DELPHI AREA Forum

Hi @ll

I've tried to make print prevew of memo by richedit, but nothing shows on preview.

My question: How make PrintPreview of TMemo including margins, footer and header of page?

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NewPage;

Canvas.DrawRect(..., WordWrap);


I'm really tired, but does this help at all?

well, I don't know I've got this code for printing on printer canvas, but i want to change it so it be compatible with PrintPreview:

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procedure TMainForm.PrintFooter(var R: TRect; LineHeight: Integer);
var
  S : String;
begin
  with Printer do begin

    { utwórz łańcuch zawierający numer strony }
    S := Format('Page %d', [PageNumber]);


    { ustal współrzędne prostokąta, którym wyświetlany będzie łańcuch }
    { zawierający numer strony }

    R.Top := PageHeight - (lineHeight * 2);
    R.Bottom := R.Top + lineHeight;


    { wyświetl centrycznie łańcuch zawierający numer strony }
    DrawText(Handle, PChar(S), -1, R, DT_CENTER);

    { podkreśl tekst zawierający numer strony }
    Canvas.MoveTo(0, R.Top - 2);
    Canvas.LineTo(R.Right, R.Top - 2);
  end;
end;

procedure TMainForm.FilePrintClick(Sender: TObject);
var
  I            : Integer;
  LineHeight   : Integer;
  LinesPerPage : Integer;
  LineCount    : Integer;
  R            : TRect;
  S            : string;
begin
  { wyświetl dialog drukowania }
  if PrintDialog.Execute then begin

    { ustal tytuł drukowanego obiektu }
    Printer.Title := 'Scratch - ' + OpenDialog.FileName;

    { ustaw czcionkę drukarkową zgodnie z czcionką Memo }
    Printer.Canvas.Font := Memo.Font;



    { Oblicz wysokość linii - na podstawie rozmiaru czcionki }
    { i rozdzielczości drukarki. Dodaj 40% na odstęp między liniami }

    LineHeight := Abs(
      MulDiv(Printer.Canvas.Font.Size,
      GetDeviceCaps(Printer.Handle, LOGPIXELSY), 72));
    Inc(LineHeight, (LineHeight * 4) div 10);

    { oblicz, ile linii zmieści się na stronie; uwzględnij }
    { trójliniowy margines                                 }

    LinesPerPage := (Printer.PageHeight div lineHeight) - 4;

    { rozpocznij drukowanie w 4. linii, by zostawić miejsce }
    { na nagłówek }
    LineCount := 4;

    { wydrukuj nagłówek }
    Printer.BeginDoc;
    R.Top    := LineHeight;
    R.Left   := 20;
    R.Right  := Printer.PageWidth;
    R.Bottom := LineHeight * 2;
    DrawText(Printer.Handle,
      PChar(OpenDialog.FileName), -1, R, DT_CENTER);

    { drukowanie poszczególnych linii }
    for I := 0 to Pred(Memo.Lines.Count) do
    begin

      { po dojściu do końca strony zresetuj licznik linii }
      { i przejdź do nowej strony                         }

      Inc(LineCount);
      if LineCount = LinesPerPage then begin
        PrintFooter(R, LineHeight);
        LineCount := 4;
        Printer.NewPage;
      end;

      { pobierz kolejną linię Memo }
      S := Memo.Lines.Strings[I];
      Printer.Canvas.TextOut(0, LineCount * LineHeight, S);
    end;

    { zakończ drukowanie }
    PrintFooter(R, LineHeight);
    Printer.EndDoc;
  end;
end;


(comments are in Polish, don't care 'bout them)

Looking at the Preview.pas source code, I think if you do not use PrintPreview.Canvas, it will not show up.

Replace 'Printer.' with 'PrintPreview.' and 'Printer.BeginDoc' with 'PrintPreview.NewPage' and see what happens.

Cheers

I did so, but page widith and height are incorrect. also DPI.

PageHeight and PageWidth are in the .Units measure, not necessarily Pixels. You can use ConvertUnit or change the .Units property to mmPixels

Cheers

Thanks, but I found solution just few minutes after disconect (by RichEdit way), but I've found bug in TPrintPreview: when I tried to change zoom to 100% then ecteption EOutOfResources raised, when I chenged Zoom to 50% it looked like zoom 500% or more! whats wrong 'bout it? [it hepend not only in my program, aslo in RichEdit print demo but it doesn't hapend in General demo.

And one more thing: why pages can't be scroled like in M$ word or Adobe Acrobat Reader(next page under previous)?

Look in their demo for paging: you have to set the CurrentPage property

OK, but what 'bout bug in zoom?

ps. CurrentPage sucks!

I don't know why you would get OutOfResources; I think you need to email the vendor so they take a look at it.

Why does .CurrentPage suck? If they have one canvas, how elese are they supposed to keep track?

I don't know what you mean by sending mail to vendor (exacly this part. mail to vendor of what?), besides try out the RichText print demo and change zoom to 100%

It might be caused by MulDiv (in UpdateZoom procedure)...

It's strange but when i changed zoom to 8 it looks like 100% in Word or Acrobat. and i can bet that it's bug in Update zoom

I found finally reason of bug! It was in CalculateViewSize function, in zsZoomOther section, whole function should be:

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function TPrintPreview.CalculateViewSize(const Space: TPoint): TPoint;
begin
  with FPaperView do
    case FZoomState of
      zsZoomOther:
      begin
        Result.X := ActualWidth(MulDiv(FPixels.X, FZoom*Screen.PixelsPerInch,GetDeviceCaps(Printer.Handle, LOGPIXELSX) * 100));{ActualWidth(MulDiv(FPixels.X, FZoom, 100));}
        Result.Y := ActualWidth(MulDiv(FPixels.Y, FZoom*Screen.PixelsPerInch,GetDeviceCaps(Printer.Handle, LOGPIXELSY) * 100));{ActualHeight(MulDiv(FPixels.Y, FZoom, 100));}
      end;
      zsZoomToWidth:
      begin
        Result.X := Space.X;
        Result.Y := ActualHeight(MulDiv(ActualWidth(Result.X), FPixels.Y, FPixels.X));
      end;
      zsZoomToHeight:
      begin
        Result.Y := Space.Y;
        Result.X := ActualWidth(MulDiv(ActualHeight(Result.Y), FPixels.X, FPixels.Y));
      end;
      zsZoomToFit:
      begin
        if (FPixels.Y / FPixels.X) < (Space.Y / Space.X) then
        begin
          Result.X := Space.X;
          Result.Y := ActualHeight(MulDiv(ActualWidth(Result.X), FPixels.Y, FPixels.X));
        end
        else
        begin
          Result.Y := Space.Y;
          Result.X := ActualWidth(MulDiv(ActualHeight(Result.Y), FPixels.X, FPixels.Y));
        end;
      end;
    end;
end;

Please summarize the changes you made.

orginal code is in comment. changes ware maded only for

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Result.X := ActualWidth(MulDiv(FPixels.X, FZoom*Screen.PixelsPerInch,GetDeviceCaps(Printer.Handle, LOGPIXELSX) * 100));{ActualWidth(MulDiv(FPixels.X, FZoom, 100));<-orginal}
        Result.Y := ActualWidth(MulDiv(FPixels.Y, FZoom*Screen.PixelsPerInch,GetDeviceCaps(Printer.Handle, LOGPIXELSY) * 100));{ActualHeight(MulDiv(FPixels.Y, FZoom, 100));<-orginal}


it was in lines 1767 and 1768 of unit preview.pas in function CalculateViewSize (protected function of TPrintPreview). Is it enought?

Thank you