带有 JPopupMenu 的 JTable [英] JTable with JPopupMenu

问题描述

仅当 Mouse Cursor 超过选定的 JTable'Row

我的问题:是否有另一种方法作为 getBounds 从所选行并确定/与 Mouse 位置进行比较...

my question: if is there another way as getBounds from selected row and determine/compare that with Mouse position...

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 从整个 JTable

my simple sscce demonstrated just un-wanted opposite status, any row could be selected and JPopupMenu is triggered from whole JTable

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);
            }
        });
    }
}

推荐答案

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

It's an interesting question, because it highlights missing api on JComponent :-)

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

As we all know, the recommended way to register popupMenus is to use the componentPopupMenu property. Related api is

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

缺少的(这个要求实际上需要)是

what is missing (and actually needed for this requirement) is

JPopupMenu getComponentPopupMenu(MouseEvent);

这种缺失更令人讨厌，因为在 getComponentPopup() 之后调用 getPopupLocation(由 LAF 深处的 AWTEventHelper).因此，对于像存储可能触发弹出窗口的最后一个鼠标事件，然后决定哪个/是否返回弹出窗口这样的 hack 没有余地.并且为该位置返回 null 只会导致在鼠标位置显示它

this lack is all the more annoying, as the getPopupLocation is called (by AWTEventHelper deep in the LAF) after getComponentPopup(). So there's no leeway for a hack like storing the last mouse event which might have triggered the popup and then decide which/if to return popup. And returning null for the location will only result in showing it at the mouse location

唯一的(肮脏的)hack(围绕我完全不愿意用 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

The only (dirty) hack (around my utter reluctance to get my hands dirty with a MouseListener ;-) is to override getComponentPopup and decide there whether or not to return it based on current mouse position

    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，弹出显示就不会由键盘触发，这可能是也可能不是问题.

the side-effect is that popup showing isn't triggered by keyboard as long as the mouse is anywhere above the table, which might or not be a problem.

这篇关于带有 JPopupMenu 的 JTable的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！