I implemented a ‘zoom’ based on Scroll wheel events.
Scroll one way, zoom in, scroll the other,zoom out
I had some feedback from people telling me that I had the direction / effect back to front, so I added a user preference to reverse the direction.
But I realised the OS already has this.
Does anyone know a cross platform way of telling which way the scroll wheel should act so that I can duplicate the OS behaviour?
I may be wrong, but I think the behavior is reversed depending on the running OS (Windows / MacOS; Linux unknow/forgotten).
I think it is not the zoom, but the scroll up/down.
I cannot check this. Sorry.
Does anyone know how to get the information?
On Mac, this works:
defaults read -g com.apple.swipescrolldirection
Windows (only tested 10) is more work. You need to determine the hardware ID of the device (trackpad/mouse/both…), open its key in the
HKLM\\System\\CurrentControlSet\\Enum\\HID hive, and check the
FlipFlopWheel value. Note that MS has removed the user preference setting for this in Win 10 (in 1903 anyway).
Dunno about Linux.
Your preference setting may be the easiest route.