Good evening.

howdy, David!

how can I help you today?

First of all, love the book and the code. Thanks.

thanks!

I do have a question regarding viewpager within actionbar tabs

David: go ahead

Hello

(jwandroid33: hi! I'll be with you shortly!)

ok

I have an application with multiple activities, some of which include a fairly deep hierarchy of fragments.

I'm looking to implement the tabhost under ABS, and need to figure out how to move the first fragement of each of these activities into tabs.

FWIW, I'm not a fan of action bar tabs, simply because they are not always presented as tabs

they can convert into a drop-down list at Android's whim

I'd rather go with PagerTabStrip or an indicator from ViewPagerIndicator

but, then again, I

Currently, all the fragments within an activity talk to each other via the activity (listeners). My question is, architecturally, should I embed activities in the pages of a view, or move the fragements into the main activity.

I'm also ok with viewpagerindicator

I recommend aversion therapy (e.g., electro-shock) to stop developers from using the phrase "embed activities" :-)

:-)

that is never the right answer, and has been deprecated for nearly two years besides

your fragments ideally should not care what activity *class* hosts them, only that the host implements some interface

in which case, just make sure your main activity implements that interface, and you should be good to go

Ok, that makes sense. I have the interfaces built and implemented in individual activities. I would move these all to the main activity and just use fragments within the pages of the viewpager.

whether "move" is the right verb, I can't say, but otherwise that sounds fine

let me take a question from jwandroid33, and I'll be back to you shortly

Ok

Cool

jwandroid33: do you have a question?

Yes. I have two but I only want general response

I am trying to ascertain if it is possible to perform peer 2 peer communications between two Android phone with no intermediate server over the cellular network

probably not

Thats what I thought

usually, over a cellular network, you are behind a NAT

just wanted to check.

yeah

and therefore you have no ability to talk directly to another device

ok

I can wait for David or I can ask my second question

?

go ahead

well, that was quick, so let's knock out your second one :-)

Ok

jwandroid33: go ahead

My second question is can I use openRTSP from say my laptop and stream MP4 video to my table using rtsp with basic Android

over WIFI

(howdy, Peri -- be with you shortly!)

Hello Mark, Let me know when it's my turn.

jwandroid33: I have no idea

good enough

I have not used RTSP with Android

OK. If I succeed I will let you know :-)

I know Android supports it, and so in theory it should work

Ok

but, in theory, lots of things should work with Android's multimedia, and don't

LOL

:-)

true

I'm good then. Talk to you soon

OK

Peri: do you have a question?

Thanks

Yes, I have three. Here's the most pressing.

I have a db file. We've talked about this before, and I took your advice and moved it to internal storage.

The problem is how to handle upgrades. Particularly, my free app comes out first. Later I'll want to release a pro and charge for it.

I understand that once an app is free, you can never charge for it. Thus, the pro needs to have a different package name.

So, the problem is how to persist the db.

One solution I thought of is to have a third app which does nothing and holds a package name for the sole purpose of db persistence.

yuck

Then the other apps can use the shared user id and access the db. I got that to work.

Ok, what's your suggestion. I agreee, yuk.

that depends

let's say that on Monday, I install the free app and use it

I was going to say, got it to work, but don't know how to launch an app with two packages.

then on Tuesday, I decide to spring for the pro app, and start to use it

presumably, on Tuesday, I will want the pro app to be able to work with the data that I had put into the free app

No problem so far - the paid app can be used as an "unlocker".

but, if on Wednesday, I go into the free app (which I did not uninstall)... what happens?

does the free app detect that the pro app is installed and redirect over to it?

does the free app work with the same data that the pro app does?

Right, but if the pro version is an unlocker, then the user would continue to run the free package. However, I guess I still need to know how to install two packages at the same time.

At the moment I have just the free. I can imagine though at some point, there will be features and data the the pro will add to the db that the free version won't be able to handler.

does that mean that the pro version, on Tuesday, will effectively "fork" the data, and have its own copy?

with the additional columns, tables, etc.?

Anyway, what's the right way to do this? I want a free version, then a series of paid versions over time. That is, the first version might cost $2, the second $5, the third $10, the fourth $100 :)

well, there is no single "right way"

I don't want to fork data. Ultimately, it could be quite large.

Or, waht do you mean by fork?

have an independent copy

No, just one copy./

OK

Android doesn't make this easy :(

it has little to do with Android

and everything to do with deciding on a business model before writing any code

you need to decide what happens to the free app once the pro app is installed

the pro app cannot be just an "unlocker" if it is adding functionality that the free app does not happ

er, have

Ok, my ideal perference is that the free becomes the pro.

