Solving the Device Fragmentation Problem
Transcript of web chat held on January 26, 2005
Guests: Greg Crawley, David Kaspar, and Adam Sotona, Software Engineers for the Sun Mobility IDE.
Moderator: Bao Phan
bao
Welcome to the Sun Developer Network Moderated Chat series.
Today's topic is "Solving the Device Fragmentation Problem." My
name is Bao Phan and I'm the moderator for this chat. Our
speakers today are Greg Crawley, David Kaspar, and Adam Sotona,
Software Engineers for the NetBeans Mobility Pack IDE.
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With that, I'd like to invite you to begin sending your questions
to our speakers. To start things off, Greg, can you give us a
quick summary of the feature in the NetBeans Mobility Pack that
addresses the device fragmentation problem?
gregcrawley
I'll start off with a quick explanation as to what the device
fragmentation problem is. We use the term to describe variations
found between mobile platforms that prevent a single application
from automatically running optimally on all phones. These
differences can be physical (like screen size, screen color
depth, available memory, etc.) or software-related (available
APIs, CLDC/MIDP version, etc.). Fragmentation usually requires
modifications to get your single application running on different
mobile platforms; managing these modifications is where our
solution comes in...
It has two main parts: project settings management and
fragmented source code management.
Both portions of the solution are based on the concept of Project
Configurations. You can create as many configurations as you'd
like for each of your projects -- typically, you will have one
for each distribution Jar that you plan on creating for your
application. Once the configurations exist, you can update
individual panels of the project properties dialog such that the
settings will only apply to individual configurations.
Also, you'll be able to mark blocks of source code as being
specific to a list of configurations. Individual code blocks
will only apply only to those configurations that you have
associated with them. An embedded preprocessor is used by
NetBeans to place code blocks to a commented-in or commented-out
state based on whether or not the block is appropriate to your
active configuration.
So that's the solution in a nutshell.
blizzard
Does this solution eliminate the need to have a separate source
file for each device I want to target?
gregcrawley
Yes, it does. Because we use a commenting pre-processor, all
versions of your code can be stored in a single source file.
blizzard
What is the key benefit of using this feature?
adamsotona
You can easily deliver an application that fits several phones
available on the market and maintain just one source base.
jojo
Gee, this sounds a lot like a new-fangled way of getting the IDE
to implement the old-fashioned #IFDEF in the C preprocessor.
Having the IDE effectively comment out some code blocks for some
cases and other code blocks for other cases sure seems like a
roundabout way of doing something that should be fundamentally
simple. Wouldn't it be simpler if Java just supported CPP-like
macros?
gregcrawley
That is, in effect, what we're doing. The code block definitions
use a CPP-like syntax -- but all within Java comments. We stayed
away from #IFDEF-type syntax as then we wouldn't have 100% pure
Java code until the preprocessor ran.
ntuple
Is there a list of configurations supported?
adamsotona
If we are talking about project configurations - there are no
limitations. It is not based on any list. You can easily create
what you need.
joe
I'm impressed by what I've seen. Will we be able to use this
facility in free-form projects (built standalone outside
NetBeans)?
davidkaspar
Currently we do not have a free-form project. We support building
projects outside of the IDE. All these device fragmentation
features are fully available in the command line, too. It is
because the whole building process is done using Ant.
JBeat
What is a clever approach to ensuring that an action game runs at
the same speed on different devices? Are there any features in
the Mobility Pack that would assist in testing runtime speed of a
game, especially with regard to simulating slower and faster
devices?
adamsotona
Mobility Pack does not provide any special emulator extensions.
Simulation of speed or, for example, network latency is up to the
emulator used. Mobility Pack includes the J2ME Wireless Toolkit
emulator that (I think) allows you to simulate slower network
speed. And definitely there are some other device emulators that
are pluggable into Mobility Pack and allow some of these special
features.
fractal@fractalgrafics.com.mx
How does it manage memory management issues, especially on
devices that have different memory specs?
davidkaspar
We do not handle that issue specifically but we are allowing
developers to handle code and resources differently for each
configuration.
patrick
How does this solution help us in the long run?
adamsotona
Our Device Fragmentation solution helps mostly in code
maintenance. You can improve your application for every new
device on the market and still base it on the same code base. Or
you can have prepared library projects fragmented according to
your needs (device providers, available APIs, series of
devices...)
fractal@fractalgrafics.com.mx
It would be very nice if you could post a
"Sample-Tutorial_Device_Fragmentation" using 3 or 4 common
configurations.
gregcrawley
There is a device fragmentation tutorial available at
http://www.netbeans.org/kb/articles/tutorial-j2mefragmentation-40.html.
