Hi.

hello, Jan!

how can I help you today?

I am using an observer and it is working okay. I followed one of your examples and observe on the viewstate. The viewstate has a hashmap that doesn't change during the user actions. But the key used for the hashmap changes based on user actions. So I'm wondering if I need another observer to watch for changes to the key? I update the textView when that change happens -- and that's on a button click.

so, they click a button, and you switch keys?

Exactly.

then, it sounds like your key is part of the viewstate

on a button click, the UI can tell the viewmodel "yo! the user clicked the button!"

the viewmodel emits a fresh copy of the viewstate, with the hashmap and the new key

the UI layer then renders the UI based on that

in *Exploring Android*, I take that approach for a filter menu, to allow the user to view all to-do items, completed ones, or incomplete ones

(though in my case there is no hashmap -- I do fresh Room queries)

I am not changing the hashmap like you do in the ToDo filter (using room queries). I'm just changing what I pull out of the hashmap when its key changes.

(hello, sudokai -- I will be with you shortly!)

So should I put the key in the viewstate along with the hashmap? It's the viewstate I'm observing.

Jan: true, but that does not really change my recommendatino

er, recommendation

yes

if your viewstate is using data classes, just copy() the existing state and replace the key in the copy

so, something like oldstate.copy(key = newkeyBasedOnButtonClick)

(and if your app is Java, my sincere apologies!)

Okay. I'll make those changes.

let me take a question from sudokai, and I'll be back with you in a bit

sudokai: your turn! do you have a question?

sudokai: if you have a question, let me know, and I'll turn back to you

Hi

hi!

So I was looking into scoped storage and when does a RecoverableSecurityException get thrown

so was I! https://commonsware.com/blog/2020/03/03/scoped-... :-)

Okay thanks I'll read it first!

ah, I thought perhaps you had run into that post already

yeah, it's probably worth reading, and if that does not fit your needs/expectations, I can try to help further

Well, basically everything is so complicated in Android Q....

yeah, well, if it makes you feel better, Android R is (generally) not dramatically worse

I'm updating an app that still uses file paths to uris

that's gonna hurt

Well, I'm gonna read that and come back if I have more questions

OK, sounds good!

in the meantime...

Jan: back to you! do you have another question?

generally, a network unlocked device can be used without a SIM card, just via WiFi

and, without a network, there is no network activation

my books are read the world over, so any purchasing recommendations that I make would be useless for lots of readers

personally, I tend to buy used devices off of eBay for older ones, and Amazon for newer ones

Well if you put the Coder's TOC as its own booklet - that'd be helpful. I have to scroll a lot just trying to find all the topics. lol

you can always search, either the PDF or online at wares.commonsware.com

but, yeah, that book got kinda big

Wow, your "Scoped Storage Stories" series is fantastic. I'll definitely read the whole series.

unfortunately, I have to keep writing more posts...

(and thanks for the kind words!)

As I understand, I need not worry about RecoverableSecurityExceptions if my app never writes to a file created by another app?

I'm using the MediaStore

correct -- if you are only updating your own content, you should be fine to do that

now, eventually (Android S?), they're probably going to need to add some sort of "transfer of ownership" feature

assuming that the permission to modify the content eventually times out

I haven't tried doing any long-term tests to see -- I know it lasts longer than a process, but that's it

Well, what I do is to copy the file and insert it again into the MediaStore before modifying it

Then it's my file

assuming the user is OK with that approach, that should be fine

and, this will only work with real media -- for the MediaStore.Downloads collection, you cannot read other apps' stuff

Okay

I'm working with images. I saw there's an additional restriction you didn't mention in your Elements of Android Q book.

It's that you need the ACCESS_MEDIA_LOCATION permission to see the location of a photo via its EXIF

I thought I covered that

Mmmm, my bad. It's in the following chapter I see

I probably should have put a forward-reference to it in the chapter on MediaStore

(BTW, Jan, if you have another question, feel free to chime in!)

