09-18-2015 04:45 PM - last edited on 09-19-2015 05:48 AM by Majestic
As suggested per this bug-report at the Google Chrome forums...
...I am now posting here as it turns out to be a driver related issue.
I am running on a Y580, Win 10, got Lenovo Touchpad drivers installed via Windows Update.
This has bugged me for a veeery long time and I finally figured out what causes it.
The problem is this:
In any application where I scroll content, the "smooth" scrolling of the touchpad makes the display scroll even after I am done performing scroll gestures. In itself that ain't a bad thing, if only the application wasn't thinking I am still performing the gesture. Well, they all do. And that is a problem, because the second I touch the CTRL key, and I do that often, a ZOOM-EVENT fires and so I am constantly forced to reset the zoomlevel.
Note that the current driver ui doesn't give me an option to disable smooth scrolling.
In general, on the level of touchpad drivers, there needs to be a clear difference between "user is actually performing a scroll action" and "driver is still busy firing scroll events thanks to some smoothifying algorithmagic".
I now disabled scrolling in the driver settings alltogether and use TwoFingerScroll to do the scrolling; it allows me to set scrolling to "compatible" rather than "smooth". Scrolling now feels a wee more staccato but seeing an end to all the unwanted zooming that ain't a bad thing, at all.
FWIW, apart from some more touchpad-troubles, upgrading my Y580 from WIN 8.1 to Win 10 went about as smooth as one can expect from an operating system upgrade thanks to having uninstalled all previous drivers beforehand.
Mod's Edit: System model added to front of Subject line to improve visibility / clarity.
10-13-2015 12:38 PM
I had this same problem when using Google Chrome on my T440s (under both Windows 7 and Windows 10). The continual zooming had been annoying me for months, until yesterday I figured out that I was pressing the control key while there was some still some scrolling momentum.
Thankfully in my case the fix is simple: I have turned down the "scrolling intertia" in the Synaptics control panel, and I am no longer experiencing unintentional zooming.