1)我建议使用JWindow而不是使用JToolTip,
2)以下示例是可能的方法之一
import java.awt.*;
import java.awt.event.*;
import java.awt.font.*;
import java.awt.geom.*;
import javax.swing.*;
import java.util.*;
import javax.swing.event.*;
public class SimplePaintSurface implements Runnable, ActionListener {
private static final int WIDTH = 1250;
private static final int HEIGHT = 800;
private Random random = new Random();
private JFrame frame = new JFrame("SimplePaintSurface");
private JPanel tableaux;
@Override
public void run() {
tableaux = new JPanel(null);
for (int i = 1500; --i >= 0;) {
addRandom();
}
frame.add(tableaux, BorderLayout.CENTER);
JButton add = new JButton("Add");
add.addActionListener(this);
frame.add(add, BorderLayout.SOUTH);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(WIDTH, HEIGHT);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
tableaux.requestFocusInWindow();
}
@Override
public void actionPerformed(final ActionEvent e) {
addRandom();
tableaux.repaint();
}
void addRandom() {
Letter letter = new Letter(Character.toString((char) ('a' + random.nextInt(26))));
letter.setBounds(random.nextInt(WIDTH), random.nextInt(HEIGHT), 16, 16);
tableaux.add(letter);
}
public static void main(final String[] args) {
SwingUtilities.invokeLater(new SimplePaintSurface());
}
}
class Letter extends JLabel {
private Font font1;
private Font font2;
private final FontRenderContext fontRenderContext1;
private final FontRenderContext fontRenderContext2;
public Letter(final String letter) {
super(letter);
setFocusable(true);
setBackground(Color.RED);
font1 = getFont();
font2 = font1.deriveFont(48f);
fontRenderContext1 = getFontMetrics(font1).getFontRenderContext();
fontRenderContext2 = getFontMetrics(font2).getFontRenderContext();
MouseInputAdapter mouseHandler = new MouseInputAdapter() {
@Override
public void mouseEntered(final MouseEvent e) {
Letter.this.setOpaque(true);
setFont(font2);
Rectangle bounds = getBounds();
Rectangle2D stringBounds = font2.getStringBounds(getText(), fontRenderContext2);
bounds.width = (int) stringBounds.getWidth();
bounds.height = (int) stringBounds.getHeight();
setBounds(bounds);
}
@Override
public void mouseExited(final MouseEvent e) {
Letter.this.setOpaque(false);
setFont(font1);
Rectangle bounds = getBounds();
Rectangle2D stringBounds = font1.getStringBounds(getText(), fontRenderContext1);
bounds.width = (int) stringBounds.getWidth();
bounds.height = (int) stringBounds.getHeight();
setBounds(bounds);
}
};
addMouseListener(mouseHandler);
}
}