Melbourne ADUG Meeting Monday 17th July 2023 - PDF file creation and Display in Delphi with Grahame Grieve

Meetings
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Topic: Melbourne ADUG Meeting - PDF file creation and Display in Delphi with Grahame Grieve
Time: Jul 17, 2023 06:00 PM Canberra, Melbourne, Sydney

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An outline of Monday’s Meeting

On Monday Evening Grahame gave a presentation on PDF Creation and Scraping.

As is common with Grahame’s presentations, it was an interesting, and wide ranging presentation.

The current PDF specification is
ISO32000-2:2020, it is available for no charge
1003 Pages PDF file.

You do have to go through a payment process giving your details, prices
is 0.00, the pdf is watermarked for you.

This and prior versions are available via the following url.
https://pdfa.org/resource/pdf-specification-index/

For Commercial, Non Open Source products, Grahame Recommended Gnostice
Document Studio Delphi. It has very capable and solid pdf handling
capabilities.

https://www.gnostice.com/XtremeDocumentStudio_Delphi.asp

Gnostice also have PDFToolkit vcl, which has additional/other functionality.

For his projects (open source), he uses the open source library pdfium
from Google Chrome (pdfium.dll) along with a delphi wrapper pdfiumlib.

PDFIUM

http://pdfium.org
https://github.com/ahausladen/PdfiumLib
https://github.com/bblanchon/pdfium-binaries (Scroll down)
https://github.com/grahamegrieve/PdfiumLib (Lazarus)

PdfiumLib Comes with example app.

There is no IDE Visual component
(At least partly because it then makes the IDE dependant on pdfium.dll)

It does have a component, you can create and configure with code.

Grahame talked about how important forms, forms he cares a lot about, he
mostly builds in code already. (so he can control exactly how they will
react)

He showed a demo of extracting all the text from a document.
And also gave a run through of the Pdfiumlib demo.

There was then a bit of a discussion about accessibility requirements.

Search WCAG
(Web Content Accessibility Guidelines)

It is VERY wide ranging.

You can specify the parts that you will meet (based on your user
population)

eg. You may elect not to specify you will make your document
comprehensible for a 6 year old in a highly technical field.

Tab traps are a particular issue, for visually impaired users.

Must ensure Tabs for moving from item to item in your forms don’t wind
up trapped somewhere (eg. tab into a Memo), or dont get trapped in a
limited number of fields.

Thanks Grahame

1 Like
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Was the meeting recorded? I wasn’t able to make the meething but this sounds like something I am intersted in.

1 Like
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Hi @vincent,
Here is the recording. It is currently still encoding for HD, so it is probably best to wait an hour or 2 from now.

1 Like
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Thanks, will wait for HD.

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I’m currently using a very old version of gnostice, but looking for something that can manipulate pdfs (merge pdfs, insert text, fill in form fields, convert to other formats) without referencing the vcl. My needs are driven by needing to run in a docker container - which doesn’t have the full windows api available.

Gnostice is fully intertwined with the vcl so that’s not usable in my case. The PDFium looked interesting, but just looking at the uses clause I see Graphics (seems to be for TBitmap) so that’s not going to fly either. I may just have to drop the feature altogether - along with image manipulation/conversion (where I am also still looking for a solution).

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Winsoft (who was a ADUG symposium prize donor :+1:) supposedly has a version of pdfium that supports linux.

See

https://www.winsoft.sk/fpdfium.htm

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Already discounted them - not a fan of commercial libraries that are basically a very thin wrapper over an open source library :man_shrugging:

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I have a fork of the wrapper library that works with osx and Linux - that might help?

Grahame

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Not sure. The issue is it references units line Graphics - for TBitmap - which is VCL or FMX. On windows TBitmap uses features (WIC api’s) that are not available in windows docker containers.

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Hmm tricky. I haven’t changed that - just done linux/osx ports… I guess the point is that you aren’t going to run under linux.

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That was a very interesting video. Thanks Grahame.

Is your Delphi code available for me to play with?

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Well, the only code I used was the PDFium example in the code linked from the slides. Which are attached. Also, I added a button with an onClick that goes like this:

function getTextFromPage(page : TPdfPage) : String;
begin
result := page.ReadText(0, page.GetCharCount);
end;

procedure TfrmMain.Button1Click(Sender: TObject);
var
ts : TStringList;
i : integer;
begin
ts := TStringList.Create;
try
for i := 0 to FCtrl.Document.PageCount - 1 do
ts.Add(getTextFromPage(FCtrl.Document.Pages[i]));
showMessage(ts.Text);
finally
ts.Free;
end;
end;

Grahame

(Attachment 2023-07-adug pdf.pptx is missing)

2 Likes
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Thanks for the session and also the synopsis - I am going to post it on the ukDevGroup newsgroup if that is OK (actually asking forgiveness rather than permission as I posted it and realised I hadn’t posted here).

I still use Envision image library in my D7 project and he added a very simple PDFPreview in his code: Interval Software - Envision

1 Like
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Thanks Grahame. Looks like I misunderstood. I thought the code you used in Free Pascal was different to the code you used in Delphi.

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It was, but the code free pascal code is in the repo. Since I can’t post the slides, the one with the links had:

https://pdfium.org - source code for dll
https://github.com/ahausladen/PdfiumLib - Delphi wrapper
https://github.com/bblanchon/pdfium-binaries/releases/tag/chromium%2F5744 - pdfium binary downloads
https://github.com/grahamegrieve/PdfiumLib (Lazarus) - my port of the Delphi wrapper to linux and osx

Grahame

2 Likes
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One thing I forgot. (Though likely in the Recording)

Geoff mentioned and gave a link for running delphi in a docker container in wine

GitHub - lmbelo/delphi4docker: Step-by-step guide to create your own Docker image to compile Delphi projects

1 Like