Zotero 7: Unresponsive reader.js

mjthoraval

I got this following error when trying to open a 64 Mo EPUB file in Zotero:

A script on this page may be busy, or it may have stopped responding. You can stop the script now, or you can continue to see if the script will complete.

Script: resource://zotero/reader/reader.js:31427

The Debug ID is D479805520.

dstillman

Are you able to upload that EPUB somewhere and send a link to support@zotero.org with a link to this thread?

mjthoraval

I have just sent the file.

dstillman

OK, try the latest beta.

mjthoraval

It can open now in Zotero 7.0.0-beta.34+367ecb66c (64-bit). Thank you very much.
It still takes between 20 to 30 seconds to open though, sometimes making Zotero hanging a bit just before opening. And also 4-5 seconds to close the tab sometimes.
When it is open, scrolling vertically is very fast.
Another issue is that it adds an horizontal scrolling bar, due to a blank space added on the right side, with around the same width as the normal page.

Debug ID: D636637114

dstillman

For performance, you can also try Paginated mode (View → Paginated). We're better able to optimize that, though we're going to continue trying to optimize scrolling mode.

mjthoraval

I have tried to switch to Paginated after opening that epub file, and the reader got frozen: Some text appeared together and I lost all ability to scroll: screenshot.
Report ID: 1421627590.

dstillman

I think you may be misunderstanding that? Paginated moves horizontally, page by page — use left/right-arrow to change pages. Currently it also displays two-page spreads unless you make the reader view fairly narrow, though we're going to add a manual setting for that and default to no spreads.

mjthoraval

I got again an unresponsive script warning.

Warning: Unresponsive script
A script on this page may be busy, or it may have stopped responding. You can stop the script now, or you can continue to see if the script will complete.
Script: resource://zotero/reader/reader.js:37954

Debug ID: D1088293267

dstillman

Go to Config Editor and set dom.max_script_run_time to 0, and then restart Zotero and try again. (It was set to 10, so if you were getting this, I guess something was taking at least 10 seconds, but we need to disable that warning dialog regardless.)

mjthoraval

I think you may be misunderstanding that? Paginated moves horizontally, page by page — use left/right-arrow to change pages.

I see, right. I was still expecting mouse scrolling and up/down to turn pages. This is the behaviour I get in Calibre and SumatraPDF when using a paginated view.
This explains the "freezing". But it does not explain how the text got cut without any way to access the hiden part of the text, as you can see in the screenshot. I am not able to reproduce this problem at the moment though.

dstillman

That's likely just a bad initial zoom/positioning — paginated mode isn't supposed to have scrollbars. We'll see if we can reproduce it.

mjthoraval

I still get problems when pressing Home, End, Page Up and Page Down. It works at first when opening in Scrolled mode. But if I switch to Paginated and then back to Scrolled, they do not work anymore.
This EPUB file seems to be quite problematic, so I switched to another one. The same process in the other EPUB file triggers a new navigation behaviour: Pressing Page Up and Page Down seems to navigate through the chapters, with vertical scrolling through the pages limited to a single chapter. Is this some upcoming feature related to the outline?

mjthoraval

But it does not explain how the text got cut without any way to access the hiden part of the text, as you can see in the screenshot. I am not able to reproduce this problem at the moment though.

I can reproduce this now. It is related to the position of the horizontal scroll bar that appears in Scrolled view for this EPUB file that I mentionned earlier:

Another issue is that it adds an horizontal scrolling bar, due to a blank space added on the right side, with around the same width as the normal page.

If the horizontal scroll bar is moved to the left, switching to Paginated view is fine. But if it is moved to the right, then it triggers the problem, hiding some text when switching to Paginated view.
I guess the horizontal scroll bar and the empty space on the right is not supposed to appear in the first place, so that is probably the origin of the problem.

AbeJellinek

Thanks for your help with finding all these issues. The scroll positioning and keyboard shortcut issues should be fixed in the next beta, and you might see some minor performance improvements on the first EPUB as well. I also noticed that it had some tables that got cut off and couldn't be scrolled in paginated mode, so that's also been fixed.

There's nothing wrong with that EPUB! It's just large and has a lot of images, so it's a good stress test for the new reader, which we had mostly tested on smaller books. By the Zotero 7 release, I'd like it to run (at least nearly) as smoothly and quickly on a book that size as it does on a small book.

mjthoraval

That first EPUB file still has a few problems.
For example, I get a vertical scrolling bar on the references at page 408 in Paginated mode: see screenshot.
Zotero 7.0.0-beta.36+3ef1f0992 (64-bit)
Windows 10

mjthoraval

Another one:
1) Restart Zotero
2) Open the EPUB file in the Zotero EPUB Viewer in Scrolled mode.
3) Switch to Paginated mode
4) Pressing any left or right keyboard shortcut jumps between the front pages of the chapters. I cannot access the other pages anymore.
Debug ID: D410310986

AbeJellinek

The vertical scrollbar is intentional. The book lays out its references sections in an unusual way that prevents them from being split between pages in the rendering engine that Zotero uses; a scrollbar is the best we can do.

I’ll take a look at the second issue, thanks.

AbeJellinek

The latter issue will be fixed in the next beta.