mouse scrool wheel events

[malafronte]

Hello!

I noted that in CVI 9.0 when  using a slide control (hot mode) with the mouse scroll wheel, the only event generated is EVENT_MOUSE_WHEEL_SCROLL.

But in CVI 2013 the same control generates EVENT_MOUSE_WHEEL_SCROLL, EVENT_VAL_CHANGED and EVENT_COMMIT.

Is this behavior correct?

Thanks in advance.

[ebalci]

That is most probably an intentional change in the runtime engine.

If you have code written in 9.0 and utilising the scroll event, it will still work in 2013.
So, it is backward compatible.

Does that cause problems in your code?

[malafronte]

Well, I need to do some adjustments once now it generates a COMMIT event, and this is unexpected by my code.

But if it is intentional, I think that could be something in "readme" file or in the "released notes", but I did not find any.

[Wolfgang]

I can't tell about CVI 9, but of course a EVENT_VAL_CHANGED event should be generated if you change the slide control setting, The same is true for the EVENT_COMMIT if the control mode is HOT.

If the EVENT_COMMIT is unexpected for you / your code it might be easiest to change the control mode of the control from HOT to NORMAL. The only difference between HOT mode and NORMAL mode is that the control generates a COMMIT event. 

Hope this helps.

[LuisG · Accepted solution]

The reason those events are sent in CVI 2013 is because operating the mouse wheel really does change the value of the control in CVI 2013, which didn't happen in 9.0. This was implemented as a result of an idea exchange submission and it was documented in the CVI 2013 release notes (search for "mouse wheel").

The events are not referenced explicitly in the release notes because the key difference was the control value changing. Once that happens, then, as Wolfgang mentioned, the events do need to be sent.

Luis

[malafronte]

Ok, now I understand!

Thanks