Use Events to update UI

[Fivezero05]

QtForumInfo.png

This picture represents the class structure.

frm => ui
cls => a normal class

So this is what happens :

1) press a button on frmMain
2) clsMainlogic does not really do something itself, but gives the task to clsCameraLogic (other classes are connected to clsMainlogic, but those are not relevant for my question)
3) in clsCameraLogic a function is running some code, but it takes a long time

alright , here is what my problem is:

The function (in clsCameraLogic) takes quite some time to complete. To update the user on its progress, an event is used to update frmLogger.

Now, I know that you can't just update an ui from another thread. So my question : how do I do it?

To complete the cycle:

4) an event from clsCameraLogic with a string is given to clsMainlogic
5) clsMainLogic gives the same data to frmMain
6) frmMain, owner of the frmLogger object, calls a function in frmLogger to update the text in a label

Step 1 to 6 work, the data reaches frmLogger, but it is not updated.

I used the events native to c++, __hook and __unhook .