Java如何在文本组件的右侧显示行号

Question

I want to display line numbers in a text component. I found this link https://tips4java.wordpress.com/2009/05/23/text-component-line-number/ And it worked. But I want to display line number on the right side of textarea. How can I do it. Thank!

Answer 1

TextLineNumber is a Swing component. How do you display multiple components in a scroll pane? You add the components to a panel and then add the panel to the viewport of the scroll pane. One way might be to use a panel with a BorderLayout:

JPanel panel = new JPanel( new BorderLayout() );
panel.add(textArea, BorderLayout.CENTER);
TextLineNumber lineNumber = new TextLineNumber(textArea, 3);
panel.add(lineNumber, BorderLayout.EAST);
JScrollPane scrollPane = new JScrollPane( panel );

Or you could use the existing code and change the orientation of the scroll pane:

scrollPane.setComponentOrientation(ComponentOrientation.RIGHT_TO_LEFT);

The line number will be on the right, but the scrollbar will now be on the left.