You can also open your NetBeans help, and in the contents menu
select J2ME MIDP Development | Getting Started | J2ME MIDP
Tutorials, there is a link to the Device Fragmentation Tutorial
With Marv The Miner. That link will take you to the tutorial on
netbeans.org.
patrick
Are there project templates in the IDE?
adamsotona
Sure there are. There is a template for a new application,
library, templates for various imports, and a lot of sample
project templates.
ntuple
So this feature is available in the latest NetBeans Mobility IDE
available now?
gregcrawley
Yep. NetBeans Mobility Pack 4.0 has this support integrated, and
it's already available for download.
patrick
How can we create our own project configurations in the IDE?
davidkaspar
Just open the Project Setting for your project. At the top of the
settings dialog there is a combo box with the list of all project
configurations created for the project. On the right side of the
box is a Manage Configurations button which leads you to the
Configuration Manager dialog. There you can manage your
configurations.
jojo
Regarding the CPP idea, I'm also wondering if using the
annotation feature of Java 5.0 could work. Is there any way to
use apt and some suitable code annotations to effectively
accomplish CPP-like #ifdef and #ifndef blocks? I asked that
question at last year's JavaOne session on apt and was told that
apt was explicitly designed to disallow such usage. I wonder if
any true hackers have figured out a way around that?
adamsotona
I don't think you can use any features from Java 1.5 because of
the CLDC/MIDP library limitations and compiler limitations. If
you want to compile CLDC/MIDP applications you cannot use a
higher version of sources than 1.3. Even assertions from 1.4
cannot be used in CLDC/MIDP applications.
WM
Would you release some more samples where the features could be
seen in wider reach?
gregcrawley
That's a good idea WM, and something that we are planning for the
4.1 release should time allow for it. If you have any specific
tutorial requests, you can file an RFE at
http://www.netbeans.org/community/issues.html. File it under the
3rd party category.
patrick
What plugins does the Mobility Pack currently have?
davidkaspar
NetBeans 4.0 Mobility Pack consists of the build/project system,
device fragmentation support, debugging support, UEI emulator
support, j2meunit library, proguard obfuscator, and many
examples. More information can be found at
http://www.netbeans.org/kb/articles/mobility.html.
bgranvea
When will you support the Doja SDK?
gregcrawley
I am not familiar with the Doja SDK specifically, but most SDKs
can integrate with NetBeans if they comply with UEI emulator
standards. You can try to add it as a platform using Tools |
Java Platform Manager. Click Add Platform and navigate to your
installation directory. If the IDE detects the SDK, it will
install automatically.
JBeat
What are the typical differences between devices that you have to
consider when using MIDP 2.0?
adamsotona
Mostly it is about proprietal vendors' APIs and availability of
optional APIs (JSRs). A lot of differences are also in available
hardware and it is usually hard to solve the differences in one
code resulting in one application distribution for any device.
Clive
Is any work being done with the KVM vendors to minimise the
fragmentation issue in the first place, e.g. like tighten up the
MMAPI so it works consistently across all devices?
adamsotona
Sure, it is a continuous process but we are just small fish
There is still a big push from device vendors to be the first in
something and to be unique.
patrick
What are the most interesting features of the Mobility Pack?
gregcrawley
The device fragmentation solution of course :)
fractal@fractalgrafics.com.mx
Once the configurations are set, and the code written, is there a
way to build all jars with just one command or do we have to go
one by one?
davidkaspar
Yes, this is possible. In the IDE just select the Build All
Project Configurations popup menu item on a project node. In the
command line run following command: ant jar-all. A full list of
supported Ant targets is listed in the build.xml file in the root
of your project directory. All jars/jads are built into the dist
directory (each jar/jad in a separate directory).
joe
Comment: The feasibility of a commenting preprocessor has been
established in J2ME tools such as antenna, jenable and
j2me-polish.
gregcrawley
Thanks joe...that's why we chose to integrate this solution.
ntuple
Will the transcript of this chat be available online?
bao
Yes, the transcript will be available on our web site. As a
registered participant, you will receive notification once it is
online. Also, be sure to subscribe to the mobility newsletter to
get all the latest news about new content. You can subscribe at:
http://developers.sun.com/prodtech/javatools/mobility/community/newsletters/index.jsp
joe
Why is there no mention of the Mobility Pack in the 4.1 EA2
announcement? Also, where is the home of the mobility project,
in case I want to report a bug or look for new releases?
