我想显示 balloon tip在 JPanel 上的特定区域。我知道如何在 JComponent 上执行此操作。
我的JPanel上有一行，是否可以仅当鼠标悬停在该行上时才显示BallonTip。
谢谢
最佳答案
请记住，JPanel 扩展自 JComponent，因此基本上，这是相同的过程。
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import net.java.balloontip.CustomBalloonTip;
import net.java.balloontip.examples.complete.Utils;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private CustomBalloonTip customBalloonTip;
private Rectangle square = new Rectangle(50, 50, 200, 200);
public TestPane() {
customBalloonTip = new CustomBalloonTip(this,
new JLabel("<html>I'm a " + Utils.monospace("CustomBalloonTip") + ".</html>"),
square,
Utils.createBalloonTipStyle(),
Utils.createBalloonTipPositioner(),
null);
customBalloonTip.setVisible(false);
addMouseMotionListener(new MouseAdapter() {
@Override
public void mouseMoved(MouseEvent e) {
if (square.contains(e.getPoint())) {
customBalloonTip.setVisible(true);
} else {
customBalloonTip.setVisible(false);
}
}
});
}
@Override
public Dimension getPreferredSize() {
return new Dimension(300, 300);
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.setColor(Color.RED);
g2d.fill(square);
g2d.dispose();
}
}
}
现在有点/线相交
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Line2D;
import java.awt.geom.Point2D;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import net.java.balloontip.CustomBalloonTip;
import net.java.balloontip.examples.complete.Utils;
public class TestBalloon {
public static void main(String[] args) {
new TestBalloon();
}
public TestBalloon() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private CustomBalloonTip customBalloonTip;
private List<Line2D> lines = new ArrayList<>(25);
private Point2D hitPoint = null;
public TestPane() {
customBalloonTip = new CustomBalloonTip(this,
new JLabel("<html>I'm a " + Utils.monospace("CustomBalloonTip") + ".</html>"),
new Rectangle(0, 0, 1, 1),
Utils.createBalloonTipStyle(),
Utils.createBalloonTipPositioner(),
null);
customBalloonTip.setVisible(false);
lines.add(new Line2D.Float(0, 0, 300, 300));
lines.add(new Line2D.Float(300, 0, 0, 300));
hitPoint = null;
addMouseMotionListener(new MouseAdapter() {
@Override
public void mouseMoved(MouseEvent e) {
Point mp = e.getPoint();
Rectangle offset = null;
for (Line2D line : lines) {
double distance = line.ptSegDist(mp);
if (distance <= 4) {
offset = new Rectangle(mp, new Dimension(1, 1));
}
}
if (offset != null) {
System.out.println(offset);
customBalloonTip.setOffset(offset);
customBalloonTip.setVisible(true);
} else {
customBalloonTip.setVisible(false);
}
repaint();
}
});
}
@Override
public Dimension getPreferredSize() {
return new Dimension(300, 300);
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.setColor(Color.RED);
for (Line2D line : lines) {
g2d.draw(line);
}
if (hitPoint != null) {
Ellipse2D ellipse = new Ellipse2D.Double(hitPoint.getX() - 5, hitPoint.getY() + 5, 10, 10);
g2d.fill(ellipse);
}
g2d.dispose();
}
}
}
关于java - JPanel 某些区域的 BalloonTip，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/21473460/