GP SoftwareTwitter
Opus FAQsManualCommandsObjects

Unwanted horizontal scrolling due to KatMouse

Disable / Adjust horizontal scrolling in dOpus Lister in Windows 10 v.1903

Trial install of Windows 10 v.1903 in VMWare 15, dOpus 12.17 --

Problem does NOT occur in Trial install of Windows 10 v.1809
same VMWare - same dOpus .ocb settings applied.

Problem = unwanted horizontal scrolling in dOpus Lister
when mouse wheel is used to scroll vertically.

Problem does NOT occur in Windows File Explorer,
nor in Acrobat or Wordpad when the same conditions apply
(document zoom exceeds available window space).

Problem seems to only occur in dOpus in v.1903 ??


Problem occurs in either single pane or double pane Lister itself --
NOT the tree (as in Preferences > Folder Tree > Options > Horizontal Scrolling Style).

If the Lister's column layout is wider than the window --
such that a horizontal scrollbar appears on the bottom,
then "normal mouse wheel scrolling" of a directory from top to bottom (or vice-versa)
causes the directory display to scroll horizontally -
seemingly in a 1:1 real-time ratio to the vertical scrolling.

I do have a complex setup of AHK, KatMouse, StrokeIt, and Active Window Manager,
and I am using a multi-button Logitech G300s mouse --

but as stated at the top, this behaviour is only happening in this new Windows 10 v.1903.

Thank You for your help ~

Whatever you're seeing isn't normal and hasn't been reported before. Windows 10 1903 has been out for some time and seems to be what most people are using (including ourselves).

I'd look at the various mouse/gesture utilities you mention in case they're doing something, or any other differences between the virtual machines (e.g. mouse utilities/drivers within the VMs themselves, or differences in how the VMs are configured).

Hi -- I solved it -- I had NOT installed KatMouse in v.1809 --
which explains why there is NO problem there!

So, I went into KatMouse settings and excluded Classes: dopus.filedisplay,
now it no longer does horizontal scrolling.

I know that KatMouse is an "abomination" from XP days,
but it still has critical time-saving features for me in my peculiar work habits!

1 Like

Glad you found the cause!

The main thing KatMouse seems to do (sending scrollwheel messages to the window under the mouse instead of the window with focus) is built into Windows 10 these days. (In fact, it's on by default, and the Start Menu no longer works properly if you turn it off, much to my annoyance.)

Maybe you're not using it for that but the middle button function it also adds, although that would mean you're not able to use the middle button in applications that support it, which wouldn't be great. (e.g. In Opus you can middle click files and it's like holding ctrl and left-clicking them, without having to use two hands. Toolbar buttons can also have distinct right and middle click actions.)

Right -- built in Win10 behavior to scroll a non-focused window I do like.

and also your point about middle wheel -- I do disable that KatMouse function,
b/c it's just too handy to depress that middle wheel for added functions -
whether in dOpus or in a browser -- to close, open in New Tab, etc - whatever.

Thx for your assistance

1 Like