带有 JPopupMenu 的 JTable

Question

我如何才能防止触发和显示JPopupMenu 仅当Mouse Cursor 超过选择JTable'Row

我的问题：是否有另一种方式作为 getBounds 从选定行中确定/比较 Mouse 位置...

我的简单 sscce 演示了不想要的相反状态，可以选择任何行，并且 JPopupMenu 是从整个 JTable 触发的

import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;

public class TableCheckBox extends JFrame {

    private static final long serialVersionUID = 1L;
    private JTable table;

    public TableCheckBox() {
        Object[] columnNames = {"Type", "Company", "Shares", "Price", "Boolean"};
        Object[][] data = {
            {"Buy", "IBM", new Integer(1000), new Double(80.50), false},
            {"Sell", "MicroSoft", new Integer(2000), new Double(6.25), true},
            {"Sell", "Apple", new Integer(3000), new Double(7.35), true},
            {"Buy", "Nortel", new Integer(4000), new Double(20.00), false}
        };
        DefaultTableModel model = new DefaultTableModel(data, columnNames);
        table = new JTable(model) {

            private static final long serialVersionUID = 1L;

            @Override
            public Class getColumnClass(int column) {
                return getValueAt(0, column).getClass();
            }
        };
        table.setPreferredScrollableViewportSize(table.getPreferredSize());
        JScrollPane scrollPane = new JScrollPane(table);
        add(scrollPane);
        createPopupMenu();
    }

    private void createPopupMenu() {
        JPopupMenu popup = new JPopupMenu();
        JMenuItem myMenuItem1 = new JMenuItem("cccccccccccccccccccccc");
        JMenuItem myMenuItem2 = new JMenuItem("bbbbbbbbbbbbbbbbbbbbbb");
        popup.add(myMenuItem1);
        popup.add(myMenuItem2);
        MouseListener popupListener = new PopupListener(popup);
        table.addMouseListener(popupListener);
    }

    private class PopupListener extends MouseAdapter {

        private JPopupMenu popup;

        PopupListener(JPopupMenu popupMenu) {
            popup = popupMenu;
        }

        @Override
        public void mousePressed(MouseEvent e) {
            maybeShowPopup(e);
        }

        @Override
        public void mouseReleased(MouseEvent e) {
            if (table.getSelectedRow() != -1) {
                maybeShowPopup(e);
            }
        }

        private void maybeShowPopup(MouseEvent e) {
            if (e.isPopupTrigger()) {
                popup.show(e.getComponent(), e.getX(), e.getY());
            }
        }
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                TableCheckBox frame = new TableCheckBox();
                frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
                frame.pack();
                frame.setLocation(150, 150);
                frame.setVisible(true);
            }
        });
    }
}

Answer 1

您是否正在寻找类似的东西？

仅在选定行上显示弹出窗口

  private void maybeShowPopup(MouseEvent e) {
     if (e.isPopupTrigger()) {

        // get row that pointer is over
        int row = table.rowAtPoint(e.getPoint());

        // if pointer is over a selected row, show popup
        if (table.isRowSelected(row)) {
           popup.show(e.getComponent(), e.getX(), e.getY());
        }
     }
  }

反之亦然，以防止弹出窗口仅显示在选定的行上：

  private void maybeShowPopup(MouseEvent e) {
     if (e.isPopupTrigger()) {
        int row = table.rowAtPoint(e.getPoint());
        int[] selectedRows = table.getSelectedRows();

        if (!table.isRowSelected(row)) {
           popup.show(e.getComponent(), e.getX(), e.getY());
        }
     }

Answer 2

这是一个有趣的问题，因为它突出显示了 JComponent 上缺少的 api :-)

众所周知，注册popupMenus的推荐方式是使用componentPopupMenu属性。相关api是

 void setComponentPopupMenu(JPopupMenu);
 JPopupMenu getComponentPopupMenu();
 Point getPopupLocation(MouseEvent);

缺少的（以及此要求实际需要的）是

JPopupMenu getComponentPopupMenu(MouseEvent);

这种缺乏更令人讨厌，因为 getPopupLocation 被调用（由 LAF 深处的 AWTEventHelper）在 getComponentPopup() 之后。因此，像存储可能触发弹出窗口的最后一个鼠标事件然后决定返回哪个/是否返回弹出窗口这样的黑客攻击没有任何余地。并且为该位置返回 null 只会导致它显示在鼠标位置

唯一的（肮脏的）hack（我完全不愿意用 MouseListener 弄脏我的手；-）是覆盖 getComponentPopup 并根据当前鼠标位置决定是否返回它

    table = new JTable(model) {

        /** 
         * @inherited <p>
         */
        @Override
        public JPopupMenu getComponentPopupMenu() {
            Point p = getMousePosition();
            // mouse over table and valid row
            if (p != null && rowAtPoint(p) >= 0) {
                // condition for showing popup triggered by mouse
                if (isRowSelected(rowAtPoint(p))) {
                    return super.getComponentPopupMenu();
                } else {
                    return null;
                }
            }
            return super.getComponentPopupMenu();
        }

    };

副作用是，只要鼠标在桌子上方的任何位置，键盘就不会触发弹出显示，这可能是也可能不是问题。