java - 在 JTable 列标题的左侧显示附加图标 (Nimbus)

Question

我希望我的 JTable 的列标题在它们的值是表的 rowFilter 的基础时在它们的左侧获得一个额外的图标。排序图标显示在右侧，因此将两个图标“粘合”为一个不算数(尽管我也无法使 Nimbus 正常工作......)。我已经尝试了几个关于渲染器的想法，但我做不到……“方法”的描述以及它们的问题包含在发布的代码中。

编辑:忘记了一个简单的 setIcon - 在这种情况下，问题出在排序图标上。使排序图标可见会隐藏其他图标。

编辑:这个Nimbus TableHeader was not highlighted as 'pressed'给出了如何通过下面的第三次尝试(使用模型背景图像的尝试)解决问题的想法。但我不知道如何知道 MouseOver、Focused 等的值……如何将它们作为 boolean 值获取？ (我的意思是 mouseOver 状态的 true/false，聚焦状态的 tru/false 等等，这样我就可以准备一个模型图像的查找表，并为列标题的当前状态获取正确的图像)...

编辑:要查看三种情况中每一种情况的输出，您必须使用所需的渲染器类修改 table.getTableHeader().setDefaultRenderer(new FilterIconHeaderRenderer3(table)); 行。

I've tried to show the problems with the three attempts on this image

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.image.BufferedImage;
import javax.swing.ImageIcon;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableCellRenderer;
import javax.swing.table.TableRowSorter;

public class TableHeaderTest extends JFrame {

    JTable table = new JTable(new DefaultTableModel(new Object[]{"Column1", "Column2", "Column3"}, 3));

    TableHeaderTest() {

        TableRowSorter sorter = new TableRowSorter(table.getModel());
        table.setRowSorter(sorter);
        table.getTableHeader().setDefaultRenderer(new FilterIconHeaderRenderer3(table));

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JScrollPane scrollPane = new JScrollPane();
        scrollPane.setViewportView(table);
        add(scrollPane, BorderLayout.CENTER);
        pack();
        setVisible(true);
    }

    public static void main(String[] args) {
        try {
            UIManager.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
        } catch (UnsupportedLookAndFeelException | ClassNotFoundException | IllegalAccessException | InstantiationException ex) {
            System.out.println("[L&F][Exception] " + ex.getMessage());
        }
        EventQueue.invokeLater(() -> {

            new TableHeaderTest();

        });
    }

}

/**
 * Trying to copy the look of a TableHeader and override its paintComponent
 * method for drawing the additional icon. However the look can't be entirely
 * copied and for example the sorting icon and background behave differently.
 * Also the indent of column name dissapeared.
 */
class FilterIconHeaderRenderer1 implements TableCellRenderer {

    TableCellRenderer delegate;
    ImageIcon filterIcon = new ImageIcon(getClass().getResource("/res/marker-dot-green.png"));

    public FilterIconHeaderRenderer1(JTable table) {
        this.delegate = table.getTableHeader().getDefaultRenderer();
    }

    @Override
    public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
        Component c = delegate.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column);
        if (c instanceof JLabel) {
            JLabelCopy label = new JLabelCopy((JLabel) c);
            return label;
        }
        return c;
    }

    class JLabelCopy extends JLabel {

        boolean withIcon = true;

        JLabelCopy(JLabel label) {
            this.ui = label.getUI();
            this.setText(label.getText());
            this.setPreferredSize(label.getPreferredSize());
            this.setVerticalTextPosition(label.getVerticalTextPosition());
            this.setHorizontalTextPosition(label.getHorizontalTextPosition());
            this.setVerticalAlignment(label.getVerticalAlignment());
            this.setHorizontalAlignment(label.getHorizontalAlignment());
            this.setIcon(label.getIcon());
            this.setIconTextGap(label.getIconTextGap());
            this.setAlignmentX(label.getAlignmentX());
            this.setAlignmentY(label.getAlignmentY());
            this.setLayout(label.getLayout());
        }

        @Override
        public void paintComponent(Graphics g) {
            super.paintComponent(g);
            if (withIcon) {
                g.drawImage(filterIcon.getImage(), 4, 4, null);
            }
        }

