procedure TForm1.FlipVertically1Click(Sender: TObject);
var
  iLayer: Integer;
  iIEBitmap: TIEBitmap;
  iImageEnProc: TImageEnProc;
begin
  if ImageEnView1.Selected then
  begin
    ImageEnView1.Proc.SaveUndoCaptioned('Flip Selection Vertically' +
      IntToStr(ImageEnView1.Proc.UndoCount));
    Undo1.Hint := ImageEnView1.Proc.UndoCaptions[0];
    { Copy selected area and create a new layer }
    iLayer := ImageEnView1.LayersCreateFromSelection;
    ImageEnView1.DeSelect;
    iImageEnProc := TImageEnProc.CreateFromBitmap
      (ImageEnView1.Layers[iLayer].Bitmap);
    try
      iImageEnProc.Flip(fdVertical);
      ImageEnView1.Layers[iLayer].Bitmap := iImageEnProc.AttachedIEBitmap;
    finally
      iImageEnProc.Free;
    end;
    ImageEnView1.Update;
    ImageEnView1.Bitmap.Modified := ImageEnView1.Proc.UndoCount > 0;
    { Turn on Layers selection }
    ImageEnView1.Gestures.Pan.Enabled := False;
    ImageEnView1.Gestures.Zoom.Enabled := False;
    ImageEnView1.MouseInteract := [miMoveLayers, miResizeLayers];
  end;
end;