howdy tunneling!

how can I help you today?

hello Mark. I don't have any specific questions. just going to hang out and see what I can learn today.

OK

if you come up with a question, just chime in

will do.

howdy Marcin

how can I help you today?

ahh found the chat input

Hi Mark

I have an issue in my android app

could u help me with it

possibly

please explain the issue

I did describe it on SO, sorry for tagging u with it

I have never attempted to apply an animation to a row in a ListView like this

however, I am not surprised that you are running into this problem

you are correct that if you call swapCursor(), ListView will reload its rows

please continue :)

thanks to row recycling, there is no guarantee that row 1 will wind up in the same visual position after the reload

it is eminently possible that, after the reload, the View that had been row 1 is now in the position of row 4

the simplest solution would be to cancel any outstanding animation just before your call to swapCursor()

however, that won't handle the case where the user scrolls while your animation is going on, as that too will cause your row to be recycled, and so your animation will finish on some other data

How I do it now is I use postDelayed - for the duration of animation

and then forceLoad on Adapter

while for duration of the animation blocking the possibility of interaction with other list items

if you feel that will be acceptable for your users, and it is behaving properly, I suppose that approach can work

This kind of works, but from time to time if I click on items really fast after the animation.. still some of the rows move

it is possible that the touch events are being registered before you get a chance to run the code to block them

let's back up a step: why are you doing this animation in the first place?

Hi!

particularly a one-second "bounce" (out then in) would seem confusing to me as a user

(BTW, howdy, Pedro -- I will take a question from you shortly)

ok no problem

its for testing now.. but users swipe left or right on items to say yes/no per item

we thought it will be faster and more intuituive

but Im not sure I agree :)

anyway we want to play with it for now

horizontal swiping in a list really should be for "remove from the list", IMHO

not for toggling a yes/no state

but, that's just me

thanks Mark, please take question from Pedro

I have another one after that

OK

Pedro: do you have a question?

dear Mark I have a question, I was wondering. Is there a way to add letters to the scrollbar of a ListView like in contact List of some phone apps?

yes

or, for a strict alphabetical one, http://developer.android.com/reference/and…

I don't have a sample handy, unfortunately

ok thanks

though there are plenty of questions on StackOverflow that discuss AlphabetIndexer, such as http://stackoverflow.com/questions/5122749…

I will try it!!

Mark, my next question : http://stackoverflow.com/questions/1262227…

what do you mean by "If user closes the app"?

lets say he will press back,back,back

till home screen appear

s

if you fail to unregister the LocationListener, you will be leaking it

you will continue to be handed locations until Android terminates your process

which could be in milliseconds or hours

oh, wait

you are using the PendingIntent flavor

hmmm...

I have not tried that

I have no idea how long that will live

it might go away when your process does, but that would be unusual for a PendingIntent-based API

more likely, it runs until a phone reboot, as you indicate

but those are guesses

if we step back a bit the question would be : "can my app BroadcastReciver get Intent that is fired whenever user lcoation changes every 100m, without being active"..

in principle, the version of requestLocationUpdates() you are using would offer that

I guess I have to check that, thanks Mark for suggestions

Pedro: do you have another question?

no, thanks. I'm playing with AlphabetIndexer for now.

hey mark, i have a question...

tunneling: go ahead

i was trying to implement an activity that used the action bar spinner navigation with a ViewPager

so if I choose Fruit from the spinner, i would have a Fragment for Apples, Bannanas, and Peaches.

then if I choose Meat from the spinner, I would have Fragments for Steak and Chicken.

and these Fragments are in the ViewPager?

yea.. listviews

they aren't updating

so if the ViewPager index 1 already had displayed a Fruit.. it wouldn't change to a Meat after choosing from the spinner

what specifically are you doing when the spinner selection changes?

i tried to instantiate a new ViewPager once I got to my wits end, but that didn't work either

I think it's because the FragmentManager belongs to the main activity.. and I can't find a way to flush it

oh, I see what you're running into

let me guess: you are using FragmentPagerAdapter or FragmentStatePagerAdapter, right?

yea

those classes cheat

they store the fragments under certain tags in the FragmentManager

and that sometimes confounds the sorts of things you're trying to do

it also messes up having multiple ViewPagers at once

hmm

is the sole content of those Fragments just a ListView?

yea.. but the ListViews are custom layouts with listeners on the data

i mean list items

that's fine

you might consider rolling your own PagerAdapter, and perhaps just use plain ListViews rather than ListFragments

ok.

or, fork whichever FragmentPagerAdapter you are using and tweak it as needed to get it to handle your scenario better

those classes are designed to handle fairly simple situations, not necessarily every possible way of using ViewPagers with fragments

i tried a few things there.. i saw one comment on stackoverflow..

but that didn't work for me

that's the default behavior, anyway, IIRC

ok, i'll play with it some more and get back with you

OK

Marcin: do you have another question?

yes

When I remove the item from ListView

is it possible to make a collapsable effect

however, this is only for API Level 11, and I'm not sure if it is in the NineOldAndroids backport

and I haven't tried that yet myself

if anyone has any other questions, chime in

Sorry for this question :) How sure are you that it can be made with info in that link ?

I'm not

:) thanks!

however, it should be related to your question

I have one more question Mark

go ahead

I have a ContentProvider with DB

I use CursorLoader to bind it with ListView

I return CursorLoader in onCreateLoader

and swap it withhin onLoadFinished

my question is

If I update the DB through contentResolver, will the ListView update?

it should

your CursorLoader will register a ContentObserver automatically

causing it to re-execute the query for the Loader and deliver that to you in onLoadFinished()

I also thought so, but it is not happening.. any idea why?

I tried to init SimpleCursorAdapter with flags 0.. and others

not off the top of my head, sorry

which corespond to ContentObservers

but to no efffect

When debuging I see that the DB is updated

but the onLoadFinished is not firing

are you doing the work in update() of your ContentProvider to trigger the observers?

let me check

getContext().getContentResolver().notifyChange(url, null);

and that's always executed in update() (i.e., it is not inside some if() check or something)?

yes

that should trigger the ContentObservers then

it does refresh when I forceLoad on CursorLoader right after I update on ContentProvider

can I check somehow if ContentObserver is existent (I have no idea about them)

?

you could look at the CursorLoader source code and see what it is doing

is the problem limited to updates? in other words, do inserts and deletes work properly?

good point.. i only use update for now

my ContentProvider sample from the book works for inserts and deletes but does not try updates

I will try that

ok Thanks Mark, that was helpful. Keep up good work!

thanks!

anyone else have a question?

im good for now. thanks mark.

BTW, I should be releasing Version 4.2 of _The Busy Coder's Guide to Android Development_ later today

Great!!

Mark are you fluent in OpenGL ?

for Android :)

definitely not

I can barely spell LoGpen

hhehe

pLoGne

OpenGL

whatever

:-)

that's a wrap for today's chat

next one is 4pm Eastern on Tuesday

have a pleasant day, all!

have a nice evng Mark