    }

}

/**
 * Also trying to copy the look of a TableHeader but without overriding its
 * paintComponent method. Instead I make the header a panel consiting of two
 * jLabels - the original column header and a jlabel of copied look with added
 * icon. Problem with this method is theseparator of the visible separator of
 * the two labels and the color difference of when a column is sorted (the
 * copied-look-label doesn't change it's background to match a sorted header).
 *
 */
class FilterIconHeaderRenderer2 implements TableCellRenderer {

    TableCellRenderer delegate;
    ImageIcon filterIcon = new ImageIcon(getClass().getResource("/res/marker-dot-green.png"));

    public FilterIconHeaderRenderer2(JTable table) {
        this.delegate = table.getTableHeader().getDefaultRenderer();
    }

    @Override
    public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
        JPanel newHeader = new JPanel(new BorderLayout());
        Component c = delegate.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column);
        if (c instanceof JLabel) {
            JLabel label = (JLabel) c;
            JLabelCopy filterIconLabel = new JLabelCopy(label);
            filterIconLabel.setText("");
            filterIconLabel.setIcon(filterIcon);
            filterIconLabel.setPreferredSize(new Dimension(filterIcon.getIconWidth() + 4, filterIconLabel.getPreferredSize().height));
            newHeader.add(filterIconLabel, BorderLayout.WEST);
            newHeader.add(label, BorderLayout.CENTER);
            return newHeader;
        }
        return c;
    }

    class JLabelCopy extends JLabel {

        boolean withIcon = true;

        JLabelCopy(JLabel label) {
            this.ui = label.getUI();
            this.setPreferredSize(label.getPreferredSize());
            this.setVerticalTextPosition(label.getVerticalTextPosition());
            this.setHorizontalTextPosition(label.getHorizontalTextPosition());
            this.setVerticalAlignment(label.getVerticalAlignment());
            this.setHorizontalAlignment(label.getHorizontalAlignment());
            this.setIcon(label.getIcon());
            this.setIconTextGap(label.getIconTextGap());
            this.setAlignmentX(label.getAlignmentX());
            this.setAlignmentY(label.getAlignmentY());
            this.setLayout(label.getLayout());
        }

    }
}

/**
 * Having an array of header mockups for each state for selected and hasFocus
 * (lacks sorted state) of the column header. Using these as background of panel
 * loaded with two labels - original header and label with just the new icon.
 * Both have setOpaque(false). Problem with this is the problem with choosing
 * the right background image for the panel as the isSelected and hasFocus
 * parameters of getRendererComponent don't work as you think they should.
 */
class FilterIconHeaderRenderer3 implements TableCellRenderer {

    private BufferedImage[][] headerImages = new BufferedImage[2][2];
    TableCellRenderer delegate;
    ImageIcon filterIcon = new ImageIcon(getClass().getResource("/res/marker-dot-green.png"));

    public FilterIconHeaderRenderer3(JTable table) {
        this.delegate = table.getTableHeader().getDefaultRenderer();

        for (int i = 0; i < 2; i++) {
            for (int j = 0; j < 2; j++) {
                JLabel comp = (JLabel) delegate.getTableCellRendererComponent(table, "     ", i == 1, j == 1, 0, 0);
                headerImages[i][j] = createUMPFake(comp);
            }
        }
    }

    @Override
    public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {

        Component c = delegate.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column);
        if (c instanceof JLabel) {
            JPanel newHeader = new JPanel(new BorderLayout()) {
                @Override
                public void paintComponent(Graphics g) {
                    super.paintComponent(g);
                    g.drawImage(headerImages[isSelected ? 1 : 0][hasFocus ? 1 : 0], 0, 0, null);
                }
            };
            JLabel label = (JLabel) c;
            label.setOpaque(false);
            JLabel filterIconLabel = new JLabel();
            filterIconLabel.setText("");
            filterIconLabel.setOpaque(false);
            filterIconLabel.setIcon(filterIcon);
            filterIconLabel.setPreferredSize(new Dimension(filterIcon.getIconWidth() + 4, filterIconLabel.getPreferredSize().height));
            newHeader.add(filterIconLabel, BorderLayout.WEST);
            newHeader.add(label, BorderLayout.CENTER);
            return newHeader;
        }
        return c;
    }

    /*
     * Following methods were taken from:
     * https://stackoverflow.com/questions/4028898/create-an-image-from-a-non-visible-awt-component
     */
    private BufferedImage createUMPFake(Component comp) {

