Re: [Ikvm-developers] How to pass a Java callable to C#?

[Jeroen F. <je...@su...>]

Hi Doug,

Your C# on_click method is callable from (IKVM) Java.

You'll need to generate a class that implements the cli.System.Func$$00602_$$$_Ljava__lang__Object_$$_Ljava__lang__Object_$$$$_$Method interface.

This class can then be instantiated and passed to the constructor of the cli.System.Func$$00602_$$$_Ljava__lang__Object_$$_Ljava__lang__Object_$$$$_ class (the delegate) and this object can be passed to the on_click method.

Regards,
Jeroen

> -----Original Message-----
> From: Doug Blank [mailto:dou...@gm...]
> Sent: Sunday, February 16, 2014 13:46
> To: Jeroen Frijters
> Cc: ikv...@li...
> Subject: Re: [Ikvm-developers] How to pass a Java callable to C#?
> 
> Jeroen,
> 
> Thanks for the feedback, but I think I didn't explain very well my
> problem. The Widget library is written in C# and is being used by the
> Java interpreter (running on the CLR). I wish to be able to register the
> callback in Java.
> 
> This works in IronPython, because IronPython knows how to map Python
> functions onto Func<object,object>:
> 
> """
> from Widgets import Widget
> def f(obj):
>     print("Click!")
> w = Widget()
> w.on_click(f)
> """
> 
> I have the same working in a Scheme running on the CLR, because I can
> define and wrap around callback1 in C#  to map it to
> Func<object,object>:
> 
> """
> (using "Widgets")
> (define f (lambda (obj) (printf "~a\n" obj)) (define w (Widget))
> (w.on_click (callback1 f)) """
> 
> So, I'm trying to figure out how to do the same thing in Java: map
> something in Java onto Func<object,object>, so something like this will
> work in DynamicJava:
> 
> """
> import static cli.Widgets.*;
> 
> public int f(Object widget) {
> }
> 
> Widget w = new Widget();
> w.on_click(f);
> """
> 
> Does ikvm have something built-in to help pass a Java function to C#? Or
> do you have a general strategy for doing this?
> 
> Thanks for any further hints,
> 
> -Doug
> 
> 
> On Sun, Feb 16, 2014 at 4:21 AM, Jeroen Frijters <je...@su...
> <mailto:je...@su...> > wrote:
> 
> 
> 	Hi Doug,
> 
> 	I'm probably misunderstanding the question, but in Java you'd use
> interfaces for this. See
> http://docs.oracle.com/javase/7/docs/api/java/awt/Button.html#addActionL
> istener(java.awt.event.ActionListener) for example.
> 
> 	Regards,
> 	Jeroen
> 
> 
> 	> -----Original Message-----
> 	> From: Doug Blank [mailto:dou...@gm...
> <mailto:dou...@gm...> ]
> 	> Sent: Sunday, February 16, 2014 0:57
> 	> To: ikv...@li... <mailto:ikvm-
> dev...@li...>
> 	> Subject: [Ikvm-developers] How to pass a Java callable to C#?
> 	>
> 	> I am doing some refining on the DynamicJava interpreter written
> in Java
> 	> that is running under Mono [1]. (C# libraries are made available
> to the
> 	> interpreted Java through ikvmstub, and the Java interpreter is
> running
> 	> by being compiled with ikvmc). Everything is working very well,
> but one
> 	> thing I would like to do is be able to pass a Java callback to a
> C#
> 	> function.
> 	>
> 	>
> 	> The C# code looks like this (although I could change it in any
> manner):
> 	>
> 	>
> 	> public class Widget {
> 	> public void on_click(System.Func<object,object> function) {
> 	>         }
> 	> }
> 	>
> 	> In general, how would a Java program register a callback to the
> C#? I
> 	> can write an interface on either the Java side, or the C# side.
> 	>
> 	> Thanks for any suggestions,
> 	>
> 	> -Doug
> 	>
> 	> [1] -
> 	>
> https://bitbucket.org/ipre/calico/src/master/languages/Java/dynamicjava/
> 
>