java - 以前选择的 JTable 单元格在按键时触发编辑器，即使明确取消选择也是如此

Question

正在关注 trashgod的优秀范例here ，我整理了一个小演示，它以一种公认的复杂方式完成了一个简单的任务。下面显示的 GUI 显示了一列代表真/假值的图标。如果您单击一个图标，它会将值更改为与其本身相反的值。非常像一个复选框，但外观不同，而且可扩展性更强(例如，我可以在将来更改它以循环显示十几个符号，而不是仅仅两个 boolean 符号)。

我是通过使用自定义编辑器完成的，该编辑器是 JComponent 的虚拟扩展。但是，您甚至看不到这个虚拟组件，因为一旦它接收到 MousePressed 事件，它就会导致编辑器 fireEditingStopped()。它工作得很好，除了我发现的一个奇怪的错误。如果你点击一个符号来改变它，然后将你的鼠标移动到屏幕上的其他地方并按下键盘键，它会在最后一个点击的单元格中调出虚拟编辑器(这有效地空白了单元格)，并且它会一直停留在那里直到你将鼠标移到单元格中或单击其他单元格。

作为对此的 hacky 修复，我在渲染器中添加了一行，它总是在渲染后取消选择整个表格。这很好用，我已经验证确实取消了整个表。然而，尽管如此，如果您按下键盘键，它仍为最后编辑的单元格执行编辑器。我怎样才能防止这种行为？我的应用程序中有其他键盘监听器，如果未选择任何单元格，我认为不应执行它们的任何编辑器。

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.EventQueue;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;

import javax.imageio.ImageIO;
import javax.swing.AbstractCellEditor;
import javax.swing.ImageIcon;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JTable;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableCellEditor;
import javax.swing.table.TableCellRenderer;

public class JTableBooleanIcons {

    private JFrame frame;
    private DefaultTableModel tableModel;
    private JTable table;

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    JTableBooleanIcons window = new JTableBooleanIcons();
                    window.frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the application.
     */
    public JTableBooleanIcons() {
        initialize();
    }

    /**
     * Initialize the contents of the frame.
     */
    private void initialize() {
        frame = new JFrame();
        frame.setBounds(100, 100, 450, 400);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        tableModel = new DefaultTableModel(new Object[]{"Words", "Pictures"},0);
        table = new JTable(tableModel);
        table.setRowHeight(40);
        tableModel.addRow(new Object[]{"click icon to change", false});
        tableModel.addRow(new Object[]{"click icon to change", true});
        tableModel.addRow(new Object[]{"click icon to change", false});
        tableModel.addRow(new Object[]{"click icon to change", true});
        tableModel.addRow(new Object[]{"click icon to change", false});
        tableModel.addRow(new Object[]{"click icon to change", true});
        tableModel.addRow(new Object[]{"click icon to change", false});
        tableModel.addRow(new Object[]{"click icon to change", true});

        frame.getContentPane().add(table, BorderLayout.CENTER);

        table.getColumn("Pictures").setCellRenderer(new BooleanIconRenderer());
        table.getColumn("Pictures").setCellEditor(new BooleanIconEditor());

    }

    @SuppressWarnings("serial")
    private class BooleanIconRenderer extends DefaultTableCellRenderer implements TableCellRenderer {

        @Override
        public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected,
                                                                        boolean hasFocus, int row, int col) {
            String iconFilename = null;
            if ((boolean) value) {
                iconFilename = "yes.png";
                value = true;
            } else {
                iconFilename = "no.png";
                value = false;
            }
            try {
                setIcon(new ImageIcon(ImageIO.read(BooleanIconRenderer.class.getResourceAsStream(iconFilename))));
            } catch (Exception e) {
                System.err.println("Failed to load the icon.");
            }
            if (isSelected) {
                this.setBackground(Color.white);
            } else {
                this.setBackground(Color.white);
            }
            table.getSelectionModel().clearSelection();
            return this;
        }
    }

    @SuppressWarnings("serial")
    private class BooleanIconEditor extends AbstractCellEditor implements TableCellEditor, MouseListener {

        private BooleanComponent boolComp;

        public BooleanIconEditor() {
            boolComp = new BooleanComponent(false);
            boolComp.addMouseListener(this);
        }

        @Override
        public Object getCellEditorValue() {
            return boolComp.getValue();
        }

        @Override
        public Component getTableCellEditorComponent(JTable table,
                Object value, boolean isSelected, int row, int column) {
            boolComp.setValue(! (boolean) value);
            return boolComp;
        }

        @Override
        public void mouseClicked(MouseEvent e) {
            this.fireEditingStopped();
        }

        @Override
        public void mousePressed(MouseEvent e) {
            this.fireEditingStopped();

        }

        @Override
        public void mouseReleased(MouseEvent e) {
            this.fireEditingStopped();
        }

        @Override
        public void mouseEntered(MouseEvent e) {
            this.fireEditingStopped();
        }

        @Override
        public void mouseExited(MouseEvent e) {
            this.fireEditingStopped();
        }

    }

    @SuppressWarnings("serial")
    private class BooleanComponent extends JComponent {
        private boolean value;

        public BooleanComponent(boolean value) {
            this.value = value;
        }

        public boolean getValue() {
            return value;
        }

        public void setValue(boolean value) {
            this.value = value;
        }
    }
}

Answer 1

你的问题的原因是你实际上没有在编辑器中渲染任何东西。您依赖于这样一个事实，即用户只会“单击”单元格以更改其值。我会认为这有点短视，但是，这是你的程序。

要立即修复它，只需添加...

