source: josm/trunk/src/org/openstreetmap/josm/actions/mapmode/DeleteAction.java@ 1150

// License: GPL. Copyright 2007 by Immanuel Scholz and others
package org.openstreetmap.josm.actions.mapmode;

import static org.openstreetmap.josm.tools.I18n.tr;

import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import java.awt.event.MouseEvent;
import java.util.Collections;

import org.openstreetmap.josm.Main;
import org.openstreetmap.josm.command.Command;
import org.openstreetmap.josm.command.DeleteCommand;
import org.openstreetmap.josm.data.osm.OsmPrimitive;
import org.openstreetmap.josm.data.osm.WaySegment;
import org.openstreetmap.josm.gui.MapFrame;
import org.openstreetmap.josm.tools.ImageProvider;
import org.openstreetmap.josm.tools.Shortcut;

/**
 * An action that enables the user to delete nodes and other objects.
 *
 * The user can click on an object, which gets deleted if possible. When Ctrl is
 * pressed when releasing the button, the objects and all its references are
 * deleted. The exact definition of "all its references" are in
 * {@link #deleteWithReferences deleteWithReferences}.
 *
 * If the user did not press Ctrl and the object has any references, the user
 * is informed and nothing is deleted.
 *
 * If the user enters the mapmode and any object is selected, all selected
 * objects that can be deleted will.
 *
 * @author imi
 */
public class DeleteAction extends MapMode {

        /**
         * Construct a new DeleteAction. Mnemonic is the delete - key.
         * @param mapFrame The frame this action belongs to.
         */
        public DeleteAction(MapFrame mapFrame) {
                super(tr("Delete Mode"),
                                "delete",
                                tr("Delete nodes or ways."),
                                Shortcut.registerShortcut("mapmode:delete", tr("Mode: {0}",tr("Delete")), KeyEvent.VK_D, Shortcut.GROUP_EDIT),
                                mapFrame,
                                ImageProvider.getCursor("normal", "delete"));
        }

        @Override public void enterMode() {
                super.enterMode();
                Main.map.mapView.addMouseListener(this);
        }

        @Override public void exitMode() {
                super.exitMode();
                Main.map.mapView.removeMouseListener(this);
        }


        @Override public void actionPerformed(ActionEvent e) {
                super.actionPerformed(e);
                if(!Main.map.mapView.isDrawableLayer())
                        return;
                doActionPerformed(e);
        }

        public void doActionPerformed(ActionEvent e) {
                if(!Main.map.mapView.isDrawableLayer())
                        return;
                boolean ctrl = (e.getModifiers() & ActionEvent.CTRL_MASK) != 0;
                boolean alt = (e.getModifiers() & ActionEvent.ALT_MASK) != 0;

                Command c;
                if (ctrl) {
                        c = DeleteCommand.deleteWithReferences(Main.ds.getSelected());
                } else {
                        c = DeleteCommand.delete(Main.ds.getSelected(), !alt);
                }
                if (c != null) {
                        Main.main.undoRedo.add(c);
                }

                Main.ds.setSelected();
                Main.map.repaint();
        }

        /**
         * If user clicked with the left button, delete the nearest object.
         * position.
         */
        @Override public void mouseClicked(MouseEvent e) {
                if (e.getButton() != MouseEvent.BUTTON1)
                        return;
                if(!Main.map.mapView.isDrawableLayer())
                        return;
                boolean ctrl = (e.getModifiers() & ActionEvent.CTRL_MASK) != 0;
                boolean shift = (e.getModifiers() & ActionEvent.SHIFT_MASK) != 0;
                boolean alt = (e.getModifiers() & ActionEvent.ALT_MASK) != 0;

                OsmPrimitive sel = Main.map.mapView.getNearestNode(e.getPoint());
                Command c = null;
                if (sel == null) {
                        WaySegment ws = Main.map.mapView.getNearestWaySegment(e.getPoint());
                        if (ws != null) {
                                if (shift) {
                                        c = DeleteCommand.deleteWaySegment(ws);
                                } else if (ctrl) {
                                        c = DeleteCommand.deleteWithReferences(Collections.singleton((OsmPrimitive)ws.way));
                                } else {
                                        c = DeleteCommand.delete(Collections.singleton((OsmPrimitive)ws.way), !alt);
                                }
                        }
                } else if (ctrl) {
                        c = DeleteCommand.deleteWithReferences(Collections.singleton(sel));
                } else {
                        c = DeleteCommand.delete(Collections.singleton(sel), !alt);
                }
                if (c != null) {
                        Main.main.undoRedo.add(c);
                }

                Main.ds.setSelected();
                Main.map.mapView.repaint();
        }

        @Override public String getModeHelpText() {
                return tr("Click to delete. Shift: delete way segment. Alt: don't delete unused nodes when deleting a way. Ctrl: delete referring objects.");
        }
}