JSpinner：自动选择onFocus

问题描述

我想在用户通过表单中的JTextFields和JSpinners选项卡时实现自动选择。为此，我正在使用这个Listener：
$ b $ pre $ public class AutoSelect实现了FocusListener {

@Override
public void focusGained（final FocusEvent e）{
SwingUtilities.invokeLater（new Runnable（）{
@Override
public void run（）{
if（e.getSource ）instanceof JTextField）{
try {
JTextField t =（JTextField）e.getComponent（）;
t.selectAll（）;
} catch（ClassCastException ex）{


} else if（e.getSource（）instanceof JSpinner）{
JSpinner spinner =（JSpinner）e.getComponent（）;
JTextField tf =（ （JSpinner.DefaultEditor）spinner.getEditor（））.getTextField（）;
tf.selectAll（）;
}
}
}）;
}

@Override
public void focusLost（FocusEvent e）{
//
}
}


只有它不适合我的纺纱工。事件发生了，正确的线路被执行，只有什么都没有发生。我怀疑我没有正确使用.getTextField（）。有没有人有这个工作的解决方案？

解决方案

tf.selectAll（）; 应该包含到 invokeLater 中，所有内容都是
Focus 是非常异步的（在Oracle教程中有更多的介绍如何使用Focus，FocusSubsystem ），

invokeLater （对于所有 JComponents ，但默认为
， c> JTextComponents 将这个事件移动到队列的末尾，
对我来说是相当正确的

  import java.awt。*; 
 import java.awt.event。*; 
 import javax.swing。*; 
 
 public class ComboBoxTwo extends JFrame {
 
 private static final long serialVersionUID = 1L; 
 private JTextField text = new JTextField（15）; 
 private JSpinner spinner = new JSpinner（new SpinnerNumberModel（0，0，15，1））; 
 
 public ComboBoxTwo（）{
 text.setText（Something selectable）; 
 text.addFocusListener（fcsListener）; 
 JFormattedTextField format =（（JSpinner.DefaultEditor）spinner.getEditor（））。getTextField（）; 
 //或JTextField tf =（（JSpinner.DefaultEditor）spinner.getEditor（））。getTextField（）; 
 format.addFocusListener（fcsListener）; 
 //或tf.addFocusListener（fcsListener）; //取决于SpinnerXxxModel的类型
 add（text，BorderLayout.NORTH）; 
 add（spinner，BorderLayout.SOUTH）; 
 
 
 public static void main（String [] args）{
 SwingUtilities.invokeLater（new Runnable（）{
 @Override 
 public void run （）{
 JFrame frame = new ComboBoxTwo（）; 
 frame.setDefaultCloseOperation（EXIT_ON_CLOSE）; 
 frame.pack（）; 
 frame.setVisible（true）; 
} 
}）; 
 
 
 private FocusListener fcsListener = new FocusListener（）{
 @Override 
 public void focusGained（FocusEvent e）{
 dumpInfo（e） ; 
 
 
 @Override 
 public void focusLost（FocusEvent e）{
 dumpInfo（e）; 
 
 $ b $ private void dumpInfo（FocusEvent e）{
 System.out.println（Source：+ name（e.getComponent（）））; 
 System.out.println（Opposite：+ name（e.getOppositeComponent（）））; 
 System.out.println（Temporary：+ e.isTemporary（））; 
 final组件c = e.getComponent（）; //可编辑JComboBox也可用
 if（c instanceof JFormattedTextField）{
 SwingUtilities.invokeLater（new Runnable（）{
 @重写
 public void run（）{
（（JFormattedTextField）c）.setText（（JFormattedTextField）c）.getText（））; 
（（JFormattedTextField）c）.selectAll ; 
} 
}）; 
} else if（c instanceof JTextField）{
 SwingUtilities.invokeLater（new Runnable（）{
 @Override 
 public void run（）{
（（JTextField） c）.setText（（（JTextField）c）.getText（））; 
（（JTextField）c）.selectAll（）; 
} 
}）; 
 
 
 
 private String name（Component c）{
 return（c == null）？ null：c.getName（）; 
} 
}; 
} 
  

I want to implement autoselect when a user tabs through the JTextFields and JSpinners in my forms. For this I am using this Listener:

public class AutoSelect implements FocusListener {

    @Override
    public void focusGained(final FocusEvent e) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                if (e.getSource() instanceof JTextField) {
                    try {
                        JTextField t = (JTextField) e.getComponent();
                        t.selectAll();
                    } catch (ClassCastException ex) {
                        // 
                    }
                }else if (e.getSource() instanceof JSpinner){
                    JSpinner spinner = (JSpinner)e.getComponent();
                    JTextField tf = ((JSpinner.DefaultEditor)spinner.getEditor()).getTextField();  
                    tf.selectAll();
                }
            }
        });
    }

    @Override
    public void focusLost(FocusEvent e) {
        // 
    }
}

Only it doesn´t work for my spinners. The event is beeing fired, the correct lines are executed, only nothing happens. I suspect I am not using the .getTextField() correctly. Does anyone have a working solution for this ?

解决方案

• tf.selectAll(); should be wrapped into invokeLater, everything withFocus is pretty asynchronous (more in Oracle tutorial How to use Focus, FocusSubsystem),

• then invokeLater (not true in all cases for all JComponents, butby default) for JTextComponents move this event to the end of queue,works for me quite correctly

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class ComboBoxTwo extends JFrame {

    private static final long serialVersionUID = 1L;
    private JTextField text = new JTextField(15);
    private JSpinner spinner = new JSpinner(new SpinnerNumberModel(0, 0, 15, 1));

    public ComboBoxTwo() {
        text.setText("Something selectable");
        text.addFocusListener(fcsListener);
        JFormattedTextField format = ((JSpinner.DefaultEditor) spinner.getEditor()).getTextField();
        // or JTextField tf = ((JSpinner.DefaultEditor) spinner.getEditor()).getTextField();
        format.addFocusListener(fcsListener);
        //or tf.addFocusListener(fcsListener); // depends of type for SpinnerXxxModel 
        add(text, BorderLayout.NORTH);
        add(spinner, BorderLayout.SOUTH);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                JFrame frame = new ComboBoxTwo();
                frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
                frame.pack();
                frame.setVisible(true);
            }
        });
    }
//
    private FocusListener fcsListener = new FocusListener() {
        @Override
        public void focusGained(FocusEvent e) {
            dumpInfo(e);
        }

        @Override
        public void focusLost(FocusEvent e) {
            dumpInfo(e);
        }

        private void dumpInfo(FocusEvent e) {
            System.out.println("Source  : " + name(e.getComponent()));
            System.out.println("Opposite : " + name(e.getOppositeComponent()));
            System.out.println("Temporary: " + e.isTemporary());
            final Component c = e.getComponent();//works for editable JComboBox too
            if (c instanceof JFormattedTextField) {
                SwingUtilities.invokeLater(new Runnable() {
                    @Override
                    public void run() {
                        ((JFormattedTextField) c).setText(((JFormattedTextField) c).getText());
                        ((JFormattedTextField) c).selectAll();
                    }
                });
            } else if (c instanceof JTextField) {
                SwingUtilities.invokeLater(new Runnable() {
                    @Override
                    public void run() {
                        ((JTextField) c).setText(((JTextField) c).getText());
                        ((JTextField) c).selectAll();
                    }
                });
            }
        }

        private String name(Component c) {
            return (c == null) ? null : c.getName();
        }
    };
}

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