Re: What is the definition of active application ?

Yoshiharu Dewa (dewa@crdl.pioneer.co.jp)
Wed, 27 Aug 1997 10:34:28 +0900

Dear Seungtaek and MUGer,

>>>>> On Mon, 25 Aug 1997 22:03:23 +0900, "Seungtaek Oh"
>>>>> <ducky@mmlab.snu.ac.kr> said:
>In MHEG spec, I can't find the absolute definition of "active =
>application".

There is no definition of "active aplication" surely, but "active"
is there. "active" means state of object when the Activation behaviour
has been completed. so..

>Is it the running application object ?

Yes, it is.

>Or is it the application object just after the "Launch" action is =
>initiated ?

In our implementation, when the MHEG engine has been started by
selecting application file, the engine issues "Launch" action
implicitly, and the application object is active.

>For understanding, let's see the example.

>A : application withOnStartUp(TransitionTo S)
>S : scene with bitmap B
>B : bitmap object

>if we call "Launch A", engine must process this elementary action.

Why not activate the application object at first?

>when engine try to process the OnStartUp, currently A is not running,
>but must process TransitionTo (to S).

>In this situation, there is no running application, but, after =
>processing of TransitionTo,
>there is running Scene Object. Futhermore, if B is initially-active,
>B must be running after TransitionTo. And B must be in DisplayStack of =
>A.
>But A is not running currently, this is uncorrect state (I think so).

>Please answer this mismatches in Spec. (Or my miss-understanding ^^)

Please refer the Annex C of IS. (bootstrap mechanism)

>Anyway, in above case, when A could begin to play a role as a active =
>application ?

>Just after prefetch encoded data of A ?
>Or just after decode that data of A ?
>Or just after the running status be true ?
>Or just before processing of OnStartUp action ?

I think just after Activation behaviour of the application has been
completed.

>Has Active same semantic as running ???

Yes, I think so. "Active" state is linked with RunningStatus.

-----
Yoshiharu Dewa
Pioneer Corp. Corporated Research and Development lab.
E-Mail: dewa@crdl.pioneer.co.jp
URL: http://www.pioneer.co.jp/crdl/staff/dewa/profile.html