cairo_interaction::set_source_rgba() is not public

[Susurrus]

This applies to a lof of the functions in that file. I've been trying to copy some C code and it's converted basically to the following Rust example:

let icon = gtk::DrawingArea::new();
icon.connect_draw(|w, c| {
    let style_context = w.get_style_context().unwrap();
    let foreground = style_context.get_color(w.get_state_flags());
    c.set_source_rgba (&foreground);
});

Unfortunately this doesn't compile because of both the missing get_color() (tracked in gtk-rs/gtk#454), but also because the equivalent of gdk_cairo_set_source_rgba() isn't available. It's implemented in gdk::cairo_interaction and I would think it'd be usable since the c argument to the closure is a cairo::Context. Is there something I'm missing here?

I should note that if you call c.get_clip_rectangle() within the callback it will compile successfully, so I'm wondering if there's a compiler bug that is allowing Context to have two set_source_rgba functions implemented on it and silently ignores the duplicate one?

[Susurrus]

@EPashkin I mentioned this in my PR for the RGBA stuff, but I figured I'd break it out as a separate issue. Any idea what's going on here?

[Susurrus]

Indeed, this looks to be a compiler bug. If I rename ContextExt::set_source_rgba to set_source_rgba2, then I can use that function in the connect_draw closure.

So here's the question, how do we want to resolve this? We have two functions, gdk_cairo_set_source_rgba and cairo_set_source_rgba. Is there a convention for how to handle duplicate function names within the gtk-rs namespace?

Pinging both @EPashkin and @GuillaumeGomez because I don't know how this should be resolved.

[Susurrus]

Looks like I was wrong, sorry about the noise! Just talked to some people on IRC and the proper way to use these functions is the do <Context as ContextExt>::set_source_rgba(&c, &foreground); where use cairo::Context; and use gdk::prelude::*; where used to bring both the struct and trait into scope.

So closing this.

[EPashkin]

IMHO ContextExt::set_source_rgba(&c, &foreground) will work too

[Susurrus]

The compiler complained about the types and using the explicit syntax fixed it.