Hiep, I committed a different fix based on your patch, please check:
https://bitbucket.org/idempiere/idempiere/commits/44054f0
and a fix here because the windows with pending save were being closed:
https://bitbucket.org/idempiere/idempiere/commits/7a7d302

Regards,

Carlos Ruiz

with pack make a issue.
when close a tab (isn't calendar) throw NPE.
I attack pack for fix this issue

I think my below issue isn't a issue. because i don't fix it.
"when open multi calendar window, refresh a calendar window, make all calendar window refresh.
because, make separate "SimpleCalendarModel scm" for calendar window "

When this this issue I detect below problem.
"when setOnCloseHandler in Tabpanel, tab can't close"
to fix this error, i also fix above problem.
if above problem isn't a issue. please point me, how to handle close tab event

change type or make event is not a reason.
reason is by all calendar window use one Model (csm object make in DPCalendar).
when close calendar window. it's not release Model.
for fix error, handle onclose calendar window (I don't know how to handle, will research)

but other issue is exist.
when open multi calendar window, refresh a calendar window, make all calendar window refresh.
because, make separate "SimpleCalendarModel scm" for calendar window (will try)

You have to change type or click on ReQuery...