I am doing my own tooltip like that for eclipse doc.
For this I use JDialog which has child JLabel wrapped inside JScrollPane.
Of course as user moves cursor I need to change text of JLabel.
The most important is that I want JLabel and JDialog to have just enough size to accomodate text only.
The problem for me is how to calculate and resize JDialog with JLabel so that jDialog is large enough to accomodate text of jlabel.
I guess I need to calculate size of JLabel using its text . But I do not know how to do that and also how to resize JDialog dynamically.