PDFViewer Panning is very slow

[Ron]

Hello,

I am using your trail PDFViewer and its nearly perfect.
I will buy it as soon as you fix the only problem I have.

The problem is that the panning is very slow, when I swipe down/up to browse the the pages, I feel like the loading speed of the page / the speed of browsing is very slow compared to scroll using the scrollbar / mousewheel

[Ron]

After testing it abit more, I think the problem is cause by the animation the ScrollViewer has when you scroll using touch.
I am talking about that the scrollbar travels the distance my finger traveled on the screen and it slows the scrollinng.

Is there a way to disable that animation so it will scroll directly - same way regular ScrollViewer with PannigMode works?

[Kammen]

Hi Ron,

Thank you for your interest in RadPdfViewer. We are happy to hear that you find the control useful.

The poor performance when swiping RadPdfViewer is a known issue. Unfortunately we had no luck investigating what causes this issue. In fact this issue only occurs when swiping is directly over the page's content. When you swipe outside the content everything works as expected.

Could you be more specific when you are saying that this issue can be caused by ScollViewer's animations? What are the steps to verify that these animations are causing the issue? We greatly appreciate your help in locating the cause of the problem!

I am looking forward to your reply.

Regards,
Kammen
Telerik

[Ron]

I was wrong. The issue is not caused by the ScrollViewer's animations (which is the PanningDeceleration).
I cant tell if the problem is caused when swiping directly over the page or not because I didnt investigate that far.

Because of the poor performance I decided to convert my PDFs to XPS and use my custom DocumentViewer - I dont like it but it is better then having swiping issues in PDFs.

If you ever solve this issue, I will be happy to use your control.

Thanks

[Michael]

Hi,
I have the same issue trying the pdf viewer control.

Touch-panning is unuseable. If I touch outside the content, it works quite well. No problems with mouse...

What I see im my output window is the following message very often:
System.Windows.Media.Animation Warning: 6 : Unable to perform action because the specified Storyboard was never applied to this object for interactive control.; Action='Remove'; Storyboard='System.Windows.Media.Animation.Storyboard'; Storyboard.HashCode='30724767'; Storyboard.Type='System.Windows.Media.Animation.Storyboard'; TargetElement='System.Windows.Media.Animation.Storyboard'; TargetElement.HashCode='30724767'; TargetElement.Type='System.Windows.Media.Animation.Storyboard.
I see this message a hundred times.

[Deyan]

Hello Michael,

We are still unable to find the cause of this performance issue. We have logged it in Telerik's feedback portal. You can vote for it and follow its implementation progress by following this link to touch-panning issue feedback item.

Regards,
Deyan
the Telerik team