zoompanel.java

openmap java写的开源数字地图程序. 用applet实现,可以像google map 那样放大缩小地图.

// **********************************************************************
// 
// <copyright>
// 
//  BBN Technologies
//  10 Moulton Street
//  Cambridge, MA 02138
//  [phone]
// 
//  Copyright (C) BBNT Solutions LLC. All rights reserved.
// 
// </copyright>
// **********************************************************************
// 
// $Source: /cvs/distapps/openmap/src/openmap/com/bbn/openmap/gui/ZoomPanel.java,v $
// $RCSfile: ZoomPanel.java,v $
// $Revision: 1.5.2.2 $
// $Date: 2005/02/11 22:51:24 $
// $Author: dietrick $
// 
// **********************************************************************

package com.bbn.openmap.gui;

import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionListener;
import java.io.Serializable;
import java.net.URL;

import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JPanel;

import com.bbn.openmap.I18n;
import com.bbn.openmap.event.ZoomEvent;
import com.bbn.openmap.event.ZoomListener;
import com.bbn.openmap.event.ZoomSupport;
import com.bbn.openmap.util.Debug;

/**
 * Bean to zoom the Map.
 * <p>
 * This bean is a source for ZoomEvents. It is a simple widget with a
 * ZoomIn button and a ZoomOut button. When a button is pressed, the
 * appropriate zoom event is fired to all registered listeners.
 * 
 * @see #addZoomListener
 */
public class ZoomPanel extends OMToolComponent implements ActionListener,
        Serializable {

    public final static transient String zoomInCmd = "zoomin";
    public final static transient String zoomOutCmd = "zoomout";

    protected transient JButton zoomInButton, zoomOutButton;
    protected transient ZoomSupport zoomDelegate;

    public final static String defaultKey = "zoompanel";

    /**
     * Default Zoom In Factor is 0.5.
     */
    protected transient float zoomInFactor = 0.5f;

    /**
     * Default Zoom Out Factor is 2.0.
     */
    protected transient float zoomOutFactor = 2.0f;

    /**
     * Construct the ZoomPanel.
     */
    public ZoomPanel() {
        super();
        setKey(defaultKey);
        //      setLayout(new BoxLayout(this, BoxLayout.X_AXIS));
        //      setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));
        this.setOpaque(false);

        JPanel panel = new JPanel();
        GridBagLayout internalGridbag = new GridBagLayout();
        GridBagConstraints c2 = new GridBagConstraints();
        panel.setLayout(internalGridbag);

        zoomDelegate = new ZoomSupport(this);
        zoomInButton = getButton("zoomIn", "Zoom In", zoomInCmd);
        c2.gridx = 0;
        c2.gridy = 0;
        internalGridbag.setConstraints(zoomInButton, c2);
        panel.add(zoomInButton);

        zoomOutButton = getButton("zoomOut", "Zoom Out", zoomOutCmd);
        c2.gridy = 1;
        internalGridbag.setConstraints(zoomOutButton, c2);
        panel.add(zoomOutButton);

        add(panel);
    }

    /**
     * Get the Zoom In Factor.
     * 
     * @return float the degree by which map scale will be multiplied
     *         when zoom in button is pressed
     */
    public float getZoomInFactor() {
        return zoomInFactor;
    }

    /**
     * Sets the Zoom In factor. The factor must be &lt; 1.0.
     * (otherwise it would make ZoomIn into a ZoomOut).
     * 
     * @param factor the degree by which map scale should be
     *        multiplied
     */
    public void setZoomInFactor(float factor) {
        if (factor < 1.0f) {
            zoomInFactor = factor;
            zoomInButton.setToolTipText(i18n.get(ZoomPanel.class,
                    zoomInCmd + "factor",
                    I18n.TOOLTIP,
                    "zoom in X" + zoomInFactor,
                    new Float(zoomInFactor)));
        } else {
            throw new IllegalArgumentException("Zoom In factor too large (must be < 1.0)");
        }
    }

    /**
     * Get the Zoom Out Factor.
     * 
     * @return float the degree by which map scale will be multiplied
     *         when zoom out button is pressed
     */
    public float getZoomOutFactor() {
        return zoomOutFactor;
    }

    /**
     * Sets the Zoom Out Factor. The factor must be &gt; 1.0
     * (otherwise it would turn ZoomOut into ZoomIn).
     * 
     * @param factor the degree by which map scale should be
     *        multiplied.
     */
    public void setZoomOutFactor(float factor) {
        if (factor > 1.0f) {
            zoomOutFactor = factor;
            //            zoomOutButton.setToolTipText("zoom out X" +
            // zoomOutFactor);
            zoomOutButton.setToolTipText(i18n.get(ZoomPanel.class,
                    zoomOutCmd + "factor",
                    I18n.TOOLTIP,
                    "zoom out X" + zoomOutFactor,
                    new Float(zoomOutFactor)));

        } else {
            throw new IllegalArgumentException("Zoom In factor too small (must be > 1.0)");
        }
    }

    /**
     * Add the named button to the panel.
     * 
     * @param name GIF image name
     * @param info ToolTip text
     * @param command String command name
     *  
     */
    protected JButton getButton(String name, String info, String command) {
        URL url = ZoomPanel.class.getResource(name + ".gif");
        ImageIcon icon = new ImageIcon(url, info);
        JButton b = new JButton(icon);
        b.setPreferredSize(new Dimension(icon.getIconWidth(), icon.getIconHeight()));
        //b.setToolTipText(info);
        b.setToolTipText(i18n.get(ZoomPanel.class, command, I18n.TOOLTIP, info));
        b.setMargin(new Insets(0, 0, 0, 0));
        b.setActionCommand(command);
        b.addActionListener(this);
        b.setBorderPainted(Debug.debugging("layout"));
        b.setOpaque(false);
        return b;
    }

    /**
     * Add a ZoomListener from the listener list.
     * 
     * @param listener The ZoomListener to be added
     */
    public synchronized void addZoomListener(ZoomListener listener) {
        zoomDelegate.addZoomListener(listener);
    }

    /**
     * Remove a ZoomListener from the listener list.
     * 
     * @param listener The ZoomListener to be removed
     */
    public synchronized void removeZoomListener(ZoomListener listener) {
        zoomDelegate.removeZoomListener(listener);
    }

    /**
     * ActionListener interface.
     * 
     * @param e ActionEvent
     */
    public void actionPerformed(java.awt.event.ActionEvent e) {
        String command = e.getActionCommand();

        if (command.equals(zoomInCmd)) {
            zoomDelegate.fireZoom(ZoomEvent.RELATIVE, zoomInFactor);
        } else if (command.equals(zoomOutCmd)) {
            zoomDelegate.fireZoom(ZoomEvent.RELATIVE, zoomOutFactor);
        }
    }

    public void setOpaque(boolean set) {
        super.setOpaque(set);
        if (zoomInButton != null) {
            zoomInButton.setOpaque(set);
        }
        if (zoomOutButton != null) {
            zoomOutButton.setOpaque(set);
        }
    }

    ///////////////////////////////////////////////////////////////////////////
    //// OMComponentPanel methods to make the tool work with
    //// the MapHandler to find objects it needs.
    ///////////////////////////////////////////////////////////////////////////

    public void findAndInit(Object obj) {
        if (obj instanceof ZoomListener) {
            addZoomListener((ZoomListener) obj);
        }
    }

    public void findAndUndo(Object obj) {
        if (obj instanceof ZoomListener) {
            removeZoomListener((ZoomListener) obj);
        }
    }
}