java - 禁用 java 边框

Question

我想在组件被禁用时禁用该组件的任何边框。

当您按原样运行下面的代码时，您会在其中一个文本区域周围看到一个红色的 LineBorder。我想在禁用 TextArea 时禁用该边框。

下面代码中的 useGenericSolution block 中是否有适用于所有边框的代码？

import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.border.Border;
import javax.swing.border.LineBorder;
import javax.swing.border.TitledBorder;

public class EnableBorder extends JFrame
{
    private static final long   serialVersionUID    = 1L;
    private static JFrame       _instance;

    public EnableBorder()
    {
        setResizable(false);
        setTitle("My Frame");
        setSize(300, 300);
        getContentPane().add(new MyPanel());
        _instance = this;
    }

    private class MyPanel extends JPanel
    {
        private static final long   serialVersionUID    = 1L;

        public MyPanel()
        {
            setLayout(new FlowLayout());
            JButton btnDisableAll = new JButton("Disable everything");
            btnDisableAll.addActionListener(new ActionListener()
            {
                @Override
                public void actionPerformed(ActionEvent e)
                {
                    EnableBorder.setEnabledAllComponents(_instance, false);
                }
            });
            add(btnDisableAll);

            // Use TitledBorder
            JTextArea titledTA = new JTextArea("This is some text that should be wide enough ");
            titledTA.setSize(400, 50);
            titledTA.setBorder(new TitledBorder("A titled border"));
            add(titledTA);

            // Use LineBorder
            JTextArea lineBorderTA = new JTextArea("This is just some more text ...");
            lineBorderTA.setSize(400, 50);
            lineBorderTA.setBorder(new LineBorder(Color.RED, 1, true));
            add(lineBorderTA);
        }
    }

    /**
     * Enables or disables a Container and all Components within a Container.
     * 
     * @param b
     *            - The value to set the 'enabled' flag to
     */
    public static void setEnabledAllComponents(Container cont, boolean b)
    {
        for (Component c : cont.getComponents())
        {
            setEnabledComponent(c, b);
        }
        setEnabledComponent(cont, b);
    }

    /**
     * Enables or disables a Component.
     * <p>
     * If the component is a Container, all of it the Components within the Container will also be modified.
     * 
     * @param c
     *            - The Component to modify
     * @param b
     *            - The value to set the 'enabled' flag to
     */
    public static void setEnabledComponent(Component c, boolean b)
    {

        if (c instanceof Container)
        {
            for (Component containerComp : ((Container) c).getComponents())
            {
                setEnabledComponent(containerComp, b);
            }
        }

        c.setEnabled(b);

        if (c instanceof JComponent)
        {

            Border border = ((JComponent) c).getBorder();
            if (border != null)
            {
                boolean useGenericSolution = true;
                if (useGenericSolution)
                {
                    Insets insets = border.getBorderInsets(c);
                    System.out.println("Insets: " + insets);
                    Graphics g = c.getGraphics();

                    if (g != null)
                    {
                        /*
                         * TODO: Is it possible to get foreground color from the current object
                         * and force the border to be painted using that color 
                         */

                        Color color = g.getColor();

                        border.paintBorder(c, g, c.getX() - 5 - insets.left, c.getY() - insets.top, c.getWidth() + insets.left + insets.right,
                                c.getHeight() + insets.top + insets.bottom);
                    }
                }
                else
                {
                    // TitledBorders can be done this way... but, a generic solution would be better
                    if (border instanceof TitledBorder)
                    {
                        if (b)
                        {
                            // Change border colors to color found in an enabled label
                            ((TitledBorder) border).setTitleColor((Color) UIManager.get("Label.enabledForeground"));
                        }
                        else
                        {
                            // Change border colors to color found in a disabled label
                            ((TitledBorder) border).setTitleColor((Color) UIManager.get("Label.disabledForeground"));
                        }
                    }
                }
            }
        }

    }

    private static void createAndShowGUI()
    {
        // Create and set up the window.
        EnableBorder frame = new EnableBorder();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }

    public static void main(String[] args)
    {
        SwingUtilities.invokeLater(new Runnable()
        {
            public void run()
            {
                try
                {
                    createAndShowGUI();
                }
                catch (Exception e)
                {
                    e.printStackTrace();
                    System.exit(0);
                }
            }
        });
    }

}

Answer 1

只需在通用解决方案 block 中添加以下行

if (useGenericSolution) {
    ((JComponent) c).setBorder(BorderFactory.createEmptyBorder());
}