NetBeans中的JMapViewer：仅将映射添加到GUI JPanel

Question

I am trying to learn JMapViewer , and have a map embedded in a JPanel , which is a part of CardLayout . At this point, I only want to display a map without zoom, mouse action listeners, etc. So, I created a GUI frame in NetBeans with CardLayout and a number of JPanel s. Inside one of the panels, I have added another panel where the map should be located. Then I added JMapViewer.jar and JMapViewer_src.jar . Then I added the following simple code:

package viewController;

import java.awt.BorderLayout;
import javax.swing.JPanel;
import org.openstreetmap.gui.jmapviewer.JMapViewer;
import org.openstreetmap.gui.jmapviewer.events.JMVCommandEvent;
import org.openstreetmap.gui.jmapviewer.interfaces.JMapViewerEventListener;

public class PanelAcars extends javax.swing.JPanel implements JMapViewerEventListener  
{

    public PanelAcars() 
    {
        super();

        setSize(400,400);

        initComponents();

        final JMapViewer map = new JMapViewer();

        pnlAcarsMapView.add(map);

    }


    @Override
    public void processCommand(JMVCommandEvent command) {
        if (command.getCommand().equals(JMVCommandEvent.COMMAND.ZOOM) ||
                command.getCommand().equals(JMVCommandEvent.COMMAND.MOVE)) {
            //updateZoomParameters();
        }
    }


    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          

     private void initComponents() {

        pnlAcarsMapView = new javax.swing.JPanel();

        ...
    }                        

    private javax.swing.JPanel pnlAcarsMapView;

}

The panel is empty. I have the Demo.java code and it works if I simply copy and paste it in a new project. But I would like to modify it starting from building a simple map and adding it to my panel. What am I missing?

Thank you!

Answer 1

Absent a complete example, it's not clear where your program goes awry. Common problems include these:

• Adding the map to an unintended container.

• Adding the map after calling pack() , without revalidating the container.

In general, avoid such problems by limiting the scope of the GUI editor as suggested here . In the example below, instances of CardPanel are added to a JPanel having CardLayout .

cards.add(new CardPanel("London", new Coordinate(51.5072, -0.1275)));
cards.add(new CardPanel("Paris", new Coordinate(48.8566, 2.3522)));

Each such instance has a GridLayout , but you might substitute a BorderLayout and experiment with adding the map to the CENTER and other components in the surrounding regions.

import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import javax.swing.AbstractAction;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import org.openstreetmap.gui.jmapviewer.Coordinate;
import org.openstreetmap.gui.jmapviewer.JMapViewer;

/**
 * @see https://stackoverflow.com/a/38934376/230513
 * @see https://stackoverflow.com/a/36392696/230513
 * @see https://stackoverflow.com/a/36243395/230513
 */
public class CardPanel extends JPanel {

    private static final JPanel cards = new JPanel(new CardLayout());
    private final String name;

    public CardPanel(String name, Coordinate coordinate) {
        super(new GridLayout());
        this.name = name;
        JMapViewer map = new JMapViewer() {

            @Override
            public Dimension getPreferredSize() {
                return new Dimension(320, 240);
            }
        };
        map.setDisplayPosition(coordinate, 12);
        this.add(map);
    }

    @Override
    public String toString() {
        return name;
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                create();
            }
        });
    }

    private static void create() {
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        cards.add(new CardPanel("London", new Coordinate(51.5072, -0.1275)));
        cards.add(new CardPanel("Paris", new Coordinate(48.8566, 2.3522)));
        JPanel control = new JPanel();
        control.add(new JButton(new AbstractAction("\u22b2Prev") {

            @Override
            public void actionPerformed(ActionEvent e) {
                CardLayout cl = (CardLayout) cards.getLayout();
                cl.previous(cards);
            }
        }));
        control.add(new JButton(new AbstractAction("Next\u22b3") {

            @Override
            public void actionPerformed(ActionEvent e) {
                CardLayout cl = (CardLayout) cards.getLayout();
                cl.next(cards);
            }
        }));
        f.add(cards, BorderLayout.CENTER);
        f.add(control, BorderLayout.SOUTH);
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }
}