Implement HasRawWindowHandle for GTK?

[cmyr]

This was added for the mac and windows in #1586.

curious to hear if this was a decision or an omission.

This was discussed. I have no access to non-Windows platforms and little knowledge about them, so rather than doing a blind implementation likely to be buggy, implementations on those missing platforms is left for a future change by whoever can contribute it. I did Windows and @rjwittams did macOS.

Originally posted by @djeedai in #1586 (comment)

[djeedai]

Some notes: I looked at GTK and X11, and X11 is probably trivial (but I'd rather someone do it who can also test it). GTK however is an odd one because it's not a platform but already a platform abstraction itself, so this would require a bit of work to go fetch the right raw platform handle for the current platform config, if at all possible (I think it is, but couldn't find the appropriate wrapper in the Rust binding).

[emigr2k1]

GTK is also easy (for x11 atleast) but I don't think the bindings have an easy way to get the xdisplay.

There's gdk_x11_window_get_xid to get the xlib window. The corresponding function in the bindings is here.

To get the xdisplay we have gdk_x11_display_get_xdisplay but in the bindings I don't see how I can get the raw pointer.

I opened an issue in the gtk-rs repo to see if I can get some help.