gregcrawley
Don't worry joe, we'll have a 4.1 release of mobility along with
EA2. There's no separate homepage for mobility on netbeans.org
... yet... but it's something we're trying to set up. In the
meantime, you can get a lot of information on the Mobility Pack
download page.
bao
joe, there is also good information on the Sun web site for the
mobility IDE:
http://developers.sun.com/prodtech/javatools/mobility/index.jsp
bgranvea
Could you add hierarchic configurations? For example Nokia S60 =>
Nokia S60 MIDP 2.0 => Nokia 6600.
adamsotona
Not yet, now you can just create a special configuration for
each. But stay tuned for the next release. The code blocks will
not be preconditioned just by the configuration names but also by
"abilities." Such ability may be, for example, a Nokia API so the
code block will be used even in, for example, a SonyEricsson
configuration where such an API is present and the ability will
be assigned.
fractal@fractalgrafics.com.mx
Have you considered having a list of available emulators in the
NetBeans Mobility section page? It would be very nice to have
most vendors list their emulator links there, once an emulator is
released by a vendor it would be much nicer to have NetBeans
recognize it and automatically define the configuration
fragmentation definition from it...
gregcrawley
NetBeans will work with any emulator that complies with UEI
(Unified Emulator Interface) standards. Fortunately, most modern
emulators do, so you shouldn't have to worry about it too much
anymore. Again, the Marv the Miner tutorial walks through how
you can also get non-UEI emulators working in the IDE.
JBeat
What would you think of having some sort of knowledge base in the
Mobility Pack, like a collection of templates that solve specific
problems for the most popular phones? On the other hand: Does
good support for fragmented devices not encourage the market to
_further_ fragment?
adamsotona
That is a really interesting idea for a new feature. I will
notice that. Thanks.
gregcrawley
fractal -- to continue my answer with regards to NetBeans
automatically creating configurations for emulators... that is
also an idea we've been tossing around but there are still no
concrete plans to implement it yet. Filing (and voting for) an
RFE on issuezilla is a good way to track an issue's progress.
bgranvea
To go on with the CPP idea, a nice feature would be to be able to
do pre-calculation to optimize the size of the code.
adamsotona
Currently I am not familiar with such pre-calculations in CPP but
in building a J2ME application, the obfuscator definitely plays
the biggest role. So you can see the size of your app just after
the obfuscation but there are no pre-calculations available.
patrick
What are you planning to add in the 4.1 release?
davidkaspar
For the 4.1 release we are planning the following features:
Visual Designer which allows you to create applications using a
drag-and-drop style of work, improved device fragmentation
solution using abilities, deployment support, project
configuration templates, improved project management, and many
more. Right now we are producing Q-builds (stabilized development
builds with the latest features) of Mobility Pack. The reports
and download links are available at
http://qa.netbeans.org/q-builds/mobility-pack/index.html.
joe
I noticed that j2meunit lib is included, but there is no other
integration as far as I can tell. What additional unit test
support is planned?
adamsotona
Yes, we did just a minimal integration of J2MEUnit now. Would you
like some kind of test generation?
fractal@fractalgrafics.com.mx
Is there now an official IRC chat for NetBeans for the mobility
section of it?
davidkaspar
Currently there is neither an IRC chat nor mobility-only mailing
list. If you have any questions you could send it to the
nbusers@netbeans.org mailing list and we will try to answer it as
soon as possible.
fractal@fractalgrafics.com.mx
Currently with NetBeans what is the best way to debug a J2ME
client and J2EE server apps?
adamsotona
J2ME client debugging works fine but I am sorry there is no J2EE
suport in NetBeans 4.0. Stay tuned for the 4.1 release. There you
will be able to debug both.
JBeat
Is J2ME device fragmentation becoming a bigger problem or is it
getting better with MIDP 2.0? I have read that Samsung wants to
use Flash for their phones. Do you consider this a threat to
J2ME? Do you think the Mobility Pack will help to strengthen the
position of J2ME?
bao
The fragmentation problem is not necessarily tied to either MIDP
1 or 2, rather, the differences/capabilities across devices. The
NetBeans Mobility IDE addresses this problem with the device
fragmentation solution.
joe
Concerning J2MEUnit, yes I'd like the same kind of support as
exists for JUnit in J2SE apps. This includes test generation in
a separate "test" source directory, "test" targets in the build.
