Android Question Service: Use CallSub or CallSubDelayed?

[rwblinn]

Hi,

following setup:
A Main Activity starts a Service.
In the Main Activity a Sub is defined which is to be called from a Service Sub to update data collated by the service.

Question: Should the Main Activity Sub be called via CallSub or CallSubDelayed from the Service?

 

[udg]

Hi Rob,
according to its tutorial, CallSubDelayed should be the preferred method.
I guess that it depends on the fact that CallSubDelayed is able to "bring to life" the Activity before calling the sub.

udg

 

[Erel]

If there are multiple activities then it might be better to use CallSub, to avoid starting the Main activity unintentionally.

 

[udg]

If there are multiple activities then it might be better to use CallSub, to avoid starting the Main activity unintentionally.

@Erel : do you mind to explain that a bit deeper? Both CallSub and CallSubDelay reference the module containing the to-be-called sub, so in which cases Main could be called unintentionally? I am surely missing the point..

 

[LucaMs]

Perhaps he means that you could have a different activity on and you do not want to stop its execution because of the opening of the Main.
In the case of data retrieved from Internet or from a database, perhaps it is better that the Service put that data in a "global container". This perhaps is best also to keep separate data and GUI.

[I have to start fiddling with Services, sooner or later ]

[Ops... I did it; I'm using a Service in my app but now I use it automatically]

 

[rwblinn]

Thanks all for advice.
Using following (pseudo code): with a MainActivity and ServiceModule

MainActivity.StartService(ServiceModule)
    ServiceModule.CollateData (interval)
    ServiceModule.CallSub(MainActivity.DisplayData) [if MainActivity is not paused]
MainActivity.DisplayData

Background
Developing of a B4A GoogleMaps Way Tracker (for personal use) using GPS, GoogleMaps Library, KeyValueStore (to store each Track (as a Type) including waypoints), ListView (listing the Tracks, click on a Track the way is displayed on GoogleMaps - data taken from KeyValueStore), long click to delete a Track... and more ...

Good learning moments so far - the B4A UserGuide is essential to read (take time to do so).