JPanel 某些区域的 BalloonTip答案

【问题标题】：BalloonTip on some region of JPanelJPanel 某些区域的 BalloonTip
【发布时间】：2014-01-31 06:01:02
【问题描述】：

我想在JPanel 的特定区域上显示balloon tip。我知道如何在JComponent 上做到这一点。

我在JPanel上有一行，是否可以在鼠标悬停时才显示BallonTip。

谢谢

【问题讨论】：

如果您引用的类不在 Java API 中，或许您应该引用 library 以避免混淆。
请创建一个Minimal, Complete, Tested and Readable example 来显示您的问题。

标签： java swing jpanel

【解决方案1】：

请记住，JPanel 是从 JComponent 扩展而来的，所以基本上，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();
        }
    }

}

现在有了点/线交点

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();
        }
    }
}

【讨论】：

我不认为 OP 指的是工具提示。
@JoshM 您可能是对的，但我认为他们说 “我知道如何在 JComponent 上执行此操作” 他们实际上是在谈论工具提示。 ..
@JoshM Ooo，这很酷，可能需要自己拿一份副本；） - 希望 OP 可以扩展它们的含义并弄清楚
我想用气球提示来做。不是 JPanel 的默认工具提示。
@user2573071 把它放在你的问题中，我看看我是否有时间检查它......