java - 在具体的地方使用 JTextPane 进行绘制

Question

假设我们有一个 JTextPane，其大小设置为 A4 纸张格式大小。页面方向是垂直的。让我们将页面分成三个相等的部分。当我在一个部分(随机位置)写一些内容时，我希望插入的文本将绘制在页面的两个剩余部分上，这样如果我将页面折叠成三个，所有三个文本都将位于同一个位置。有什么办法可以实现这一点吗？

这应该看起来像这样:

Answer 1

我不确定我理解你想要什么，所以如果我误解了，请纠正我。您可以在显示时保存文本 Pane 的图像，并根据需要绘制恢复或正常的图像。见下文:

public class Test {

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                JFrame mainFrame = new JFrame("test");
                mainFrame.setSize(300, 100);
                mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

                //layout to make every part the same size
                Container pane = mainFrame.getContentPane();
                pane.setLayout(new GridLayout(3,1));

                //create the elements
                JTextPane source = new Source();
                final JPanel copy = new Copy();
                final JPanel revertedCopy = new RevertedCopy();

                //add the elements
                pane.add(source);
                pane.add(revertedCopy);
                pane.add(copy);

                //This is just to display the splitting lines
                source.setBorder(BorderFactory.createMatteBorder(1, 0, 1, 0, Color.BLACK));

                //this is just to repaint the other panels when image changes
                source.addPropertyChangeListener(new PropertyChangeListener() {
                    @Override
                    public void propertyChange(PropertyChangeEvent evt) {
                        if(evt.getPropertyName().equals("drawing")) {
                            copy.repaint();
                            revertedCopy.repaint();
                        }
                    }
                });

                mainFrame.setVisible(true);
            }
        });
    }

    static BufferedImage image;
    static class Source extends JTextPane {
        @Override
        public void paint(Graphics g) {
            super.paint(g);
            //we edit the image each time the textPane is repainted
            image = new BufferedImage(getWidth(), getHeight(), BufferedImage.TYPE_3BYTE_BGR);
            boolean caretVisible = getCaret().isVisible(), selectionVisible = getCaret().isSelectionVisible();
            if(caretVisible) getCaret().setVisible(false);
            if(selectionVisible) getCaret().setSelectionVisible(false);
            super.paint(image.createGraphics());
            if(caretVisible) getCaret().setVisible(true);
            if(selectionVisible) getCaret().setSelectionVisible(true);

            //we let the copies know about the changes
            firePropertyChange("drawing", null, image);
        }
    }
    static class Copy extends JPanel {
        @Override
        public void paint(Graphics g) {
            super.paint(g);
            //we just draw the image
            if(image!=null) g.drawImage(image, 0, 0, this);
        }
    }
    static class RevertedCopy extends JPanel {
        @Override
        public void paint(Graphics g) {
            super.paint(g);
            //we just draw the image reverted
            if(image!=null) g.drawImage(image, 0, image.getHeight(), image.getWidth(), -image.getHeight(), this);
        }
    }
}