事实上，我知道如何使用 CTRL + Z （撤销）和 CTRL + Y （重做）有一个JTextField。但是我的Swing应用程序中有数百个文本组件，所以有没有办法将它应用于我的应用程序中的所有文本组件，所以当我单击 CTRL + Z 时任何文本组件它会撤消该字段中的最后一个条目吗？
我试图在EventQueue中实现它，但它没有用！
答案 0 :(得分：5)
要使所有文本组件“可撤消”，您只需使用自己的子类创建它们，如：
public class MyTextField extends JTextField {
public MyTextField() {
final UndoManager undoMgr = new UndoManager();
// Add listener for undoable events
getDocument().addUndoableEditListener(new UndoableEditListener() {
public void undoableEditHappened(UndoableEditEvent pEvt) {
undoMgr.addEdit(pEvt.getEdit());
}
});
// Add undo/redo actions
getActionMap().put(UNDO_ACTION, new AbstractAction(UNDO_ACTION) {
public void actionPerformed(ActionEvent pEvt) {
try {
if (undoMgr.canUndo()) {
undoMgr.undo();
}
} catch (CannotUndoException e) {
e.printStackTrace();
}
}
});
getActionMap().put(REDO_ACTION, new AbstractAction(REDO_ACTION) {
public void actionPerformed(ActionEvent pEvt) {
try {
if (undoMgr.canRedo()) {
undoMgr.redo();
}
} catch (CannotRedoException e) {
e.printStackTrace();
}
}
});
// Create keyboard accelerators for undo/redo actions (Ctrl+Z/Ctrl+Y)
getInputMap().put(KeyStroke.getKeyStroke(KeyEvent.VK_Z, InputEvent.CTRL_DOWN_MASK),
UNDO_ACTION);
getInputMap().put(KeyStroke.getKeyStroke(KeyEvent.VK_Y, InputEvent.CTRL_DOWN_MASK),
REDO_ACTION);
}
}
然后创建JTextField s而不是创建MyTextField。限制是您可能还想为JTextArea创建另一个子类，依此类推其他JTextComponent的子类。因此，也可以使用实用程序方法将撤消/重做功能添加到任何现有JTextCompoent：
public final static String UNDO_ACTION = "Undo";
public final static String REDO_ACTION = "Redo";
public static void makeUndoable(JTextComponent pTextComponent) {
final UndoManager undoMgr = new UndoManager();
// Add listener for undoable events
pTextComponent.getDocument().addUndoableEditListener(new UndoableEditListener() {
public void undoableEditHappened(UndoableEditEvent evt) {
undoMgr.addEdit(evt.getEdit());
}
});
// Add undo/redo actions
pTextComponent.getActionMap().put(UNDO_ACTION, new AbstractAction(UNDO_ACTION) {
public void actionPerformed(ActionEvent evt) {
try {
if (undoMgr.canUndo()) {
undoMgr.undo();
}
} catch (CannotUndoException e) {
e.printStackTrace();
}
}
});
pTextComponent.getActionMap().put(REDO_ACTION, new AbstractAction(REDO_ACTION) {
public void actionPerformed(ActionEvent evt) {
try {
if (undoMgr.canRedo()) {
undoMgr.redo();
}
} catch (CannotRedoException e) {
e.printStackTrace();
}
}
});
// Create keyboard accelerators for undo/redo actions (Ctrl+Z/Ctrl+Y)
pTextComponent.getInputMap().put(
KeyStroke.getKeyStroke(KeyEvent.VK_Z, InputEvent.CTRL_DOWN_MASK), UNDO_ACTION);
pTextComponent.getInputMap().put(
KeyStroke.getKeyStroke(KeyEvent.VK_Y, InputEvent.CTRL_DOWN_MASK), REDO_ACTION);
}
最终且绝对透明的解决方案是使用Lnf features实现您自己的UI类，但是您可能需要在使所有TextComponents可撤消之前三思而后行，因为内存消耗原因，例如，如果您经常执行大量文本修改这些组件......
