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我用 GlazedList eventList 创建了一个 JTable。我搜索了 API，但不知道如何向该表添加撤消/重做可能性。我在 API 中发现了以下类：

UndoRedoSupport undoRedoSupport = new UndoRedoSupport<"what here?">("argument?"); UndoSupport undoSupport = new UndoSupport<"what to write here?">("argument?");

有没有人知道如何使用它？

private void createComponents() {
    EventList<Dien> eventList = new BasicEventList<Dien>();
    actionList  = GenericsUtil.makeList();
    table  = new WebTable();
    searchField = new WebTextField(60);
    String[] headers = new String[]{"Code", "Name", "Number"};
    String[] properties = new String[]{"Code", "Name", "Number"};
    TextFilterator<Dien> dienFilterator = new TextFilterator<Dien>() {
        public void getFilterStrings(List baseList, Dien dien) {
            baseList.add(dien.getCode());
            baseList.add(dien.getName());
            baseList.add(dien.getNumber());
        }
    };
    MatcherEditor<Dien> textMatcherEditor = new TextComponentMatcherEditor<Dien>(searchField, dienFilterator);
    eventList = toolModel.getDiens();
    FilterList<Dien> filterList = new FilterList<Dien>(eventList, textMatcherEditor);
    TableFormat tableFormat = GlazedLists.tableFormat(properties, headers, new boolean[]{true,true,true});
    model = new EventTableModel<Dien>(filterList, tableFormat);
    model.addTableModelListener(new TableModelListener() {
        public void tableChanged(TableModelEvent e) {
            if(e.getType()==TableModelEvent.UPDATE){
                if(!panel.isPendingChanges())
                    panel.setPendingChange(true);
            }
        }
    });
    selectionModel = new EventSelectionModel<Dien>(filterList);

    table.setSelectionModel(selectionModel);
    table.setModel(model);

}
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1 回答 1

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GlazedLists 内置的 Undo/Redo 类不带有公共构造函数；相反，您通过静态方法安装对特定事件列表的支持。UndoRedoSupport.install()

当然，如果您使用的是 Swing，那么利用 Swing 的UndoManager类是有意义的，而 GlazedLists 为其UndoSupport类提供了一个简单的包装器。同样，这只是用它的install()方法初始化。

我创建了一个简单的 Swing 示例应用程序作为示例来说明如何使用这些类。在我的示例中，我使用了一个简单EventList的字符串和一个 JList。但它同样适用于任何 GlazedList 支持的组件——UndoRedoSupport适用于EventList自身而不是 Swing 组件。

import ca.odell.glazedlists.BasicEventList;
import ca.odell.glazedlists.EventList;
import ca.odell.glazedlists.swing.EventListModel;
import ca.odell.glazedlists.swing.UndoSupport;
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextField;
import javax.swing.undo.UndoManager;


public class GlazedListsUndoSample {

    private JFrame mainFrame;
    private JButton addItemButton;
    private JButton undoButton;
    private JButton redoButton;
    private UndoManager undoManager;

    private EventList<String> eventList = new BasicEventList<String>();

    public GlazedListsUndoSample() {
        //populateAvailableBooks();
        createGui();
        mainFrame.setVisible(true);

    }

    private void updateButtons() {        
        //addBookButton.setEnabled(!books.isEmpty());
        undoButton.setEnabled(undoManager.canUndo());
        redoButton.setEnabled(undoManager.canRedo());
    }

    private void createGui() {
        undoManager = new UndoManager();
        UndoSupport.install(undoManager, eventList);

        mainFrame = new JFrame("GlazedLists Undo Example");
        mainFrame.setSize(600, 400);
        mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        EventListModel model = new EventListModel(eventList);
        JList list = new JList(model);

        JPanel mainPanel = new JPanel(new BorderLayout());
        mainPanel.add(new JScrollPane(list), BorderLayout.CENTER);

        JPanel addBookPanel = new JPanel(new BorderLayout());
        addBookPanel.add(new JLabel("Item"), BorderLayout.WEST);
        final JTextField titleTextField = new JTextField(50);
        addBookPanel.add(titleTextField, BorderLayout.CENTER);

        addItemButton = new JButton("Add Item");
        addItemButton.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                eventList.add(titleTextField.getText());

                updateButtons();
            }
        });
        addBookPanel.add(addItemButton, BorderLayout.EAST);


        JPanel buttonPanel = new JPanel();

        undoButton = new JButton("Undo");
        undoButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                if (undoManager.canUndo()) {
                    undoManager.undo();
                }

                updateButtons();
            }
        });

        redoButton = new JButton("Redo");
        redoButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                if (undoManager.canRedo()) {
                    undoManager.redo();
                }

                updateButtons();
            }
        });

        updateButtons();

        buttonPanel.add(undoButton);
        buttonPanel.add(redoButton);

        mainPanel.add(addBookPanel, BorderLayout.NORTH);
        mainPanel.add(buttonPanel, BorderLayout.SOUTH);

        mainFrame.getContentPane().setLayout(new BorderLayout());
        mainFrame.getContentPane().add(mainPanel, BorderLayout.CENTER);
    }

    public static void main(String[] args) {
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
              new GlazedListsUndoSample();
            }
        });
    }
}

值得注意的是，文档确实强烈暗示了它的功能限制：

并非 ListEvent 中描述的每个更改都会导致可撤消的编辑。具体来说，列表元素 IN PLACE 的突变不会产生可撤消的编辑。例如，观察元素变化的 ObservableElementList 或在该索引处使用相同对象调用 List.set(int, E) 会产生没有对应 UndoRedoSupport.Edit 对象的 ListEvent。这些 ListEvent 被忽略，因为它们缺乏足够的信息来撤消或重做更改。

一般来说，UndoRedoSupport 仅适用于 BasicEventList 或 BasicEventList 周围的普通包装器，它不会影响元素的顺序或类型，例如 ObservableElementList。高级转换，例如 SortedList 或 FilterList 将无法按预期使用此 UndoRedoSupport 类，因为它们的内容由它们自身之外的信息（比较器和匹配器）控制。

于 2014-07-18T14:30:49.620 回答