hello, Pao!

how can I help you today?

Hi Mark, I have 2 questions. The first one is the difference about `test` and `androidTest` in an android project. I know these can be used for unit testing but do I need to have duplicated tests for a certain class that should exists in both directories?

most of the time, you test one app class either using instrumented tests (androidTest/) or unit tests (test/)

sometimes, though, while you would prefer to test the app class with unit tests (as they run faster), some features of the app class are too tightly tied to Android

in that case, you might wind up testing different parts of the app class in androidTest/ and test/

however, you should not need *duplicated* tests

Ohhhh. I see, so basically the test requires android stuff it goes to `androidTest/` and I don't need to do it in `test/`. I get it now. Thanks!

Is it storing the API keys in Android Native Module good enough layer for an additional protection of API keys?

Btw, that's my second question :)

storing API keys in NDK code (C/C++) does virtually nothing to help secure them

anybody talented enough to want to get your API keys will be talented enough to get to them regardless of where in the APK that they reside

Okay, so additional effort will be useless. Since, there's no bullet proof solution to it.

the NDK trick isn't even a decent "speed bump" to slow people down

let alone a bulletproof solution

I thought storing the API keys in NDK will have another layer of protection

it does, but that layer is not very good and IMHO is not worth the headache

in general, there is no bulletproof solution, unless the provider of the API offers one

I see. Thanks Mark! That's all for me today :)

Have a great day or night! Thank you for the answers

OK, sounds good!

you're welcome!

hello, Joel!

how can I help you today?

hi, Im actually the person who posted about how to build mobile app in object oriented way in commonsware community

OK -- hi!

what im having problem about is the fact that i dont know where to start in terms of starting to visualize the components in mobile app

for your very first Android app, I would start by thinking about what screens you want, and then work your way inwards from there

right now, I recommend that your top priority be to learn how Android works

for example if within a normal software application, i will just need to draw class diagram and identify what are the necessary classes and objects to determine how program works

but as for mobile app im quite clueless on it

I have not seen anyone create a class diagram in 20 years or so

I guess some people still do that

could you just maybe describe a general way as to how people normally work their way up in mobile app development

cause im trying to get a job by my own through self learning so i will need to develop a prototype in proving my ability

well, you have access to some books, through the Warescription -- you could read *Elements of Android Jetpack* (a traditional programming guide) or *Exploring Android* (a set of tutorials to help you build an app)

in terms of "proving my ability", worry about that later

right now, focus on learning how Android works, by creating "throwaway" apps, ones that require no real design work

as you gain some experience with the Android framework and the requirements it imposes, things like that YouTube video on Android architecture will start to make a bit more sense

does the book you mentioned using Java language

and then you can start to work out how you preferred software design approaches fit modern Android architectures

*Elements of Android Jetpack* shows both Java and Kotlin for the vast majority of the book, with a couple of chapters purely showing Kotlin

*Exploring Android* uses Kotlin

what does the android jetpack includes

Jetpack is a "brand" that Google is applying to a lot of existing technology and some new stuff: https://developer.android.com/jetpack

of those, the things that nearly all developers use include: AppCompat, Test, Lifecycles, LiveData, ViewModel, Permissions, Fragment, and Layout

(all of which pre-date the "Jetpack" branding)

some of the other things listed on that page, like data binding, navigation, Room, and WorkManager, are popular but are not needed by every app

so mobile app design is very different from other software in terms of design approach?

I would phrase it more as: software design fills in the gaps between the platform, the architecture, and the business requirements

as such, software design needs to take the platform and architecture into account

you would not design a Web service the same way that you would design a mobile app

*elements* of OO design techniques may be valid for both cases, but the way those elements get applied may differ

that is all the time that I have for today

could you provide an example on that?

the chat transcript will be posted to https://commonsware.com/office-hours/ shortly

and the next chat is scheduled for tomorrow at 8:30am US Eastern (so, 12 hours from now)

have a pleasant day!

ok thx