@Override
public boolean isCellEditable(EventObject e) {
    return (e instanceof MouseEvent);
}

给你 BooleanIconEditor。

旁注。

在您的单元格渲染器中，您不应该加载图像。这些应该作为构造函数的一部分预先缓存，甚至更好，作为 static 字段变量。您可能正在这样做，但以防万一。

已更新

当我在谈论这个话题时。您应该避免从渲染器中更改表的状态。这真的很不安全，当表格试图一次又一次地重新呈现您所做的更改时，您可能会陷入无限循环……

如果您真的想隐藏选择(我不确定您为什么会这样做)，您可以将表格的选择设置为与表格背景颜色相匹配，或者将其设置为透明颜色。也不要忘记更改选择前景；)

更新#2

支持键盘的例子 ;) - 无法抗拒......

public class JTableBooleanIcons {

    private JFrame frame;
    private DefaultTableModel tableModel;
    private JTable table;
    private ImageIcon yesIcon;
    private ImageIcon noIcon;

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    JTableBooleanIcons window = new JTableBooleanIcons();
                    window.frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the application.
     */
    public JTableBooleanIcons() {
        try {
            yesIcon = (new ImageIcon(ImageIO.read(BooleanIconRenderer.class.getResourceAsStream("/yes.png"))));
            noIcon = (new ImageIcon(ImageIO.read(BooleanIconRenderer.class.getResourceAsStream("/no.png"))));
        } catch (Exception e) {
            e.printStackTrace();
        }
        initialize();
    }

    /**
     * Initialize the contents of the frame.
     */
    private void initialize() {
        frame = new JFrame();
        frame.setBounds(100, 100, 450, 400);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        tableModel = new DefaultTableModel(new Object[]{"Words", "Pictures"}, 0);
        table = new JTable(tableModel);
        table.setRowHeight(40);
        tableModel.addRow(new Object[]{"click icon to change", false});
        tableModel.addRow(new Object[]{"click icon to change", true});
        tableModel.addRow(new Object[]{"click icon to change", false});
        tableModel.addRow(new Object[]{"click icon to change", true});
        tableModel.addRow(new Object[]{"click icon to change", false});
        tableModel.addRow(new Object[]{"click icon to change", true});
        tableModel.addRow(new Object[]{"click icon to change", false});
        tableModel.addRow(new Object[]{"click icon to change", true});

        frame.getContentPane().add(table, BorderLayout.CENTER);

        table.getColumn("Pictures").setCellRenderer(new BooleanIconRenderer());
        table.getColumn("Pictures").setCellEditor(new BooleanIconEditor());

    }

    @SuppressWarnings("serial")
    private class BooleanIconRenderer extends DefaultTableCellRenderer implements TableCellRenderer {

        public BooleanIconRenderer() {
        }

        @Override
        public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected,
                boolean hasFocus, int row, int col) {
            super.getTableCellRendererComponent(table, null, isSelected, hasFocus, row, col);
            if ((boolean) value) {
                setIcon(yesIcon);
            } else {
                setIcon(noIcon);
            }
            return this;
        }
    }

    @SuppressWarnings("serial")
    private class BooleanIconEditor extends AbstractCellEditor implements TableCellEditor, MouseListener {

        private BooleanComponent boolComp;
        private boolean isMouseEvent;

        public BooleanIconEditor() {
            boolComp = new BooleanComponent(false);
            boolComp.addMouseListener(this);
            InputMap im = boolComp.getInputMap(JComponent.WHEN_FOCUSED);
            ActionMap am = boolComp.getActionMap();

            im.put(KeyStroke.getKeyStroke(KeyEvent.VK_SPACE, 0), "click");
            im.put(KeyStroke.getKeyStroke(KeyEvent.VK_ENTER, 0), "click");

            am.put("click", new AbstractAction() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    System.out.println("Clicked");
                    boolComp.setValue(!boolComp.getValue());
                }
            });

        }

        @Override
        public boolean isCellEditable(EventObject e) {
            isMouseEvent = e instanceof MouseEvent;
            return true; //(e instanceof MouseEvent);
        }

        @Override
        public Object getCellEditorValue() {
            return boolComp.getValue();
        }

        @Override
        public Component getTableCellEditorComponent(JTable table,
                Object value, boolean isSelected, int row, int column) {
            boolean state = (boolean) value;
            if (isMouseEvent) {
                state = !state;
            }
            boolComp.setValue(state);
            boolComp.setOpaque(isSelected);
            boolComp.setBackground(table.getSelectionBackground());
            return boolComp;
        }

        @Override
        public void mouseClicked(MouseEvent e) {
            this.fireEditingStopped();
        }

        @Override
        public void mousePressed(MouseEvent e) {
            this.fireEditingStopped();

        }

        @Override
        public void mouseReleased(MouseEvent e) {
            this.fireEditingStopped();
        }

        @Override
        public void mouseEntered(MouseEvent e) {
            this.fireEditingStopped();
        }

        @Override
        public void mouseExited(MouseEvent e) {
            this.fireEditingStopped();
        }
    }

    @SuppressWarnings("serial")
    private class BooleanComponent extends JLabel {

        private boolean value;

        public BooleanComponent(boolean value) {
            this.value = value;
        }

        public boolean getValue() {
            return value;
        }

        public void setValue(boolean value) {
            this.value = value;
            if (value) {
                setIcon(yesIcon);
            } else{
                setIcon(noIcon);
            }
        }
    }
}