Are there guidelines to help understand how fine grained to make activities?

I've heard people state that an activity should be just one screen and that multi-screen applications should have one activity per screen. But this model can seem awkward, more work, and I'm not sure what value you get in return.
What are the pros and cons of many activites vs few.

I've also heard debate about how much processing can occur in an activity and some people suggesting that any complex work should occur in a service. That doesn't seem obvious to me. How is the browser implemented? A bunch of activities and a service to do the real work, or just one actiity to render a web page and that activity does all the work?

Are there issues with threads that determines how you should design you app, ie few or many activities and need for a service?

Thanks

Sent from my iPhone

On Feb 2, 2010, at 9:43 AM, android-beginners+nore...@googlegroups.com wrote:

  Today's Topic Summary
Group: http://groups.google.com/group/android-beginners/topics

الآن إفتح اى موقع ممنوع او محجوب فى بلدك وجرب بنفسك [1 Update]
'drawable' vs. 'drawable-hdpi' in Online Tutorial [5 Updates]
list view button error [2 Updates]
Eclipse can't seem to locate R.java [1 Update]
Bug in SDK Manager: cannot update [1 Update]
Not able to start Call Log Activity [1 Update]
SDK Setup.exe not working [1 Update]
No market on HTC hero [1 Update]
I have note pad where are notepads files saved??? [1 Update]
Can't create new class in Eclipse (Google Map View official tutorial) [1 Update] Topic: الآن إفتح اى موقع ممنوع او محجوب فى بلدك وجرب بنفسك
alagmy <smsm_egy2...@yahoo.com> Feb 02 06:28AM -0800 ^

الآن إفتح اى موقع ممنوع او محجوب فى بلدك وجرب بنفسك

الأن يمكنك فتح أى موقع محجوب ببلدك فقط من خلال هذا الموقع

open all blocked sites now for free and have fun

http://translatorproxy.zzl.org/vb


 Topic: 'drawable' vs. 'drawable-hdpi' in Online Tutorial
Indicator Veritatis <mej1...@yahoo.com> Feb 01 12:17PM -0800 ^

It seems the online tutorials have not been rewritten to reflect
Android 2.1. For they still refer to 'drawable' and 'res/drawable',
but when I create a new project for 2.1 using the wizard, I do not GET
any such directory. Instead, I get 'res/drawable-hdpi', 'res/drawable-
ldpi' and 'res/drawable-mdpi'.

Now for some tutorials, I have been able to get by by putting files in
'res/drawable-hdpi'. But for the TabLayout tutorial,
http://developer.android.com/resources/tutorials/views/hello-tabwidget.html ,
this does not work. I still get the error message (on completion of
step 3) "R.drawable.ic_tab_artists cannot be resolved".

The files "ic_tab_artists_grey.png" and "ic_tab_artists_whit.png"
really are in res/drawable-hdpi.

I also tried changing the name 'drawable' to 'drawable-hdpi', but Java
did not like the '-' in the name (no surprise).

So how are we supposed to get this to work? Go back to 1.5? Surely
there is a better way.

Just for clarity's sake, the line of code I get the error on is: spec
= tabHost.newTabSpec("artists").setIndicator("Artists",
// res.getDrawable
(R.drawable.ic_tab_artists))
.setContent(intent);

in HelloTabWidget.java.

I get the same class of error message on the other three
res.getDrawable calls, too.


"Ben & Jerry's South Bay" <mochama...@gmail.com> Feb 01 03:01PM -0800 ^

I just created a new folder within eclipse called 'drawable' and then
created my new files there. It worked for me.

On Feb 1, 2010 12:18 PM, "Indicator Veritatis" <mej1...@yahoo.com> wrote:

It seems the online tutorials have not been rewritten to reflect
Android 2.1. For they still refer to 'drawable' and 'res/drawable',
but when I create a new project for 2.1 using the wizard, I do not GET
any such directory. Instead, I get 'res/drawable-hdpi', 'res/drawable-
ldpi' and 'res/drawable-mdpi'.

Now for some tutorials, I have been able to get by by putting files in
'res/drawable-hdpi'. But for the TabLayout tutorial,
http://developer.android.com/resources/tutorials/views/hello-tabwidget.html ,
this does not work. I still get the error message (on completion of
step 3) "R.drawable.ic_tab_artists cannot be resolved".

The files "ic_tab_artists_grey.png" and "ic_tab_artists_whit.png"
really are in res/drawable-hdpi.

I also tried changing the name 'drawable' to 'drawable-hdpi', but Java
did not like the '-' in the name (no surprise).

So how are we supposed to get this to work? Go back to 1.5? Surely
there is a better way.

Just for clarity's sake, the line of code I get the error on is: spec
= tabHost.newTabSpec("artists").setIndicator("Artists",
// res.getDrawable
(R.drawable.ic_tab_artists))
.setContent(intent);

in HelloTabWidget.java.

I get the same class of error message on the other three
res.getDrawable calls, too.

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Indicator Veritatis <mej1...@yahoo.com> Feb 01 03:28PM -0800 ^

And switching back to 1.5 usually works for me. But both your approach
and mind sound like kludges. There should be a better solution. I
really do not want, for example, to have to create this extra
directory for EVERY tutorial I complete using SDK 2.1. Do you?

On Feb 1, 3:01 pm, "Ben & Jerry's South Bay" <mochama...@gmail.com>
wrote:


"Ben & Jerry's South Bay" <mochama...@gmail.com> Feb 01 04:16PM -0800 ^

It was a bit kludgie...but for me as a newbie to eclipse...it was not to
painful :-).