The basics.
adamsotona
J2ME architecture is slightly different so a separate source root
doesn't make much sense. You still need to create one application
jar containing both (application and tests) so we will probably
look for another solution than the one implemented in J2SE. For
J2ME, a build test means to create a different project
configuration that will also include tests. You can see the basic
support in the Filtering category in Project Properties where you
can exclude all tests for any project configuration using one
click.
fractal@fractalgrafics.com.mx
ETA for Netbeans 4.1?
johnmuchow
Sometime this Spring we plan to release 4.1.
WM
Although this is collateral to this subject, when do you plan to
release some more info, tutorials and documents about MIDP Visual
Designer?
davidkaspar
The latest version of Visual Designer is included in the q-builds
which are usually released every 2 weeks. Also, we are preparing
a 4.1 Beta release in the near future.
fractal@fractalgrafics.com.mx
Have you considered hosting a list of links to available UEI
emulators, that would be great if kept current, would save a lot
of time for us and would give an important statement on current
UEI acceptance.
gregcrawley
We actually have an article that just went up explaining how to
install UEI emulators into NetBeans. This article has a link to
a partial list of emulators that work within NetBeans.
http://developers.sun.com/mobility/nbpack/reference/techart/nbmp40-emulators.html.
Unfortunately, we don't have the resources to maintain a current
list of emulators that comply with UEI.
JBeat
(This is not very specific to the Mobility Pack) What is useful
to use/do when trying to deal with the different screen sizes of
mobile devices?
adamsotona
If you mention some bitmap graphics, for example, of some game,
you can fine-tune and create several distributions of some common
sizes and just choose the best matching size for every real phone.
bgranvea
Doja doesn't belong to the MIDP family, it has been developed
above CLDC by NTT Docomo, so it is more like a cousin of MIDP.
They are both very similar though, so its support shouldn't be
too difficult to add for you. Doja becomes more and more popular
in Europe (and already is of course in Japan), I think it is
worth taking a look.
fractal@fractalgrafics.com.mx
I would love to see a sample jar for the Location API (JSR 179).
davidkaspar
We will think about adding this example into the pack.
WM
The Visual Designer will cover Screen subclasses and Canvas?
davidkaspar
Yes. All Screen subclasses like TextBox, Form, List, Alert. Also
you would be able to add your own screens (classes which extend
Displayable or Item class).
fractal@fractalgrafics.com.mx
It would be nice to have a place where there are unified links to
info on NetBeans Mobility info and Sun's mobility info, at times
seems confusing to search both sites for info on a theme...
bao
Thanks for the feedback, this is definitely something that we are
trying to bridge. We recognize that there is some confusion, and
are working toward making the information as easy to access as
possible.
joe
I don't understand the statement that J2ME Architecture is
different with regard to separate source roots. I've set this up
in a free-form project so that I can build a Midlet JAD/JAR or a
combined MIDlet+TestRunner JAD/JAR. Works nicely. It'd be great
if mobility could automate this in its own projects. By the way,
the advantage of separate source roots is that it makes a clean
separation of test src from non-test src in the project tree.
adamsotona
It is a hard implementaion issue. Multiple source roots
supporting project configurations including actions working
"for-all-configurations" is really hard to implement without
using the usability. We will probably supply it another way.
bao
Okay, we are coming to the end of our hour. Greg, David, and
Adam, do you have any last thoughts for our guests?
gregcrawley
Just want to say we hope you have a better understanding of the
NetBeans Mobility 4.0 device fragmentation solution, and about
mobility in general. We have a lot of cool new features coming
out in version 4.1, so keep a lookout for those emails alerting
you to its release! Oh, and please use issuezilla
(http://www.netbeans.org/community/issues.html) to report any
problems or any other suggestions that you have. Bye for now!
patrick
Thank you mr. greg, mr. adam, and mr . david for answering my
questions. I wish you good luck on the Mobility Pack.
adamsotona
You are welcome.
JBeat
Thank you all for sharing information with us.
bao
Thank you for attending!
fractal@fractalgrafics.com.mx
Thanks a lot for your time and help and see you next chat...!!!
bao
Thanks, we look forward to your continued participation.
WM
Bye folks, and thank very much!
bao
Thanks for your participation, WM. Look for the transcript soon.
bao
Great, thank you. This wraps up our chat for today. I'd like to
thank you all for your active participation, and our speakers for
doing a great job in answering your questions. I hope you found
this information helpful, and this live chat valuable.
An archive of today's chat will be posted on our web site. All
registrants will be notified via email once it is available. On
behalf of the team here at Sun, thank you and goodbye!
