Swing: add help button [?] To window title bar

Question

I want to add a new button with a question mark icon to the left of the maximize, hide, and close buttons. how to do it (as in the picture)?

Answer 1

You need to create a custom RootPane / TitleBar.

That means you need to set the JFrame to unecorated and then set your own instance, which extends RootPane to your JFrame

Answer 2

It is difficult to change your own title bar because it comes from the operating system. But you can remove your own header line setUndecorated(true); and create your own title bar. See a simple tutorial here

OR

You can see another way in substance in style