test.java

《Java2图形设计卷II：Swing》配套光盘源码

import java.net.URL;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;

public class Test extends JApplet implements SwingConstants {
	JLabel        	label 	= new JLabel("Action!");
	JPanel       	controlPanel 	= new JPanel();
	JComboBox     	alignmentHorizontal 	= new JComboBox();
	JComboBox 		alignmentVertical 	= new JComboBox();

	public void init() {
		Container contentPane = getContentPane();
		ImageIcon icon = new ImageIcon("slate.gif");

		label.setIcon(icon);
		label.setHorizontalAlignment(CENTER);
		label.setFont(new Font("Times-Roman", Font.ITALIC, 20));

		label.setMaximumSize(new Dimension(0, 150));

		setupComboBoxes();
		setupControlPanel();

		contentPane.setLayout(new BorderLayout());
		contentPane.add(controlPanel, "North");
		contentPane.add(label, "Center");

		alignmentVertical.addItemListener(new ItemListener() {
			public void itemStateChanged(ItemEvent event) {
				JComboBox b = (JComboBox)event.getSource();
				String    s = (String)b.getSelectedItem();
				int       c = getSwingConstantByName(s);

				label.setVerticalAlignment(c);
			}
		});
		alignmentHorizontal.addItemListener(new ItemListener() {
			public void itemStateChanged(ItemEvent event) {
				JComboBox b = (JComboBox)event.getSource();
				String    s = (String)b.getSelectedItem();
				int       c = getSwingConstantByName(s);
				
				label.setHorizontalAlignment(c);
			}
		});
	}
	void setupComboBoxes() {
		alignmentVertical.addItem("Top");
		alignmentVertical.addItem("Center");
		alignmentVertical.addItem("Bottom");

		alignmentHorizontal.addItem("Left");
		alignmentHorizontal.addItem("Center");
		alignmentHorizontal.addItem("Right");

		alignmentVertical.setSelectedItem(
			getSwingConstantName(
				label.getVerticalAlignment()));

		alignmentHorizontal.setSelectedItem(
			getSwingConstantName(
				label.getHorizontalAlignment()));
	}
	void setupControlPanel() {
		controlPanel.setBorder(
			BorderFactory.createTitledBorder("Alignment"));

		controlPanel.add(new JLabel(
						"Vertical:"));
		controlPanel.add(alignmentVertical);
		controlPanel.add(Box.createHorizontalStrut(5));

		controlPanel.add(Box.createHorizontalStrut(25));

		controlPanel.add(new JLabel(
						"Horizontal:"));
		controlPanel.add(Box.createHorizontalStrut(5));

		controlPanel.add(alignmentHorizontal);
	}
	int getSwingConstantByName(String s) {
		if(s.equalsIgnoreCase("left"))        	return LEFT;
		else if(s.equalsIgnoreCase("center")) 	return CENTER;
		else if(s.equalsIgnoreCase("right"))  	return RIGHT;
		else if(s.equalsIgnoreCase("top"))    	return TOP;
		else if(s.equalsIgnoreCase("bottom")) 	return BOTTOM;

		return -1;
	}
	String getSwingConstantName(int c) {
		if(c == LEFT) 			return "Left";
		else if(c == CENTER)	return "Center";
		else if(c == RIGHT) 	return "Right";
		else if(c == TOP) 		return "Top";
		else if(c == BOTTOM) 	return "Bottom";

		return "undefined";
	}
}