How to use nested class with arsd.jni

[Adam D. Ruppe]

On Wednesday, 4 March 2020 at 09:35:31 UTC, fp wrote:
> What is the correct way to declare/use the nested Inner class ?

Lemme hsow you the code first:

---
import std.stdio;
import arsd.jni;

final class Outer : JavaClass!("", Outer) {
	@Import this();
}

@JavaName("Outer$Inner") // the name here has teh separator dot 
replaced with a $. note it is the same  as the .class file if you 
need help figuring it out
final class Inner : JavaClass!("", Inner)
{
    @Import this(Outer); // then add a constructor taking the 
outer class as an arg
    @Import void printHello();
}


void main()
{
	auto jvm = createJvm();
	auto o = new Outer();
	// and then construct it like this
	Inner inner = new Inner(o);
         inner.printHello();
}
---



Basically, direct inner classes hit a bunch of compiler bugs, so 
the way to make it work is to flatten it, taking the inner class 
out and declaring as if it was a top-level thing. Which is what 
the JVM does internally and that's why it works btw.

If you try to add a convenience method in Outer for it, you're 
liable to hit a "forward reference" error, which is again a 
compiler bug brought on by the recursive reflection done inside 
jni.d (I hit more compiler bugs working on this project than I 
have in the last 5 years of writing D combined).

As seen above, you don't need to declare them together, but if 
you do want to try, just be sure Inner is declared before Outer 
in the file. Then you can do a `final` method (not @Import) that 
just `return new .Inner(this);` or something like that.

But I think you'll probably have better luck keeping it simple 
and flattening like this.