JScrollPane破损量

Question

我有一个相当简单的视图类，我正在构建过程中。我进行测试，所以代码还远远没有完成。然而，当我测试时，一切看起来都很好，直到我滚动。如果我通过单击滚动条上的打开区域一次滚动一个页面，那么一切都很好。如果使用滚动箭头、拖动滚动条或使用鼠标轮，新显示的内容将完全损坏。这在1.6.35和1.7.09中都会出现。我还注意到，当我单击并拖动“日志行”( JTextField )时会出现故障。请告诉我我在做错事。代码应该按原样运行。

package com.mycompany.utility.logs;

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.Font;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JSplitPane;
import javax.swing.JTextField;
import javax.swing.JTextPane;
import javax.swing.ScrollPaneConstants;
import javax.swing.border.EmptyBorder;

/**
 * This class implements the log viewer view.
 */
public class LogViewer extends JFrame
{
    private static final long serialVersionUID = 1L;
    private static final Color TRANSPARENT = new Color(255, 255, 255, 0);
    private JPanel contentPane;

    /**
     * Launch the application.
     */
    public static void main(String[] args)
    {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run()
            {
                try
                {
                    LogViewer frame = new LogViewer();
                    frame.setVisible(true);
                }
                catch (Exception e)
                {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the view.
     */
    public LogViewer()
    {
        GridBagConstraints gridBagConstraints = null;
        int row = 0;

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 713, 684);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        contentPane.setLayout(new BorderLayout(0, 0));
        setContentPane(contentPane);

        JPanel topPanel = new JPanel();
        contentPane.add(topPanel, BorderLayout.NORTH);
        GridBagLayout gbl_topPanel = new GridBagLayout();
        gbl_topPanel.columnWidths = new int[] { 0 };
        gbl_topPanel.rowHeights = new int[] { 0 };
        gbl_topPanel.columnWeights = new double[] { Double.MIN_VALUE };
        gbl_topPanel.rowWeights = new double[] { Double.MIN_VALUE };
        topPanel.setLayout(gbl_topPanel);

        JLabel titleLabel = new JLabel("Tattle Tail Log Viewer");
        titleLabel.setFont(new Font("Lucida Sans", Font.BOLD, 12));
        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridy = 0;
        gridBagConstraints.gridx = 0;
        topPanel.add(titleLabel, gridBagConstraints);

        JPanel bottomPanel = new JPanel();
        contentPane.add(bottomPanel, BorderLayout.SOUTH);

        JSplitPane splitPane = new JSplitPane();
        splitPane.setResizeWeight(0.75);
        splitPane.setOneTouchExpandable(true);
        splitPane.setOrientation(JSplitPane.VERTICAL_SPLIT);
        contentPane.add(splitPane, BorderLayout.CENTER);

        JPanel scrollPanel = new JPanel();
        scrollPanel.setBackground(Color.WHITE);
        scrollPanel.setLayout(new GridBagLayout());

        JScrollPane scrollPane = new JScrollPane();
        scrollPane.setViewportView(scrollPanel);
        scrollPane.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
        splitPane.setLeftComponent(scrollPane);

        final JTextPane textPane = new JTextPane();
        splitPane.setRightComponent(textPane);
        textPane.setFont(new Font("Courier New", Font.PLAIN, 11));

        for (int i = 0; i < 25; i++)
        {
            addLogEntry(scrollPanel, textPane, row,
                    "2013-03-11 15:40:19,123 INFO  com.mycompany.business.logic.ImportantProcess",
                    "Something of which you need to be aware happened " + i + ".");
            row++;
        }

        JPanel fillPanel = new JPanel();
        fillPanel.setBackground(Color.LIGHT_GRAY);
        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = row;
        gridBagConstraints.gridwidth = 2;
        gridBagConstraints.weighty = 1D;
        gridBagConstraints.fill = GridBagConstraints.BOTH;
        scrollPanel.add(fillPanel, gridBagConstraints);
    }

    private void addLogEntry(final JPanel scrollPanel, final JTextPane textPane, final int row, final String logText,
            final String messageText)
    {
        GridBagConstraints gridBagConstraints = null;

        JPanel entryPanel = new JPanel();
        entryPanel.setBackground(TRANSPARENT);
        entryPanel.setLayout(new GridBagLayout());
        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = row;
        gridBagConstraints.anchor = GridBagConstraints.NORTHWEST;
        gridBagConstraints.weightx = 1D;
        gridBagConstraints.weighty = 0D;
        gridBagConstraints.fill = GridBagConstraints.HORIZONTAL;
        scrollPanel.add(entryPanel, gridBagConstraints);

