vimium-c + Midnight Lizard = delay in scrolling on some websites

[maciejmotyka]

I recently switched from philc/vimium and was positively surprised by Vimium C. One negative thing that I've noticed was a noticeable delay between pressing j or k and the onset of scrolling on some of the pages, e.g. amazon.com or youtube.com. The majority of other websites didn't have this issue.
I did some detective work and tracked it down to a bad synergy with the Midnight Lizard extension.

To reproduce:

• install Vimium C
• install Midnight Lizard
• load https://www.amazon.com/dp/B07666LR6X
• scroll with j or k

Note: the delay occurs even when Midnight Lizard is set to not change the theme of the website, i.e. the extension is enabled but not changing the website look at that moment.

That situation is very unfortunate 😢 . Midnight Lizard is a 5 star extension with 40k+ users, and Vimium C seems to be better than the original. For now, I'm going back to philc/vimium.
Tagging @Midnight-Lizard just in case.

OS: Ubuntu MATE 20.04
Browsers: Vivaldi 3.0.1874.38, Chrome 81.0.4044.138
Extensions: Vimium C 1.83.1, Midnight Lizard 10.5.0

[gdh1995]

Thanks for this report. A work-around is to add options to scroll* commands, like:

map j scrollDown keepHover
map k scrollUp keepHover

The keepHover option tells Vimium C not to modify page styles, so that the browser responses quicker.

detalied analysis

This is because:

• Amazon has tons of CSS rules and JS code
• Midnight Lizard adds some CSS rules
• Vimium C tries to add a new CSS rule on beginning to scroll
  • this new rule, with the impact of those Midnight Lizard's, causes Chrome executes a very heavy task
  • then the first scrolling effect gets delayed

On my computer, this process takes 40ms on amazon and with the M-L extension disabled, while requires as much as 150ms (sometimes 200ms) with M-L enabled.

[maciejmotyka]

It works. Thank you!

Is there any downside of using keepHover? Am I sacrificing some functionality?

[gdh1995]

without keepHover, 'scrollby' will prevent your mouse pointer from triggering 'hover' effects when some elements scroll to its position. Such effects may be tiny, like button/link changes text colors, while some can be really expensive, like github shows a card if an avatar is hovered. Chrome has implemented this feature nativelly, but there's no API for extensions to use it, so I chose a naive way to simulate it - and as you saw, my way could also be too expensive. I'll reverse this option to make it enabled by default, and test some other ways to simulate this feature.

…

---Original--- From: "Maciej Motyka"<notifications@github.com&gt; Date: Thu, May 21, 2020 03:01 AM To: "gdh1995/vimium-c"<vimium-c@noreply.github.com&gt;; Cc: "Comment"<comment@noreply.github.com&gt;;"Dahan Gong"<gdh1995@qq.com&gt;; Subject: Re: [gdh1995/vimium-c] vimium-c + Midnight Lizard = delay in scrolling on some websites (#175) It works. Thank you! Is there any downside of using keepHover? Am I sacrificing some functionality? — You are receiving this because you commented. Reply to this email directly, view it on GitHub, or unsubscribe.

[Monirzadeh]

side note: @maciejmotyka chrome has flag Force Dark Mode for Web Contents i get better result and performance compare to Midnight-Lizard

[maciejmotyka]

Thank you both! Closing.

[gdh1995]

Hello, you may try this: vimium_c-1.83.2-chrome-9041514.zip, vimium_c-1.83.2-firefox-9041514.zip.

keepHover has been default to true.

Install:

• unzip a zip file into an empty folder
• if on Chrome, open chrome://extensions/ and enable the "developer mode"
• if on Firefox, open about:debugging#/runtime/this-firefox manually
• click the "load extension" button and select the extension folder or manifest.json

[maciejmotyka]

Tested in Vivaldi, on amazon.com - works fine. Occasionally the scroll pauses for few milliseconds, when some hover effect gets triggered, but this is a minor inconvenience compared to the original issue. I will report if I encounter pages that have hover effects that cause bad scrolling experience.

Thanks!