whoops -- hello, Susheel!

how can I help you today?

(sorry about the delay there -- got distracted...)

Hey Mark

No problem at all

I just have a couple quick questions

go right ahead

1. I need a viewpager style widget that will allow me to scroll through views/fragments but I will only need to use two layout files and the first view is an introduction page(first layout) and the remaining views will be of the second type of layout file. I am wondering if I can use any type of view recycling mechanism for the '2nd' type of views. Does that make sense?

personally, I have switched away from ViewPager to RecyclerView for this sort of horizontal swiping scenario

recycling of the pages is one reason, as ViewPager doesn't really offer that, though you could probably rig up a custom PagerAdapter that did it

that contains four sample projects demonstrating the technique

one uses a third-party RecyclerViewPager library

the others use PagerSnapHelper

I see. I had no idea. Do you mention this repo in your book?

yup, whole chapter on it

Great! You are amazing!

I try to be useful :-)

:) Now to my second question...Do you have a chapter on mvp or clean architecture?

not presently

Are you familiar with an architecture called VIPER?

I have heard of it

I will be covering some of that sort of thing in "Android's Architecture Components" later this year

It's based on SINGLE Responsibility. Our company has just adopted it.

I know you already have a book on architecture components.

Hello

(Ndrocchietto -- hi! I will be with you momentarily!)

(OK thanks)

that book's current focus is literally on the Architecture Components libraries from Google

but, I plan on exploring their use in MV* scenarios

though my current lean is towards MVI (model-view-intent)

Right. I will need to go through the main book to see where you talk about the recycling mechanism we were talking about.

I will make a point to read more on VIPER and see if it makes sense to include as part of that architecture material

Thank you

Ndrocchietto: hi! your turn! do you have a question?

HI Mark, do you know something about Clean Architecture?

(for Android, not Uncle Bob for Java)

I was just about to point out that the term gets overloaded

ah ah

I am a bit more familiar with the Uncle Bob formulation than how it is being used in Android apps, but I know bits about it

as I was telling Susheel, this sort of subject will eventually make its way into the "Android's Architecture Components" book

that is fantastic

just I cannot get why you the Android community uses ThreadPoolExecutor with java

sorry I mean RXJava

sorry, but I did not understand that comment

well when you use Clean Architecture you want that all your interactors act asyncronously

in a separate way

so there is the tendency to combine ThreadPoolExecutor, to insure that a certain number of Thread are executed sequentially with RXJava2

and this is a bit confusing to me, especially when I use Kotlin

I haven't seen that particular combination

you definitely want to manage your thread count, so that you don't wind up with far too many forked threads

ah ok

your abstractions are only as good as the environment lets them be

because with RXJava you cannot do that

and in Android, with mobile device CPUs, limited heap space, etc., the environment is unfriendly to abstractions

so, in this case, perhaps they are trying to enforce a thread pool semantic on RxJava to allow for N threads but for a controlled value of N

ok I leave you the link of the blogger guy that everybody is following, just in the case you are curious, not to reply to me (https://fernandocejas.com/2015/07/18/architecti...)

ah I get

makes perfectly sense

note that the blog post that you linked to is from 2015, so it will be RxJava, not RxJava2

you are right

Susheel: do you have another question?

is with RXJava

Do you remember the name of the chapter with the recyclerview viewpager off the top of your head? Is it Recyclerview as a pager from Advanced Recyclerview?

that's it

Sounds great.

that's a wrap for today's chat

Have you heard the release of ARCore for Android?

Oh cool.

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

have a pleasant day

yes, I saw it

I have a tenuous grip on reality, so perhaps augmented reality will help :-)

I was wondering if you will cover it in the book sometime but I will continue this question in the next chat

:)

the time is over:)

no, AR/VR isn't my area, sorry

Oh okay

the next chat is Tuesday at 9am US Eastern

Thank you Mark

have a pleasant day!

Bye

Have a pleasant day gentlemen

youtoo