答案 1 :(得分：3)
你可以凝固API中实现的built_in KeyBindings short_cuts列表
请注意，您必须检查或准备所有可访问外观的代码
你可以获得build_in KeyBindings short_cuts并按照你的预期替换它，系统ClipBoard经常被修改，
从未尝试过但在此论坛上您可以找出相关信息如何更改，替换KeyBindings short_cuts
built_in KeyBindings short_cuts列表
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.*;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.table.*;
import javax.swing.filechooser.*;
public class KeyBindings implements ItemListener {
private static final String PACKAGE = "javax.swing.";
private static final String[] COLUMN_NAMES = {"Action", "When Focused", "When In Focused Window", "When Ancestor"};
private static String selectedItem;
private JComponent contentPane;
private JMenuBar menuBar;
private JTable table;
private JComboBox comboBox;
private Hashtable<String, DefaultTableModel> models;
/*
* Constructor
*/
public KeyBindings() {
models = new Hashtable<String, DefaultTableModel>();
contentPane = new JPanel(new BorderLayout());
contentPane.add(buildNorthComponent(), BorderLayout.NORTH);
contentPane.add(buildCenterComponent(), BorderLayout.CENTER);
resetComponents();
}
/*
* The content pane should be added to a high level container
*/
public JComponent getContentPane() {
return contentPane;
}
/*
* A menu can also be added which provides the ability to switch
* between different LAF's.
*/
public JMenuBar getMenuBar() {
if (menuBar == null) {
menuBar = createMenuBar();
}
return menuBar;
}
/*
* This panel is added to the North of the content pane
*/
private JComponent buildNorthComponent() {
comboBox = new JComboBox();
JLabel label = new JLabel("Select Component:");
label.setDisplayedMnemonic('S');
label.setLabelFor(comboBox);
JPanel panel = new JPanel();
panel.setBorder(new EmptyBorder(15, 0, 15, 0));
panel.add(label);
panel.add(comboBox);
return panel;
}
/*
* Check the key name to see if it is the UI property
*/
private String checkForUIKey(String key) {
if (key.endsWith("UI") && key.indexOf('.') == -1) {
String componentName = key.substring(0, key.length() - 2);// Ignore these components
if (componentName.equals("PopupMenuSeparator") || componentName.equals("ToolBarSeparator") || componentName.equals("DesktopIcon")) {
return null;
} else {
return componentName;
}
}
return null;
}
/*
** Build the emtpy table to be added in the Center
*/
private JComponent buildCenterComponent() {
DefaultTableModel model = new DefaultTableModel(COLUMN_NAMES, 0);
table = new JTable(model) {
private static final long serialVersionUID = 1L;
@Override
public boolean isCellEditable(int row, int column) {
return false;
}
};
table.setAutoCreateColumnsFromModel(false);
table.getColumnModel().getColumn(0).setPreferredWidth(200);
table.getColumnModel().getColumn(1).setPreferredWidth(200);
table.getColumnModel().getColumn(2).setPreferredWidth(200);
table.getColumnModel().getColumn(3).setPreferredWidth(200);
Dimension d = table.getPreferredSize();
d.height = 350;
table.setPreferredScrollableViewportSize(d);
table.getTableHeader().setFocusable(true);
return new JScrollPane(table);
}
/*
* When the LAF is changed we need to reset all the items
*/
private void resetComponents() {
models.clear();
((DefaultTableModel) table.getModel()).setRowCount(0);
Vector<String> comboBoxItems = new Vector<String>(50);// buildItemsMap();
UIDefaults defaults = UIManager.getLookAndFeelDefaults();
for (Object key : defaults.keySet()) { // All Swing components will have a UI property.
