How can I adjust the sensitivity/increment of the mouse wheel on a linear horizontal slider control? Can I call something similar to the velocity mode parameters or do I have to override something?
Don't think we have a way to adjust that, TBH..
It would be a useful addition. We've had a lot of feature requests from users who want to use the same modifier keys that are present elsewhere in JUCE. It's fairly inconsistent that holding Ctrl turn on fine parameter adjustment when dragging, but not with the mouse wheel.
I've also just gotten a request for this. On Windows, with a slider that has a range of 127 (common for MIDI) the step size when using the mouse wheel seems to be 4. I've gotten a request to increase sensitivity when holding CTRL. I did a bit of searching the forum and saw that this issue goes back a ways and there doesn't seem to be any way to resolve it because it's apparently a compromise of different OSs and mouse wheels. I haven't looked at it enough to know those details. But it's not easy to modify yourself because the functions in question aren't virtual, besides I assume if you fixed it on one OS you'd break it on another OS.
Yet, this is software, right? There should be some way to fix the problem without having to tell users "Sorry, you can't have that". I would think that you could at least make it so that holding CTRL just reduces the step size no matter what the scale is (maybe accumulation of the wheel is needed). Then for those cases where it's too sensitive the user just won't use it, because they probably won't need it anyway. Maybe I need to understand the details more to appreciate the problem. But again, it's software, right? There must be something. Even if I need to expose a control to let users adjust the sensitivity the way they like. It may be ugly, but at least it's something.
On another semi-related slider issue, I noticed that although CTRL-drag increases sensitivity, it is disabled when the sliderlength/sliderrange is greater than 1. This sort of makes sense because you can theoretically achieve increments of one without needed CTRL. But if the ratio is just over 1, it can still be fiddly to slide to a particular value. It would be nice to still allow CTRL to work to increase the sensitivity so that it's easier. I'm not sure why it needs to be disabled at all.