Observe Region cannot be unregistered

An observer is registered with a Region object and run against that region.

With one Region object you can register one or more events (onChange, onAppear, ...).
For one region it does not make sense to define more than one onChange event.

When the observer is run (reg.observe() foreground/blocking or background/non-blocking) it checks all the currently registered events for that Region object until stopped (timebased or by stopObserver() in a handler).

So this is not true:
Workaround: New Region for every handler

... this is by design to configure a more complex behavior.

--- to wait for changes on a Region

def handler(event):
    global changes
    changes = event.getChanges()
    event.stopObserver()

changes = None
reg.onChange(handler)
reg.observe(10)
if changes:
    print "got changes"
else:
    print "no changes within 10 seconds"

see: https://sikulix-2014.readthedocs.io/en/latest/region.html#observing-visual-events-in-a-region

Hi!
Thanks for the real quick answer!

So I now understand, that Reg.stopObserver() needs to be within the handler function. I will try that.

Still I would like to point out, I spend a lot of time with that doc page you gave. I was not able to figure that out. I still believe with reg.observe(10) it should stop automatically after 10 second - it does not.

However I do have a good workaround now.

For bug 2) - it still don't throw an exception in case there is an error within the handler function.

Thanks a lot!
Michael

--- reg.observe(10) it should stop automatically after 10 second
... correct --- I will check

--- it still don't throw an exception in case there is an error within the handler function.
... an example would be helpful

HI!
Example for the Error issue:

def observertest():

        Reg=Region(1,234,2049,1154)
        Reg.onChange(160, observerhandler)
        Reg.observe(3)
        print ("End")

def observerhandler(event):
        print "Event"
        print 10/0
        print "after division by zero"
        print "Important code, which will never run. And I will never know."

observertest()
exit()

results in:
Event
Event
Event
Event
Event
Event
Event
Event
[info] Exit code: 0
End

no exception

ok. thanks.

... but that at least means, that the observe stops after 3 seconds ...

yes seems so, you fixed that bug (events running after exit) 2 years ago. I opened it..:-)
however, the "End" is print after Exit... maybe just a buffer issue