String componentName = checkForUIKey(key.toString());
if (componentName != null) {
comboBoxItems.add(componentName);
}
}
Collections.sort(comboBoxItems);
comboBox.removeItemListener(this);
comboBox.setModel(new DefaultComboBoxModel(comboBoxItems));
comboBox.setSelectedIndex(-1);
comboBox.addItemListener(this);
comboBox.requestFocusInWindow();
if (selectedItem != null) {
comboBox.setSelectedItem(selectedItem);
}
}
/**
* Create menu bar
*/
private JMenuBar createMenuBar() {
JMenuBar menuBar1 = new JMenuBar();
menuBar1.add(createFileMenu());
menuBar1.add(createLAFMenu());
return menuBar1;
}
/**
* Create menu items for the Application menu
*/
private JMenu createFileMenu() {
JMenu menu = new JMenu("Application");
menu.setMnemonic('A');
menu.addSeparator();
menu.add(new ExitAction());
return menu;
}
/**
* Create menu items for the Look & Feel menu
*/
private JMenu createLAFMenu() {
ButtonGroup bg = new ButtonGroup();
JMenu menu = new JMenu("Look & Feel");
menu.setMnemonic('L');
String lafId = UIManager.getLookAndFeel().getID();
UIManager.LookAndFeelInfo[] lafInfo = UIManager.getInstalledLookAndFeels();
for (int i = 0; i < lafInfo.length; i++) {
String laf = lafInfo[i].getClassName();
String name = lafInfo[i].getName();
Action action = new ChangeLookAndFeelAction(laf, name);
JRadioButtonMenuItem mi = new JRadioButtonMenuItem(action);
menu.add(mi);
bg.add(mi);
if (name.equals(lafId)) {
mi.setSelected(true);
}
}
return menu;
}
/*
* Implement the ItemListener interface
*/
@Override
public void itemStateChanged(ItemEvent e) {
String componentName = (String) e.getItem();
changeTableModel(getClassName(componentName));
selectedItem = componentName;
}
/*
* Use the component name to build the class name
*/
private String getClassName(String componentName) {
if (componentName.equals("TableHeader")) {// The table header is in a child package
return PACKAGE + "table.JTableHeader";
} else {
return PACKAGE + "J" + componentName;
}
}
/*
* Change the TabelModel in the table for the selected component
*/
private void changeTableModel(String className) {
DefaultTableModel model = models.get(className); // Check if we have already built the table model for this component
if (model != null) {
table.setModel(model);
return;
}
model = new DefaultTableModel(COLUMN_NAMES, 0); // Create an empty table to start with
table.setModel(model);
models.put(className, model);
JComponent component = null; // Create an instance of the component so we can get the default Action map and Input maps
try {
if (className.endsWith("JFileChooser")) {// Hack so I don't have to sign the jar file for usage in Java Webstart
component = new JFileChooser(new DummyFileSystemView());
} else {
Object o = Class.forName(className).newInstance();
component = (JComponent) o;
}
} catch (Exception e) {
Object[] row = {e.toString(), "", "", ""};
model.addRow(row);
return;
}
ActionMap actionMap = component.getActionMap(); // Not all components have Actions defined
Object[] keys = actionMap.allKeys();
if (keys == null) {
Object[] row = {"No actions found", "", "", ""};
model.addRow(row);
return;
}
// In some ActionMaps a key of type Object is found (I have no idea why)
// which causes a ClassCastExcption when sorting so we will ignore it
// by converting that entry to the empty string
for (int i = 0; i < keys.length; i++) {
Object key = keys[i];
if (key instanceof String) {
continue;
} else {
keys[i] = "";
}
}
Arrays.sort(keys);
for (int i = 0; i < keys.length; i++) { // Create a new row in the model for every Action found
Object key = keys[i];
if (key != "") {
Object[] row = {key, "", "", ""};
model.addRow(row);
}
}
// Now check each InputMap to see if a KeyStroke is bound the the Action
updateModelForInputMap(model, 1, component.getInputMap(JComponent.WHEN_FOCUSED));
updateModelForInputMap(model, 2, component.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW));
updateModelForInputMap(model, 3, component.getInputMap(JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT));
}
/*
* The model is potentially update for each of the 3 different InputMaps
*/
private void updateModelForInputMap(TableModel model, int column, InputMap inputMap) {
if (inputMap == null) {
return;
}
KeyStroke[] keys = inputMap.allKeys();
if (keys == null) {
return;
}
// The InputMap is keyed by KeyStroke, however we want to be able to
// access the action names that are bound to a KeyStroke so we will create
// a Hashtble that is keyed by action name.
