On Wed, 12 Apr 2000, Vince Darley wrote:
> I'm trying to have more heavy interaction between my Tcl code and Java. In
> particular I want to be able to pass in a Tcl command to the Java, and have
> it executed at certain intervals, where that command takes a Java object as
> a parameter:
>
> proc callback {javaobj} {
> puts stdout [java::info class $javaobj]
> }
>
> ----
> // TclCallback.java
>
> ....
>
> public class TclCallback {
> public TclCallback(String command, Interp interp) {
> this.command = command;
> this.interp = interp;
> }
> String command;
> Interp interp;
>
> public void call(MyJavaObject mjo) {
> try {
> interp.eval(command + " " + mjo, 0);
> } catch (TclException te) {
> Debug.bug("Tcl exception thrown: " +te);
> }
> }
> }
>
> However the callback proc doesn't receive a java-object, but rather a string
> looking like:
> MyJavaObject@d531bf4b
>
> So, I guess my 'interp.eval' statement is wrong. What should it look like?
>
> thanks,
>
> Vince.
You have two problems there. You can not just call interp.eval()
from random Java code because it is not thread safe (this is
by design). To make a thread safe call you need to create another
"event" object, add it to the interps event queue, and then
let it get done "later". Like so:
(from src/jacl/tcl/lang/Shell.java)
ConsoleEvent evt = new ConsoleEvent(interp, sbuf.toString());
interp.getNotifier().queueEvent(evt, TCL.QUEUE_TAIL);
evt.sync();
(from src/jacl/tcl/lang/ConsoleEvent.java)
public int
processEvent(
int flags) // Same as flags passed to Notifier.doOneEvent.
{
try {
interp.eval(script, 0);
} catch (TclException e) {
evalException = e;
} finally {
evalResult = interp.getResult();
evalResult.preserve();
}
return 1;
}
I will be the first to admit that this is kind of ugly.
I am looking to redesign this part of the interface in the 1.3
tree.
You other problem is that you need to create a "reflect object"
and pass that to your Tcl code.
MyJavaObject mjo = ...
ReflectObject ro = ReflectObject.newInstance(interp, MyJavaObject.class,
mjo);
The reflect object creating also needs to be done in the event
callback, not in the thread unsafe Java callback.
Mo DeJong
Red Hat Inc.
----------------------------------------------------------------
The TclJava mailing list is sponsored by Scriptics Corporation.
To subscribe: send mail to [EMAIL PROTECTED]
with the word SUBSCRIBE as the subject.
To unsubscribe: send mail to [EMAIL PROTECTED]
with the word UNSUBSCRIBE as the subject.
To send to the list, send email to '[EMAIL PROTECTED]'.
An archive is available at http://www.mail-archive.com/tcljava@scriptics.com
