Panic with 'assertion failed: self.is::<T>()'

[haecker-felix]

thread 'main' panicked at 'assertion failed: self.is::<T>()', /home/haecker-felix/Dokumente/Projekte/Shortwave/_build/cargo-home/git/checkouts/gtk-rs-48ef14c1f17c79fb/a2568f0/glib/src/object.rs:275:9
stack backtrace:
   0: rust_begin_unwind
             at /rustc/cb75ad5db02783e8b0222fee363c5f63f7e2cf5b/library/std/src/panicking.rs:493:5
   1: core::panicking::panic_fmt
             at /rustc/cb75ad5db02783e8b0222fee363c5f63f7e2cf5b/library/core/src/panicking.rs:92:14
   2: core::panicking::panic
             at /rustc/cb75ad5db02783e8b0222fee363c5f63f7e2cf5b/library/core/src/panicking.rs:50:5
   3: glib::object::Cast::unsafe_cast_ref
             at ./Dokumente/Projekte/Shortwave/_build/cargo-home/git/checkouts/gtk-rs-48ef14c1f17c79fb/a2568f0/glib/src/object.rs:275:9
   4: glib::object::Cast::upcast_ref
             at ./Dokumente/Projekte/Shortwave/_build/cargo-home/git/checkouts/gtk-rs-48ef14c1f17c79fb/a2568f0/glib/src/object.rs:128:18
   5: <shortwave::model::station_model::SwStationModel as core::convert::AsRef<gio::auto::list_model::ListModel>>::as_ref
             at ./Dokumente/Projekte/Shortwave/_build/cargo-home/git/checkouts/gtk-rs-48ef14c1f17c79fb/a2568f0/glib/src/object.rs:966:17
   6: gtk4::auto::flow_box::FlowBox::bind_model::{{closure}}
             at ./Dokumente/Projekte/Shortwave/_build/cargo-home/git/checkouts/gtk4-rs-e74ad56283dfeb5e/4552124/gtk4/src/auto/flow_box.rs:80:31
   7: core::option::Option<T>::map
             at /usr/lib/sdk/rust-stable/lib/rustlib/src/rust/library/core/src/option.rs:453:29
   8: gtk4::auto::flow_box::FlowBox::bind_model
             at ./Dokumente/Projekte/Shortwave/_build/cargo-home/git/checkouts/gtk4-rs-e74ad56283dfeb5e/4552124/gtk4/src/auto/flow_box.rs:80:17
   9: shortwave::ui::station_flowbox::SwStationFlowBox::init
             at ./Dokumente/Projekte/Shortwave/src/ui/station_flowbox.rs:86:9
  10: shortwave::ui::pages::library_page::SwLibraryPage::setup_widgets
             at ./Dokumente/Projekte/Shortwave/src/ui/pages/library_page.rs:103:9
  11: shortwave::ui::pages::library_page::SwLibraryPage::init
             at ./Dokumente/Projekte/Shortwave/src/ui/pages/library_page.rs:88:9
  12: shortwave::ui::window::SwApplicationWindow::setup_widgets
             at ./Dokumente/Projekte/Shortwave/src/ui/window.rs:152:9
  13: shortwave::ui::window::SwApplicationWindow::new
             at ./Dokumente/Projekte/Shortwave/src/ui/window.rs:140:9
  14: shortwave::app::SwApplication::create_window
             at ./Dokumente/Projekte/Shortwave/src/app.rs:176:22
  15: <shortwave::app::SwApplicationPrivate as gio::subclass::application::ApplicationImpl>::activate
             at ./Dokumente/Projekte/Shortwave/src/app.rs:124:22
  16: gio::subclass::application::application_activate
             at ./Dokumente/Projekte/Shortwave/_build/cargo-home/git/checkouts/gtk-rs-48ef14c1f17c79fb/a2568f0/gio/src/subclass/application.rs:372:5
  17: <unknown>
  18: g_signal_emit_valist
  19: g_signal_emit
  20: <unknown>
  21: <T as gio::subclass::application::ApplicationImplExt>::parent_local_command_line
             at ./Dokumente/Projekte/Shortwave/_build/cargo-home/git/checkouts/gtk-rs-48ef14c1f17c79fb/a2568f0/gio/src/subclass/application.rs:232:23
  22: gio::subclass::application::ApplicationImpl::local_command_line
             at ./Dokumente/Projekte/Shortwave/_build/cargo-home/git/checkouts/gtk-rs-48ef14c1f17c79fb/a2568f0/gio/src/subclass/application.rs:99:9
  23: gio::subclass::application::application_local_command_line
             at ./Dokumente/Projekte/Shortwave/_build/cargo-home/git/checkouts/gtk-rs-48ef14c1f17c79fb/a2568f0/gio/src/subclass/application.rs:415:15
  24: g_application_run
  25: <O as gio::application::ApplicationExtManual>::run
             at ./Dokumente/Projekte/Shortwave/_build/cargo-home/git/checkouts/gtk-rs-48ef14c1f17c79fb/a2568f0/gio/src/application.rs:23:13
  26: shortwave::app::SwApplication::run
             at ./Dokumente/Projekte/Shortwave/src/app.rs:171:9
  27: shortwave::main
             at ./Dokumente/Projekte/Shortwave/src/main.rs:89:5
  28: core::ops::function::FnOnce::call_once
             at /usr/lib/sdk/rust-stable/lib/rustlib/src/rust/library/core/src/ops/function.rs:227:5

I'm using commit 4552124
That code snippet worked before, that was commit c430251

    pub fn init(&self, model: SwStationModel, sender: Sender<Action>) {
        let imp = imp::SwStationFlowBox::from_instance(self);

        //let sorter = gtk::StringSorter::
        //let sortlist_model = gtk::SortListModel::new(model, sorter);

        imp.flowbox.get().bind_model(
            // 9: shortwave::ui::station_flowbox::SwStationFlowBox::init
            // at ./Dokumente/Projekte/Shortwave/src/ui/station_flowbox.rs:86:9
            Some(&model),
            clone!(@strong sender => move |station|{
                let station = station.downcast_ref::<SwStation>().unwrap();
                let row = SwStationRow::new(sender.clone(), station.clone());
                row.upcast()
            }),
        );

        self.setup_signals(sender);
    }

Complete code is available here: https://gitlab.gnome.org/World/Shortwave/-/commits/wip/haecker-felix/gtk-rs-ugprade

[sdroege]

That's probably my fault, let's see...

[sdroege]

The listbox_model example from gtk-rs also does not build anymore FWIW (gtk-rs/gtk3-rs#354). I assume this can be reproduced with that example, we'll see :)

[sdroege]

You're missing an type Interfaces = ... here.

You can write the whole thing as follows now (note the Default deriving and the lack of fn new() also):

#[derive(Debug, Default)]
pub struct SwStationModel {
    pub vec: RefCell<Vec<SwStation>>,
}

#[glib::object_subclass]
impl ObjectSubclass for SwStationModel {
    const NAME: &'static str = "SwStationModel";
    type ParentType = glib::Object;
    type Type = super::SwStationModel;
    type Interfaces = (gio::ListModel, );
}

[sdroege]

See also the listbox_model.rs example after gtk-rs/gtk3-rs#355

[haecker-felix]

Yep, that fixed it. Also thanks a lot for the hint with Default 👍

Implementing that was really satisfying :D