Kakoune: Change scroll speed?

[Luflosi]

Is it possible to change how many lines kakoune scrolls per mouse scroll event? I didn't find any related config option or issue mentioning something like this. Right now kakoune scrolls by three lines per scroll event.

[Screwtapello]

Currently this is hard-coded, see line 140 of src/input_handler.cc
(or just search in that file for Key::Modifiers::MouseWheelDown).

[Luflosi]

I can see that it makes sense to scroll three lines per mouse event when using an actual mouse wheel and a terminal that doesn't support a setting like this but I'm using a touch pad, not a mouse wheel. Currently kakoune scrolls three times as fast as all the other programs I'm using, which is a bit annoying. I also cannot control the scroll position to the exact line I may want by just using the touch pad.
Is there interest in changing the default value or making this configurable?

[lenormf]

I think it makes sense to create a UI option for the amount of lines scrolled.

However, what behaviour do you suggest to handle accurate scrolling? Prevent scrolling when the mouse cursor is already hovering main selection?

[Screwtapello]

The xterm mouse protocol just sends "mouse scroll up" and "mouse scroll down" events, corresponding to the clicks of a "clicky" mouse wheel, or the synthetic "clicky" events generated for smooth-scrolling input devices. So Kakoune doesn't have access to "smooth" events, and can't do anything about them.

[Luflosi]

I didn't mean to suggest any kind of "accurate" or "smooth" scrolling in a sense that that would somehow increase the resolution to better than one line. I was suggesting changing the hardcoded 3 and -3 to 1 and -1 (which is likely not going to happen) or to make these values configurable so I can change it to 1 in my config.

[mawww]

I guess it could make sense to make this configurable, however I think it would be good to have that as a UI-side option, as non-terminal UIs could want to handle smooth scrolling events "intelligently".

That means we should change to mouse wheel keys to more general "scroll " keys so that the UI can chose what to put in . Then add a 'ncurses_scroll_line_count' ui_option value.

How does that sound ?

[Screwtapello]

That would be a good idea. "Number of lines to scroll per scroll-click" is generally a GUI toolkit setting (although it happens to be kind of a mess on Linux right now), so it definitely makes sense to leave it up to the UI.

[Luflosi]

A new UI option sounds good. I'm looking forward to this change 😄.

[lenormf]

b1f5639d8 heh

[Luflosi]

I've been using this feature for a while now and it's working as expected. Thank you very much for implementing it!

[mawww]

No problem, you are welcome.