The zoom factor of page thumbnails in Thumbnails pane is carried over from the last document used to the new document

[rakunavi]

Hello all,

Pages thumbnail size in Thumbnails pane can be changed with the "Zoom In" and "Zoom Out" commands, but currently it appears that the thumbnail zoom factor in the immediately preceding document is inherited when another document is opened. When the application is started anew, the thumbnail zoom level is inherited from the last time the application was closed.

On the other hand, Acrobat does not inherit thumbnail zoom factor. In some cases, like PDF-XChange Editor, it is better to let the zoom factor be inherited, and in other cases, like Acrobat, it is better to reset the zoom factor to the default value every time. Is there a setting that switches between these two?

• Animation.gif

Every user probably has a favorite page thumbnail zoom factor that depends on the size of the display they are using, the type of work they are doing, etc. Perhaps rarely does that preference match the default zoom factor in the application. So I am not saying that the behavior in Acrobat is better. But that may not mean that it is always preferable to keep the thumbnail zoom factor used in the previous document when you open a new document. That would probably depend on the situation.

In other words, it might be easier to use than it is now if there is an option in the thumbnail pane options menu to "Set page thumbnail zoom factor for new documents to a fixed value," and if the option is checked, the zoom factor when set will be the default value thereafter, and if unchecked, the zoom factor of the previous document will be taken over as in the current behavior.

Thank you for taking the time to read this message.

Best regards,
rakunavi

- PDF-XChange Editor PRO Version: 10.5.2 build 395
- Adobe Acrobat Reader Continuous Release Version 2025.001.20435 (64-bit)
- OS Version: Windows 11 Pro / Home 24H2 Build 26100.3476
- PC Model: GMKtec Nucbox M7 Pro with HUION Kamvas Pro 19 / Lenovo IdeaPad C340-15IWL

[Daniel - PDF-XChange]

Hello, rakunavi

The zoom factor in the Thumbnail pane is an application wide value, it is not that this is being inherited from the "previous" document on open, but instead that the pane itself only has one stored zoom value, shared for all documents. You can see the same change occurring when you zoom in or out in one document, then switch another already opened file.

This is by design, and to my knowledge there is no way to change it currently. I am unsure if it is likely to see a change, given the intent was to ensure that the appearance of the pane is consistent from one document to the next.

Kind regards,

[rakunavi]

Hello Daniel, thank you for your reply.

What triggered me to write the opening post was that I was trying to edit an extremely long and narrow PDF file that contained a web page on a single page. When I increased the page thumbnail zoom factor to the maximum level to improve the overall view of that long vertical page, the thumbnails of other normal aspect ratio documents that I opened separately became too large.

At that time, while watching the behavior in Acrobat, the following questions came to mind.

• Regarding consistency of zoom factor in spatial sense...
  It may not necessarily be a good idea to display thumbnails of documents that are open at the same time at the same thumbnail zoom factor.
• Regarding consistency of zoom factor in temporal sense...
  The zoom factor of the thumbnail of the immediately preceding document may not necessarily be appropriate for the next document that is opened.

For the latter temporal zoom factor consistency, a possible workaround is to use the registry "d.ZoomLevel"(*) to restore the default value when the application is launched, but there is no workaround for the former.
(*) [HKEY_CURRENT_USER\Software\Tracker Software\PDFXEditor\3.0\Settings\PageThumbnailsView]

In this respect, PDF-XChange Editor and Acrobat probably have different design policies, but since PDF-XChange are probably reluctant to complicate the settings any further, it seems we have no choice but to accept the current situation.

Best regards,
rakunavi

[Daniel - PDF-XChange]

Hello, rakunavi

If nothing else, it is certainly a design choice, From my investigation, it seems that this was changed in build 389.

It would be more accurate to say this was "fixed" at that time however. Previous builds still only recorded one value, but the appearance would not change for secondary documents until you tried to change their zoom level again, at which point it would "snap" to the current recorded zoom value, before changing a notch from that. which could lead to some interesting situations...

PDFXEdit_MT0FCn3QI3.gif

As this coincides with implementation of pinch zoom capabilities for the thumbnails pane, It seems this bug was discovered during that process, and fixed to work in the intended way at that time.

I wont say that this is never going to change, but it is not something that is currently slated for a change. For now, it is safe to say this handling will stay for quite some time.

Kind regards,

[rakunavi]

Hello Daniel, thank you for your detailed investigation.

Regarding the synchronization of thumbnail zoom factor across multiple files, it seems to me that users who disable the "Synchronize the layout of document panes across all opened documents box" option do not want the zoom factor to be synchronized.

• figure.png

As shown in the video below, changing the panel size requires only one rendering after the panel size is determined, but changing the zoom factor consumes machine resources because it is a continuous rendering process. In particular, changing the zoom factor by pinch-in/pinch-out tends to consume more resources because the zoom factor changes more continuously than when changing by Ctrl+Wheel, etc., which can lead to complaints of slow refresh rates and flickering.

• Animation.gif

Given that many users have many files open at the same time in PDF-XChange Editor, it seems likely that there are a good number of users who do not want synchronization. However, as you say, it is certainly better to wait a little longer for feedback obtained from users on items that have only recently been changed.

As for the synchronization of zoom factor between documents (synchronization in the spatial sense) and the saving of customized zoom factor (synchronization in the temporal sense), I hope that one day they will be approved by other users and light will be shed on them again.

Best regards,
rakunavi

[Daniel - PDF-XChange]

Hello, rakunavi

That may be the case (regarding unchecking the "sync layout" option), but we will have to wait and see what others think. Regarding the resource drain, in the context of modern systems, this one feature is of very small impact, even on a lower end device. It is another case of "if we see more reports about it, something may happen".

In any case, this topic will remain open for others to comment on should they run into the same issue and want a change, if we see large enough demand, then something more may happen. Until then, I will hold back from bothering the Devs about this again.

Kind regards,