In https://www.chrisnewland.com/swt-best-practice-single-display-multiple-shells-111 is sample for multiple shell but not MDI. What need set to obtain MDI?
It will be good if in options would be GIMP style.
Advantages of GIMP style: no need grows main windows to whole screen and windows can be in any place of screen.
Advantages of MDI: if I close main window, close application.
In GIMP style no different kind main-child windows. Each windows is the same with menu, but coolbar is one as a tool kit. First is one widows which is empty, opening new document creates drawable component, opening second document creates new window. It is problem: windows can be closed in arbitrary order. In SWT coding in main window is event loop. Where move event loop if multiple window is the same kind?