{+------------------------------------------------------------
| Function ListviewBinarySearch
|
| Parameters :
| listview: listview to search, assumed to be sorted, must
| be <> nil.
| Item : item caption to search for, cannot be empty
| index : returns the index of the found item, or the
| index where the item should be inserted if it is not
| already in the list.
| Returns : True if there is an item with the passed caption
| in the list, false otherwise.
| Description:
| Uses a binary search and assumes that the listview is sorted
| ascending on the caption of the listitems. The search is
| case-sensitive, like the default alpha-sort routine used by
| the TListview class.
| Note:
| We use the lstrcmp function for string comparison since it
| is the function used by the default alpha sort routine. If
| the listview is sorted by another means (e.g. OnCompare event)
| this needs to be changed, the comparison method used must
| always be the same one used to sort the listview, or the
| search will not work!
| Error Conditions: none
| Created: 31.10.99 by P. Below
+------------------------------------------------------------}
 function ListviewBinarySearch(listview: TListview; const Item: string;
  var Index: Integer): Boolean;
 var
  First, last, pivot, res: Integer;
 begin
  Assert(Assigned(listview));
  Assert(Length(item) > 0);
  Result := False;
  Index := 0;
  if listview.Items.Count = 0 then Exit;
  First := 0;
  last := listview.Items.Count - 1;
  repeat
  pivot := (First + last) div 2;
  res := lstrcmp(PChar(item), PChar(listview.Items[pivot].Caption));
  if res = 0 then
  begin
  { Found the item, return its index and exit. }
  Index := pivot;
  Result := True;
  Break;
  end { If }
  else if res > 0 then
  begin
  { Item is larger than item at pivot }
  First := pivot + 1;
  end { If }
  else
  begin
  { Item is smaller than item at pivot }
  last := pivot - 1;
  end;
  until last < First;
  Index := First;
 end; { ListviewBinarySearch }