Updated Transformer's generic parameters

[ntoskrnl]

Return type Transformer<T, T> was updated to Transformer<? super T, ? extends T> to support Kotlin type inference.
This should fix #44 issue.

[dlew]

Thanks! Also, if you want to submit a PR to upgrade onAttach() I'd take it, too. (I can do it myself, too.)

[ntoskrnl]

I actually don't know how to correctly change it. Looks like onAttach(Context) appeared in 23 SDK. If I change it for both RxFragment and support.RxFragment, the former one doesn't pass the test. When fragment.onAttach((Context) null) is called from within the test, it fails with NoSuchMethod exception.

[dlew]

Yeah, back-compat can be tricky. I doubt that it's strictly necessary here, but for correctness' sake probably worth it. I'll make an issue.

[almozavr]

Unhappy with that as compiler can't infer type now, have to write it every time :(

myTypeObservable.compose(RxLifecycle.<MyType>bindView(view));

vs.

myTypeObservable.compose(RxLifecycle.bindView(view));

[dlew]

You could write a wrapper around the current RxLifecycle that uses <T, T>.

[bensandee]

To be honest, the 0.3.1 seems like a step backwards for what I suspect is the predominant platform -- Java 7 + Retrolambda -- because of the fact that it won't infer types properly with these updated signatures. The change may have made Kotlin support cleaner, but it seems to be at the expense of standard Java which is likely to have many more users. But yes, a wrapper is easy enough to write but the same could be said for Kotlin users, no?

[vanniktech]

This change also broke the existing code in our applications.

[bensandee]

Because I'm obsessed to use the newest rev of every library, I'm working on this alternative bind wrapper function in my base activity. Here's what I've come up with -- any comments as to whether this is the best possible?

  @SuppressWarnings("unchecked")
  @Nonnull
  public final <T> Observable.Transformer<T, T> localBindToLifecycle() {
    return (Observable.Transformer<T, T> )this.<T>bindToLifecycle();
  }

[vanniktech]

I reverted back to 0.3.0. Currently I don't have the time to deal with those changes.

[dlew]

Another fix is to use the Java 8 compiler, since it can infer the types correctly.

It's perfectly safe to use Java 8 on Android (just avoid using any newer constructs like lambdas unless you're using something like retrolambda).

[bensandee]

I am using the Java 8 compiler + Retrolambda to rehost onto Android/Java 7 and it's not inferring properly for me. The 0.3.0 works fine, but 0.3.1 forces me to use the this.<T>bindToLifeCycle to compile.

[dlew]

I've made #58 to discuss this further, instead of polluting an old PR.