General Discussion - DrawCapturedPage and "AutoRotation"

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DrawCapturedPage and "AutoRotation"

Printed From: Debenu Quick PDF Library - PDF SDK Community Forum
Category: For Users of the Library
Forum Name: General Discussion
Forum Description: Discussion board for Debenu Quick PDF Library and Debenu PDF Viewer SDK
URL: http://www.quickpdf.org/forum/forum_posts.asp?TID=2071
Printed Date: 23 Nov 24 at 4:39AM
Software Version: Web Wiz Forums 11.01 - http://www.webwizforums.com

Topic: DrawCapturedPage and "AutoRotation"

Posted By: twaldorff
Subject: DrawCapturedPage and "AutoRotation"
Date Posted: 15 Dec 11 at 11:14AM

I'm using version 8.12

I'm using the CapturePage-DrawCapturedPage functions to insert pages from an other pdf in a report while preserving report header/footer.

I have got the process working OK, but there is something I don't understand:

My main report is in A4 portrait and contains a number of blank pages (except for header/footer) reserved for the other pdf. The other report is in A4 landscape.

Using plain DrawCapturedPage works OK, where I would have expected having to use DrawCapturedPageEx to include rotation information, but that is apparently not required.

Is this an "AutoRotation" feature? Or is there something else at play?

Thomas

Replies:

Posted By: edvoigt
Date Posted: 23 Dec 11 at 2:52PM

Hi Thomas,

please explain what you want. I understand only, that there is a PDF1 in A4 portrait, which has pages with a free area for pages from PDF2, which are A4 landscape. What is the goal? Clear is, you want to get a Page of PDF2 in smaller size on a reserved page of PDF1. What automatism do you expect or really get?

Want you while drawing PDF2-Page onto a Page of PDF1 leave the orientation as is or not?

Please show a code snippet and the both used PDFs to answer your question.

Cheers,

Werner

Posted By: twaldorff
Date Posted: 31 Dec 11 at 2:58PM

Hi Werner

I'm not trying achieve something beyond an explanation.

From a PDF point-of-view I'm getting what I want to get.

My "problem" is that I don't understand why I get it.

You have understood the basic input OK.

First I attach the landscape PDF to the main portrait PDF. (qp.merge)

Stopping here and looking into the file, the pages show in portrait and landscape as expected.

Then I capturepage/drawcapturedpage taking a landscape page and superimposing it on a portrait page. I'm not doing any scaling or rotating in this process.

In this situation this is fine, the landscape page is "autorotated", but why?

That is the question,

Thomas

Posted By: edvoigt
Date Posted: 31 Dec 11 at 4:04PM

Hi Thomas,

I'm rather sure, that there is any kind of rotate-command in one of your PDFs. Here is my test, which shows what with normal PDFs happens:

var
pid: integer;
pw, ph: double;
begin
QP := TQuickPDF.Create;
QP.UnlockKey({$I PDFkey.inc});
QP.NewDocument;
QP.SetMeasurementUnits(1);
QP.SetOrigin(0);
QP.SetPageDimensions(210, 297);
QP.DrawText(25, 250, 'Portrait-Page');
QP.SetLineColor(0, 0, 1);            // blue
QP.SetLineWidth(1);
QP.DrawBox(1, 296, 208, 295, 0);     // borderline
QP.SaveToFile('PDF1_Portrait.pdf');

QP.NewDocument;
QP.SetMeasurementUnits(1);
QP.SetOrigin(0);
QP.SetPageDimensions(297, 210);
QP.DrawText(150, 100, 'Landscape-Page');
QP.SetLineColor(1, 0, 0);            // red
QP.SetLineWidth(1);
QP.DrawBox(1, 209, 295, 208, 0);     // borderline
QP.SaveToFile('PDF2_Landscape.pdf');

QP.Free; // to forget all, no sideeffects possible

QP := TQuickPDF.Create;
QP.UnlockKey({$I PDFkey.inc});
QP.MergeFiles('PDF1_Portrait.pdf', 'PDF2_Landscape.pdf', 'PDF_mixed.pdf');

// now the imposition
QP.LoadFromFile('PDF_mixed.pdf', '');
QP.SelectPage(2);
pw := QP.PageWidth;          // after capture we can't ask for this
ph := QP.PageHeight;
pid := QP.CapturePage(2);    // get the landscape-page

QP.SelectPage(1);            // the page where we want to put the captured page down
QP.DrawCapturedPage(pid, 0, ph, pw, ph); // without scaling the landscape is clipped
QP.SaveToFile('PDF_done.pdf');
QP.Free;

Because I was thinking in this direction, I did ask for the PDFs, you are using. In them is anything disturbing you.

