CSS scroll-behavior

Pathduck

@Thot So Smooth Scrolling works for you in Vivaldi on MacOS?

Thot

@Pathduck said in CSS scroll-behavior:

So Smooth Scrolling works for you in Vivaldi on MacOS?

Yes.

lemontheme

@Thot Alright, that's odd then. Is this on an Intel or Apple Silicon model?

lemontheme

@Pathduck It's the same with a clean profile. I even tried re-installing Vivaldi at one point.

In all cases Vivaldi starts with --disable-smooth-scrolling by default (as can be seen in vivaldi:about and vivaldi:gpu)

Thot

@lemontheme said in CSS scroll-behavior:

Is this on an Intel or Apple Silicon model?

Apple Silicon. Could also be my Logitech Mouse. Set to smooth scrolling with a scroll speed of 60%.

lemontheme

@Thot What happens when you press spacebar – does the page scroll down smoothly?

Thot

@lemontheme said in CSS scroll-behavior:

What happens when you press spacebar – does the page scroll down smoothly?

Yes, but also pretty fast, when holding the Spacebar.

Pathduck

@Thot said in CSS scroll-behavior:

Could also be my Logitech Mouse.

Could you check in Help > About if the --disable-smooth-scrolling argument is set?

That could exclude or not Vivaldi's smooth scrolling.

Thot

@Pathduck said in CSS scroll-behavior:

Could you check in Help > About if the --disable-smooth-scrolling argument is set?

Where? Under About Vivaldi there is no such argument.

Pathduck

@Thot Yes, in the Help > About or vivaldi://version.

In the Command Line part. If there's no mention of --disable-smooth-scrolling there, it means smooth scrolling is available.

Then the question is why @lemontheme gets it. Maybe it's a difference of MacOS 14 vs 15, no clue.

Thot

@Pathduck said in CSS scroll-behavior:

If there's no mention of --disable-smooth-scrolling there, it means smooth scrolling is available.

Ahh, now I get it. But otherwise I don’t understand why smooth scrolling on the other hand should be disabled anyway?

Pathduck

@Thot said in CSS scroll-behavior:

I don’t understand why smooth scrolling on the other hand should be disabled anyway?

Well, that's what needs to be figured out

Could you also, while you're at it, check if the flag:
vivaldi://flags/#smooth-scrolling
Is also set as "Unavailable on your system"?

@lemontheme
The Smooth Scroll setting should/could be saved in the file Preferences in your browser profile. Check Help > About for its location. It's a JSON file, so an advantage if you have a text editor that can format it properly or use a proper JSON tool for MacOS. Or just search the file.

If the setting is changed, it would look like:

"webpages": {
	"smooth_scrolling": {
		"enabled": false
	}
},

If the setting has never been changed, it might not exist at all.
But I've seen rare cases where the actual setting is inconsistent with what the UI shows.
So would be good to verify that value is set or not.

If you have the tool jq you can also list the value from the terminal like this:

$ jq '.vivaldi.webpages.smooth_scrolling' Preferences
{
  "enabled": false
}

https://jqlang.github.io/jq/

Thot

@Pathduck said in CSS scroll-behavior:

Could you also, while you're at it, check if the flag:
vivaldi://flags/#smooth-scrolling
Is also set as "Unavailable on your system"?

Unavailabe. And it says: Animate smoothly when scrolling page content. – Windows, Linux, ChromeOS, Android, Lacros; not mentioning MacOS.

Does this mean, that maybe MacOS scrolls smoothly by design?

Pathduck

@Thot said in CSS scroll-behavior:

Does this mean, that maybe MacOS scrolls smoothly by design?

I don't know but I suspect the flag is unavailable because it should just work. At least it works in the other browsers and it works for you so the question is why lemontheme gets the disable-smooth-scrolling argument set.

