You need to have an idea about AWT and component class. AWT have three component class which are Frame, Window and Panel. AWT have non component class which includes Button, TextField ,TextArea, ...

When using the SWT-AWT bridge at high DPI, SWT_AWT.new_Frame() schedules an async task that calls setSize() on the new frame with the width and height taken from the enclosing SWT composite's client ...