LiveBindings Demo AfterScroll Event Handler

TMDLBO.AfterBranchScroll.pas

{ When the Branch list changes, either because of a scroll, or add or delete, this routine adjusts the
  Employee list to display the appropriate employees }

procedure TMDLBO.AfterBranchScroll(ABindSourceAdapter: TBindSourceAdapter);
var
  LBranch: TBranch;                                                       // currently displayed Branch
begin

  { A series of casts extracts the current TBranch object being displayed }

  LBranch := TBranch(TListBindSourceAdapter(ABindSourceAdapter).Current); // obtain the current TBranch object
  if Assigned(LBranch) then                                               // might be an empty list if all entries have been deleted
    begin
      EmployeeWrapper.SetList(                                            // change the Employee Wrapper to point to
        LBranch.BranchEmployees,                                          // the TObjectList<TEmployee> in the currently
        False);                                                           // displayed Branch

      EmployeeWrapper.First;                                              // position to the first Employee
      EmployeeWrapper.Active := True;                                     // this will populate the list and make it visible
    end
  else
    begin
      EmployeeWrapper.SetList(                                            // If there is no current branch
        nil,                                                              // there can be no current employees
        False);
    end;
end;

Shows the event handler code needed to update the child ListView display when the focus of the parent ListView changes ListItems.