s05.htm

Java2Swingt界面设计

		colors.add(new JMenuItem(yellowIcon));

		mb.add(colors);
		setJMenuBar(mb);
	}
}
</pre>
            <hr size="1" noshade>
            <p> 5.2.2 在组件中共享图标</p>
            <p>&nbsp;</p>
            <p align="center"><b>例5-10 修改后的ColorIcon类清单</b></p>
            <hr noshade size="1"><pre>import java.awt.*;
import javax.swing.*;

class ColorIcon implements Icon {
	private Color fillColor;
	private int w, h;

	public ColorIcon(Color fillColor, int w, int h) {
		this.fillColor = fillColor;
		this.w = w;
		this.h = h;
	}
	public void paintIcon(Component c, Graphics g, int x, int y) {
		g.setColor(Color.black);
		g.drawRect(x, y, w-1, h-1);
		g.setColor(fillColor);
		g.fillRect(x+1, y+1, w-2, h-2);
	}
	public int getIconWidth() {
		return w;
	}
	public int getIconHeight() {
		return h;
	}
}
</pre>
            <hr size="1" noshade>
            <p align="center"><b>例5-11 在许多组件中共享单图标的小应用程序</b></p>
            <hr noshade size="1"><pre>import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Test extends JApplet {
	private ColorIcon colorIcon = new ColorIcon(40, 15);
	private JPopupMenu popup = new JPopupMenu();
	private JButton button = new JButton("select a color ...", 
											colorIcon);
	public void init() {
		addPopupMenuItems();

		button.putClientProperty("fill color", Color.red);

		Container contentPane = getContentPane();
		contentPane.setLayout(new FlowLayout());
		contentPane.add(button);

		button.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e) {
				Dimension buttonsz = button.getSize();
				popup.show(button,buttonsz.width,
									buttonsz.height);
			}
		});
	}
	private void addPopupMenuItems() {
		JMenuItem 	redItem = new JMenuItem(colorIcon),
					blueItem = new JMenuItem(colorIcon),
					grayItem = new JMenuItem(colorIcon),
					yellowItem = new JMenuItem(colorIcon),
					blackItem = new JMenuItem(colorIcon),
					whiteItem = new JMenuItem(colorIcon),
					orangeItem = new JMenuItem(colorIcon);

		MenuItemListener listener = new MenuItemListener();

		redItem.putClientProperty("fill color", Color.red);
		redItem.addActionListener(listener);
		popup.add(redItem);

		blueItem.putClientProperty("fill color", Color.blue);
		blueItem.addActionListener(listener);
		popup.add(blueItem);

		grayItem.putClientProperty("fill color", Color.gray);
		grayItem.addActionListener(listener);
		popup.add(grayItem);

		yellowItem.putClientProperty("fill color", Color.yellow);
		yellowItem.addActionListener(listener);
		popup.add(yellowItem);

		blackItem.putClientProperty("fill color", Color.black);
		blackItem.addActionListener(listener);
		popup.add(blackItem);

		whiteItem.putClientProperty("fill color", Color.white);
		whiteItem.addActionListener(listener);
		popup.add(whiteItem);

		orangeItem.putClientProperty("fill color", Color.orange);
		orangeItem.addActionListener(listener);
		popup.add(orangeItem);
	}
	class MenuItemListener implements ActionListener {
		public void actionPerformed(ActionEvent e) {
			JComponent jc = (JComponent)e.getSource();

			button.putClientProperty("fill color",
							jc.getClientProperty("fill color"));

			button.repaint();
		}
	}
}
</pre>
            <hr size="1" noshade>
            <p>&nbsp;</p>
            <p> 5.2.3 图像图标</p>
            <p>&nbsp;</p>
            <p align="center"><b>例5-12 有一个ImageIcon的小应用程序</b></p>
            <hr noshade size="1"><pre>import java.awt.*;
import javax.swing.*;

public class Test extends JApplet {
	ImageIcon icon = new ImageIcon(this.getClass().getResource("coffeeCup.jpg"));

	public void paint(Graphics g) {
		icon.paintIcon(this, g, 20, 15);
	}
}
</pre>
            <hr size="1" noshade>
            <p> 5.2.4 动画的图像图标</p>
            <p>&nbsp;</p>
            <p align="center"><b>例5-13 带一个动画的图标的小应用程序</b></p>
            <hr noshade size="1"><pre>import java.awt.*;
import javax.swing.*;

public class Test extends JApplet {
	public void init() {
		JPanel panel = new MyJPanel();
		getContentPane().add(panel, "Center");
	}
}
class MyJPanel extends JPanel {
	ImageIcon animatedIcon = new ImageIcon(getClass().getResource("globe.gif"));

	public void paintComponent(Graphics g) {
		super.paintComponent(g);
		animatedIcon.paintIcon(this, g, 20, 20);
	}
}
</pre>
            <hr size="1" noshade>
            <p> 5.3 动作</p>
            <p>&nbsp;</p>
            <p align="center"><b>例5-14 带一个菜单条的小应用程序</b></p>
            <hr noshade size="1"><pre>import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Test extends JApplet {
	public void init() {
		JMenuBar mb = new JMenuBar();
		JMenu fileMenu = new JMenu("File");
		JMenuItem exitItem = new JMenuItem("exit");

		exitItem.addActionListener(new ExitListener());

		fileMenu.add(exitItem);
		mb.add(fileMenu);
		setJMenuBar(mb);
	}
}
class ExitListener implements ActionListener {
	public void actionPerformed(ActionEvent e) {
		System.exit(0);
	}
}
</pre>
            <hr size="1" noshade>
            <p align="center"><b>例5-15 用一个动作创建一个菜单项</b></p>
            <hr noshade size="1"><pre>import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Test extends JApplet {
	public void init() {
		JMenuBar mb = new JMenuBar();
		JMenu fileMenu = new JMenu("File");

