How does JEditorPane determine its preferred size?

Question

Could someone explain how JEditorPane determines the initial preferred
size? Its default sizing is not giving me what I need and I'm not sure
how to control it, other than explicitly setting the size with
setPreferredSize().
A simple example:
        String s = "1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 10 20" +
                   "21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39";
        JEditorPane ed = new JEditorPane("text",s);
        JPanel pan = new JPanel();
        pan.setLayout(new BoxLayout(pan,BoxLayout.Y_AXIS));
        pan.add(ed);
        JFrame f = new JFrame();
        f.getContentPane().add(pan);
        f.pack();
        f.setVisible(true);This code generates a window that shows one line, with "1 2 3 4 5 6 7 8 9"
showing. I'd like to have a larger area showing initially.
Does the choice of layout manager effect this? (I actually prefer to use
TableLayout; the above example with a 1x1 TableLayout and widths set to
PREFERRED yields exactly the same results.)
Thanks,
bw

Answer 1

Set your ruler increments to pixels Preferences>Units & Increments. You can fill the text box with placeholder text Type>Fill with Placeholder text and get a word count from the Info panel with Show Options turned on from the flyout.
From the Transform panel you can set a text box's width and height