A: |
Very probably you do
OldHandler = EV_captureEvents (NewHandler);
then you call OldHandler from NewHandler . There would be nothing
wrong in doing so, but function EV_captureEvents
returns NULL when there is no any user handlers previously
installed, which is very common case. So, you can call OldHandler only if
it is not null. In other words, it is illegal to call an event handler when it is not
actually installed. From the other side, function EV_defaultHandler
calls the TIOS handler which is used for default dispatching of some common events. It works independently of
which handler is currently installed and whether it is installed at all. This is a function
which you probably need to call in your event handler to process all unprocessed events.
|