CefSharp browser jumps (scrolls up) when "PrintToPdfAsync" method is called

[hoquras]

I am using the "PrintToPdfAsync" method https://cefsharp.github.io/api/63.0.0/html/M_CefSharp_WebBrowserExtensions_PrintToPdfAsync.htm to export HTML view to pdf. However I am experiencing following issues:

1. With this API (PrintToPdfAsync), I am unable to pass complete "viewport" that I want to be exported. I can pass width and height (possibly page dimension in micron). Question: How cefSharp determines the "view port"? Which element window or body?

2. The major issue I am experiencing is that just after the call to the method, "view is scrolled up", thereby the exported pdf does not contain the expected view port area. Here is a screen capture:

So the exported pdf is contains area (top part) that was not part of the intended export.

[amaitland]

I am using the "PrintToPdfAsync" method https://cefsharp.github.io/api/63.0.0/html/M_CefSharp_WebBrowserExtensions_PrintToPdfAsync.htm to export HTML view to pdf.

Firstly the API doc is version specific http://cefsharp.github.io/api/
You are referencing version 63 which is very old.

I can pass width and height (possibly page dimension in micron).

There are no width/height properties, there are PageWidth/PageHeight which are intended to specify the page size, A4, A5, letter etc.

The major issue I am experiencing is that just after the call to the method, "view is scrolled up", thereby the exported pdf does not contain the expected view port area.

Testing with version 101.0.180 using WinForms, default settings and I'm not seeing any jump. How does the default page size behave?

Rendering and PDF generation are all implemented at the Chromium level, make sure you are using the latest version.

[amaitland]

How does Cef determines the view port? Is there any relation with zoom level?

The question should be how does Chromium? I'm not sure in this context, you'd have to look at the source.

May be the important question, is "PrintToPdfAsync" right API to export a partial page (scrollable) i.e "viewport" to pdf? The api does not let us to pass "view port".

No. There's no such API that I'm aware of. Chromium expresses PDFs as pages.

[hoquras]

Thanks for your reply.

[amaitland]

CEF doesn't currently expose all the functionality that Chromium has to offer.

https://github.com/chromiumembedded/cef/blob/cb83a7c3fddacb984df60d303701a3d25ad1f826/libcef/browser/printing/print_view_manager.cc#L60
There are other settings like PageRange that can give finer control of the output.

You can capture a screenshot for a given rect.

[hoquras]

Yes I understand now. The issue here is that screenshot won't work. We are exporting high quality SVG image to pdf. Screenshot won't help, I think.

Thanks again. I highly appreciate your comments.
Regards-

[amaitland]

Perhaps something like https://github.com/dlemstra/Magick.NET would be better suited to converting SVG to PDF.