To exclude your Logitech smooth scrolling, I believe it should be enough to test the CSS pages, as the Logitech mouse stuff should not affect that at all (far as I know).

https://developer.mozilla.org/en-US/docs/Web/CSS/scroll-behavior
https://www.w3schools.com/cssref/tryit.php?filename=trycss_scroll_behavior

If the smooth scroll tests work there, then smooth scroll should work in MacOS, at least on your MacOS 15 system.

Thot

@Pathduck said in CSS scroll-behavior:

If the setting is changed, it would look like:

"webpages": {
> 	"smooth_scrolling": {
> 		"enabled": false

in my Preferences File, opened with a Text Editor, it says:

"smooth_scrolling":{"enabled":true}

I don’t get it why @lemontheme doesn’t have this.

lemontheme

@Pathduck Good idea to check the JSON directly. Here's the output of the jq query:

{
  "enabled": true
}

So I think we can reject that hypothesis, but it was worth a try!

lemontheme

@Thot Would you mind confirming if the --disable-smooth-scrolling flag is visible on your vivaldi://about/ page?

Pathduck

@lemontheme Yeah worth a try.

I believe I've run out of diagnostics stuff to try.
Might be a difference in MacOS 14 vs 15 but then again it works in other browsers so

We need more people actually using MacOS

I do have some access to developers so will try to ask if they know anything, being dev types they probably use MacOS

AltCode

@lemontheme Hey, I'm testing this out on my mac and I think I've found the root of the problem. Do you perchance use multiple profiles on a regular basis? Furthermore, do have Vivaldi start up with the profile selector, or do you have it start up with your last used profile?

What I've noticed so far is that smooth scrolling does work correctly, but under certain circumstances related to the profile manager, it is disabled without any clear notice as to why.

In my first test, I created two profiles: profile A where "Smooth Scrolling" is enabled in vivaldi://settings/webpages/, and profile B where it is not. Additionally, I disabled the profile selector so that it would not appear on startup and the last used profile would always be restored.
Thus, when I started up Vivaldi with profile A restored, smooth scrolling would work correctly. However, if at any point I opened profile B, smooth scrolling would inadvertently be disabled in profile A as well. This is unexpected as Vivaldi does not indicate that the setting is shared between profiles, but appears to be the case.

In my second test, I enabled "Smooth Scrolling" for both profile A and profile B, and this time, I also enabled the profile selector to appear on startup. Since the setting is enabled for both profiles, smooth scrolling should always work. But no matter what, the setting appears to be ignored, and the --disable-smooth-scrolling flag is always present in vivaldi://about/ like you observed for any profile.

Pathduck

@AltCode

Great catch
I think I can reproduce this - even in Windows, at least part of it

This is unexpected as Vivaldi does not indicate that the setting is shared between profiles, but appears to be the case.

This makes sense though - Vivaldi's "Smooth Scrolling" setting actually enables/disables a flag - the --disable-smooth-scrolling one.
And flags are in fact shared between profiles, that's just how Chromium handles it as flags (or "experiments" as they call it) are global. Just a Chromium thing, but "abusing" flags like Vivaldi does messes things up when users expect a setting is only for one profile but it's actually a global setting.

So when you launch the second profile with the option disabled, even if one is already open, it disables the global flag/setting for all open profiles

I believe Vivaldi also does some "memory" toggling of this flag/experiment on-the-fly causing it to toggle off once the second profile is opened.

In my second test, I enabled "Smooth Scrolling" for both profile A and profile B, and this time, I also enabled the profile selector to appear on startup. Since the setting is enabled for both profiles, smooth scrolling should always work. But no matter what, the setting appears to be ignored, and the --disable-smooth-scrolling flag is always present in vivaldi://about/ like you observed for any profile.

I was not able to reproduce this part in Windows. If both profiles have the option Enabled, smooth scrolling works even when using the profile selector. But maybe I'm not following the steps exactly. Possibly the MacOS profile selector causes some issue when opened.

TIP: To open the "Profile Manager" press F2, type "manage" and the "Manage Profiles" option should appear. This is the standard Chromium profile selector.
vivaldi://profile-internals/ should also show what profiles exist.
(in case someone does not know this...)