Re: java package

[Ben Abbott]

On May 9, 2012, at 1:28 PM, Michael Goffioul wrote:

> On Wed, May 9, 2012 at 6:09 PM, Alexander Hansen
> <address@hidden> wrote:
>> On 5/9/12 9:49 AM, John W. Eaton wrote:
>>> I received a request to make the java package from Octave Forge part
>>> of Octave.  A number of the functions provided by the Octave Forge
>>> java package are distributed as part of Matlab, not a separate
>>> toolbox, so it makes sense to me to include them in Octave as well.
>>> Is there any objection to doing that?
>>> 
>>> jwe
>> 
>> The existing java package has a couple of issues on Mac OS X:
>> 
>> 1)  It sets JAVA_INCS improperly for current OS X Java, so it doesn't
>> build out of the box. Using
>> 
>> JAVA_INCS="-I/System/Library/Frameworks/JavaVM.framework/Versions/A/Headers"
>> 
>> works on 10.5, 10.6, and 10.7.
>> 
>> 2)  Items like msgbox() which are supposed to open up a window don't
>> seem to work:
>> 
>> octave-3.4.3:4> msgbox("foo")
>> 2012-05-09 10:04:28.573 octave-3.4.3[88991:1603] Apple AWT Java VM was
>> loaded on first thread -- can't start AWT.
>> error: [java] java.lang.InternalError: Can't start the AWT because Java
>> was started on the first thread.  Make sure StartOnFirstThread is not
>> specified in your application's Info.plist or on the command line
>> error: called from:
>> error:   /sw/share/octave/3.4.3/packages/java-1.2.8/msgbox.m at line 52,
>> column 7
>> 
>> (previously reported).
> 
> That's unfortunately a general problem on the Mac OS X platform: you
> must run a GUI loop in the main program thread, which in the case of
> octave is the main readline loop. Any toolkit that I have used suffer
> from the same problem. This is the main (only?) reason that you are
> warned in Qt when creating a QApplication outside of the main thread.
> 
> Maybe there are workarounds for that problem, but that would require a
> knowledgeable developer using Mac OS X, and I'm not.
> 
> Michael.

My guess is that Matlab's java stuff only works when running their GUI.

... makes me wonder if we may want to use Java for the GUI.

Ben