        JFrame invisibleFrame = new JFrame();
        invisibleFrame.setSize(comp.getPreferredSize());
        JPanel colorPanel = new JPanel();
        colorPanel.setOpaque(false);
        colorPanel.setLayout(new BorderLayout());
        colorPanel.setBackground(new Color(0, 0, 255, 0));
        colorPanel.setSize(invisibleFrame.getSize());
        colorPanel.add(comp, BorderLayout.CENTER);

        invisibleFrame.add(colorPanel);

        colorPanel.setVisible(true);

        return createImage((JComponent) colorPanel, new Rectangle(invisibleFrame.getBounds()));

    }

    /**
     * Create a BufferedImage for Swing components. All or part of the component
     * can be captured to an image.
     *
     * @param component component to create image from
     * @param region The region of the component to be captured to an image
     * @return image the image for the given region
     */
    private static BufferedImage createImage(Component component, Rectangle region) {
        //  Make sure the component has a size and has been layed out.
        //  (necessary check for components not added to a realized frame)

        if (!component.isDisplayable()) {
            Dimension d = component.getSize();

            if (d.width == 0 || d.height == 0) {
                d = component.getPreferredSize();
                component.setSize(d);
            }

            layoutComponent(component);
        }

        BufferedImage image = new BufferedImage(region.width, region.height, BufferedImage.TYPE_INT_ARGB);
        Graphics2D g2d = image.createGraphics();

        //  Paint a background for non-opaque components,
        //  otherwise the background will be black
        if (!component.isOpaque()) {
            g2d.setColor(component.getBackground());
            g2d.fillRect(region.x, region.y, region.width, region.height);
        }

        g2d.translate(-region.x, -region.y);
        component.paint(g2d);
        g2d.dispose();
        return image;
    }

    private static void layoutComponent(Component component) {
        synchronized (component.getTreeLock()) {
            component.doLayout();

            if (component instanceof Container) {
                for (Component child : ((Container) component).getComponents()) {
                    layoutComponent(child);
                }
            }
        }
    }

}

Answer 1

或者更简单，您可以使用 HTML 标记在 HeaderRenderer 上显示图标:

import java.awt.*;
import java.awt.event.*;
import java.net.URL;
import java.util.Objects;
import javax.swing.*;
import javax.swing.table.*;

public class TableHeaderIconTest {
  //private final URL url = getClass().getResource("a.png");
  public JComponent makeUI() {
    String[] columnNames = {"Column1", "Column2", "Column3"};
    JTable table = new JTable(new DefaultTableModel(columnNames, 3));
    TableColumnModel m = table.getColumnModel();
    for (int i = 0; i < m.getColumnCount(); i++) {
      TableColumn column = m.getColumn(i);
      column.setHeaderRenderer(new FilterIconHeaderRenderer4());
      //column.setHeaderValue(
      //  String.format("<html><table><td><img src='%s'/><td>%s", url, columnNames[i]));
    }
    table.setAutoCreateRowSorter(true);

    JPanel p = new JPanel(new BorderLayout());
    p.add(new JScrollPane(table));
    return p;
  }
  public static void main(String[] args) {
    EventQueue.invokeLater(new Runnable() {
      @Override public void run() {
        createAndShowGUI();
      }
    });
  }
  public static void createAndShowGUI() {
    try {
      for (UIManager.LookAndFeelInfo laf : UIManager.getInstalledLookAndFeels()) {
        if ("Nimbus".equals(laf.getName())) {
          UIManager.setLookAndFeel(laf.getClassName());
        }
      }
    } catch (Exception e) {
      e.printStackTrace();
    }
    JFrame f = new JFrame();
    f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    f.getContentPane().add(new TableHeaderIconTest().makeUI());
    f.setSize(320, 240);
    f.setLocationRelativeTo(null);
    f.setVisible(true);
  }
}

class FilterIconHeaderRenderer4 implements TableCellRenderer {
  private final URL url = getClass().getResource("Ok2mc.png");
  @Override public Component getTableCellRendererComponent(
      JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
    TableCellRenderer r = table.getTableHeader().getDefaultRenderer();
    String str = Objects.toString(value, "");
    String html = String.format("<html><table><td><img src='%s'/><td>%s", url, str);
    return r.getTableCellRendererComponent(table, html, isSelected, hasFocus, row, column);
  }
}