JTable + JPopupMenu + ActionListener = 噩梦

Question

我的主要 class 是一个 window，包含图形组件，其中包括一个 JTable。

我创建了 public class ContextMenu，它是 JPopupMenu 的自定义实现，包含多个 JMenuItem.

我已经在 JTable 上注册了一个 mouseListener，以便在检测到右键单击时显示 ContextMenu 的实例。

问题如下："How to pass the selected rows to different function according to the chosen JMenuItem?"

显而易见的答案是在我的 JMenuItem 上设置 ActionListener，但请记住 JTable 与 JPopupMenu.

在不同的 class/object 中

一些代码片段值一千字。

public class Tab implements ITab {
private ContextMenu contextMenu;
private JTable table;
private List<SomeObject> toProcess;
--- code --
private JScrollPane drawScrollTable() {
        Object columns[] = {
            "something",
            "somethingElse"
        };
        Object rows[][] = {};
        table = new JTable(new DefaultTableModel(rows, columns));
        JScrollPane scrollPane = new JScrollPane(table);

        table.setSelectionForeground(Color.BLACK);
        table.addMouseListener(new MouseAdapter() {         
            @Override
            public void mouseReleased(MouseEvent e) { 
                int selectedRow = table.rowAtPoint(e.getPoint());

                if (selectedRow >= 0 && selectedRow < table.getRowCount()) {
                    if (!table.getSelectionModel().isSelectedIndex(selectedRow)) {
                        table.setRowSelectionInterval(selectedRow, selectedRow);
                    }
                }

                if (e.isPopupTrigger() && e.getComponent() instanceof JTable) {  
                    this.show(e);
                }
            }

            private void show(MouseEvent e){
                contextMenu.show(e.getComponent(), e.getX(), e.getY());
            }
        });

        return scrollPane;
    }
-- code --
}

public class ContextMenu extends JPopupMenu {
    JMenuItem item;

    public ContextMenu(IBurpExtenderCallbacks callbacks){
        this.item= new JMenuItem("item");

        this.item(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {     
                 // Do action involving the selected row, even better if possible action involving the value hold in the column 0 of the selected row and the toProcess private field 
            }
        });

        add(item);
    }
}

不知道我问的是否可行

Answer 1

肮脏的方式：传递引用。
更简洁的方式：通过 M-C-V

构建程序

我的Minimal, Complete, and Verifiable example的肮脏方式：

import java.awt.BorderLayout;
import java.awt.event.*;

import javax.swing.*;
import javax.swing.table.DefaultTableModel;

public class TableTest extends JPanel {
    private TableClass tableClass = new TableClass();

    public TableTest() {
        setLayout(new BorderLayout());
        add(tableClass);
    }

    private static void createAndShowGui() {
        JFrame frame = new JFrame("TableTest");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().add(new TableTest());
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

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

class ContextMenu extends JPopupMenu {
    private JMenuItem item;
    private TableClass tableClass;  // dirty direct reference *****

    public ContextMenu(TableClass tableClass){
        this.tableClass = tableClass;
        this.item= new JMenuItem("item");

        this.item.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {     
                int row = tableClass.getSelectedRow();
                JTable table = tableClass.getTable();
                System.out.println("row: " + row);
                StringBuilder sb = new StringBuilder("Data: ");
                for (int i = 0; i < table.getColumnCount(); i++) {
                    sb.append(table.getValueAt(row, i));
                    if (i != table.getColumnCount() - 1) {
                        sb.append(", ");
                    }
                }
                System.out.println(sb);
            }
        });

        add(item);
    }
}

class TableClass extends JPanel {
    // ***** passing **this** into the ContextMenu class
    private ContextMenu contextMenu = new ContextMenu(this); 
    private static final Integer[][] DATA = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};
    private static final String[] COLUMN_NAMES = {"A", "B", "C"};
    private DefaultTableModel model = new DefaultTableModel(DATA, COLUMN_NAMES);
    private JTable table = new JTable(model);

    public TableClass() {
        table.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseReleased(MouseEvent e) {
                int selectedRow = table.rowAtPoint(e.getPoint());
                if (selectedRow >= 0 && selectedRow < table.getRowCount()) {
                    if (!table.getSelectionModel().isSelectedIndex(selectedRow)) {
                        table.setRowSelectionInterval(selectedRow, selectedRow);
                    }
                }
                if (e.isPopupTrigger() && e.getComponent() instanceof JTable) {
                    showPopUp(e);
                }
            }

            private void showPopUp(MouseEvent e) {
                contextMenu.show(e.getComponent(), e.getX(), e.getY());                
            }
        });

        setLayout(new BorderLayout());
        add(new JScrollPane(table));
    }

    public int getSelectedRow() {
        return table.getSelectedRow();
    }

    public int getSelectedColumn() {
        return table.getSelectedColumn();
    }

    public JTable getTable() {
        return table;
    }
}

Answer 2

MouseListener 应该为您的 ContextMenu 收集所有相关信息，将其打包在传输中（内部私有？）class 并在实际 [=13= 之前传递此信息]打开上下文菜单。

    table.addMouseListener(new MouseAdapter() {         
        @Override
        public void mouseReleased(MouseEvent e) { 
            int selectedRow = table.rowAtPoint(e.getPoint());

            if (selectedRow >= 0 && selectedRow < table.getRowCount()) {
                if (!table.getSelectionModel().isSelectedIndex(selectedRow)) {
                    table.setRowSelectionInterval(selectedRow, selectedRow);
                }
            }

            if (e.isPopupTrigger() && e.getComponent() instanceof JTable) {  
                this.show(e);
            }
        }

        private void show(MouseEvent e){
            int clickedRow=table.rowAtPoint(e.getPoint());
            int clickedCol=table.columnAtPoint(e.getPoint());
            Object data=table.getValueAt(row, i);

            DataClickedOnTable transportMeThere=new DataClickedOnTable(
              table, data, clickedRow, clickedColumn
            );
            contextMenu.setDataFromTable(transportMeThere);
            contextMenu.show(e.getComponent(), e.getX(), e.getY());
        }
    });
   ///....
   ///...


// Just an example of structure transporting the data
// Add whatever data members are relevant
private /* inner */ class DataClickedOnTable {
   public TestTable source;
   public Object data;
   public int row;
   public int column;

   public DataClickedOnTable(
     TestTable source, Object data, int row, int col
   ) {
     this.source=source;
     this.data=data;
     this.col=col;
     this.row=row;
   }
}
public class ContextMenu extends JPopupMenu {
    JMenuItem item1;
    JMenuItem item2; 

    Object dataFromTable; // make it an Integer 

    public ContextMenu(IBurpExtenderCallbacks callbacks){
        this.item1 = new JMenuItem("item");
        this.item2 = new JMenuItem("item");

        this.item1(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {     
                // You already have the relevant data in the dataFromTable
                // Do want you need in this context
            }
        });
        this.item2(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {     
                // You already have the relevant data in the dataFromTable
                // Do want you need to do in this context
            }
        });

        add(item1);
        add(item2);
    }

    void setDataFromTable(DataClickedOnTable data) {
      this.dataFromTable=data;
      // filter possible actions based on the received data - some
      // actions are possible, some won't.
      // Example:
      this.item1.setEnabled(null!=data && (data.row % 2)==0);
      this.item2.setEnabled(
            null!=data 
         && ((data.row % 2)==1 || data.data instanceof Number)
      );

    }
}

JTable + JPopupMenu + ActionListener = 噩梦

JTable + JPopupMenu + ActionListener = Nightmare

java

swing

awt

actionlistener

actionevent