When displaying search results in Two Pages mode and Fit Height mode, horizontal scrolling may not function correctly

[rakunavi]

Hello all,

When displaying search results pages in the Search pane, I noticed that horizontal auto-scroll does not occur under specific conditions. Please refer to the following verification steps for details.

First, this report assumes the following conditions:

1. Set to Two Pages mode and non-continuous mode
2. Set zoom mode to “Fit Height”
3. Set the page view width to be narrower than two pages but wider than one page

• figure1.png

Video #1

Under these conditions, when you open the Search pane and display search results using arrow keys or similar, the window will automatically scroll horizontally as needed to show the relevant search results. The following video demonstrates searching for the keyword “support” in the PDF version of the PDF-XChange Editor manual (PDFXE10_MAN.pdf) using both PDF-XChange Editor and Adobe Acrobat. Please pay attention to whether the results on the odd-numbered pages on the left scroll horizontally correctly. In the first video, both applications function as intended.

• Video1.webm

Video #2

Here, insert two blank pages between pages 10 and 11, each with the following dimensions:

• Page 1 of the inserted pages (this will become the new Page 11)
  Width: 1221 pt, Height: 792 pt
• Page 2 of the inserted pages (this will become the new Page 12)
  Width: 3 pt, Height: 792 pt

In the second video, the following “insert.pdf” with these blank pages is inserted immediately after page 10.

• insert.pdf

After inserting pages, save the file with a different name, such as “PDFXE10_MANnew.pdf”. If you search immediately after saving, the horizontal scrolling works correctly, just as before. However, if you close the file and reopen it, then perform the same search, the horizontal scrolling inexplicably stops working correctly. Note that in Acrobat, horizontal scrolling works normally even after inserting pages.

• scroll_error.png
  
  
  Video2.webm

Video #3

Even this is strange enough, but when this abnormal behavior occurs, executing the “Normalize Pages” command somehow causes horizontal scrolling to work correctly even for odd-page search results. The appearance of the following dialog indicates that the file is already normalized, meaning the normalization command has no effect on it. This is also evident because the file save command icon (the floppy disk icon) remains inactive, and no asterisk appears at the end of the title.

• figure2.png

Nevertheless, it is a fact that horizontal scrolling works correctly after executing the “Normalize Pages” command, so it can only be concluded that some kind of setting reset occurs. Unfortunately, the effect of this strange workaround is temporary, so you must re-execute the “Normalize Pages” command every time you reopen the file or execute Search.

• Video3.webm

Final Note

I have now finished writing everything I wanted to report as an issue this time. You may be wondering why I inserted pages with a special size like “insert.pdf” and what my intention was, so I will briefly explain below for your reference.

When viewing documents in two-page mode, you may want to insert a wide chart or figure that spans two pages horizontally in the middle of a document. Of course, to add such a chart, you need to insert a page whose width matches the combined width of two pages placed side by side. However, simply adding one page causes the relationship between odd and even pages to shift after insertion. Specifically, before insertion, odd pages appeared on the left and even pages on the right. After insertion, the left-right display order reverses for the pages following the insertion point.

Therefore, to maintain the relationship between odd and even pages, insertion must occur in units of two pages. In such cases, by setting one page's width extremely short, as in “insert.pdf”, you can simultaneously achieve the need to insert a landscape document and the need to maintain the relationship between odd and even pages.

• finalnote.png

Hoping that the above information will be of some help to you.
Thank you so much for your continued support.

Best regards,
rakunavi

- PDF-XChange Editor PRO Version: 10.7.2 build 400
- Adobe Acrobat Reader Continuous Release Version 2025.001.20693
- OS Version: Windows 11 Pro / Home 24H2 Build 26100.6584
- PC Model: GMKtec Nucbox M7 Pro with HUION Kamvas Pro 19 / Lenovo IdeaPad C340-15IWL

[Dimitar - PDF-XChange]

Hello Rakunavi,

Thank you for your detailed report regarding the issue.

I have forwarded the information to our development team for further investigation.

As always, we will keep you informed of any updates or progress.

Best regards.

[rakunavi]

Hello Dimitar, thank you for contacting the developers.

This report might be more appropriate for the Touchscreen Devices Forum, but since the conditions under which the issue occurs are almost identical to those reported in this topic, I am posting it as a follow-up.

When zooming in or out on a touchscreen using pinch-out or pinch-in gestures, the zoom center is the midpoint between the two points touched on the screen. This is a fundamental operation common to modern devices with touchscreens and likely requires no detailed explanation. In PDF-XChange Editor, for documents with uniform page sizes, zooming in or out centers on the midpoint between the two fingers touching the screen, regardless of whether you're viewing Single Page or Two Page layouts.

However, after inserting "insert.pdf" into the "PDFXE10_MAN.pdf" file mentioned in the above example, I noticed that issues occur when the following three conditions are met simultaneously. The first condition is identical to the one reported at the beginning of this topic.

• Set to "Two Pages" mode and non-continuous mode
• The zoom level is greater than the zoom level equivalent to Fit Page
• Perform a pinch gesture on the left page.

Specifically, when pinching out or pinching in anywhere on the left page displayed in "Two Pages" and non-continuous mode, the zoom in/zoom out action centers on the right edge of the right page (which is off-screen), rather than the midpoint between the two fingers touching the screen. The Y-coordinate likely corresponds to the center of the two touch points, but the X-coordinate seems to center the zoom operation on the edge of the off-screen portion of the right page. Particularly strange is that when the zoom level becomes so high that only the left page is visible, performing a pinch-out gesture causes the screen to switch to the right page and zoom in on it.

As reported in the opening post of this topic, executing the "Normarize Pages" command will also resolve this issue for that session only, allowing pinch gestures to zoom in and out centered on the midpoint between the two touched points. The fact that the "Normarize Pages" command serves as a temporary workaround is equally peculiar, just as noted in the initial report.

In the verification video below, for each file (sample A.pdf and sample B.pdf), two fingers are placed right around the center of the Page View, as indicated by the red arrow in the figure below, and then pinched out vertically as shown by the red arrow. All pages in sample A.pdf are the same size, while sample B.pdf has pages with special sizes inserted on pages 9 and 10. In the first example of the topic, this corresponds to the file “PDFXE10_MANnew.pdf”.

• figure.jpg

• sample A.pdf
• sample B.pdf

The first half of the video opens sample A.pdf and demonstrates that pinching out works perfectly fine. The second half of the video performs the exact same operation on sample B.pdf and shows that it suddenly jumps to the right page.

• Video.webm

I've attached a video for reference, but I'm concerned that unless I record footage of the actual pinch gesture operation, the issue may not be conveyed accurately. If there are any parts of the video that are difficult to understand, please let me know so I can work on delivering a more effective presentation.

Anyway, if you try it on a touchscreen-enabled computer under the conditions shown here, you should be able to see the abnormality in the behavior. On the left page, pinch gestures are almost impossible to perform.

Hoping that the above information will be of some help to you.
Thank you so much for your continued support.

Best regards,
rakunavi

- PDF-XChange Editor PRO Version: 10.7.3 build 401
- OS Version: Windows 11 Pro / Home 24H2 Build 26100.6584
- PC Model: GMKtec Nucbox M7 Pro with HUION Kamvas Pro 19 / Lenovo IdeaPad C340-15IWL

[Dimitar - PDF-XChange]

Thank you for the additional information provided.

I will also pass this along to our developers for further review.

Regards.