uses
  BCEditor.Types;

procedure TForm1.BCEditor1ReplaceText(ASender: TObject; const ASearch,
  AReplace: string; ALine, AColumn: Integer; ADeleteLine: Boolean;
  var AAction: TBCEditorReplaceAction);
const
  s = 'Заменить %s на %s?';
begin
   case MessageDlg(Format(s, [ASearch, AReplace]), mtConfirmation, [mbYes, mbYesToAll, mbIgnore, mbCancel], 0) of
      mrYes: begin
         AAction := raReplace;
         Exit;
      end;
      mrYesToAll: AAction := raReplaceAll;
      mrIgnore: AAction := raSkip;
      mrCancel: AAction := raCancel;
   end;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
   BCEditor1.Replace.SetOption(roPrompt, True);
   
   BCEditor1.ReplaceText('SearchText', 'ReplaceText');
   BCEditor1.SetFocus;
end;

// Способ первый
procedure TForm1.Button1Click(Sender: TObject);
begin
   case BCEditor1.SelectionAvailable of
      True: ShowMessage('Есть выделенный текст');
      False: ShowMessage('Нет выделенныого текста');
   end;
end;

// Способ второй
procedure TForm1.Button1Click(Sender: TObject);
begin
   case BCEditor1.SelectionLength > 0 of
      True: ShowMessage('Есть выделенный текст');
      False: ShowMessage('Нет выделенныого текста');
   end;
end;

// Способ третий
procedure TForm1.Button1Click(Sender: TObject);
begin
   case BCEditor1.SelectedText <> '' of
      True: ShowMessage('Есть выделенный текст');
      False: ShowMessage('Нет выделенныого текста');
   end;
end;

// Способ первый
procedure TForm1.Button1Click(Sender: TObject);
begin
   with BCEditor1 do
      ShowMessage(Format('%d - %d', [SelectionStart, SelectionStart + SelectionLength]));
end;

// Способ второй
procedure TForm1.Button1Click(Sender: TObject);
begin
   with BCEditor1 do
      ShowMessage(
         Format('%d:%d - %d:%d',
                [SelectionBeginPosition.Line, SelectionBeginPosition.Char,
                 SelectionEndPosition.Line, SelectionEndPosition.Char])
      );
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
   BCEditor1.Selection.Mode := smColumn;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
   BCEditor1.Selection.Mode := smNormal;
end;

uses
  BCEditor.Types, BCEditor.Editor.Utils;

var
  NewPosition: TBCEditorDisplayPosition = (Column: -1; Row: -1);
  StartPosition: TBCEditorDisplayPosition = (Column: -1; Row: -1);

function CtrlDown: Boolean;
begin
   Result := (GetAsyncKeyState(VK_CONTROL) shr 16) and 1 = 1;
end;

function ShiftDown: Boolean;
begin
   Result := (GetAsyncKeyState(VK_SHIFT) shr 16) and 1 = 1;
end;

function AltDown: Boolean;
begin
   Result := (GetAsyncKeyState(VK_MENU) shr 16) and 1 = 1;
end;

procedure TForm1.BCEditor1CaretChanged(ASender: TObject; X, Y: Integer);
begin
   if not AltDown then
   begin
      NewPosition := BCEditor1.DisplayCaretPosition;
      StartPosition := BCEditor1.DisplayCaretPosition;
   end;
end;

procedure TForm1.BCEditor1KeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
   if (ssAlt in Shift) and (ssShift in Shift) then
   begin
      BCEditor1.Selection.Mode := smColumn;
      BCEditor1.SelectionBeginPosition := GetTextPosition(StartPosition.Column, StartPosition.Row-1);
      case Key of
         VK_LEFT: BCEditor1.DisplayCaretX := BCEditor1.DisplayCaretX - 1;
         VK_RIGHT:  BCEditor1.DisplayCaretX := BCEditor1.DisplayCaretX + 1;
         VK_UP: BCEditor1.DisplayCaretY := BCEditor1.DisplayCaretY - 1;
         VK_DOWN: BCEditor1.DisplayCaretY := BCEditor1.DisplayCaretY + 1;
      else
         NewPosition := BCEditor1.DisplayCaretPosition;
         StartPosition := BCEditor1.DisplayCaretPosition;
      end;
      BCEditor1.SelectionEndPosition := GetTextPosition(BCEditor1.DisplayCaretX, BCEditor1.DisplayCaretY-1);
   end;
end;

procedure TForm1.BCEditor1MouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
   if ssAlt in Shift then
   begin
      NewPosition.Column := BCEditor1.PixelsToTextPosition(X, Y).Char;
      NewPosition.Row := BCEditor1.PixelsToTextPosition(X, Y).Line+1;
      StartPosition.Column := BCEditor1.PixelsToTextPosition(X, Y).Char;
      StartPosition.Row := BCEditor1.PixelsToTextPosition(X, Y).Line+1;
   end;
   
   if not BCEditor1.IsTextPositionInSelection(BCEditor1.PixelsToTextPosition(X, Y)) then
   begin
      BCEditor1.SelectionEndPosition := BCEditor1.SelectionBeginPosition;
      BCEditor1.Selection.Mode := smNormal;
   end
   else
      if BCEditor1.Selection.Mode = smNormal then
         BCEditor1.Cursor := crDrag;
end;

procedure TForm1.BCEditor1MouseMove(Sender: TObject; Shift: TShiftState; X,
  Y: Integer);
begin
   if ssAlt in Shift then
   begin
      BCEditor1.Selection.Mode := smColumn;
	  BCEditor1.SelectionBeginPosition := GetTextPosition(StartPosition.Column, StartPosition.Row-1);
	  BCEditor1.SelectionEndPosition := GetTextPosition(BCEditor1.DisplayCaretX, BCEditor1.DisplayCaretY-1);
   end;
end;

procedure TForm1.BCEditor1MouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
   if (BCEditor1.Selection.Mode = smNormal) and (BCEditor1.Cursor = crDrag) then
      BCEditor1.Cursor := crDefault;
end;