Re: [xmlvm-users] Support for J2ME (MIDP) to IPhone cross compilation, commercial usage, Apple AppStore?

[Arno P. <ar...@pu...>]

Gergely,

> I have to admit, I know less about the Apple AppStore submission process 
> than I would like. What does "submission for review" mean? Is this some 
> kind of dry run, where Apple checks if the submitted application 
> complies to the submission guidelines? Did Xokoban pass? :)

Its really quite simple: Apple keeps in total control over which 
applications get accepted to the AppStore. You first have to submit your 
application (only the binary, not the source), Apple reviews it, and 
then they may or may not accept it to their AppStore. We have submitted 
Xokoban on July 1st for review; exactly a month ago and we are still 
waiting. Apple is not very consistent with its decisions. If you search 
the web, you will find plenty of such stories.

> So just to clarify: If we, as a company receive the "linking exception" 
> license in exchange for our contribution, are we allowed to develop 
> commercial applications for our clients, so that our clients would 
> release these applications to the public (basically "work made for 
> hire")? Also: would there be some kind of "expiration date" on this 
> linking exception license, or it would apply to all future revisions of 
> xmlvm?

The linking exception is granted to an individual or a company who makes 
the contribution to XMLVM. This linking exception is non-transferable. 
This means that you yourself can do work for hire for your clients 
without having to release your application under the GPL, but your 
client could not do the development work.

> Now back to the interesting stuff:
> One important issue in any embedded development scenario is the on 
> device debugging. It would be nice to provide a way for Java 
> applications translated by xmlvm to be debugged on the IPhone.

I agree that debugging capabilities are important. As long as there is a 
Java version of the Cocoa Touch classes, you can debug under Eclipse. If 
you want to debug on the device, you have to use Xcode. The big downside 
here is that you would be debugging the Objective-C source code that 
XMLVM generates. That is like debugging assembler code. It should be 
possible to insert meta-information (i.e., line numbers) into the 
generated Objective-C code and build a bridge to an external Java 
debugger. That is no easy task.

> One solution comes to mind: Create a protocol bridge between the 
> debugging protocol used by the IPhone (I think they use GDB/MI, but I 
> have to check further), and Eclipse, which uses the standard Java 
> debugger interface. As part of the translation process xmlvm could 
> output a mapping file which maps the source line information in the 
> class files to source line information in the Objective-C sources.

That's basically it. A first step would be to look at Java class files 
with debug information and map that debug information to XMLVM so it can 
be used during code generation. Generating debug info would have to be 
done in class ParseJVM by making use of BCEL. Patches are welcome. :-)

> The big IF in this approach is of course whether an external program 
> outside of Xcode can access the GDB/MI connection to the IPhone. I have 
> seen some indication on the net that this can be done.

Well, how about just doing a plain old TCP socket? Or simpler, just use 
HTTP to communicate with the device.

Arno