Office Hours — Today, October 15

← Friday, October 11

Oct 15
3:50 PM
Mark M.
has entered the room
Mark M.
turned on guest access
3:55 PM
Sean D.
has entered the room
Mark M.
hello, Sean!
how can I help you today?
Sean D.
hi
I had a couple (hopefully quick) questions...
Mark M.
go right aheae
er, ahead
Sean D.
In my app, I'm syncing objects in the DB to Google Drive on startup. This process could take a while, so I use a service with broadcasts to an activity.
View paste 
I'm wondering if it's safe to have a public static variable on the service to indicate when syncing is finished,
because if syncing finishes when the screen is turned off, for example, the activity won't get the broadcast.
Mark M.
um
Sean D.
Or if there is a better way to get that information in Activity.onStart, when I re-register the BroadcastReceiver?
Mark M.
are you using regular broadcasts, or LocalBroadcastManager?
Sean D.
regular broadcasts
4:00 PM
Mark M.
I would suggest switching to an event bus: LocalBroadcastManager, Otto, greenrobot's EventBus, etc.
EGHDK
has entered the room
Mark M.
I added a chapter on that in today's Version 5.2 of the book
Sean D.
Oh okay, cool, I'll check it out, thanks
Mark M.
they should not be subject to the "can't receive when the screen is off" limitation
Sean D.
I also just discovered sync adapters in the docs... would that be a better route than my own service?
Mark M.
also, Otto and greenrobot's EventBus will give you options for being able to basically "pull" the last broadcast
which you can use if the user got rid of your activity, then starts it up again
Sean D.
Ah, perfect.
Mark M.
with respect to sync adapters, there's a fair amount of baggage that comes along with those
such as the whole Accounts system
that's one of the reasons I haven't gotten into it in the book yet
some people love sync adapters, others detest them
hence, I cannot say if it's a good choice for you right now
let me take a question from EGHDK, and I'll be back with you shortly
Sean D.
Okay, I think I'll stick with my own service for now. I'll give the event bus thing a try.
Mark M.
EGHDK: do you have a question?
EGHDK
Yeah, it's about something that I've been now working on for about a week and a half, but I just can't figure out how to do it.
I want to create chat bubbles for my application I'm doing. Very similar to whatsapp: http://imgur.com/2i4Bw96
The thing is... I realize that I can do this with 9patch, BUT one of my requirements is to let the user change the color of the bubbles. Which means I would have to accomplish this programmatically (not using images).
4:05 PM
Mark M.
use a nine-patch for the edges, and layer on top of that a colored fill as a ShapeDrawable
combine the two via a LayerListDrawable
EGHDK
But I'm just stuck at drawing these things now. I don't know whether I should try to create a BubbleView extends View or what.
Mark M.
(actually, ColorDrawable is even better for a solid fill than ShapeDrawable)
EGHDK
Okay... So... create a 9 patch for the edges... and ShapeDrawable as a fill?
Hmm... okay I think I will try that. The reason I am getting frusterated is because I am working with an iOS developer and he is creating these bubbles with a "bezier path" and he insists I should be able to do that in android.
Mark M.
that would basically require you to roll your own View and use low-level Canvas drawing primitives
that would work, but does not strike me as being particularly easy
EGHDK
It's annoying because it is basically just a rounded rectangle...
Mark M.
you could also see how others solved it, such as http://www.androidviews.net/2012/11/mapview-bal...
let me take another question from Sean, and I'll be back with you shortly
Sean: do you have another question?
4:10 PM
Sean D.
Yeah, one more... going back to syncing, I want the user to still be able to interact with the app.
For example, the can open a detail activity from the main activity's list view, etc.
View paste 
The problem is that currently when he opens the detail activity it doesn't load the details until the sync has finished,
presumably because it's using a writable SQLiteDatabase. Is there a standard way for the sync process to periodically relinquish the
db lock and let someone else read from it?
Oops, that pasted weird. I admit I had these questions prepared :P
Mark M.
the sync is doing writing, I take it?
Sean D.
Yes
It has to at the very least update a record's last modified date so it doesn't get updated again on next sync
Mark M.
you could try yieldIfContendedSafely() on SQLiteDatabase, though I have not tried it personally
Alex
has entered the room
Sean D.
Hmm, okay, thanks
Mark M.
Alex: do you have a question?
ok... EGHDK: do you have a question?
4:15 PM
Alex
I'm trying to figure out how to implement an overscroll on a listview to reveal some text at the top as the user pulls down. any ideas on the approach to this?
Mark M.
Alex: there are a few pull-to-refresh libraries out there. See http://androidviews.net
ok... Sean: do you have another question?
Sean D.
No, I don't think so... thanks
Mark M.
