Continuous Zoom in Full Screen mode doesn't snap to 'fit page' magnification when using Ctrl + mouse wheel

[DIV]

When viewing a PDF document in Full Screen mode I may want to use various magnifications/zooms, and I have the following settings.

image.png

When in Full Screen mode I am familiar with two three ways to change the magnification:

• Ctrl + mouse wheel
• hover over the bottom-left of the screen until the floating toolbar pops up, then click the "+ or "–" button
• Ctrl + "Numeric keypad +" / Ctrl + "-"

The latter two methods both provide that the zoom will be automatically snapped to exactly 'fit page' magnification, as one of the various levels of zoom.
But the first method (Ctrl + mouse wheel) doesn't do that: typically I can get to within a few percent of the desired zoom, and the page boundary then moves up or down the screen as I Page Up or Page Down through the document.

I would find it more user-friendly if the zoom snapped to exactly 'fit page' magnification, as one of the levels, when using Ctrl + mouse wheel in Full Screen mode. Is there any good reason not to do that?

[Daniel - PDF-XChange]

Hello, DIV

In terms of the actual steps that are done on the current page, ctrl+Scroll DOES stop at the equivalent percentage zoom to the "fit page" level reliably. If you cannot hit that level, your scrollwheel sensitivity may be too high - but it certainly exists.

However, I do see that after achieving that level, the actual "fit page" option does not appear to be selected (instead the equivalent static percent value for the page you were viewing is active). Reaching that same point with the other two methods allows you to scroll through a document which has varied paper sizes on each sheet and all be displayed at "fit page" level, the same is not true if you reached that level with Ctrl+Scroll, it instead stays at the static zoom percent corresponding to what fit page would be on the sheet you originally zoomed using.

Kind regards,

[DIV]

Hi, Daniel.

Thanks for your input, but I'm still not convinced.

Yes, when I use the Ctrl + Scroll wheel in full-screen mode I can reach a zoom on the current page (most conveniently the first or last page) that appears to exactly fit the page to the full-screen view.
The problem is manifest when I press Page Up or Page Down to step through the pages, and the page boundaries gradually migrate up/down the screen.

Two theories:

• Maybe Ctrl + Scroll wheel only jumps to integer values, but the perfect value is a decimal??? [Maybe not. See below.]
• Possibly it's a consequence of not being in "fit page" mode. Without that, maybe the grey space between pages causes the issue.

Could you (or other readers) please confirm the following.

• Have you verified the behaviour when pressing Page Up or Page Down to step through the pages in full-screen view after Ctrl + Mouse wheel scroll?
• How can you confirm the precise percentage magnification that should be used? [I tried one idea. See below.]

OK, I have an idea. Let's try.
Method as follows.

Full screen view. Home to the first page at some arbitrary zoom. Ctrl + Mouse wheel to get nearest to page fit. Back out of full screen view.
Zoom = 65.83%.
Page view = Continuous.
Page retains zoom level (as per my preference setting, "Keep current page layout and zoom when switching to/from Full Screen mode" enabled).
(Same for the last page.)

Full screen view. Home to the first page at some arbitrary zoom. Ctrl + "Numeric keypad +" / Ctrl + "-" to get nearest to page fit. Back out of full screen view.
Zoom = 41.96%.
Page view = Continuous.
Page is fit to the new view, despite reverting out of full-screen view, and despite my preference setting (see above).
(Same for the last page.)

This looks like a bug to me. Or possibly a couple of bugs.

[Daniel - PDF-XChange]

Hello, DIV

I was not trying to "convince", simply stating how this currently works, my observations in testing, and indicating that I did reproduce part of the issue described - as well as noted where exactly the difference is observed.
If the Dev team do not have a specific reason for the difference in handling of Scroll zooming compared to the other zoom methods, I do expect that the fit page zoom percentage step will be adjusted so the scroll wheel zoom works in the same way as the others.

To address your other question - yes, the blank space between pages in continuous mode will affect scrolling. Page up/down moves the height of the display area. If you use the "single page" view, this is not an issue - but in continuous mode it is expected.

Regarding the zoom level question - that is an impossible test, as we cannot observe the "fit page" zoom percentage in fullscreen mode - fit page is a zoom scale that is affected by the window size, so when you are not in fullscreen mode, it will be a different value than it was at fullscreen.
In practice, the ~65% that you see with mouse wheel is actually what fit page zoom percentage is in fullscreen mode, but as before, since the mousewheel zooming puts that in as a static value, instead of selecting the "fit page" option specifically - exiting Fullscreen mode will have the same effect as scrolling to another page which is a vastly different size.
meanwhile, the ~42% zoom percent appears because "fit page" itself was selected, and so the document dynamically changes its zoom level to fit the display area. You will see this number change if you resize the editor window as well:

PXCEditor_zyBLlHNI1v.gif

It is also worth noting that "fit page" works differently in continuous modes than in single page mode, and this may be why you struggled to enable it. Fit page is connected to the largest seen page when in continuous mode. If you have a sheet that is slightly off sized which is nearby enough to have loaded into memory, there is no "fit page" snap point at the smaller paper size you have in the document while continuous mode is active - you need to switch to "single page" view mode, to allow that option to be selected on the smaller pages.

Kind regards,