RT#7554: FR: Improve the current page number calculation method

[rakunavi]

Hello all,

When a document with wide aspect pages is displayed in continuous mode, after accessing the bookmark and displaying the corresponding page, using the page navigation toolbar buttons or shortcut keys to navigate back and forth through the pages causes discontinuous page number transitions. When testing the following verification scenario on your PC, I recommend that you activate the ruler in advance to make it easier to visually determine which is the current page in the main document area.

PDF-XChange Editor

• For example, if you click on page 27 in the bookmark of the sample file, it will scroll so that page 27 appears at the top edge of the main document area. At this time, the page 36 displayed in the center of the main document area will be the current page. At the same time, the Thumbnails pane scrolls so that page 36 is displayed. Please note that the page numbers at this time will vary depending on the window size and zoom factor of your PC. What I just wrote can be summarized as a list as follows.
  
  
  • sample.pdf
  • Item clicked on in the bookmarks pane: page 27
  • Page at the top of the main document area: page 27
  • Thumbnail highlighted as the current page in the Thumbnails pane: page 36
  • Current page on the navigation toolbar: page 36
  Then, when the Next command on the Navigation toolbar is executed by clicking a button or using a shortcut key, it will jump non-continuously from page 27, which was displayed immediately before, to page 37, which is the next page after the current page, and the page will scroll to the top edge of the main document area.
  
  If you look at the page numbers at the top of the main document area, they change through a series of operations from page 27 to page 37, and I call this change non-continuous.
  
  
  • figure1.png
    PDFXCE.gif

Other common PDF software (Adobe Acrobat, Foxit PDF Editor...)

• Even in other common PDF software, if you click on page 27 of the bookmark, it will scroll so that page 27 appears at the top edge of the main document area. However, the current page is just page 27, and the Thumbnails pane scrolls so that page 27 is displayed. It is an extremely intuitive behavior, and there is nothing to lead the user astray. What I just wrote can be summarized as a list as follows.
  
  
  • Item clicked on in the bookmarks pane: page 27
  • Page at the top of the main document area: page 27
  • Thumbnail highlighted as the current page in the Thumbnails pane: page 27
  • Current page on the navigation toolbar: page 27
    (The list is written in the name of PDF-XChange Editor, but of course the name may vary slightly from application to application.)
  Therefore, if you execute the Next command on the Navigation toolbar, page 28, which is the next page after the previous page 27, will be displayed. In other words, the page transition is continuous.
  
  
  • figure2.png
    Acrobat.gif
    
    
    figure3.png
    Foxit.gif

Closing Remarks

• I do not intend to say that this is a bug at all, but it seems to me that it might confuse users who do not understand the unique behavior of PDF-XChange Editor, as it is different from the behavior of other common PDF software. Personally, I believe that the behavior of other common PDF software, which matches all four pages listed above, is more intuitive and easier for users to understand.
  
  In particular, it is virtually impossible to use shortcut keys without looking at the screen in a series of operations, because which page the current page transitions to after accessing a bookmark depends on the window height and zoom factor at that time. This not only makes shortcut key operation difficult, it is also problematic for the visually impaired. In addition, because the results of the operations are unpredictable, it is difficult to automate the operations using scripts or other means.
  
  As I said at the beginning of this article, I only see differences in the wide aspect page document, but I personally think there is room for improvement.

Thank you for taking the time to read this message.

Best regards,
rakunavi

- PDF-XChange Editor PRO Version: 10.6.0 build 396
- Adobe Acrobat Reader Continuous Release Version 2025.001.20531
- Foxit PDF Editor Pro 13.1.2.22442
- OS Version: Windows 11 Pro / Home 24H2 Build 26100.4349
- PC Model: GMKtec Nucbox M7 Pro with HUION Kamvas Pro 19 / Lenovo IdeaPad C340-15IWL

[Daniel - PDF-XChange]

Hello, rakunavi

The same issue does happen with portrait orientation pages as well, you just need to be zoomed out far enough to see a few of them at once.

image.png

I will pass this along to the dev team for further review.