More if needed next year.

Cheers,
Werner

Posted By: twaldorff
Date Posted: 01 Jan 12 at 12:21PM

Hi Werner

Happy new year and thanks for responding.

The behaviour you describe is the one I would have expected.

Since the forum does not allow me to upload files I have stored a zip-file here

http://ge.tt/9eLsxnB - http://ge.tt/9eLsxnB

The file contains main1.pdf and appe1.pdf

The files are NOT created by QuickPDF but by a PDF printer (Bluebeam) from Word and Excel respectively.

They are used by the following example demonstrating my point

procedure superimpose;

var
QP: TQuickPDF0813;
UnlockResult: Integer;

unlockkey: String;
FileA: integer;
FileB: integer;
CapturedPageID: integer;
PageHeight: Double;
PageWidth: Double;

begin
qp := TQuickPDF0813.Create;
unlockkey := 'whatever';
try
    begin
      UnlockResult := qp.UnlockKey(unlockkey);
      if UnlockResult = 1 then
        begin
          If qp.LoadFromFile('main1.pdf', '') = 1 Then
            begin
              FileA := qp.SelectedDocument;
              PageHeight := qp.PageHeight;
              PageWidth := qp.PageWidth;
              If qp.LoadFromFile('appe1.pdf', '') = 1 Then
                begin
                  FileB := qp.SelectedDocument;
                  qp.SelectDocument(FileA);
                  qp.MergeDocument(FileB);

qp.SaveToFile('tmp.pdf');

// In this file you will se the two page in portrait and landscape respectively.

                  CapturedPageID := qp.CapturePage(2);
                  qp.SelectPage(1);
                  qp.DrawCapturedPage(CapturedPageID, 0, PageHeight, PageWidth, PageHeight);
                End;
              qp.SaveToFile('main1_final.pdf');
            end;
        end
     else
        begin
          ShowMessage('Invalid license key');
        end;
    end;
finally
    qp.Free;
end;
end;

Please give it a try and see if you experience the same as I do.

Thomas

Posted By: edvoigt
Date Posted: 01 Jan 12 at 3:55PM

Hi Thomas,

we are on the right way. As I did guess, in the landscape-PDF is one /Rotate-command in the object, which describes the contents of the PDF.

But step by step to understand the problem. A first search for Mediabox shows:

/MediaBox[0 0 595.22 842]

that is a A4-portrait in points. Therefore the PDF is primary build as portrait. To bring it in the wished landscape-orientation, there is a few bytes later this:

... >>/Rotate 90/Type/Page>>

If you use a good editor like notepad++ change it carefully (don't change the length of anything and beware all binarys as they are):

... >>/Rotate 00/Type/Page>>

Proof: In this form Adobe Reader shows it as portrait, as it really is.

Anyway there goes the rotate lost during capture, thats because subject of the rotation seems to be a page, but if we draw it as captured, it becomes to be a part of a page , what means no own rotation. Then it is drawn as constructed - portrait. So I think about this, explaining the automatic. It may be good and it may disturb, depending on the PDF-Quality.

We may bring all in correct state with a short code:

var
rotation: integer;
...
rotation := QP.PageRotation; // the page of interest has to be selected
if (rotation<>0)
then begin
    QP.DrawText(1,150, Format('Rotation %d',[rotation])); // only to see this as test
    QP.RotatePage(rotation);             // realize the defined rotation
end;
pw := QP.PageWidth;          // after capture we can't ask for this
ph := QP.PageHeight;
pid := QP.CapturePage(...    // the now rotated sourcepage

With asking for the rotation we get informed about the build in rotation-statement. With RotatePage this is really performed, then we get the better formed PDF and get the correct values for pagedimensions. Read for this carefully the QP-ReferenceGuide at p. 508.

With the value of rotation and the relation between pagewith and pageheight, you should be able to handle all PDFs as you want and draw them with the right rotation-value.

Cheers,

Werner

Posted By: twaldorff
Date Posted: 01 Jan 12 at 8:13PM

Hi Werner

Thank you very much for the elaborate explanation, and also for directing me to the commands required to handle this issue in a more generic fashion.

Thanks again

Thomas