[winswitch] Scrolling with mouse wheel not working

[Antoine Martin]

(..)
> You are right - it is CentOS 6 ;-)
> 
>> [...]
>> You can try running the client with "-d mouse" and you should see events
>> like those:
>> _button_action(4, ...
>> (4 for up and 5 for down. 6 for left and 7 for right)
> 
> Ok. When I use scroll up using the mouse wheel I get tons of these messages:
> 
> 2017-02-02 17:28:29,496 mousewheel: orientation=vertical distance=30.0, units=0, new value=0.0, keys=0x0, x=439, y=360, client=gtk2.client, wid=218
> 
> When I scrool down (the one that works) the messages are slightly different:
> 
> 2017-02-02 17:29:41,362 mousewheel: send 1 wheel events to the server for distance=-120, remainder=0
> 2017-02-02 17:29:41,382 mousewheel: orientation=vertical distance=-30.0, units=-1, new value=-30.0, keys=0x0, x=434, y=375, client=gtk2.client, wid=218
MS Windows clients have extra code for handling scrolling acceleration:
https://xpra.org/trac/ticket/1131

The "distance" is accumulated until we reach 120. (this is a MS Windows
constant)

It looks like your system uses a non-standard vertical acceleration set
to just 30 (4 times slower than normal), so it may take 4 wheel scroll
steps to generate one scroll event server side. (and up to 7 events if
you had already scrolled 3 events in the opposite direction)

This code could be improved to tiemout or at least reset the distance
when the scrolling changes direction. Feel free to file a ticket for it.

(..)
> Do I interpret it correctly that the client does not forward the "up wheel" messages to the server (since there is no "send 1 wheel events to the server ..." for up scrolling?
Yes.

Antoine