[fpc-pascal] Assigning Interface method to event handler

[Graeme Geldenhuys]

Hi,

Can I safely assign a method from an Interface reference to an event
handler. The code below works, but I'm not sure if it is safe to do so,
and allowed.

==================================
  TTestApp = class(TObject)
  private
    rpt: TFPReportReport;
    FReportFilter: IFPReportFilter; // can hold any export filter
  ...

constructor TTestApp.Create;
begin
  rpt := TFPReportReport.Create(nil);
  rpt.Author := 'Graeme Geldenhuys';
  rpt.Title := 'FPReport Demo 4 - Frames and Fonts';

  FReportFilter := TFPReportExportPDF.Create;  // PDF output
  //FReportFilter := TFPReportExportAggPas.Create;  // PNG output
  rpt.OnRenderReport := @FReportFilter.RenderReport;
  ...
end;

destructor TTestApp.Destroy;
begin
  rpt.Free;
  FReportFilter := nil;
  inherited Destroy;
end;
==================================

Regards,
  Graeme

-- 
fpGUI Toolkit - a cross-platform GUI toolkit using Free Pascal
http://fpgui.sourceforge.net/

My public PGP key:  http://tinyurl.com/graeme-pgp