为什么Jtoolbar破坏了我的keyBindings? [英] Why does Jtoolbar break my keyBindings?
问题描述
我一直在尝试将箭头键用作应用程序的一部分.按照最佳实践，我坚持使用键绑定.我知道arow键不会产生键类型的事件，所以我使用了这个 answer .
I have been trying to use the arrow keys as part of my application. Following the best practice I have stuck with using key bindings. I gound that the arow keys do not produce a key typed event so I employed this answer.
但是，我的应用程序具有许多组件，并且我发现，如果我的JFrame中有一个JToolbar，则上一个链接中的方法将不再起作用.为什么会这样?我如何拥有JToolbar并使用键绑定?
However, my application has a number of components and I found that if I have a JToolbar in my JFrame the method in the previous link no longer works. Why is this and how do I have a JToolbar and use key bindings?
这是SSCCE
public class ArrowTest extends JFrame {
public static void main(final String[] args){
final ArrowTest at = new ArrowTest();
at.setSize(100,200);
final JPanel jp = new JPanel();
jp.setBackground(Color.BLUE);
at.getContentPane().add(jp);
final JToolBar toolbar = new JToolBar();
toolbar.add(new JButton());
//at.add(toolbar);
at.setVisible(true);
}
public ArrowTest() {
super();
this.getContentPane().setLayout(new GridBagLayout());
this.getContentPane().setBackground(Color.BLACK);
this.setKeyBindings();
}
public void setKeyBindings() {
final int condition = JComponent.WHEN_IN_FOCUSED_WINDOW;
final ActionMap actionMap = this.getRootPane().getActionMap();
final InputMap inputMap = this.getRootPane().getInputMap(condition);
for (final Direction direction : Direction.values()) {
inputMap.put(KeyStroke.getKeyStroke(KeyEvent.VK_V,0), direction.getText());
inputMap.put(direction.getKeyStroke(), direction.getText());
actionMap.put(direction.getText(), new MyArrowBinding(direction.getText()));
}
}
enum Direction {
UP("Up", KeyStroke.getKeyStroke(KeyEvent.VK_UP, 0)),
DOWN("Down", KeyStroke.getKeyStroke(KeyEvent.VK_DOWN, 0)),
LEFT("Left", KeyStroke.getKeyStroke(KeyEvent.VK_LEFT, 0)),
RIGHT("Right", KeyStroke.getKeyStroke(KeyEvent.VK_RIGHT, 0));
Direction(final String text, final KeyStroke keyStroke) {
this.text = text;
this.keyStroke = keyStroke;
}
private String text;
private KeyStroke keyStroke;
public String getText() {
return text;
}
public KeyStroke getKeyStroke() {
return keyStroke;
}
@Override
public String toString() {
return text;
}
}
private class MyArrowBinding extends AbstractAction {
private static final long serialVersionUID = -6904517741228319299L;
public MyArrowBinding(final String text) {
super(text);
putValue(ACTION_COMMAND_KEY, text);
}
@Override
public void actionPerformed(final ActionEvent e) {
final String actionCommand = e.getActionCommand();
System.out.println("Key Binding: " + actionCommand);
}
}
}
推荐答案
默认情况下，JToolBar为KeyStroke的UP/DOWN/LEFT/RIGHT注册一个动作，并且您自动添加到JFrame的JToolBar抓住焦点，因此绑定到根窗格时您什么也看不到(工具栏会捕获您之前的事件).
By default, JToolBar registers an action for the KeyStroke's UP/DOWN/LEFT/RIGHT, and the JToolBar you add to the JFrame automatically grabs the focus, hence you don't see anything when binding to the rootpane (the toolbar catches the events before you).
一种解决方案是使JToolBar和JButton不能聚焦，并允许JPanel聚焦(实际上，您可以离开JToolBar和JButton并请求将焦点放在面板上，但是这也意味着您必须处理面板的焦点管理):
One solution is to make the JToolBar and the JButton not focusable and allow your JPanel to be focusable (actually you could leave the JToolBar and the JButton and request the focus on your panel but this also means that you have to handle the focus management of your panel):
import java.awt.Color;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import javax.swing.AbstractAction;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JToolBar;
import javax.swing.KeyStroke;
public class ArrowTest extends JFrame {
public static void main(final String[] args) {
final ArrowTest at = new ArrowTest();
at.setSize(100, 200);
final JPanel jp = new JPanel();
jp.setBackground(Color.BLUE);
jp.setFocusable(true);
at.getContentPane().add(jp);
final JToolBar toolbar = new JToolBar();
JButton comp = new JButton();
toolbar.add(comp);
at.add(toolbar);
at.setVisible(true);
}
public ArrowTest() {
super();
this.getContentPane().setLayout(new GridBagLayout());
this.getContentPane().setBackground(Color.BLACK);
this.setKeyBindings();
}
public void setKeyBindings() {
for (final Direction direction : Direction.values()) {
MyArrowBinding binding = new MyArrowBinding(direction.getText());
getRootPane().registerKeyboardAction(binding, direction.getText(), direction.getKeyStroke(),
JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT);
}
}
enum Direction {
UP("Up", KeyStroke.getKeyStroke(KeyEvent.VK_UP, 0)), DOWN("Down", KeyStroke.getKeyStroke(KeyEvent.VK_DOWN, 0)), LEFT("Left",
KeyStroke.getKeyStroke(KeyEvent.VK_LEFT, 0)), RIGHT("Right", KeyStroke.getKeyStroke(KeyEvent.VK_RIGHT, 0));
Direction(final String text, final KeyStroke keyStroke) {
this.text = text;
this.keyStroke = keyStroke;
}
private String text;
private KeyStroke keyStroke;
public String getText() {
return text;
}
public KeyStroke getKeyStroke() {
return keyStroke;
}
@Override
public String toString() {
return text;
}
}
private class MyArrowBinding extends AbstractAction {
private static final long serialVersionUID = -6904517741228319299L;
public MyArrowBinding(final String text) {
super(text);
putValue(ACTION_COMMAND_KEY, text);
}
@Override
public void actionPerformed(final ActionEvent e) {
final String actionCommand = e.getActionCommand();
System.out.println("Key Binding: " + actionCommand);
}
}
}
我还用一次调用javax.swing.JComponent.registerKeyboardAction(ActionListener, String, KeyStroke, int)
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