Scrolling through PDF documents is laggy when moving the mouse

YanWittmannHSMA
Hello,

I am using Zotero 7.0.15 on my 2019 MacBook Pro with MacOS 15.4.1 (24E263) and similarly to this post here:

https://forums.zotero.org/discussion/119199/zotero-7-experiences-lag-in-pdf-scrolling-compared-to-zotero-6-on-a-2018-mac-mini

I am experiencing huge lag spikes (up to multiple seconds of freeze-frame) when scrolling through a PDF document and moving my mouse over the Zotero window at the same time.
After the freeze-frame has completed, the document scrolls very quickly in the direction I scrolled in, much further than I would expect to have scrolled I feel like.

I do not have any plugins installed, have restarted Zotero and my Laptop, and re-installed Zotero.

It's a pretty big deal to me, since I use the magic mouse and it's pretty hard to not move the mouse while scrolling, or the other way around. It really makes it hard to use.

I am open to any help and appreciate you taking the time to check this issue out,
Yan Wittmann
  • martynas_b
    1. Does the zoom level affect the issue?
    2. Could you make a video demonstrating the problem?
  • YanWittmannHSMA
    1. No, window size and zoom level do not change the behavior, both still lag.
    2. I can, but how would I share the video? I can't add mov files on this platform, I tried using the button below.
  • martynas_b
    Could you upload the video to Dropbox, Google Drive, or similar and share the link here?
  • YanWittmannHSMA
    edited 13 days ago
    It's hard to show without seeing the mouse in real life, but each of the scrolls in the video consistently happens 0.5-1.5 seconds before the editor starts to scroll visually, and each one consists only of a quick swipe on the mouse. Meaning the stuttering, dragging scroll that is seen is not me starting and stopping repeatedly, but it happens automatically; but only if the mouse moves during the scroll, that's the point.

    https://drive.google.com/file/d/1N6WXA8fnvrSmKY50NbeDGOBGk3o7LE0D/view
  • YanWittmannHSMA
    If you need me to provide any more information, just ask! I'm just not sure what else would be useful to you in this issue.
  • martynas_b
    @YanWittmannHSMA Just to confirm — you’re not experiencing any slowdown in Firefox’s built-in PDF.js reader? (Since Zotero uses the same engine.)
  • YanWittmannHSMA
    edited 13 days ago
    I am not having issues with any other PDF-Viewing software on my Laptop, including the built-in Firefox reader, Okular, Apple's Preview or Chrome.

    (I do have issues with Apple's Preview, but those are unrelated to performance issues)
  • martynas_b
    Now, could you check if there’s any slowdown when viewing the same PDF in the Zotero Web Library using Firefox?
  • YanWittmannHSMA
    Smooth as well, aside from the document having to load new pages but that is understandable for the web context. No matter whether I move the mouse or not.

    https://drive.google.com/file/d/1Rlnko_A42-1q1fwUVoj13-CwsOUWlOSN/view
  • martynas_b
    Thanks. A few more things to test:

    1. When you zoom out and gray margins appear on both sides, is there any slowdown when scrolling and moving the mouse only over the gray area?
    2. Try drawing something using the ink annotation tool to see if there’s a noticeable slowdown, since this action is much more demanding.
  • YanWittmannHSMA
    edited 13 days ago
    1. When I zoom out to have the PDF only cover 50% of the width I actually get a dramatic performance boost and the slow-down almost fully disappears. I can barely read anything that way, so it's not an option, but it's interesting. However it does not make a difference for whether I scroll on the PDF or next to it in the gray area.

    2. I notice no difference for when I did draw something on the document or not, it's the same scrolling experience before and after. Also the other types of highlighting or underlining make no difference in their count or presence, and it does not matter what document I use.
  • YanWittmannHSMA
    I also wanted to note that when I scroll using the touchpad this issue does not appear, simply because the file stops scrolling when the mouse is moved and therefore the two actions can not happen simultaneously.
  • martynas_b
    It’s not clear why this happens — it seems like a graphics acceleration issue. We’ve added a possible fix that should help: it temporarily stops mouse movement from triggering PDF page re-rendering while scrolling. It should be available in the next beta.
  • YanWittmannHSMA
    Yeah, it seems to be an issue very specific to me and my laptop, since my peers that also use MacBooks don't have the issue.
    Very cool, I'll make sure to check it out when the version is published - do you have a link for me where the betas can be accessed? I was unable to find the option on the base download page: https://www.zotero.org/download
  • martynas_b
    https://www.zotero.org/support/beta_builds

    Are your colleagues using Intel-based MacBooks and a mouse?
  • YanWittmannHSMA
    edited 13 days ago
    Just to document it:

    I have a 2,4 GHz 8-Core Intel Core i9 and when I use the magic mouse, it has the above-described effect.
    My colleague has an Apple M2 and when they use the same mouse (we switched mice) to scroll, the document just stops to scroll as soon as they move the mouse. (same as with the touchpad for both of us)

    We both use the latest versions of Zotero. We did not change any settings related to this.
  • martynas_b
    @YanWittmannHSMA Can you check if you can still reproduce the issue in the latest Zotero beta?
  • YanWittmannHSMA
    The issue is gone! Scrolling is now just as smooth whether I move my mouse or not. Thank you so much for your help in this issue, I am really happy we managed to get this resolved in such a nice manner.
Sign In or Register to comment.