Components for Delphi and C++ Builder.

function TBMListEh.Find(const Item: TUniBookmarkEh; var Index: Integer): Boolean;
var
  L, H, I, C: Integer;
begin
  if (Compare(Item, FCache) = 0) and (FCacheIndex >= 0) then
  begin
    Index := FCacheIndex;
    Result := FCacheFind;
    Exit;
  end;
  Result := False;
  L := 0;
  H := GetCount - 1;
  if H >= 0 then
  begin
    if Compare(FList[L], Item) > 0 then
      L := 0
    else if Compare(FList[H], Item) < 0 then
      L := H + 1
    else
    begin
      while L <= H do
      begin
        I := (L + H) shr 1;
        C := Compare(FList[I], Item);
        if C < 0 then L := I + 1 else
        begin
          H := I - 1;
          if C = 0 then
          begin
            Result := True;
            L := I;
          end;
        end;
      end;
    end;
  end;
  Index := L;
  FCache := Item;
  FCacheIndex := Index;
  FCacheFind := Result;
end;

L := 0;
  H := GetCount - 1;
  while L <= H do
  begin
    I := (L + H) shr 1;
    C := Compare(FList[I], Item);
    if C < 0 then L := I + 1 else
    begin
      H := I - 1;
      if C = 0 then
      begin
        Result := True;
        L := I;
      end;
    end;
  end;

  public
    { Public declarations }
    Row0Bookmark: TUniBookmarkEh;
    Row1Bookmark: TUniBookmarkEh;
  end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  Row0Bookmark := MemTableEh1.Bookmark;
  DBGridEh1.SelectedRows.CurrentRowSelected := True;
  MemTableEh1.Next;
  DBGridEh1.SelectedRows.CurrentRowSelected := True;
  Row1Bookmark := MemTableEh1.Bookmark;

  DBMemoEh1.Lines.Add('Two rows seleced');
end;

procedure TForm1.Button2Click(Sender: TObject);
var
  Idx: Integer;
begin
  if (DBGridEh1.SelectedRows.Find(Row0Bookmark, Idx)) then
    DBMemoEh1.Lines.Add('Row0Bookmark is in Index = ' + Idx.ToString)
  else
    DBMemoEh1.Lines.Add('Row0Bookmark is not found');

  if (DBGridEh1.SelectedRows.Find(Row1Bookmark, Idx)) then
    DBMemoEh1.Lines.Add('Row1Bookmark is in Index = ' + Idx.ToString)
  else
    DBMemoEh1.Lines.Add('Row1Bookmark is not found');
end;

   
    oRow1 := GetRowFromBookmark(Bookmark1, i1, iRS1);
    oRow2 := GetRowFromBookmark(Bookmark2, i2, iRS2);
    if oRow1 = oRow2 then
      Result := 0
    else if not IsRowValid(oRow1, iRS1) or not IsRowValid(oRow2, iRS2) then
      Result := -1
    else begin
      i1 := FSourceView.IndexOf(oRow1, rvDefault, i1);
      i2 := FSourceView.IndexOf(oRow2, rvDefault, i2);
      if i1 < i2 then
        Result := -1
      else if i1 > i2 then
        Result := 1
      else
        Result := 0;
    end;