"becomes"?

That's not allowed, so the next best thing would be to install a pro and have the free automatically disappear.

meaning, the free app has the pro functionality, and the pro is truly an unlocker?

you cannot uninstall the free one truly automatically

"becomes" - it's an upgrade of the same package; not allowed.

well, that depends

the "unlocker" strategy says that you really only have one app

it is distributed as free but has the pro functionality, just disabled

when the user buys pro (or, better yet, uses an in-app purchase), you "unlock" the pro features

The unlocker approach is not my preferred solution - it's just that others are using it.

in-app purchases to unlock app capabilities is pretty darn popular nowadays, from what I can tell

Right, I get that.

I don't have the functionality for the pro version yet.

all the more reason to not have a separate pro app

So, please elaborate on in-app purchases.

have one app and use in-app purchases to unlock pro functionality

Is that pretty easy to do?

I mean,

I mean, am I safe to launch with the free version, then offer a free upgrade that includes code to do an in-app purchase for the pro functionaltiy?

AFAIK, yes

OH, cool!

but I am not an expert on in-app purchasing terms and conditions

nor am I a lawyer

I can deal with that later, then.

right

Well, are you saying that google might not allow it?

more importantly, from an architecture standpoint, you don't have to fuss with two apps trying to access one data store

again, AFAIK, what you are describing is perfectly fine

Your last comment is right on.

but I am not an expert on in-app purchasing terms and conditions

I haven't even read them

as I don't use in-app purchasing

Ok, that's enough on this question. I'll deal with it in Jan or Feb.

from what I see being done, it should be fine, but I can't vouch for it

OK, I'll be back with you in a bit

scottt: do you have a question?

OK, scottt, if you return later, let me know

David: back to you -- do you have another question?

The viewpager in my app has five pages. There's a starting fragment within each page. During use, the user may drill down through related fragments (think Master->Detail->Action) within any given page. I would like (through state retention) for the users position (current fragement) within each page to be retained as he/she swipes between pages; I'm assuming I'll be using extending FragmentStatePagerAdapter. I'm a bit worried about losing track of all these fragments, and also that the back-stack will become spaghetti. I'm looking for a good direction in implementing this.

personally, I wouldn't do that in the first place

Ok, I'm open.

I am not a fan of replacing-the-tab-content as a form of navigation

I was worried with your original description, but it wasn't what you were asking about, so I didn't say anything

I agree with the concerns that you have outlined here in this question

My app has four main functions (e.g. pages). Each function has multiple screens in depth.

and therefore I do not know what the point of having the tabs/ViewPager is

why are they pages?

They aren't right now, but I was looking to make them pages.

why aren't they just independent activities, the way you have them now (if I understand correctly)?

why are you trying to make them be pages in a ViewPager?

A couple of reasons. I've avoided the dashboard metaphor and just have a small number of buttons on the home screen to launch each activity. Now, I find myself adding additional major functions and want the display to remain compact.

The use of viewpager (or tabs) was intended to make additional functional areas directly accessible from the main activity.

so, use action bar items, or possibly the "sliding menu" stuff (tap on the upper-left icon, get navigation bar sliding out from left)

I intend to implement menu-drawer for secondary functions. The app provides access to a university for student use, there's a lot of functionality involved.

then keep your pages in the ViewPager to top-level stuff, and when they 'drill down', launch a separate activity

for example, in Contacts, tapping on a contact opens a separate activity

Fair enough. Just to be clear, I should try to avoid swapping fragments within individual pages.

that's my design recommendation

Thanks. I'll take it! :-)

sorry, i got dragged into an active conf call. i have a quick question: do you have a discount code for the boston adndevcon?

I have my own take on what constitutes good mobile design

scottt: I don't think they're set up yet

ok

mainly because the call for papers is still active and there's no conference agenda yet

jwandroid33: do you have another question?

Not today. POssibly tommorow :-)

OK

Peri: do you have another question?

just lietening in

This has to do with writing files to the external storage. I'm using Environment.getExternalStorageDirectory(), which appears to be working fine. The problem is that on my Windows machine, I'm not seeing the file I create. It shows up in the eclipse file explorer, among some other files. But my windows explorer doesn't show it, though other subfolders in the same directory (from other apps) do show up. Ever seen this?

yes

first, though, ideally, don't use getExternalStorageDirectory()

What do you recommend?

use something app-specific (getExternalFilesDir())

or getExternalStoragePublicDirectory() for common locations for photos, movies, etc.

