如何使JTextComponent的插入符号跳过所选文本? [英] How do I make the caret of a JTextComponent skip selected text?
问题描述
许多环境中原生文本字段的正常行为如下:
the normal behaviour of native text fields in many environments is as follows:
带文本abcdefg的文本字段。我用鼠标从左到右选择efg。插入符号现在落后于g。当我通过按左光标键一次将插入符号向左移动时,删除选择并且插入符号在e之前。当我在JTextField或JTextArea(在Mac OS上测试)中做同样的事情时,完全相同的事情会导致插入符号在g之前。
Textfield with text "abcdefg". I use the mouse to select "efg" from left to right. The caret is now behind "g". When I move the caret to the left by pressing the cursor left key once, the selection is removed and the caret is right before "e". When I do the same in a JTextField or JTextArea (tested on Mac OS) doing the exact same thing results in the caret being right before "g".
我知道如何我可以通过使用KeyListener并以每个组件注册它来以编程方式更改它,但我正在寻找一种方法来更改我的整个应用程序。那可能吗?有没有国旗,我找不到或者我不得不破解我的外表和感觉?
I know how I could change that programmatically by using a KeyListener and registering it with each component but I am looking for a way to change that for my entire application. Is that possible? Is there a Flag, I am not finding or do I have to hack my look and feel?
谢谢
推荐答案
我正在寻找一种方法来改变我的整个应用程序
I am looking for a way to change that for my entire application
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.text.*;
public class CaretAction extends TextAction
{
private boolean caretForward;
public CaretAction(boolean caretForward)
{
super(caretForward ? "Caret Forward" : "Caret Backward");
this.caretForward = caretForward;
}
public void actionPerformed(ActionEvent e)
{
JTextComponent textComponent = getFocusedComponent();
int start = textComponent.getSelectionStart();
int end = textComponent.getSelectionEnd();
int offset = textComponent.getCaretPosition();
if (start != end)
{
if (caretForward)
offset = (offset == end) ? offset + 1 : end;
else
offset = (offset == start) ? offset -1 : start;
}
else
{
offset += (caretForward) ? 1 : -1;
}
offset = Math.max(offset, 0);
offset = Math.min(offset, textComponent.getDocument().getLength());
textComponent.setCaretPosition( offset );
}
private static void createAndShowUI()
{
JTextField textField1 = new JTextField(10);
JTextField textField2 = new JTextField(10);
JPanel panel = new JPanel();
panel.add( textField1 );
panel.add( textField2 );
JFrame frame = new JFrame("SSCCE");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add( panel );
frame.pack();
frame.setLocationByPlatform( true );
frame.setVisible( true );
ActionMap map = (ActionMap)UIManager.get("TextField.actionMap");
map.put(DefaultEditorKit.backwardAction, new CaretAction(false));
map.put(DefaultEditorKit.forwardAction, new CaretAction(true));
}
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
createAndShowUI();
}
});
}
}
您还需要更改JTextArea的ActionMap, JFormattedTextField ...
You would also need to change the ActionMap for JTextArea, JFormattedTextField ...
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