that shares points with another line
*
* Aimed at those who want to draw two or more lines related with
* each other, but carry different information (i.e. a river acts as boundary at
* some part of its course. It preferable to have a separated boundary line than to
* mix totally different kind of features in one single way).
*
* @author Germán Márquez Mejía
*/
public class FollowLineAction extends JosmAction {
public FollowLineAction() {
super(
tr("Follow line"),
"followline.png",
tr("Continues drawing a line that shares nodes with another line."),
Shortcut.registerShortcut("tools:followline", tr(
"Tool: {0}", tr("Follow")),
KeyEvent.VK_F, Shortcut.DIRECT), true);
}
@Override
protected void updateEnabledState() {
if (getCurrentDataSet() == null) {
setEnabled(false);
} else {
updateEnabledState(getCurrentDataSet().getSelected());
}
}
@Override
protected void updateEnabledState(Collection<? extends OsmPrimitive> selection) {
setEnabled(selection != null && !selection.isEmpty());
}
@Override
public void actionPerformed(ActionEvent evt) {
OsmDataLayer osmLayer = Main.main.getEditLayer();
if (osmLayer == null)
return;
if (!(Main.map.mapMode instanceof DrawAction)) return; // We are not on draw mode
Collection<Node> selectedPoints = osmLayer.data.getSelectedNodes();
Collection<Way> selectedLines = osmLayer.data.getSelectedWays();
if ((selectedPoints.size() > 1) || (selectedLines.size() != 1)) // Unsuitable selection
return;
Node last = ((DrawAction) Main.map.mapMode).getCurrentBaseNode();
if (last == null)
return;
Way follower = selectedLines.iterator().next();
if (follower.isClosed()) /* Don't loop until OOM */
return;
Node prev = follower.getNode(1);
boolean reversed = true;
if (follower.lastNode().equals(last)) {
prev = follower.getNode(follower.getNodesCount() - 2);
reversed = false;
}
List<OsmPrimitive> referrers = last.getReferrers();
if (referrers.size() < 2) return; // There's nothing to follow
Node newPoint = null;
for (final Way toFollow : Utils.filteredCollection(referrers, Way.class)) {
if (toFollow.equals(follower)) {
continue;
}
Set<Node> points = toFollow.getNeighbours(last);
points.remove(prev);
if (points.isEmpty()) // No candidate -> consider next way
continue;
if (points.size() > 1) // Ambiguous junction?
return;
// points contains exactly one element
Node newPointCandidate = points.iterator().next();
if ((newPoint != null) && (newPoint != newPointCandidate))
return; // Ambiguous junction, force to select next
newPoint = newPointCandidate;
}
if (newPoint != null) {
Way newFollower = new Way(follower);
if (reversed) {
newFollower.addNode(0, newPoint);
} else {
newFollower.addNode(newPoint);
}
Main.main.undoRedo.add(new SequenceCommand(tr("Follow line"),
new ChangeCommand(follower, newFollower),
new SelectCommand(newFollower.isClosed() // see #10028 - unselect last node when closing a way
? Arrays.<OsmPrimitive>asList(newFollower)
: Arrays.<OsmPrimitive>asList(newFollower, newPoint)
))
);
// "viewport following" mode for tracing long features
// from aerial imagery or GPS tracks.
if (Main.map.mapView.viewportFollowing) {
Main.map.mapView.smoothScrollTo(newPoint.getEastNorth());
}
}
}
}