// Note that multiple KeyStrokes can be bound to the same action name.
Hashtable<Object, String> actions = new Hashtable<Object, String>(keys.length);
for (int i = 0; i < keys.length; i++) {
KeyStroke key = keys[i];
Object actionName = inputMap.get(key);
Object value = actions.get(actionName);
if (value == null) {
actions.put(actionName, key.toString().replace("pressed ", ""));
} else {
actions.put(actionName, value + ", " + key.toString().replace("pressed ", ""));
}
}
for (int i = 0; i < model.getRowCount(); i++) {
// Now we can update the model for those actions that have KeyStrokes mapped to them
String o = actions.get(model.getValueAt(i, 0));
if (o != null) {
model.setValueAt(o.toString(), i, column);
}
}
}
/*
* Change the LAF and recreate the UIManagerDefaults so that the properties
* of the new LAF are correctly displayed.
*/
private class ChangeLookAndFeelAction extends AbstractAction {
private static final long serialVersionUID = 1L;
private String laf;
protected ChangeLookAndFeelAction(String laf, String name) {
this.laf = laf;
putValue(Action.NAME, name);
putValue(Action.SHORT_DESCRIPTION, getValue(Action.NAME));
}
@Override
public void actionPerformed(ActionEvent e) {
try {
JMenuItem mi = (JMenuItem) e.getSource();
JPopupMenu popup = (JPopupMenu) mi.getParent();
JRootPane rootPane = SwingUtilities.getRootPane(popup.getInvoker());
Component c = rootPane.getContentPane().getComponent(0);
rootPane.getContentPane().remove(c);
UIManager.setLookAndFeel(laf);
KeyBindings bindings = new KeyBindings();
rootPane.getContentPane().add(bindings.getContentPane());
SwingUtilities.updateComponentTreeUI(rootPane);
rootPane.requestFocusInWindow();
} catch (Exception ex) {
System.out.println("Failed loading L&F: " + laf);
System.out.println(ex);
}
}
}
private class ExitAction extends AbstractAction {
private static final long serialVersionUID = 1L;
public ExitAction() {
putValue(Action.NAME, "Exit");
putValue(Action.SHORT_DESCRIPTION, getValue(Action.NAME));
putValue(Action.MNEMONIC_KEY, new Integer(KeyEvent.VK_X));
}
@Override
public void actionPerformed(ActionEvent e) {
System.exit(0);
}
}
private class DummyFileSystemView extends FileSystemView {
@Override
public File createNewFolder(File containingDir) {
return null;
}
@Override
public File getDefaultDirectory() {
return null;
}
@Override
public File getHomeDirectory() {
return null;
}
}
private static void createAndShowGUI() {
KeyBindings application = new KeyBindings();
JFrame.setDefaultLookAndFeelDecorated(true);
JFrame frame = new JFrame("Key Bindings");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setJMenuBar(application.getMenuBar());
frame.getContentPane().add(application.getContentPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
//UIManager.put("swing.boldMetal", Boolean.FALSE);
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
createAndShowGUI();
}
});
}
}
答案 2 :(得分：1)
如果您想在应用程序上运行“全局事件”而不管当前焦点在哪里，您将需要使用KeyboardFocusManager：
KeyboardFocusManager kfm = KeyboardFocusManager.getCurrentKeyboardFocusManager();
kfm.addKeyEventDispatcher(new KeyEventDispatcher() {
@Override
public boolean dispatchKeyEvent(KeyEvent e) {
// do your stuff here
return done;
}
});
希望这有帮助。