java - JPanel 上的 JLabel 定位

Question

这几天我一直在尝试让一些 JLabels 对 JPanel 上的行进行编号，但没有任何乐趣。我尝试过所有我能想到的布局管理器。目前，我使用 GridLayout 获得了最好的结果(这不是我想要的)。请帮忙!

有问题的区域是 AddLabels() 方法。

问题:如何让下面代码中的 JLabels 与每一行对齐？

import javax.swing.*;
import javax.swing.border.EmptyBorder;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.Ellipse2D;
import java.util.*;
import java.util.List;

@SuppressWarnings("serial")
public class DrawPanelMain extends JPanel {

    private static final int PREF_W = 1200;
    private static final int PREF_H = 700;

    //Points for Ellipse2D
    private List<Point> POINT_LIST = Arrays.asList(
            new Point(60, 40),
            new Point(60, 100),
            new Point(60, 160),
            new Point(60, 220),
            new Point(60, 280),
            new Point(60, 340),
            new Point(60, 400),
            new Point(60, 460),
            new Point(60, 520),
            new Point(60, 580),
            new Point(120, 100),
            new Point(120, 160),
            new Point(120, 220),
            new Point(120, 280),
            new Point(120, 340),
            new Point(120, 400),
            new Point(120, 460),
            new Point(120, 520),
            new Point(120, 580),
            new Point(180, 160),
            new Point(180, 220),
            new Point(180, 280),
            new Point(180, 340),
            new Point(180, 400),
            new Point(180, 460),
            new Point(180, 520),
            new Point(180, 580),
            new Point(240, 220),
            new Point(240, 280),
            new Point(240, 340),
            new Point(240, 400),
            new Point(240, 460),
            new Point(240, 520),
            new Point(240, 580),
            new Point(300, 280),
            new Point(300, 340),
            new Point(300, 400),
            new Point(300, 460),
            new Point(300, 520),
            new Point(300, 580),
            new Point(360, 340),
            new Point(360, 400),
            new Point(360, 460),
            new Point(360, 520),
            new Point(360, 580),
            new Point(420, 400),
            new Point(420, 460),
            new Point(420, 520),
            new Point(420, 580),
            new Point(480, 460),
            new Point(480, 520),
            new Point(480, 580),
            new Point(540, 520),
            new Point(540, 580),
            new Point(600, 580));

    //Points for labels
    private List<Point> POINT_LIST2 = Arrays.asList(
            new Point (20, 40),
            new Point (20, 100),
            new Point (20, 160));

    private JTabbedPane tabbedPane = new JTabbedPane();
    private int tabIndex = 0;

    public DrawPanelMain() {
        JPanel btnPanel = new JPanel();
        JPanel infoPanel = new JPanel();
        btnPanel.add(new JButton(new AddSwitchAction("Add Switch Panel")));
        btnPanel.add(new JButton(new PushConfigAction("Push Config")));
        btnPanel.add(new JButton(new ActivateAllAction("Activate All")));
        infoPanel.add(new JTextField(20));

        setLayout(new BorderLayout());
        add(tabbedPane, BorderLayout.CENTER);
        add(btnPanel, BorderLayout.PAGE_END);
        add(infoPanel, BorderLayout.EAST);
    }

    @Override
    public Dimension getPreferredSize() {
        if (isPreferredSizeSet()) {
            return super.getPreferredSize();
        }
        return new Dimension(PREF_W, PREF_H);
    }

    private class AddSwitchAction extends AbstractAction {
            public AddSwitchAction(String name) {
                super(name);
                int mnemonic = (int) name.charAt(0);
                putValue(MNEMONIC_KEY, mnemonic);
            }

