Welcome to the Ranch.
I have never used SWT myself. I don't know of any "best practice" code for a full-size application.
I presume you have been through
the part of the Java tutorial about Swing GUIs? [Note there are several people on the Ranch, myself included, who disagree with the use of addActionListener(this); in Java, even though the Tutorial uses it
passim.]
You will find instructions about Swing in any of the larger Java textbooks, but it tends to be in bits:-
Example of how to set up a JFrameExample of how to add a JPanelExample of how to draw a circle on your JPaneletc etc.The Java tutorial also teaches in bits like that. So you would have to go through the many bits and put them all together.
There is supposed to be a GUI palette NetBeans, but I have never actually worked out how to use it. If you go to
the Java Sun Developers' Network website, they are offering Studio Creator at a special reduced price of $0.00(!). I don't know, but that might be what you are looking for.
CR