OK, if anyone has any questions, chime in
Gabriele
has entered the room
EGHDK
Do you know of any good layer list drawables by any chance?
Mark M.
um, LayerListDrawable is a class
EGHDK
Or rolling my own view by useing low level canvas drawing primitives?
oh...
Gabriele
hi all, I'm just here reading :)
Mark M.
oh, sorry, the class name is LayerDrawable, my mistake
http://developer.android.com/reference/android/...
(BTW, hello, Gabriele!)
4:20 PM
Mark M.
EGHDK: <layer-list> is the XML element for defining one as a resource, which is where I got mixed up
EGHDK
View paste 
Any resources on this though? I'm not sure where I would start to do this method:
use a nine-patch for the edges, and layer on top of that a colored fill as a ShapeDrawable
combine the two via a LayerListDrawable
Mark M.
um, well, you are a subscriber to a book
the book has a chapter on custom drawables
EGHDK
So do I use the LayerList XML or LayerList Class?
Mark M.
including LayerDrawable and ShapeDrawable there, plus a separate bit of coverage of nine-patch PNGs elsewhere
that depends whether you wish to assemble the layers in Java or in XML
EGHDK
I guess if I want them to be easily customizeable... I would do them in Java?
Mark M.
if you are letting users choose one of millions of colors, perhaps
if you are giving the user a choice of one, say, a dozen colors, perhaps not
with respect to drawing your own custom Views using the Canvas, that is not in my book, though it is in others, plus various blog posts and such
if anyone has any questions, chime in
4:25 PM
EGHDK
Okay I will try LayerDrawable Class.
Sean D.
Oh I had another question... I was trying StrictMode in my app and I've been getting disk read errors coming from the Maps API... for example, inflating a map inside my fragment
Is there anything I can do about those or are they out of my control?
Mark M.
probably they are out of your control
unfortunately, too many things with Maps V2 need to be on the main application thread
Sean D.
Oh, okay
Mark M.
I'd file an issue with the Maps team if you can document a scenario
Sean D.
Thanks
Alex
when an overscroll is performed, is the actual listview being shifted down? or is the space that appears above the listview part of the listview?
Mark M.
Alex: sorry, I do not know how overscroll works
Alex
darn, ok. thanks anyway
4:30 PM
Mark M.
if anyone has any questions, chime in
4:35 PM
Gabriele
is there any specific reason why no pdf reader have tabs, on android?
Mark M.
no clue, sorry
4:40 PM
Sean D.
has left the room
4:45 PM
EGHDK
Hey Mark, so for one of my apps, I just push the same notification. But I just got a screenshot from one of my users that the notifications icons in his notification tray (not pulled down) are different sizes. Any ideas?
Mark M.
sorry, I do not understand your question
EGHDK
So my application sends notifications to the top bar across the top of the phone.
4:50 PM
Mark M.
OK
4:50 PM
EGHDK
It only has one icon it uses for that top bar of the phone. Yet, on one persons device, my app has two notifications in the top bar, right next to each other. But they are different sizes.
Tiny detail, but wondering if you've encountered that before.
Mark M.
I still do not understand. You seem to be simultaneously saying that you are only showing one Notification and showing two Notifications. Since 1!=2, I am lost
Gabriele
Mark, thank you, see you the next time! Bye all :)
Gabriele
has left the room
4:55 PM
EGHDK
Eh. Not that important I guess. My application pushed two identical notifications. SO there are two icons in the top bar. One icon is smaller than the other for some reason.
Mark M.
you are using the same drawable resource for both?
EGHDK
Yep.
Mark M.
I can't explain that, outside of a device (or possibly home screen) bug
EGHDK
okay cool
Before todays chat is over... do you have any thoughts on 4.4? =)
Mark M.
I think Android 4.4 is chocolate coated, with crispy wafers inside
I am guessing that it might not come out until after October 22, to come out after Apple's iPad announcements
but that's just a guess
EGHDK
Nice. Haven't been able to find one myself though. Disappointed. Really looking forward to the first time I see a candy bar wrapper with a bugdroid on it.
Yeah, I was hoping for today. And then KitKat posted that song lyric on Google Plus, and everyone thinks the date is now October 18th.
Mark M.
Friday would be an odd launch day
can't rule it out, of course, but firms usually like to do launches earlier in the work week, for better media coverage
5:00 PM
Mark M.
and that's a wrap for today's chat
next one is Thursday at 10am Eastern
Alex
has left the room
EGHDK
Hmm... that true. Alright, well thanks for pointing me in the right direction for the drawables. I'll be back tomorrow morning if I can't figure it out.
Mark M.
this chat transcript will be archived at http://commonsware.com/office-hours/ shortly
have a pleasant day!
EGHDK
has left the room
Mark M.
turned off guest access

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People in this transcript

  • Alex
  • EGHDK
  • Gabriele
  • Mark Murphy
  • Sean Durkin