hello Damian!

how can I help you today?

Hi Mark

I was going to ask you about animations. Give me some time to write a proper question, please

I would like to create a layout with ListView, where first item is special. Initially, special item will be bigger presenting an image, when user scroll down first item smoothly change into regular item. When it is collapsed to regular item view, the list view scroll further normal way. Scrolling up should revert transition. How would you proceed with this?

I have absolutely no idea

:)

it's possible there is an existing library that offers this sort of "hero element" aspect

if there is, I'd use it

ok, i will look for it

by the way, did you try RecycleView from support library?

I have not yet played with it

from all reports, it is rather skeletal

requiring lots of additional code to get anywhere

(at least, for some definition of "lots")

true, that's my opinion too

my focus this month is on getting my book moved over to cover Android Studio

that, and some camera library updates, are consuming all my time

I won't be poking at "L" too much until late this month, at best

so, RecyclerView is probably going to be a Very Good Thing over time

do you think there will be beta release of L before offical release?

possibly

there were hints that Google might do that, when this was all discussed at I|O

most of the screams of anguish appear to be tools-related (e.g., can't build for L and test on older environments)

that would seem to lessen any extrinsic pressure for a beta

it may be that they are adding enough new stuff than an L2 will be warranted

but I wouldn't be surprised if what we have is all we get before the next Android release

considering that it's more than we normally get before an upcoming release

another question just come to my mind, there is a lot of talk recently regarding Card UI, there is also new Cards view from Google. Is it not just another pattern? Why would they create separate view for that?

mostly for the drop-shadow backport, as I understand it

on "L", that's all being handled natively in the GPU, as I understand it

but CardView will provide a similar, if not as slick, shadow on older devices

given the library name, the backport should work to API Level 7

the whole elevation-and-shadow thing is a big part of Material Design (motto: We Change Our Design Instructions More Frequently Than We Change Our Socks)

i see, so in the future I could is it once and it will work nicely on older versions, instead handling version prior to L with additional if statements

yes

basically, the if statements are baked into the CardView

I like new Design but i am worried that my code will get messy, probably Google will not provide support for all aspect of that design, there will be similar situation like with ActionBar for example

agreed

though the picture should become a bit clearer once "L" turns into Android 5.0 (or whatever number they use)

I prefer wait longer for L release but get it with full backport for older versions

hello, ming!

HI MARK IM SO EXCITED!! ALL CAPS :D

Damian: I am not certain that the availability of a backport is necessarily tied to "L"'s ship date

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

ming: it's your turn! do you have a question?

yes, i have a question about fragment and backstack

so I have activity A that is hosting fragment A

I have to leave now, my daily meeting starts in 3 min. Thanks for talking, bye

inside fragment A, i have a take picture button, it invokes the camera app, capture the picutre, and save it inside the PICTURES file

Damian: see you later!

once it finishes the task, it returns to the fragment A and sets a preview which is an imageview that was not visible until the image is captured

now i hit back button, go back in to the fragment A, the preview image is gone.

I want it to show the preview image, i tried setInstanceState(true) but it does not work

if the user pressed BACK, there is no instance state to save, as the instance is being destroyed

you will need to consider that the photo you took is part of your model data

and when the activity and fragment are created, see if the image is available, then use it if it is

where do i save it?

do i save it in onSaveInstanceState()?

no

you already saved it

"save it inside the PICTURES file"

oh yes, the actual image is saved but the uri is not saved

i dont want to save it to database, since the preview is only supposed to show the last image taken

:: shrug ::

I cannot really help you with your business logic

..............ok

I always come up with some weird ideas...

the biggest question, from a core implementation standpoint, is how long you need to remember about the "last image taken"

let's suppose the user runs your app and takes a picture

then the user leaves your app via BACK, as you described

hours pass

your process is terminated to free up memory for other apps

then the user returns to your app and brings up fragment A again

should you be showing the "last image taken" to the user in this case?

hmm, i guess not hours

minutes probably

OK

since I want to preserve the state for user if they hit back button accidently

in that case, you will probably wind up keeping a lastImageTaken static data member

if that static data member is null, you start over from scratch

if that static data member is not null, that's your Uri of the last picture taken, and you use it

this means that you will remember the last picture taken only so long as your process is around

how does "static" make a difference

your fragment and activity are being destroyed

which means either you are caching this data in global scope (i.e., static in Java) or you are writing it to disk

you cannot just save the data in a non-static data member of the activity or fragment, as they are being destroyed and will no longer be relevant

BTW, I am assuming that the activity is being destroyed upon pressing the BACK button, as you did not indicate that the activity has any content other than the fragment

yes

i gtg now

Thanks a lot!!!! See you next time!

have a pleasant day!

you too thank you !

hello again, Damian!

do you have another question?

hi

yes

are you planning to add to your book chapter about AsyncAdapter?

AsyncAdapter?

there's nothing by that name in the Android SDK

is this some library?

or do you mean SyncAdapter?

sorry, yes SyncAdapter

yes, I hope to cover it by the end of the year

assuming that I can work out some implementation of it that is not inextricably tied to the AccountAuthenticator system

or at least does not require a pile of icky permissions

great, I like to see your point of view

recently I have went through video training from Udacity by Google, have you seen it?

I know of it

I haven't watched any of it

it' really well prepared, I have to watch last part about SyncAdapter :)

by the way, I am wondering how do you find time for learning all this stuff, writing book, running webinars and writing answers on stackoverflow :)

well, that's my job

time is running out, i will stop asking :) thanks again for talking, can't wait to see your opinion about SyncAdapter

bye

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