RT#7554: FR: Improve the current page number calculation method

Kind regards,

[rakunavi]

Thank you, Daniel, for creating the ticket!

Thank you for taking a more general view of the issue. When I write a report on my own, I tend to have a narrow perspective, so it is very helpful to receive an objective review like this.

Please give my best regards to developers.

Best regards,
rakunavi

[Daniel - PDF-XChange]

[rakunavi]

Hello all,

This is supplementary information regarding ticket RT#7544. While I believe you already have a thorough understanding, I would like to offer the following more general case for your reference.

When using two-page display mode and bookmarks or links point to even-numbered pages, switching from two-page to single-page display mode after navigating will show the odd-numbered page from one page back (specifically, the page that was on the left side of the center of the page view). Users often change the display mode to improve document readability.

In such cases, users clicked that bookmark or link precisely because they were interested in that specific even-numbered page. Given that, most users would not want the displayed destination page to change arbitrarily just because they changed the page display mode. Regarding this point, typical PDF applications do not change the current page in such scenarios.

The verification procedure is as follows. The video compares the behavior of PDF-XChange Editor and Acrobat for the following two cases.

• Case A: Two-page display mode, and non-continuous mode
  Case B: Two-page display mode, and continuous mode, and a low zoom level displaying multiple pages

Since I tested the behavior in these two cases for each application, there are four patterns total, but the operations performed are identical as follows:

1. As preparation, set the page display mode, continuous/non-continuous mode, and zoom level according to each case.
2. Open the Bookmarks pane and select “Page 10”.
3. Switch to single-page non-continuous mode.

In the sample file, the document properties are initially set to two-page display mode, non-continuous mode, and page fit. Therefore, adjustments are only made when necessary.

• sample.pdf

Case A (Two-page display mode, and non-continuous mode)

• The page finally displayed in each application:
  • PDF-XChange Editor: Page 9, which differs from the bookmark's destination page, is displayed.
  • Adobe Acrobat: The bookmark's destination page, page 10, will continue to be displayed.
  
  
  Video1.webm

Case B (Two-page display mode, and continuous mode, and a low zoom level displaying multiple pages)

• The page finally displayed in each application:
  • PDF-XChange Editor: Page 13, which differs from the bookmark's destination page, is displayed.
  • Adobe Acrobat: The bookmark's destination page, page 10, will continue to be displayed.
  
  
  Video2.webm
  
  Using Case B as an example, the following diagram illustrates the order in which PDF-XChange Editor and Acrobat determine the Current Page. As indicated by the yellow dotted line in the PDF-XChange Editor diagram, any page positioned to the left of the center of the page view is unconditionally selected as the current page.
  
  
  figure.png

Thank you for taking the time to read this message.

Best regards,
rakunavi

- PDF-XChange Editor PRO Version: 10.7.1 build 399
- Adobe Acrobat Reader Continuous Release Version 2025.001.20643
- OS Version: Windows 11 Pro / Home 24H2 Build 26100.4946
- PC Model: GMKtec Nucbox M7 Pro with HUION Kamvas Pro 19 / Lenovo IdeaPad C340-15IWL

[Daniel - PDF-XChange]

Hello, rakunavi

Thank you for the extended details, and the videos to better showcase the issues. Just in case, I have attached this information to the ticket directly as well.

Kind regards,

[rakunavi]

Hello Daniel, thank you for your reply.

To my embarrassment, I realized that I had posted the exact same content as my previous post in the past. The verification procedure was the same up to displaying the even-numbered pages on page 10.

• RT#6816: Editor 385: Issues with which page is active when navigating explicitly to an Even page in two pages continuous mode
  viewtopic.php?t=41710

I'm truly sorry.

Best regards,
rakunavi

[Daniel - PDF-XChange]

Hello, rakunavi

No worries, it happens on this end as well (evidently), we end up with duplicate tickets fairly often, merging them is not hard.

Kind regards,