		fileMenu.add(new ExitAction());
		mb.add(fileMenu);
		setJMenuBar(mb);
	}
}
class ExitAction extends AbstractAction {
	public ExitAction() {
		super("exit");
	}
	public void actionPerformed(ActionEvent e) {
		System.exit(0);
	}
}
</pre>
            <hr size="1" noshade>
            <p>&nbsp;</p>
            <p> 5.3.1 作为控制中心点的动作</p>
            <p>&nbsp;</p>
            <p align="center"><b>例5-16 与一个工具条按钮和一个菜单项相关联的动作</b></p>
            <hr noshade size="1"><pre>import java.awt.*;
import java.awt.event.*;
import java.beans.*;
import javax.swing.*;

public class Test extends JApplet
					implements PropertyChangeListener {
	JPanel jp = new JPanel();
	JPanel cp = new JPanel();  // cp = checkbox panel

	JCheckBox jc = new JCheckBox("action enabled");
	JMenuBar mb = new JMenuBar(); 
	JToolBar tb = new JToolBar();

	Action saveAction = new SaveAction();
	Action exitAction = new ExitAction();
	
	

	public void init() {
		JMenu fileMenu = new JMenu("File");
		

		fileMenu.add(saveAction);
		fileMenu.add(exitAction);
		tb.add(saveAction);

		JCheckBoxMenuItem checkBoxItem = 
						  new JCheckBoxMenuItem("saved");

		associateActionAndCheckBoxItem(saveAction, checkBoxItem);
		fileMenu.add(checkBoxItem);

		mb.add(fileMenu);

		saveAction.addPropertyChangeListener(this);

		jp.setLayout(new BorderLayout(2,2));
		jp.add(tb, "North");  // toolbar
		jp.add(cp, "Center"); // checkbox panel

		cp.setLayout(new FlowLayout());
		cp.add(jc);

		Container contentPane = getContentPane();

		contentPane.setLayout(new BorderLayout());
		getRootPane().setJMenuBar(mb);
		contentPane.add(jp, "Center");

		jc.setSelected(saveAction.isEnabled());

		jc.addItemListener(new ItemListener() {
			public void itemStateChanged(ItemEvent event) {
				saveAction.setEnabled(!saveAction.isEnabled());
			}
		});
	}
	public void propertyChange(PropertyChangeEvent e) {
		boolean b = ((Boolean)e.getNewValue()).booleanValue();
		showStatus("save action " + (b ? "enabled" : "disabled"));
	}
	private void associateActionAndCheckBoxItem(
								final Action action,
								final JCheckBoxMenuItem item) {
		item.setHorizontalTextPosition(JButton.LEFT);
		item.setVerticalTextPosition(JButton.CENTER);
		item.setEnabled(action.isEnabled());
		item.addActionListener(action);
		action.addPropertyChangeListener(
									new PropertyChangeListener() {
			public void propertyChange(PropertyChangeEvent e) {
				String name = e.getPropertyName();

				if(name.equals(Action.NAME)) {
					item.setText((String)e.getNewValue());
					item.revalidate();
				}
				else if(name.equals("enabled")) {
					item.setEnabled(
						((Boolean)e.getNewValue()).booleanValue());
					item.repaint();
				}
				else if(name.equals(Action.SMALL_ICON)) {
					item.setIcon((Icon)e.getNewValue());
					item.revalidate();
				}
			}
		});
	}
}
class SaveAction extends AbstractAction {
	public SaveAction() {
		//super("save", new ImageIcon( this.getClass().getResource("save.gif")));
									//("save.gif")));
		super("save",new ImageIcon("save.gif"));
		setEnabled(false);
	}
	
	
	
	public void actionPerformed(ActionEvent event) {
		String s = new String();
		Object o = event.getSource();

		if(o instanceof JButton) 		s += "ToolBar:  ";
		else if(o instanceof JMenuItem) s += "MenuBar:  ";

		System.out.println(s + " save");
	}
}
class ExitAction extends AbstractAction {
	public ExitAction() {
		super("exit");
	}
	public void actionPerformed(ActionEvent event) {
		System.exit(0);
	}
}
</pre>
            <hr size="1" noshade>
            <p> 5.3.2 动作常量</p>
            <p>&nbsp;</p>
            <p align="center"><b>例5-17 在一个定制组件中使用Action.SHORT_DESCRIPTION</b></p>
            <hr noshade size="1"><pre>import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Test extends JApplet {
	public void init() {
		Container contentPane = getContentPane();
		CustomAction action = new CustomAction();
		CustomButton button = new CustomButton(action);

		contentPane.setLayout(new FlowLayout());
		contentPane.add(button);
	}
}
class CustomButton extends JButton {
	public CustomButton(Action action) {
		super((String)action.getValue(Action.NAME),
			  (Icon)action.getValue(Action.SMALL_ICON));

		String shortDescription = (String)action.getValue(
									Action.SHORT_DESCRIPTION);

		setToolTipText(shortDescription);
		addActionListener(action);
	}
}
class CustomAction extends AbstractAction {
	public CustomAction() {
		super("doit", new ImageIcon("skelly.gif"));
		putValue(Action.SHORT_DESCRIPTION, "a short description");
	}
	public void actionPerformed(ActionEvent e) {
		System.out.println("Custom action performed");
	}
}
</pre>
            <hr size="1" noshade>
            <p> 5.4 本章回顾</p>
            <p>&nbsp;</p>
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