source: josm/src/org/openstreetmap/josm/actions/OpenAction.java@ 30

package org.openstreetmap.josm.actions;

import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.InputEvent;
import java.awt.event.KeyEvent;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.Collection;

import javax.swing.Box;
import javax.swing.JCheckBox;
import javax.swing.JFileChooser;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.KeyStroke;
import javax.swing.filechooser.FileFilter;

import org.jdom.JDOMException;
import org.openstreetmap.josm.Main;
import org.openstreetmap.josm.data.GeoPoint;
import org.openstreetmap.josm.data.osm.DataSet;
import org.openstreetmap.josm.gui.GBC;
import org.openstreetmap.josm.gui.MapFrame;
import org.openstreetmap.josm.gui.layer.Layer;
import org.openstreetmap.josm.gui.layer.OsmDataLayer;
import org.openstreetmap.josm.gui.layer.RawGpsDataLayer;
import org.openstreetmap.josm.io.GpxReader;
import org.openstreetmap.josm.io.OsmReader;
import org.openstreetmap.josm.io.RawGpsReader;

/**
 * Open a file chooser dialog and select an file to import. Than call the gpx-import
 * driver. Finally open an internal frame into the main window with the gpx data shown.
 * 
 * @author imi
 */
public class OpenAction extends JosmAction {

        /**
         * Create an open action. The name is "Open GPX".
         */
        public OpenAction() {
                super("Open", "open", "Open a file.", null, KeyStroke.getAWTKeyStroke(KeyEvent.VK_O, InputEvent.CTRL_DOWN_MASK));
        }

        public void actionPerformed(ActionEvent e) {
                JFileChooser fc = new JFileChooser("data");
                fc.setFileFilter(new FileFilter(){
                        @Override
                        public boolean accept(File f) {
                                String name = f.getName().toLowerCase();
                                return f.isDirectory() || name.endsWith(".gpx") || name.endsWith(".xml");
                        }
                        @Override
                        public String getDescription() {
                                return "GPX or XML Files";
                        }});
                
                // additional options
                JCheckBox rawGps = new JCheckBox("Raw GPS data", true);
                rawGps.setToolTipText("Check this, if the data were obtained from a gps device.");
                JCheckBox newLayer = new JCheckBox("As Layer", true); 
                newLayer.setToolTipText("Open as a new layer or replace all current layers.");
                if (Main.main.getMapFrame() == null) {
                        newLayer.setEnabled(false);
                        newLayer.setSelected(false);
                }
                
                JPanel p = new JPanel(new GridBagLayout());
                p.add(new JLabel("Options"), GBC.eop());
                p.add(rawGps, GBC.eol());
                p.add(newLayer, GBC.eol());
                p.add(Box.createVerticalGlue(), GBC.eol().fill());
                fc.setAccessory(p);

                if (fc.showOpenDialog(Main.main) != JFileChooser.APPROVE_OPTION)
                        return;
                
                File filename = fc.getSelectedFile();
                if (filename == null)
                        return;

                try {
                        Layer layer;
                        if (rawGps.isSelected()) {
                                Collection<Collection<GeoPoint>> data = new RawGpsReader(new FileReader(filename)).parse();
                                layer = new RawGpsDataLayer(data, filename.getName());
                        } else {
                                DataSet dataSet = filename.getName().toLowerCase().endsWith(".gpx") ?
                                                new GpxReader(new FileReader(filename)).parse() :
                                                new OsmReader(new FileReader(filename)).parse();
                                layer = new OsmDataLayer(dataSet, filename.getName());
                        }
                        
                        if (Main.main.getMapFrame() == null || !newLayer.isSelected())
                                Main.main.setMapFrame(filename.getName(), new MapFrame(layer));
                        else
                                Main.main.getMapFrame().mapView.addLayer(layer);

                } catch (JDOMException x) {
                        x.printStackTrace();
                        JOptionPane.showMessageDialog(Main.main, x.getMessage());
                } catch (IOException x) {
                        x.printStackTrace();
                        JOptionPane.showMessageDialog(Main.main, "Could not read '"+filename.getName()+"'\n"+x.getMessage());
                }
        }
}