Re: [pclasses-devel] signals/slots for IODevices?

[Christian P. <cp...@se...>]

Am Samstag 18 Dezember 2004 14:03 schrieb stephan beal:
> Yo again!
>
> Question: would it be feasible/realistic to add signals to IODevice.
> Something like:
>
> signalRead( const IODevice &, const char * buff, size_t count );
> signalWrite( const IODevice &, const char * buff, size_t count );
>
> The first arg is so that one client slot could listen to multiple IODs,
> but we wouldn't want them changing the IOD from the slot, thus the
> const.

Yes, good idea !  Don't know why it's missing ;-)

> This would allow:
>
> a) send read/write progress feedback in, zB, a UI.
>
> b) me to plug in the s11n Serializers to IOD, by simply capturing read()
> input via a slot, then sending it to the Serializers via an
> istringstream copy of the input. (They're designed to read
> std::istreams and write to std::ostreams.)
>
> Or are there good reasons not to do this?
>
> Quasi-related:
>
> For streambuffer support, i'm thinking something like this:
>
> IODevice * my_io_device = new SomeIODevType(...);
> IODevStreambuf sb( my_io_device );
> // ^^^^ basically proxies over/underflow() to read/write()
> std::ostream os( &sb );
> // use any IODevice via any std::stream
>
> i don't know if it'll work, though. When i've tried to implement custom
> stream buffers i've failed horribly - the architecture, while sound,
> confuses me. Too many low-level details to track at once for my mind to
> keep up with.
>
> Hell, this support may already exist in P. If so, i haven't found it
> yet.

Please have a look at P::IOStream.


Regards,

Christian