Occurs before auto-complete list box is displayed.
property OnGetAutoCompleteList: TGetAutoCompleteList;
In this event handler you can dynamically fill items (List) and display items (Display).
List and Display are references to the Items and DisplayItems correspondingly.
If you want prevent pop-up list box to be displayed you have to clear List.
Parameter Pos indicates starting position of the auto-completed text. If you want to get current text to be completed, extract substring from the line Pos.Y from position Pos.X to SyntMemo.CaretPos.X.