        JPanel logLinePanel = new JPanel();
        logLinePanel.setBackground(TRANSPARENT);
        logLinePanel.setFocusable(true);
        logLinePanel.setLayout(new GridBagLayout());
        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 0;
        gridBagConstraints.weightx = 1D;
        gridBagConstraints.fill = GridBagConstraints.HORIZONTAL;
        gridBagConstraints.anchor = GridBagConstraints.NORTHWEST;
        entryPanel.add(logLinePanel, gridBagConstraints);

        JLabel logLineLevelLabel = new JLabel("  ");
        logLineLevelLabel.setOpaque(true);
        logLineLevelLabel.setBackground(new Color(0, 128, 0));
        logLineLevelLabel.setFont(new Font("Courier New", Font.BOLD, 11));
        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 0;
        gridBagConstraints.anchor = GridBagConstraints.NORTHWEST;
        logLinePanel.add(logLineLevelLabel, gridBagConstraints);

        JTextField logLineText = new JTextField(logText);
        logLineText.setEditable(false);
        logLineText.setBackground(TRANSPARENT);
        logLineText.setBorder(null);
        logLineText.setFont(new Font("Courier New", Font.PLAIN, 11));
        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 1;
        gridBagConstraints.gridy = 0;
        gridBagConstraints.weightx = 1D;
        gridBagConstraints.fill = GridBagConstraints.HORIZONTAL;
        gridBagConstraints.anchor = GridBagConstraints.NORTHWEST;
        logLinePanel.add(logLineText, gridBagConstraints);

        JPanel messageLinePanel = new JPanel();
        messageLinePanel.setBackground(TRANSPARENT);
        messageLinePanel.setLayout(new GridBagLayout());
        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 1;
        gridBagConstraints.weightx = 1D;
        gridBagConstraints.fill = GridBagConstraints.HORIZONTAL;
        gridBagConstraints.anchor = GridBagConstraints.NORTHWEST;
        entryPanel.add(messageLinePanel, gridBagConstraints);

        JLabel hasMoreMessageLineLabel = new JLabel("+ ");
        hasMoreMessageLineLabel.setFont(new Font("Courier New", Font.BOLD, 11));
        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 0;
        gridBagConstraints.gridy = 0;
        gridBagConstraints.anchor = GridBagConstraints.NORTHWEST;
        messageLinePanel.add(hasMoreMessageLineLabel, gridBagConstraints);

        JLabel messageLineLabel = new JLabel(messageText);
        messageLineLabel.setBackground(TRANSPARENT);
        messageLineLabel.setFocusable(true);
        messageLineLabel.setFont(new Font("Courier New", Font.PLAIN, 11));
        gridBagConstraints = new GridBagConstraints();
        gridBagConstraints.gridx = 1;
        gridBagConstraints.gridy = 0;
        gridBagConstraints.weightx = 1D;
        gridBagConstraints.fill = GridBagConstraints.HORIZONTAL;
        gridBagConstraints.anchor = GridBagConstraints.NORTHWEST;
        messageLinePanel.add(messageLineLabel, gridBagConstraints);

        entryPanel.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseEntered(MouseEvent e)
            {
                final JPanel containerPanel = (JPanel) e.getComponent();
                final JPanel messagePanel = (JPanel) containerPanel.getComponent(1);
                final JLabel messageLabel = (JLabel) messagePanel.getComponent(1);
                String text = messageLabel.getText();
                textPane.setText(text);
            }

            @Override
            public void mouseExited(MouseEvent e)
            {
                textPane.setText("");
            }
        });
    }
}

Answer 1

private static final Color TRANSPARENT = new Color(255, 255, 255, 0);

我猜这是你的问题。用透明的颜色设置背景时要小心。请参阅透明背景以了解为什么这是一个问题。

在您的情况下(因为您使用的是完全透明的)，您可以只使用：

setOpaque( false );

Answer 2

伙计，这样子真奇怪。

对于任何寻找更多信息的人来说:当滚动文本面板时，滚动面板中的面板内容并不能保持它们的完整性；部分字母行留在后面，而它们的原件向下滚动，使其看起来有点“融化”。换句话说，' mangling‘并不意味着损坏文本，而是图像的像素造成了损坏。

我会尝试在滚动面板中制作没有GridBag的面板。我对GridBag并不那么熟悉，我觉得它令人不快，到目前为止，我已经成功地摆脱了它。但是你的内部面板的结构看起来很简单，你也不需要它:看起来你有一个图像上面，然后一个文本行，然后可能另一个图像，然后另一行文本。创建两个JPanels，每个行一个，您可以使用流布局和水平方向，只需将图像和文本插入其中，然后将两个JPanels插入一个面板中，现在您可以添加到滚动面板中了。

我不知道这是否能解决问题，但是GridBag是您代码中唯一看起来与我以前做过的事情不同的东西，它没有这种行为。我只是不太容易在GridBag中快速找出它的问题所在。