I have the following JLabel code:
JLabel someJLabel = new JLabel("<html>first line<br>second line</html>");
someJLabel.setFont(new Font("Arial", Font.PLAIN, 16));
What I'd like to do is be able to control the line height/spacing between the two lines.
PS: I've also looked at using paragraphs instead of breaklines, but it's the same thing. And I don't know if you can do that within an html tag without using css (you can't use css within html code in a JLabel in Java Swing).
You could try using two labels, and setting the distance between the two, as well as the whitespace, using a LayoutManager. I like GridBoxLayout, myself.
Edit: GridBagLayout. Whoops!
Check out the setStyleSheet(...) method of the HTMLEditorKit. I've never used it before but I believe it provides some basic support.
Otherwise you can use a JTextPane to control the line spacing. I think you would use:
StyleConstants.setLineSpacing(...);
You can then change the foreground/background etc to make the text pane look like a label.
This should work, but it's not. color: green works though.
content.add(new JLabel("<html><p style=\"line-height: 150%;\">hi<br>world</p></html>"));
I guess line-height doesn't work. That's how you'd do it if you were to use CSS, so maybe you can't do it that way. Here's a nice tool I found which you can use to test if your HTML will work quickly.
Does setting empty border helps, like
label.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));
method syntax BorderFactory.createEmptyBorder(int top, int left, int bottom, int right)
Hmm .. CSS in JLabel seems to work for me, if one sticks to supported properties. Try padding (or margin) and font-size:
someJLabel = new JLabel("<html><body><p style=\"padding:10; font-size:30\">First line</p><p style=\"padding:10; font-size:20\">Second line</p></body></html>");