Fix remaining deprecations

[tknopp]

Gtk master now passes test on Julia 0.7 but there are remaining things:

• the current_module deprecations cannot be replaced by @__MODULE__ since it says that Gtk is not defined

• the remaining cfunction replacements do not work, because the depend on local scope

@vtjnash: I definitely need help on the remaining cfunction deprecations. Would be wonderful if you could have a look.

[tknopp]

I fixed the cfunction issue by using a direct call into libjulia:

cfunction_(f, r, a::Tuple) = cfunction_(f, r, Tuple{a...})
@noinline function cfunction_(f, r, a)
    @nospecialize(f, r, a)
    return ccall((:jl_function_ptr,:libjulia), Ptr{Cvoid}, (Any, Any, Any), f, r, a)
end

Is that ok for now @vtjnash? Otherwise we need a fix for @cfunction in local scope.

The module thing has been worked around by

curr_module() = ccall((:jl_get_current_module,:libjulia), Ref{Module}, ())

That certainly is not ok, since that function is not present in 1.0 anymore. @vtjnash or @JeffBezanson: I would be very thankful for a fix. I don't fully get the interaction between GLib and Gtk and this is your code @vtjnash. When this is done Gtk should be deprecation free and work on 1.0. This is important for depending packages.

[vtjnash]

No, this function is supposed to be deleted. That function call usages should be replaced with a macro to create the function pointer of the correct type at each use site.

[tknopp]

Then I need you help. The @cfunctiondepends on local scope:
https://github.com/JuliaGraphics/Gtk.jl/blob/master/src/GLib/signals.jl#L11
cb is local scope.

[tknopp]

The other ones are here:

Gtk.jl/src/events.jl

Line 90 in 9e7b9da

cb = cfunction_(move_cb, Cint, (Ptr{GObject}, Ptr{GdkEventMotion}, T))

So its these 3 cfunctions that I was not able to replace by @cfunction

[vtjnash]

Yes, signal_connect should also be made a macro, so it can access the types for the cfunction method signature at compile time.

[vtjnash]

Those other ones can just be deleted (optionally keep the Ref version, or delete those too). It's a primitive implementation of FunctionWrappers.jl (from long before that existed), but it is not really necessary.

[tknopp]

No, this function is supposed to be deleted.

Are the deleted in Julia 1.0? Or not. If it is still there my "hotfix" is probably ok and we can redesign signal_connect in the second step?

Yes, signal_connect should also be made a macro, so it can access the types for the cfunction method signature at compile time.

I understand this, but doesn't this mean that one cannot apply closures anymore to the function? What about all those on_* functions, these in turn all need to go right? I actually don't know how to redesign the file
https://github.com/JuliaGraphics/Gtk.jl/blob/master/src/events.jl
then.

What is with the simple signal_connect that is used in do expressions:
https://github.com/JuliaGraphics/Gtk.jl/blob/master/src/GLib/signals.jl#L26
This is ok, since it does not compile a cfunction?!

So in summary, we will have @signal_connect for the compiled version and signal_connect for the runtime version, is this correct Jameson? And I don't know what we do with events.jl