Android Question best way to do some kind of templating or inheritance

[leitor79]

Hi,

I know inheritance is not supported (yet?).

I have some activities and I'd like to give all of them the same look&fell and share some controls (like a navigatordrawer).

So, using inheritance, I would define the navigatordrawer on the base class and inherit it form the children. But since this is not supported I'm wondering: which would be the best approach to have the same "suff" in all my activities wihouth having to touch the code of all of them if I need to make some change?

Regards!

 

[Erel]

Implement the shared logic and UI in a class and create a class instance in each of the activities.

 

[LucaMs]

Implement the shared logic and UI in a class and create a class instance in each of the activities.

I would need a little example
-------------------------------

To get the same "look & feel" don't you should use xml files, as you do with CSS for html pages?

 

[LucaMs]

To get the same "look & feel" don't you should use xml files, as you do with CSS for html pages?

Well, we should use B4A layouts; also, it's very likely that he wanted also some code "duplicated" (like the views event handlers).

 

[Erel]

Lets say that you want to add a toolbar at the bottom of all activities.

Create a layout for the toolbar. Load the layout in the class:

Public Sub Initialize(Activity act)
 act.LoadLayout(..)
End Sub

Handle the views events in the class.

 

[LucaMs]

So, I should have, in each Activity, something like:

Sub Globals
    Private MyTemplate As clsMyTemplate

Sub Activity_Create
    MyTemplate.Initialize(Activity)

But then I have to declare the views in the activity and the class should expose the views' events, right?

 

[Erel]

So, I should have, in each Activity, something like:

Yes.

But then I have to declare the views in the activity and the class should expose the views' events, right?

No. The relevant views should be declared in the class.

 

[leitor79]

thanks for the answer! very nice!

I have one question regarding your interchange... should MyTemplate.Initialize(Activity) be called before or after the current activity's call to loadlayout?

Thank you very much!

 

[LucaMs]

should MyTemplate.Initialize(Activity) be called before or after the current activity's call to loadlayout?

It is irrelevant (same thing).


P.S. More precisely, no matter the order in which two layouts are loaded (mixed).

 

[leitor79]

Hi again,

What if I have a button on my template class, and I want it to fire a sub on the activity I implement it? I think about a callsubdelayed, guided by a some kind of flag marking the activity it is implemented and therefore should be called, but this solution... too little ooped, too "unclean" seem to me...

Regards,

 

[LucaMs]

Hi again,

What if I have a button on my template class, and I want it to fire a sub on the activity I implement it? I think about a callsubdelayed, guided by a some kind of flag marking the activity it is implemented and therefore should be called, but this solution... too little ooped, too "unclean" seem to me...

Regards,

I don't know what you exactly mean.
I hope the test project I'm attaching can help you.

 

[leitor79]

I'll try it, thank you very much!