I read that if you uninstall, it will delete stuff

yes, getExternalFilesDir() gets cleaned up on uninstall

I tried getExternalStoragePublicDirectory(), too. Don't remember the specific problem - might have been the same.

if it is supposed to live beyond that, it needs to be a type of file the user wants to hang onto

such as photos, movies, etc.

It is: exported data from the db.

but, anyway, back to your problem

that probably should go in DOWNLOADS, which is kinda a dumping ground for random stuff

in terms of your visibility issue, read: http://commonsware.com/blog/2011/08/31/mtp-exte...

(also covered in the book, IIRC)

It could. That's a good alternative.

Ok, I'll have alook right now. I'll be here in eh background

so, in addition to the MediaScannerConnection stuff you'll read about in that post, some MTP clients cache data, requiring you to unplug and re-plug in the device before the changes show up

nothing much we can do about that

Hi, have I caught the end of this hour?

Atual: hi! we still have a few minutes left

Atual: so, it's your turn -- do you have a question?

yes please :D

I'm using SimpleContentProvider, a lib for creating CPs for use with SQLite dbs

my issue is that in my DB I have several tables, and CPs seem to only return data from one

CPs can return data from several tables

I saw loaderex

whether SimpleContentProvider handles that, I can't say

were I override or add this (I don't think it does handle it, it's relatively new)

though it looks like it does, based on the description

o rly :(

it talks about foreign key relationships

which implies multiple table support

I'll have another look then

BTW I assume you are referring to https://github.com/mitmel/SimpleContentProvider

that's the one

sounds like the sample code does not demonstrate it, but the tests do

or something like that

I was also attempting to siphon away all the CRUD operations to an abstract class, passing only Context from my activities - would that be discouraged?

so long as you are careful how long you hold onto the Context, to avoid memory leaks, that should be fine

sounds good, thanks! Will have another read of SCP (I was only looking at the example project), so thanks for the direction

sure, no problem

have a good evening guys:)

scottt: do you have another question?

not at the moment

OK

David: do you have another question?

I'm good. Appreciate the help.

Peri: do you have another question?

So, you talk about using scanFile(). But I need a MediaScannerConnection. Is that something I do independently of writing the file?

scanFile() is a static method on MediaScannerConnection, IIRC

with the best level of early bird registration ending next week (and needing to get the stuff booked this year), was just looking for the code. i'll do some googling

after you have written and closed the file, call scanFile()

scottt: O

Ok, that sounds pretty straightforward.

scottt: I'll make an inquiry and will contact you if there's a code to use

thx

if anyone has a question, feel free to chime in

Well, I've got a simple one. When an end user experiences a crash, what is sent to the developer console?

that depends on whether or not they click the Report... button

if they decline to send a report, I don't think you get anything

Assuming they do.

since I don't distribute apps on the Play Store, I can't say for certain

I know it includes stack trace data

Oh, how do you distribute?

well, the book APK is on your Warescription page

so I use ACRA to collect crash logs, etc.

my impression is that the Developer Console does not give you as much as ACRA does

I can confirm that. You'll only get the stack trace from the developer console.

but that's just based on developer comments more than first-hand experience

ok, cool. I'll look into ACRA.

Thanks david, too

David: do you get any device model or OS version data?

that seems to be important, and that's specifically what I thought the Console might not supply (for whatever reason) based on what I was hearing

Do you get the text from the exception itself?

Hang on. I'll go look (not that my apps have ever crashed. :0

Peri: that should be part of the stack trace, regardless of whether it is from the Console or ACRA

I would think so, but just asking

it's definitely in the ACRA stack trace

No. Just the stack trace and the version of your app that was involved.

#fail

:-)

Sucks. Ok, ACRA it will be.

ACRA is free, though you'll have to choose a back-end or host your own

Google is putting pressure on ACRA to stop stuffing all the data in a Drive spreadsheet

Hey, well thanks so much for the help today. These were questions I had on SEx and no one answered over several days.

Peri: this isn't a great time of year for developer support

Well, I'm so suprised :)

ha! my conf call just ended

Have a nice evening.

you too

Mark jumping off. Thanks for the help!

no problem!

Thanks again. Good night.

that's a wrap for today's chat

next one is tomorrow, 10am Eastern

i saw some interesting questions/answers that i need to go back and review

thx. bye

I'll be posting the transcript shortly

check http://commonsware.com/office-hours/ in a few minutes

have a pleasant evening!