聚焦时使JSpinner选择文本

Question

我想更改JSpinner的行为，以便在单击文本时将其选中。这样可以更轻松地将字段替换为所需的值。不幸的是，我无法使该行为起作用，它只是将光标插入文本中，而没有选择已经存在的内容。

我曾尝试通过既向JSpinner本身又向文本区域本身添加了一个焦点侦听器((DefaultEditor) this.getEditor()).getTextField()，但这些似乎都没有达到预期的效果。我的代码（针对JSpinner本身）如下：

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

我不确定是什么问题。如果有关系，我正在运行Mac OS 10.7.5和Java 6u43。

编辑：我System.out.println在focusGained方法的开头放了一个权利，发现它从未被调用过。因此，似乎专注于JSpinner并未注册。再次，我尝试将focusAdpater放在微调器和文本字段上（尽管不是同时）。

Answer 1

您面临的许多问题与在焦点事件（以及其他一些状态事件）发生后，旋转器如何验证旋转器中的任何值有关，这将避免突出显示。

MacOS甚至更糟。

我最终要做的是启动一个Thread等待了很短时间（大约25毫秒）的代码，然后用来SwingUtilities.invokeLater实际执行选择…

用示例更新

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();
            }            
        }        
    }
}

Now, right about now, I’m praying for some really nice, simple, undocumented
property that we can set that will mean we don’t need to do all this :P