source: josm/src/org/openstreetmap/josm/actions/OpenAction.java@ 68

package org.openstreetmap.josm.actions;

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 java.util.LinkedList;

import javax.swing.JFileChooser;
import javax.swing.JOptionPane;
import javax.swing.KeyStroke;

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.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.OsmReaderOld;
import org.openstreetmap.josm.io.RawCsvReader;
import org.openstreetmap.josm.io.RawGpsReader;
import org.xml.sax.SAXException;

/**
 * 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 a file".
         */
        public OpenAction() {
                super("Open", "open", "Open a file.", "Ctrl-O", KeyStroke.getKeyStroke(KeyEvent.VK_O, InputEvent.CTRL_DOWN_MASK));
        }

        public void actionPerformed(ActionEvent e) {
                JFileChooser fc = new JFileChooser(Main.main.currentDirectory);
                for (int i = 0; i < ExtensionFileFilter.filters.length; ++i)
                        fc.addChoosableFileFilter(ExtensionFileFilter.filters[i]);
                fc.setAcceptAllFileFilterUsed(true);

                if (fc.showOpenDialog(Main.main) != JFileChooser.APPROVE_OPTION)
                        return;
                
                Main.main.currentDirectory = fc.getCurrentDirectory();

                File filename = fc.getSelectedFile();
                if (filename == null)
                        return;

                openFile(filename);
        }

        /**
         * Open the given file.
         */
        public void openFile(File filename) {
                String fn = filename.getName();
                try {
                        Layer layer;

                        if (asRawData(fn)) {
                                Collection<Collection<GeoPoint>> data;
                                if (ExtensionFileFilter.filters[ExtensionFileFilter.GPX].acceptName(fn)) {
                                        data = new RawGpsReader(new FileReader(filename)).parse();
                                } else if (ExtensionFileFilter.filters[ExtensionFileFilter.CSV].acceptName(fn)) {
                                        data = new LinkedList<Collection<GeoPoint>>();
                                        data.add(new RawCsvReader(new FileReader(filename)).parse());
                                } else
                                        throw new IllegalStateException();
                                layer = new RawGpsDataLayer(data, filename.getName());
                        } else {
                                DataSet dataSet;
                                if (ExtensionFileFilter.filters[ExtensionFileFilter.GPX].acceptName(fn))
                                        dataSet = new GpxReader(new FileReader(filename)).parse();
                                else if (ExtensionFileFilter.filters[ExtensionFileFilter.OSM].acceptName(fn)) {
                                        try {
                                                // temporary allow loading of old xml format.
                                                dataSet = OsmReader.parseDataSet(new FileReader(filename));
                                        } catch (SAXException x) {
                                                if (x.getMessage().equals("Unknown version: null")) {
                                                        int answer = JOptionPane.showConfirmDialog(Main.main, 
                                                                        "This seems to be an old 0.2 API XML file.\n" +
                                                                        "JOSM can try to open it with the old parser. This option\n" +
                                                                        "will not be available in future JOSM version. You should\n" +
                                                                        "immediatly save the file, if successfull imported.",
                                                                        "Load as 0.2 API file?",
                                                                        JOptionPane.YES_NO_OPTION);
                                                        if (answer != JOptionPane.YES_OPTION)
                                                                return;
                                                        dataSet = new OsmReaderOld(new FileReader(filename)).parse();
                                                } else 
                                                        throw x;
                                        }                                       
                                } else if (ExtensionFileFilter.filters[ExtensionFileFilter.CSV].acceptName(fn)) {
                                        JOptionPane.showMessageDialog(Main.main, "CSV Data import for non-GPS data is not implemented yet.");
                                        return;
                                } else {
                                        JOptionPane.showMessageDialog(Main.main, "Unknown file extension: "+fn.substring(filename.getName().lastIndexOf('.')+1));
                                        return;
                                }
                                layer = new OsmDataLayer(dataSet, "Data Layer", true);
                        }
                        
                        if (Main.main.getMapFrame() == null)
                                Main.main.setMapFrame(new MapFrame(layer));
                        else
                                Main.main.getMapFrame().mapView.addLayer(layer);

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

        /**
         * @return Return whether the file should be opened as raw gps data. May ask the
         * user, if unsure.
         */
        private boolean asRawData(String fn) {
                if (ExtensionFileFilter.filters[ExtensionFileFilter.CSV].acceptName(fn))
                        return true;
                if (!ExtensionFileFilter.filters[ExtensionFileFilter.GPX].acceptName(fn))
                        return false;
                return JOptionPane.YES_OPTION == JOptionPane.showConfirmDialog(
                                Main.main, "Do you want to open the file as raw gps data?",
                                "Open as raw data?", JOptionPane.YES_NO_OPTION);
        }
}