Composite are controls which are capable of containing other controls. Controls are placed inside a composite in the same manner that Controls are placed on a shell. The position of each widget inside a composite is relative to the composite, so if the composite is moved on the shell, the Controls inside the composite retain their relative positions.
The styles supported by composites are NO_BACKGROUND, NO_FOCUS, NO_MERGE_PAINTS, NO_REDRAW_RESIZE, NO_RADIO_GROUP, EMBEDDED, DOUBLE_BUFFERED.
Combo are controls that allow the user to choose an item from a list of items, or optionally enter a new value by typing it into an editable text field. Often, Combos are used in the same place where a single selection List widget could be used but space is limited. A Combo takes less space than a List widget and shows similar information.
The following are the important constructors of Combo class.
Combo(Composite parent, int style)
Constructs a new instance