Yes Jan, go ahead :)

I'm considering enabling a long click on my list of items in RecyclerView. If you wanted to display a short description, how would you do it? I'm considering popupwindow, snackbar, or toast.

actually, I try to minimize the use of that sort of popup, so I'd aim to display the information in the main UI somewhere

but, of those three, I would go with a Snackbar, if you are using the Material Components for Android

(or want to go with a third-party Snackbar implementation)

Thanks. That's how I was leaning - if I decide to do it.

That's all for me. Have a good night, everyone.

you too!

Goodnight see you around Jan!

Mark Murphy: What's the difference between getApplicationContext().getContentResolver() vs getContentResolver()?

the first one takes longer to type

otherwise, there shouldn't be any difference

unless somebody is overriding getContentResolver() in an unexpected place

for UI concerns, your choice of Context matters (use the Activity)

Okay, because in your MediaStore example I saw the latter, but in Google's Android docs on MediaStore I saw the former and I was wondering

¯\_(ツ)_/¯

I wind up filing corrections for their samples a fair bit

:)

on occasion, it turns out that I'm flat-out wrong or misread the sample

on occasion, they agree and fix it

and most of the time, the issue gets ignored

I think your books and blog are the best Android reference I've ever seen

thanks! tell your friends! :-)

Yes, I wouldn't mind paying more for the subscription tbh

I was planning on bumping the price a bit -- it's stayed flat for a few years now

probably two options: $25/six months or $40/year

The app of the company I work for used to cost $5 a year, and we just bumped it to $10 and made the subscription auto-renewable.

as a consumer, auto-renew on some things is fine

as a privacy-and-security-focused business owner, I am uncomfortable with it

Some people complained, but when you look at the numbers, it was actually a loud minority

that doesn't surprise me

Yeah, me too tbh. Google controls the subscription cycle completely.

It's pretty inflexible too.

Like, Stripe payments for example are great

They give you a lot of flexibility

yes, I have had pretty good luck with them overall

Oh, you use Stripe? Nice to know.

yes, the Warescription can be purchased by either PayPal or Stripe

Another Android question, still on the same images topic: when I request ACCESS_MEDIA_LOCATION after the user has accepted the WRITE_EXTERNAL_STORAGE permission, I get no additional permissions prompt

Nor I see the permission listed in my app settings

Have you encountered this before?

no, but I only lightly experimented with ACCESS_MEDIA_LOCATION

I focused more on seeing if the redaction worked in places other than the MediaStore, using ExifInterface

(answer: it does not)

so, I doubt I paid attention to what was in the Settings screen

Oh, on that topic...

and I honestly don't recall the specifics of the permissions prompts

I'm trying to find the code

So I open the native gallery and select a file. I get a "temporary" uri.

ACTION_PICK?

It seems that reading that Uri gives you the EXIF location, but I've seen people say otherwise

I mean it works on my phone

well, in general, ACTION_PICK gives you permissions to work with the item that was picked

for example, if you pick a contact, you can get at the name, email, etc. even though you do not hold READ_CONTACTS

new Intent(Intent.ACTION_GET_CONTENT)

so, I am not terribly surprised that what you describe works, though I'm sure I didn't try it

intent.putExtra(Intent.EXTRA_ALLOW_MULTIPLE, true);

intent.setType("image/jpeg");

startActivityForResult(intent, REQ_ADD_PICTURE);

yeah, I would expect that to work as well -- after all, you could always use ExifInterface and get the location that way

Okay, yeah, it works for me as well.

I'm trying to refactor a RecyclerView ViewHolder that observes 2 RxJava Observable streams, one coming from an EventBus and it's a nightmare

the ViewHolder observes RxJava streams?

eek

Yeah

Haha, and not only one but two

And of course the RecyclerView itself is connected to Realm

As in, it's Realm that manages the list

through RealmRecyclerViewAdapter

while I'm not a Realm fan, that part at least isn't scary

but, that's a wrap for today's chat

Okay

the next one is Tuesday at 8:30am US Eastern

Thanks Mark

Stay healthy during these days!

you too!

It's scary out there

Thanks!!