使用Tab键从JTextArea移动焦点
问题内容:
如前所述,我想更改内的默认TAB行为JTextArea
(以使其充当类似JTextField
或类似的组件)
这是事件动作
private void diagInputKeyPressed(java.awt.event.KeyEvent evt) {
if(evt.KEY_PRESSED == java.awt.event.KeyEvent.VK_TAB) {
actionInput.transferFocus();
}
}
这是听众
diagInput.addKeyListener(new java.awt.event.KeyAdapter() {
public void keyPressed(java.awt.event.KeyEvent evt) {
diagInputKeyPressed(evt);
}
});
我也尝试过evt.KEY_TYPED,没有任何喜悦。
有任何想法吗?
快速编辑:我也尝试requestFocus()
代替transferFocus()
问题答案:
根据此类:
/**
* Some components treat tabulator (TAB key) in their own way.
* Sometimes the tabulator is supposed to simply transfer the focus
* to the next focusable component.
* <br/>
* Here s how to use this class to override the "component's default"
* behavior:
* <pre>
* JTextArea area = new JTextArea(..);
* <b>TransferFocus.patch( area );</b>
* </pre>
* This should do the trick.
* This time the KeyStrokes are used.
* More elegant solution than TabTransfersFocus().
*
* @author kaimu
* @since 2006-05-14
* @version 1.0
*/
public class TransferFocus {
/**
* Patch the behaviour of a component.
* TAB transfers focus to the next focusable component,
* SHIFT+TAB transfers focus to the previous focusable component.
*
* @param c The component to be patched.
*/
public static void patch(Component c) {
Set<KeyStroke>
strokes = new HashSet<KeyStroke>(Arrays.asList(KeyStroke.getKeyStroke("pressed TAB")));
c.setFocusTraversalKeys(KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS, strokes);
strokes = new HashSet<KeyStroke>(Arrays.asList(KeyStroke.getKeyStroke("shift pressed TAB")));
c.setFocusTraversalKeys(KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS, strokes);
}
}
请注意,patch()
可以更短,根据[约书亚·戈德堡的意见,因为我们的目标是获得通过重写回默认行为JTextArea
:
component.setFocusTraversalKeys(KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS, null);
component.setFocusTraversalKeys(KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS, null);
这用于问题“
我如何修改标签中的Tab键的行为JTextArea? ”
在以前的实现确实是一个参与Listener
,和一个transferFocus()
:
/**
* Override the behaviour so that TAB key transfers the focus
* to the next focusable component.
*/
@Override
public void keyPressed(KeyEvent e) {
if(e.getKeyCode() == KeyEvent.VK_TAB) {
System.out.println(e.getModifiers());
if(e.getModifiers() > 0) a.transferFocusBackward();
else a.transferFocus();
e.consume();
}
}
e.consume();
可能是您错过了使其适合您的情况的原因。