JLabel在重新绘制其他组件时会调整大小

Question

我的Java布局有问题。我试图在顶部放置一个JLabel，然后是一个由五个WorldWindowGLCanvas组成的网格。类似于：

------------------------------------------------
                     JLabel
------------------------------------------------
                       |
         WWCanvas      |       WWCanvas
                       |
------------------------------------------------
                       |
         WWCanvas      |       WWCanvas
                       |

---

我目前正在JPanel中使用GridBagLayout。当程序第一次启动时，一切看起来都是应该的。然而，在第一次重新绘制所有WorldWindowGLCanvas时，顶部JLabel的大小立即翻倍，占用了太多空间。以下是一些相关代码：

JFrame f = new JFrame("ScintDisplay");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setLayout(new GridBagLayout());
        JLabel timeLabel = new JLabel(getTime(), JLabel.CENTER);
        timeLabel.setSize(new Dimension(200,200));

        WorldWindowGLCanvas wwd1 = new WorldWindowGLCanvas();
        wwd1.setPreferredSize(new java.awt.Dimension(960, 1000));
        WorldWindowGLCanvas wwd2 = new WorldWindowGLCanvas();
        wwd2.setPreferredSize(new java.awt.Dimension(500, 480));
        WorldWindowGLCanvas wwd3 = new WorldWindowGLCanvas();
        wwd3.setPreferredSize(new java.awt.Dimension(500, 480));
        WorldWindowGLCanvas wwd4 = new WorldWindowGLCanvas();
        wwd4.setPreferredSize(new java.awt.Dimension(500, 480));
        WorldWindowGLCanvas wwd5 = new WorldWindowGLCanvas();
        wwd5.setPreferredSize(new java.awt.Dimension(500, 480));
        wwd1.setModel(new BasicModel());
        wwd2.setModel(new BasicModel());
        wwd3.setModel(new BasicModel());
        wwd4.setModel(new BasicModel());
        wwd5.setModel(new BasicModel());
        addComponent(f, wwd2, 0, 2, 1, 4, GridBagConstraints.CENTER, GridBagConstraints.BOTH);
        addComponent(f, wwd1, 1, 2, 2, 8, GridBagConstraints.CENTER, GridBagConstraints.BOTH);            
        addComponent(f, wwd3, 3, 2, 1, 4, GridBagConstraints.CENTER, GridBagConstraints.BOTH);
        addComponent(f, wwd4, 0, 6, 1, 4, GridBagConstraints.CENTER, GridBagConstraints.BOTH);
        addComponent(f, wwd5, 3, 6, 1, 4, GridBagConstraints.CENTER, GridBagConstraints.BOTH);
        addComponent(f, timeLabel, 0, 0, 4, 1, GridBagConstraints.WEST, GridBagConstraints.NONE);
        f.setSize(1920, 1200);
        f.setVisible(true);

        double lat1 = getTimeLon();
        for( ; ; )
        {
            //System.out.println(lat);
            timeLabel.setText(getTime());
            System.out.println(timeLabel.getSize());
            wwd1.getView().setEyePosition(Position.fromDegrees(0, lat1, 10500000));
            wwd2.getView().setEyePosition(Position.fromDegrees(0, 0, 23500000));
            wwd3.getView().setEyePosition(Position.fromDegrees(0, 0, 23500000));
            wwd4.getView().setEyePosition(Position.fromDegrees(0, 0, 23500000));
            wwd5.getView().setEyePosition(Position.fromDegrees(0, 0, 23500000));
            wwd1.redraw();
            wwd2.redraw();
            wwd3.redraw();
            wwd4.redraw();
            wwd5.redraw();
            Thread.sleep(30000);
            lat1 = getTimeLon();
        }
     private static void addComponent(Container container, Component component, int gridx, int gridy, int gridwidth, int gridheight, int anchor, int fill)
    {
            GridBagConstraints gbc = new GridBagConstraints(gridx, gridy, gridwidth, gridheight, 1.0, 1.0, anchor, fill, insets, 0, 0);
            container.add(component, gbc);
    }

我以前从未用GL组件重新绘制过GUI。我是不是错过了什么？这是布局问题吗。还是与重画有关？

谢谢，-B

Answer 1

您试图要求GridBagLayout做太多，而应该使用嵌套的JPanels来实现这一点。当然，让中心JPanel使用GridBagLayout，但让另一个使用BorderLayout的JPanel持有它。使用JPanel的BorderLayout.NORTH或BorderLayout.PAGE_START位置将中心面板添加到BorderLayout.center位置，并将JLabel添加到主BorderLayout。还要确保JLabel已设置为以文本为中心显示。

此外，从Swing线程的角度来看，这里的代码看起来很危险。该非停止循环和Thread.sleep(...)似乎是在Swing事件线程或EDT上调用的，这可能会导致应用程序冻结。考虑使用SwingWorker来允许在后台线程上调用此代码。