Java font size - how to change the JTextArea, JTextPane, JEditorPane font size

I'm currently writing a customized text editor in Java, and as part of that, I want to make it easy for the user to increase or decrease the font size in the text editing area (technically a JTextPane). I didn't expect this to be easy, but I've been pleasantly surprised that the following approach seems to work just fine:

Java caret position - Getting the caret position in a text document

Java caret position FAQ: How do I get the Java caret position in a JTextComponent, such as a JTextArea or JEditorPane?

Wow, this was a bear to find anything about. Everyone always wants to show you how to use a JPopupMenu with a mouse click, such as a right-mouse click, but nobody ever shows you how to display a JPopupMenu when someone uses a keystroke, or keyboard accelerator.

So, using a little Java mojo, here is how I get the caret position in a JTextComponent (JTextArea, etc.) to display a JPopupMenu near the current caret position: