java - 带图标的圆形 JButton；不直接指向时会被点击；将光标设置为 HAND_CURSOR 适用于图标之外的区域

Question

所以，我有 JFrame 和 JPanel 。 JPanel 有两个 JToggleButtons。每个按钮都显示为圆形按钮的图标。当光标悬停在按钮上方时，它应该变成一只手。

public class UserInterface extends JFrame  {
        int width;
        int height;

        JPanel panel;
        public static void main(String[] args)  {
                run();
        }
        public UserInterface()  {
                setup();
        }

        private void setup()  {
            width=800;
            height=600;

            panel=new UserInterfacePanel();
            add(panel);

            setSize(width, height);
            setLocationRelativeTo(null);
            setDefaultCloseOperation(EXIT_ON_CLOSE);
        }

        public static void run()  {
                UserInterface gui=new UserInterface();
                gui.setVisible(true);
        }
}   


class UserInterfacePanel extends JPanel {
            private JToggleButton startButton;
            private JToggleButton stopButton;

            public static void main(String[] args)  {

            }

            public UserInterfacePanel()  {
                setup();
            }

            private void setup()  {
                setLayout(new GridLayout(1,2));

                setupButtons();
                setupButtonsActions();
                add(startButton);
                add(stopButton);
            }

            private void setupButtons()  {

                    ImageIcon iconStartButton = new ImageIcon("C:\\Users\\parsecer\\Desktop\\imgs\\greenReleased.png");
                    ImageIcon iconStopButton=new ImageIcon("C:\\Users\\parsecer\\Desktop\\imgs\\redReleased.png");

                    startButton=new JToggleButton(iconStartButton);
                    stopButton=new JToggleButton(iconStopButton);

                    startButton.setCursor(new Cursor(Cursor.HAND_CURSOR));
                    stopButton.setCursor(new Cursor(Cursor.HAND_CURSOR));

                    startButton.setHorizontalAlignment(JButton.CENTER);
                    stopButton.setHorizontalAlignment(JButton.CENTER);
                    startButton.setAlignmentX(CENTER_ALIGNMENT);
                    stopButton.setAlignmentX(CENTER_ALIGNMENT);
                    startButton.setAlignmentY(CENTER_ALIGNMENT);
                    stopButton.setAlignmentY(CENTER_ALIGNMENT);

                    setupButtonIcon(startButton);
                    setupButtonIcon(stopButton);

                    ImageIcon iconStartButtonPressed=new ImageIcon("C:\\Users\\parsecer\\Desktop\\imgs\\greenPressed.png");
                    startButton.setDisabledIcon(iconStartButton);
                    startButton.setPressedIcon(iconStartButtonPressed);
                    startButton.setSelectedIcon(iconStartButtonPressed);

                    ImageIcon iconStopButtonPressed=new ImageIcon("C:\\Users\\parsecer\\Desktop\\imgs\\redPressed.png");
                    stopButton.setDisabledIcon(iconStopButton);
                    stopButton.setPressedIcon(iconStopButtonPressed);
                    stopButton.setSelectedIcon(iconStopButtonPressed);

            }


             private void setupButtonIcon(JToggleButton button)  {
                   button.setBorder(BorderFactory.createEmptyBorder());
                   button.setBorderPainted(false);
                   button.setContentAreaFilled(false);
                   button.setFocusable(false);
                   button.setPreferredSize(new Dimension(80, 80));
                   button.setFocusPainted(false);
                   button.setOpaque(false);
            }
        }

问题是，光标变成了手形，超出了图标本身。单击按钮也是如此 - 只要我垂直单击，按钮就会被按下 - 假设它与按钮位于同一列中或者当我水平相对接近它时。

我想第一个问题可能与按钮图像有关，但背景已被删除。第二个可以链接到 GridLayout 吗？

Answer 1

我会做这样的事情:定义按钮的形状，大概是圆形/椭圆形。在您的点击和运动监听器中检查事件是否发生在该形状内部。如果是这样，那就做你的事吧。

将其放入代码中(对于运动监听器)如下所示:

Cursor handCursor = new Cursor(Cursor.HAND_CURSOR);
Cursor normalCursor = new Cursor(Cursor.DEFAULT_CURSOR);
// create your shape here
Shape shape = new Ellipse2D.Float(0, 0, 30, 30);
MouseMotionAdapter motionListener = new MouseMotionAdapter() {
        @Override
        public void mouseMoved(MouseEvent e) {
            super.mouseMoved(e); 
            JToggleButton src = (JToggleButton) e.getSource();
            if (shape.contains(e.getPoint())) {
                src.setCursor(handCursor);
            } else {
                src.setCursor(normalCursor);
            }
        }
    };
startButton.addMouseMotionListener(motionListener);
stopButton.addMouseMotionListener(motionListener);