When I hover over sliders and popups, and use the scroll wheel, the value of the slider or popup changes. I find this incredibly disconcerting. Often, I will be scrolling through a window and coincidentally hover over one of these, inadvertently changing the value. For example, in the screenshot below (from Inkscape), if I scroll through the sidebar, I often accidentally change the value of "Blend mode" and "Opacity". How can I prevent the scroll wheel from modifying these values, and limit it to scrolling windows?

Are you using focus follows mouse by any chance?

I suspect this is caused by the sliders and popups having focus instead of the main widget - causing the scroll events to be translated into up/down changes on them instead of acting to move the scroll bar.

bcooksley wrote:Are you using focus follows mouse by any chance?

No, I'm using click to focus.

bcooksley wrote:I suspect this is caused by the sliders and popups having focus instead of the main widget - causing the scroll events to be translated into up/down changes on them instead of acting to move the scroll bar.

Perhaps I misunderstand, but isn't it just the default behaviour to have the scroll wheel modify the values of sliders and popups? Hence in my case it's technically "user error", because I'm hovering over these features rather than the blank window area. In practice though, it's difficult to restrict my hover over blank window areas.

Inkscape is a Gtk+ application ("wrong forum" and you cannot prevent the mousewheel from regular action in any toolkit (w/o hacking it of course) - also interaction with spinboxes w/o a scrollwheel is incredibly nasty.
The "bug" here is the "ability" (read: "need") to scroll this kind of window in the first place.

-> Maybe stack the docks in tabs if you've not enough screen estate - otherwise get used to scroll the scrollbar and not over the window.
-> If you're lucky, gtk+ implements a modifier for this (ie. try scrolling with alt, shift or ctrl down)

luebking wrote:you cannot prevent the mousewheel from regular action in any toolkit (w/o hacking it of course)

Ah okay. That's unfortunate. Thanks for that advice.

luebking wrote:If you're lucky, gtk+ implements a modifier for this (ie. try scrolling with alt, shift or ctrl down)

Nice idea, but none of those work. Ctrl and Alt don't change the default behaviour, and Shift restricts the mousewheel to only working on sliders! The opposite of what I want… That would have been nice if it had worked, because then I could have mapped modifier-mousewheel to the mousewheel actions.

In case that's not clear - scrolling the "window" is feature of the toolkit/application - not KWIn.

luebking wrote:In case that's not clear - scrolling the "window" is feature of the toolkit/application - not KWIn.

Okay. I was also replying just as a FYI.

Also, I seem to remember some KDE applications doing this too, but I can't seem to find any now I'm looking for them. Certainly I can find KDE apps that use scrolling to scroll, and scrolling to change settings, but I just can't find any that do it in the same window. Perhaps you are right, and the "bug" is avoided here (being that both never coexist).