        @Override
        public void actionPerformed(ActionEvent e) {
            tabIndex++;
            String title = "Switch " + tabIndex;
            DrawPanel2 tabComponent = new DrawPanel2(POINT_LIST);
            DrawLabels tabComponent2 = new DrawLabels(POINT_LIST2);
            tabbedPane.add(title, tabComponent);
        }
    }

    private class PushConfigAction extends AbstractAction {
        public PushConfigAction(String name) {
            super(name);
            int mnemonic = (int) name.charAt(0);
            putValue(MNEMONIC_KEY, mnemonic);
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            /*Add code sending the configuration to the switch panel*/
            JOptionPane.showMessageDialog(DrawPanelMain.this, "Configuration Pushed to Panel");
        }
    }

    private class ActivateAllAction extends AbstractAction {
        public ActivateAllAction(String name) {
            super(name);
            int mnemonic = (int) name.charAt(1);
            putValue(MNEMONIC_KEY, mnemonic);
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            Component comp = tabbedPane.getSelectedComponent();
            if (comp instanceof DrawPanel2) {
                DrawPanel2 drawPanel = (DrawPanel2) comp;
                drawPanel.activateAll();
            }
        }
    }

    private static void createAndShowGui() {
        DrawPanelMain mainPanel = new DrawPanelMain();
        final double version = 0.1;
        JFrame frame = new JFrame("RF Connection Panel " + version);
        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        frame.getContentPane().add(mainPanel);
        frame.pack();
        frame.setLocationByPlatform(true);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> createAndShowGui());
    }

}

@SuppressWarnings("serial")
class DrawPanel2 extends JPanel {
    private static final int OVAL_WIDTH = 30;
    private static final Color INACTIVE_COLOR = Color.RED;
    private static final Color ACTIVE_COLOR = Color.green;
    private List<Point> points;
    private List<Ellipse2D> ellipses = new ArrayList<>();
    private Map<Ellipse2D, Color> ellipseColorMap = new HashMap<>();

    public DrawPanel2(List<Point> points) {
        this.points = points;
        for (Point p : points) {
            int x = p.x - OVAL_WIDTH / 2;
            int y = p.y - OVAL_WIDTH / 2;
            int w = OVAL_WIDTH;
            int h = OVAL_WIDTH;
            Ellipse2D ellipse = new Ellipse2D.Double(x, y, w, h);
            ellipses.add(ellipse);
            ellipseColorMap.put(ellipse, INACTIVE_COLOR);
        }

        MyMouseAdapter mListener = new MyMouseAdapter();
        addMouseListener(mListener);
        addMouseMotionListener(mListener);
        setLayout(new GridLayout(12, 4, 0, 0));
        setBorder(new EmptyBorder(10, 10, 0, 0));
    }

    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D g2 = (Graphics2D) g;
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                RenderingHints.VALUE_ANTIALIAS_ON);
        for (Ellipse2D ellipse : ellipses) {
            g2.setColor(ellipseColorMap.get(ellipse));
            g2.fill(ellipse);
        }
    }

    private class MyMouseAdapter extends MouseAdapter {
        @Override
        public void mousePressed(MouseEvent e) {
            for (Ellipse2D ellipse : ellipses) {
                if (ellipse.contains(e.getPoint())) {
                    Color c = ellipseColorMap.get(ellipse);
                    c = (c == INACTIVE_COLOR) ? ACTIVE_COLOR : INACTIVE_COLOR;
                    ellipseColorMap.put(ellipse, c);
                }
            }
            repaint();
        }
    }

    public void activateAll() {
        for (Ellipse2D ellipse : ellipses) {
            ellipseColorMap.put(ellipse, ACTIVE_COLOR);
        }
        repaint();
    }
}

@SuppressWarnings("serial")
class DrawLabels extends JPanel {
    private List<Point> points2;
    private List<JLabel> jLabels = new ArrayList<>();
    private int i = 0;

    public DrawLabels(List<Point> points2) {
        this.points2 = points2;
        for (Point p : points2) {
            JLabel jLabel = new JLabel("Row" + i);
            jLabels.add(jLabel);
            i++;
        }
    }
}

Answer 1

您遇到的问题是试图解决不同系统之间字体规范的差异，这通常会使标签总是略有不同。即使使用布局管理器，作为一个工作单元也很难完成，相反......

你可以...

创建一个自定义JPanel，其唯一职责是绘制单行点。然后，您可以使用 GridLayout 或 GridBagLayout

之类的内容添加 JLabel 并将其添加到行中

你可以...

使用Graphics#drawString将行号直接绘制到带有点的面板上