Indicator Veritatis <mej1...@yahoo.com> Feb 01 10:14PM -0800 ^

Oh, well, thanks for your response anyway. But I am going to wait in
the hopes that some who unlike us, it not a newbie, can come up with a
suggestion that is not one of our newbie kludges;)

On Feb 1, 4:16 pm, "Ben & Jerry's South Bay" <mochama...@gmail.com>
wrote:


 Topic: list view button error
Sam B <bassmansa...@googlemail.com> Feb 01 02:09PM -0800 ^

Hi guys im trying to put a button on each row of a list but i get null
pointer exception, i'll show the java files below. The list view is in
a seperate xml file to the button because button is inside a relative
layout. Can anyone help?.

This class gets data from a database and puts it in array and displays
in a list view which works fine until i try to put a button in each
row.
Java:

package project.Maps;
public class SatMain extends Activity {
/** Called when the activity is first created. */
ArrayList<String> results = new ArrayList<String>();
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
dbAdapter db = new dbAdapter(this);

;



//---get all titles---
db.open();
db.InsertData();

Cursor c = db.getSat1();

if (c.moveToFirst())
{
do {
String pub = c.getString(c.getColumnIndex
(db.KEY_Artist));
String pub1 = c.getString(c.getColumnIndex
(db.KEY_Time));



results.add(pub + pub1 );
} while (c.moveToNext());
}
db.close();

ListView listProducts;
List<String> results = new ArrayList<String>();
Context cont = null;
customArray ca = new customArray(cont, R.layout.button,
results);
listProducts = (ListView)findViewById(R.id.list123);
listProducts.setAdapter(ca);
ca.notifyDataSetChanged();
}}



Code for my custom adapter.

Java:

package project.Maps;
import java.util.List;
public class customArray extends ArrayAdapter<String> {
int resource;

public customArray(Context cont, int _resource, List<String>
results) {
super (cont, _resource, results);
resource = _resource;
}

@Override
public View getView(int position, View convertView, ViewGroup
parent) {
RelativeLayout rl;

// String prod = getItem(position);
if (convertView == null) {
rl = new RelativeLayout(getContext());
LayoutInflater vi = (LayoutInflater)getContext
().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
vi.inflate(resource, rl, true);
} else {
rl = (RelativeLayout)convertView;
}


return rl;
}
}


Justin Anderson <janderson....@gmail.com> Feb 01 09:36PM -0700 ^

Can you give us a little more info, like where the NullPointerException
happens in the code?

----------------------------------------------------------------------
There are only 10 types of people in the world...
Those who know binary and those who don't.
----------------------------------------------------------------------




 Topic: Eclipse can't seem to locate R.java
Xavier Ducrohet <x...@android.com> Feb 01 03:50PM -0800 ^

That's not a dependency issue.

Creating the R.java file is part of the build process, and if you
don't let Eclipse build automatically, you will need to force a
project compilation every time you add/remove a resources so that the
R class is updated.

People who work with the Ant build script already have to do this.
Eclipse does improve on this by using the automatic build, but you can
do without if you remember to manually recompile when needed.

Xav


--
Xavier Ducrohet
Android SDK Tech Lead
Google Inc.

Please do not send me questions directly. Thanks!


 Topic: Bug in SDK Manager: cannot update
Xavier Ducrohet <x...@android.com> Feb 01 03:46PM -0800 ^

Yes. this is the solution.

The problem is that older version of Java lack a XML schema validator.
Unfortunately, the SDK tools revert to the wrong code path when this
happens and it looks like the schema is more recent that the tools and
it requires to update the tools first.

Use the MacOS X software update feature to get the newest version of Java.

Xav



--
Xavier Ducrohet
Android SDK Tech Lead
Google Inc.

Please do not send me questions directly. Thanks!


 Topic: Not able to start Call Log Activity
jaydip makadia <jaydip.makadia...@gmail.com> Feb 02 12:38AM +0530 ^

Hi,

I am not able to start Call Log Activity from below code, so please help me
how to start call Log activity.

Intent i = new Intent();
i.setAction(Intent.ACTION_VIEW);
i.setData(android.provider.CallLog.CONTENT_URI);
startActivity(i);

Thanks
Jaydip


 Topic: SDK Setup.exe not working
Liviu Ungureanu <smartli...@gmail.com> Feb 01 08:01AM -0800 ^

Hi!

You have to install Java JDK:
http://java.sun.com/javase/downloads/index.jsp


 Topic: No market on HTC hero
Kevin Duffey <andjar...@gmail.com> Feb 01 07:54AM -0800 ^

I don't think 1.6 or 2.x will add market for you. Your service location will
not permit you to have the Market store period..until Google and your
country work out the details. It's not the version of Android, but the
country you live in and Google not yet supporting the Market in your
country.



 Topic: I have note pad where are notepads files saved???
Kitzy <kitzyk...@gmail.com> Feb 01 07:02AM -0800 ^

To view files on the emulator you open a new view and under the
android folder select file explorer.

The files get put, I think, into /data/data/my.project.path/

Files have the permissions of the program that created them, and no
other programs can access them unless they are signed by the same
developer. Since the project is in java, have you considered doing
your parsing in java?

Also, you may be able to upload them to your web-server and have them
manipulated off of the device.

Happy coding,
-Kitzy



Topic: Can't create new class in Eclipse (Google Map View official tutorial)
Kitzy <kitzyk...@gmail.com> Feb 01 06:45AM -0800 ^

You need to be sure that you have given it a package name and sometime
you also have to select the project you're working in, even if you
only have one open project.

-Kitzy



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