Question

希望拥有一个JTextPane，其内容始终可由用户选择。因此，我创建了自己的JTextPane子类，并始终在方法＆＃34; isEnabled（）＆＃34;中返回true。另外，我引入了一个新成员m_enabled，它负责返回正确的前景色（启用/禁用）。

它按预期工作，但如果我设置默认前景色（例如Color.RED）并在启用和禁用之间切换，前景色将不再是红色。

你能帮我解决这个问题吗？

public class StylesExample1 {
public static final String text = "Lorem ipsum dolor...";
public static boolean m_enabled = true;

public static void main(String[] args) throws BadLocationException {
    try {
        UIManager
                .setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
    } catch (Exception evt) {
    }

    JFrame f = new JFrame("Frame");
    final JTextPane pane = new MyPane();
    pane.setText(text);

    pane.setPreferredSize(new Dimension(200, 200));
    f.getContentPane().add(pane);
    JButton b = new JButton("Toggle Enabled state");
    b.addActionListener(new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent e) {
            m_enabled = !m_enabled;
            System.err.println("setting textpane enabled to " + m_enabled);
            pane.setEnabled(m_enabled);
        }
    });

    pane.setForeground(Color.red);

    f.getContentPane().add(b);
    f.getContentPane().setLayout(new FlowLayout());
    f.setSize(400, 300);
    f.setVisible(true);
}
}

class MyPane extends JTextPane {

private static final long serialVersionUID = 1L;
private boolean m_enabled = true;
private Color defaultForegroundColor, disabledTextColor;

public MyPane() {
    defaultForegroundColor = getForeground();
    disabledTextColor = getDisabledTextColor();
}

public void setEnabled(boolean enabled) {
    m_enabled = enabled;

    if (m_enabled) {
        setForeground(defaultForegroundColor);
    } else {
        setForeground(disabledTextColor);
    }
}

@Override
public boolean isEnabled() {
    return true;
}
}

Answer 1

您的班级MyPane extends JTextPane不会覆盖WindowsLookAndFeel所需的具体方法和正确方法，
DeafultHightLigter/Painter/Caret/Selection
（我建议）在UIManager中使用和覆盖键Windows(Classic)LookAndFeel
编辑来自UIManager by @camickr

enter image description here

import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextPane;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.text.BadLocationException;

public class StylesExample1 {

    private final String text = "Lorem ipsum dolor...";
    private boolean m_enabled = true;

    public StylesExample1() {
        final JTextPane pane = new MyPane();
        pane.setText(text);
        pane.setPreferredSize(new Dimension(200, 200));
        JButton b = new JButton("Toggle Enabled state");
        b.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                m_enabled = !m_enabled;
                System.err.println("setting textpane enabled to " + m_enabled);
                pane.setEnabled(m_enabled);
            }
        });
        pane.setDisabledTextColor(Color.red);
        pane.setForeground(Color.red);
        JFrame f = new JFrame("Frame");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.getContentPane().add(pane);
        f.add(b);
        f.getContentPane().setLayout(new FlowLayout());
        f.setSize(400, 300);
        f.setVisible(true);
    }

    public static void main(String[] args) throws BadLocationException {
        try {
            UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
        } catch (Exception evt) {
        }
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                new StylesExample1();
            }
        });
    }
}

class MyPane extends JTextPane {

    private static final long serialVersionUID = 1L;
    private boolean m_enabled = true;
    private Color defaultForegroundColor, disabledTextColor;

    public MyPane() {
        defaultForegroundColor = getForeground();
        disabledTextColor = getDisabledTextColor();
    }

    @Override
    public void setEnabled(boolean enabled) {
        m_enabled = enabled;
        if (m_enabled) {
            UIManager.put("TextPane.disabledBackground", Color.RED);
            UIManager.put("TextPane.foreground", Color.RED);
            UIManager.put("TextPane.inactiveForeground", Color.RED);
            SwingUtilities.updateComponentTreeUI(this); // don't to use this
        } else {
            UIManager.put("TextPane.disabledBackground", Color.RED);
            UIManager.put("TextPane.foreground", Color.RED);
            UIManager.put("TextPane.inactiveForeground", Color.RED);
            SwingUtilities.updateComponentTreeUI(this); // don't to use this
        }
    }

    @Override
    public boolean isEnabled() {
        return true;
    }
}

Answer 2

在“MyPane”的构造函数中，您将默认前景色设置为JTextPane的默认前景，但是在构造函数之后调用setForeground（Color.red）。问题是MyPane中的“defaultForegroundColor”成员不知道它是红色的。进行以下调整：

public MyPane(Color defaultForegroundColor)
{
  this.defaultForegroundColor = defaultForegroundColor;
  this.disabledTextColor = getDisabledTextColor();
}

并使用以下代码创建它：

final JTextPane pane = new MyPane(Color.red);

如果要在施工后更改前景，请执行以下操作：

public void setNewForeground(Color c)
{
   this.defaultForegroundColor = c;
}

Answer 3

希望拥有一个JTextPane，其内容始终可由用户选择。

然后我会用：

setEditable( false );

而不是

setEnabled( false );

JTextPane和前景色

3 个答案: