Smooth scrolling

[Shamaoke]

Is there any way to enable smooth scrolling in Luakit?

[c0dev0id]

In :settings, there is a setting webview.enable_smooth_scrolling you can enable.

[Shamaoke]

I enabled it, but nothing happened. Scrolling is still discrete.

Linux (Arch); Luakit 2.1

[aidanholm]

That setting doesn't do what I'd guess @Shamaoke is probably asking about, which is smooth scrolling when you scroll with j/k. I'm actually not sure what that setting does: it's just a wrapper for the webkit setting, and i've never noticed it making any difference.

Scrolling with j/k uses webkit_dom_dom_window_scroll_to() to scroll, which is effectively a window.scrollTo() call in javascript. It's not something that can support smooth scrolling. It'd need a rewrite.

That API is actually deprecated in favour of the JavascriptCore API. Unfortunately webkit does not currently support the smooth scrolling option for window.scrollTo() (webkit bug https://bugs.webkit.org/show_bug.cgi?id=188043), and it would be a lot of work to switch to those new APIs anyway.

TL;DR: No, unfortunately :(

[Shamaoke]

@aidanholm Thank you for the explanation.

[c0dev0id]

The smooth scrolling setting does something. It enables smooth scrolling for the mouse wheel. So it's not entirely useless.

[Shamaoke]

@c0dev0id For me it does nothing. Scrolling is still discrete neither by keys nor by mouse.

Here's my configuration file:

-- ~/.config/luakit/userconf.lua
local webview = require "webview"

webview.enable_smooth_scrolling = true

[aidanholm]

Hrm, well as a workaround you might be able to hack things so that j/k/etc keys sent scrollwheel events to the webview instead. Of course, this would break the scrollstep setting, and wouldn't work for page-based or absolute scrolls, so it'd never be mergable, but if you really want your j/k keys to smoothscroll, you could do that.

[aidanholm]

@Shamaoke Ah, that's because that's not set correctly. You'd need to do this:

local settings = require "settings"
settings.webview.enable_smooth_scrolling = true

This can be pretty confusing, admittedly, but module properties and settings are explicitly separate.

You can check (and change) your settings here: luakit://settings/

[Shamaoke]

@aidanholm Thank you for the correction. This way it works. I still prefer using a configuration file in order to version control it.

[aidanholm]

You're welcome!

To be clear, the lack of support and API issues and all that stuff is something that we'd very much like to have fixed. Ideally, smooth scrolling would piggyback on the webview.enable_smooth_scrolling setting, with a new setting for scroll speed. I'll leave this open as a feature request for now. Unfortunately my time for luakit development is pretty limited, so an ETA is not really possible.