Duplicate object warning when creating GtkCssProvider objects

[nlw0]

Creating more than one GtkCssProvider object throws a "duplicate Julia object creation detected for GObject" warning message. While this doesn't seem to be a problem, it might indicate a potential issue. Plus it's nagging.

julia> using Gtk

julia> css = GtkCssProvider(data = "#thing {color: #fafef1}")
GtkCssProviderLeaf()

julia> css = GtkCssProvider(data = "#thing {color: #fafef1}")
┌ Warning: Duplicate Julia object creation detected for GObject
└ @ Gtk.GLib ~/.julia/packages/Gtk/C22jV/src/GLib/gtype.jl:468
GtkCssProviderLeaf()

julia> css = GtkCssProvider(data = "#thing {color: #fafef1}")
┌ Warning: Duplicate Julia object creation detected for GObject
└ @ Gtk.GLib ~/.julia/packages/Gtk/C22jV/src/GLib/gtype.jl:468
GtkCssProviderLeaf()

julia>

[jonathanBieler]

I think it's because the GtkCssProvider constructor is calling gtk_css_provider_get_default so you end up having several objects "pointing" to the default provider.

Apparently gtk_css_provider_get_default is deprecated and we should use gtk_css_provider_new instead :

https://developer.gnome.org/gtk3/stable/GtkCssProvider.html#gtk-css-provider-get-default

[tknopp]

To my defense, at the time I implemented the GtkCssProvider the function was not yet deprecated ;-). PR welcome