Composite Controls

[juliagraphics]

Composite Controls

[vtjnash]

On my phone so I'll be short:
This is like Canvas. Should it be wrapper or subtype. I think direct subtype so that convert is indempotent. Known need to fix methods in Gtk.jl anyways

[tknopp]

Not sure that I can follow you here. If MyType subtypes from GtkWidgetI doesent it than require to have a handle field? We could of course follow the following sheme

type MyWidget <: GtkWidgetI
    handle::Ptr{GObject}
    btn::GtkButton
end
function MyWidget(label)
    btn = GtkButton(label)
    MyWidget(btn.handle, btn)
end   

[vtjnash]

the btn field would not be necessary. I would add a function called reinherit which transfers ownership of a handle from one Julia object to another and destroys the old reference object. Thus the MyWidget constructor would look something like:

type MyWidget <: Gtk.GtkButtonI
    handle::Ptr{Gtk.GObjectI}
    other_fields
function MyWidget(label)
  btn = GtkButton(label)
  Gtk.gc_move_ref(new(btn), btn)
end
end

where gc_move_ref is a function I just added to GLib:

function Gtk.gc_move_ref(old::GObjectI, new::GObjectI)
  @assert old.handle == new.handle != C_NULL
  Gtk.gc_unref(old) # destroys old, but does nothing to it's gc ref
  Gtk.gc_force_floating(new) # forced the gc ref in old to floating
  Gtk.gc_ref(new) # adopt the floating gc ref from old and return new
end

[tknopp]

@vtjnash: Like that! This should go into the documentation. The button was not the best example though. In practice one would subtype a container

[tknopp]

Great. Thanks for documenting this