Well I know it is some work and that's why I don't propose to maintain it...
If he is OK, perhaps he could get the techFAQ page that Tom had installed
on his web site and find a place for it on your MUG site. Then one of us
could try to correctly format an answer to each frequently asked question
on this list when it occurs once more. This would minimize the work needed
to maintain this kind of page. Any suggestion or opinion are welcome.
>> I think the main problem is that scene variables are not active when the
>> OnStartup is executed. Moreover, shared application variables are neither
>> active when the first scene onStartup is executed. This doesn't allow us to
>> use these variables in the Onstartup action.
>
>Right. But I don't see a good solution for this. A possibility might be
>to use some variables in the Application object, but this is not very
>feasable.
Another solution would be that a new version of MHEG-5 specify that
variables only need to be available in order to be used, or that a variable
is always active. Any thought whether this could be a problem ?
>> The conclusion of all this is that the onStartup should only be used to
>> make things on available ingredients (for instance setPosition or
>> setBoxSize of an application visible that is available) and before it is
>> displayed.
>
>This is quite useless (SetPosition) because you usualy have the screen
>coordinates for the objects :-)
>No, we haven't found a useful purpose for the Scene::OnStartUp attribute.
>We use it in the Application object to make a TransitionTo the Scene but
>this can also be done with the method you described below.
Not true. About SetPosition/SetBoxSize, this would be only useful if you
want to display an application items at different location/size depending
on the scene. But I will give you some case where the onStartup could be
useful. That's the ones I use in my Authoring tool. Just look at this two
examples (there are a few other cases) :
1. Suppose you want a stream to play continuously over a scene transition.
You have to share it in the application file, with the shared attribute
true. Suppose also that you must have a background behind this stream that
is defined in the scene. During the scene transition, the stream is not
stopped and remain in the displayStack so you have to put it before the new
background.
In that case, a PutBefore action in the onStartup allow to activate the
background behind the stream.
2. Suppose you want to define some action-slots for a ListGroup that should
be empty (or at least has less items than cells). You are obliged to define
dummy items in the ListGroup in order to be able to attach some action
slots. Then the OnStartup is a good place for "DelItem" with reference to
all the dummy items you don't want to activate.
Hope this could help you to find a useful purpose for this onstartup attribute.
Best regards,
__________________________________________________________________
Emmanuel BEUQUE mailto:ebeuque@pratique.fr
MediaServ tel: +33 (0) 2 99 64 35 64
Multimedia consultant & developer fax: +33 (0) 2 99 64 36 65