让 JSpinner 在聚焦时选择文本

Question

我想更改 JSpinner 的行为，以便当您单击文本时，它会选择它。这样可以更轻松地将字段替换为所需的值。不幸的是，我无法让该行为起作用，相反，它只是将光标插入文本中，而不选择已经存在的内容。

我尝试通过

((DefaultEditor) this.getEditor()).getTextField()

将焦点监听器添加到 JSpinner 本身和文本区域本身，但这些似乎都没有达到预期的效果。我的代码（对于 JSpinner 本身）如下：

spinner.addFocusListener(new FocusAdapter(){
            @Override
            public void focusGained(FocusEvent e) {
                ((DefaultEditor) ((JSpinner) e.getSource()).getEditor()).getTextField().selectAll();
            }
        }); 

我不确定问题是什么。如果重要的话，我正在运行 Mac OS 10.7.5 和 Java 6u43。

编辑：我将

System.out.println

放在 focusGained 方法的开头，发现它从未被调用。所以看起来关注 JSpinner 并没有注册。再次，我尝试将 focusAdpater 放在微调器和文本字段上（但不是同时）。

Answer 1

不了解 Mac，但我在 Windows 上使用过此代码：

JSpinner.DefaultEditor editor = (JSpinner.DefaultEditor)spinner.getEditor();
JTextField textField = editor.getTextField();
textField.addFocusListener( new FocusAdapter()
{
    public void focusGained(final FocusEvent e)
    {
        SwingUtilities.invokeLater(new Runnable()
        {
            @Override
            public void run()
            {
                JTextField tf = (JTextField)e.getSource();
                tf.selectAll();
            }
        });

    }

});

我还使用此代码在 JFormattedTextField 上选择文本。

Answer 2

您面临的大部分问题与旋转器如何在焦点事件（以及其他几个状态事件）之后验证旋转器内的任何值有关，这将绕过突出显示。

MacOS 更糟糕。

我最终做的是启动一个

Thread

，等待很短的时间（大约 25 毫秒），然后使用

SwingUtilities.invokeLater

实际执行选择...

更新了示例

import java.awt.Component;
import java.awt.EventQueue;
import java.awt.GridBagLayout;
import java.awt.event.FocusAdapter;
import java.awt.event.FocusEvent;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JSpinner;
import javax.swing.SpinnerNumberModel;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.text.JTextComponent;

public class AutoFocusSpinner {

    public static void main(String[] args) {
        new AutoFocusSpinner();
    }

    public static final SelectOnFocusGainedHandler SHARED_INSTANCE = new SelectOnFocusGainedHandler();

    public AutoFocusSpinner() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException ex) {
                } catch (InstantiationException ex) {
                } catch (IllegalAccessException ex) {
                } catch (UnsupportedLookAndFeelException ex) {
                }

                JSpinner spinner = new JSpinner(new SpinnerNumberModel(1, 0, 100, 1));
                installFocusListener(spinner);

                JFrame frame = new JFrame("Test");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new GridBagLayout());
                frame.add(spinner);
                frame.add(new JButton("Here for testing"));
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }

        });
    }

    public void installFocusListener(JSpinner spinner) {

        JComponent spinnerEditor = spinner.getEditor();

        if (spinnerEditor != null) {

            // This is me spending a few days trying to make this work and 
            // eventually throwing a hissy fit and just grabbing all the 
            // JTextComponent components contained within the editor....
            List<JTextComponent> lstChildren = findAllChildren(spinner, JTextComponent.class);
            if (lstChildren != null && lstChildren.size() > 0) {

                JTextComponent editor = lstChildren.get(0);
                editor.addFocusListener(SHARED_INSTANCE);

            }

        }

    }

    public static <T extends Component> List<T> findAllChildren(JComponent component, Class<T> clazz) {

        List<T> lstChildren = new ArrayList<T>(5);
        for (Component comp : component.getComponents()) {

            if (clazz.isInstance(comp)) {

                lstChildren.add((T) comp);

            } else if (comp instanceof JComponent) {

                lstChildren.addAll(findAllChildren((JComponent) comp, clazz));

            }

        }

        return Collections.unmodifiableList(lstChildren);

    }

    public static class SelectOnFocusGainedHandler extends FocusAdapter {

        @Override
        public void focusGained(FocusEvent e) {

            Component comp = e.getComponent();
            if (comp instanceof JTextComponent) {
                final JTextComponent textComponent = (JTextComponent) comp;
                new Thread(new Runnable() {
                    @Override
                    public void run() {
                        try {
                            Thread.sleep(25);
                        } catch (InterruptedException ex) {
                        }
                        SwingUtilities.invokeLater(new Runnable() {
                            @Override
                            public void run() {
                                textComponent.selectAll();
                            }
                        });
                    }
                }).start();
            }            
        }        
    }
}

现在，就现在，我正在祈祷一些非常好的、简单的、无证的属性，我们可以设置它们，这意味着我们不需要做所有这些:P

Answer 3

在 JFrame 或 JDialog 中使用侦听器

    JFrame frame = new JFrame();
    
    frame.addWindowListener( new WindowAdapter() {
        @Override
        public void windowOpened( WindowEvent e ) {

            JSpinner.DefaultEditor editor = (JSpinner.DefaultEditor)spiPage.getEditor();
            JTextComponent txt = editor.getTextField();

            SwingUtilities.invokeLater( txt::selectAll );

        }

    } );