No rendering after drop (#6911)

app/gui/src/ide/initializer.rs

@@ -81,7 +81,7 @@ impl Initializer {
         match self.initialize_ide_controller_with_retries().await {
             Ok(controller) => {
                 let can_manage_projects = controller.can_manage_projects();
-                let ide = Ide::new(ensogl_app, view.clone_ref(), controller);
+                let ide = Ide::new(ensogl_app, view, controller);
                 if can_manage_projects {
                     if let Some(project) = &self.config.project_to_open {
                         ide.open_or_create_project(project.clone());

app/gui/src/lib.rs

@@ -203,12 +203,20 @@ pub fn main() {
 #[wasm_bindgen]
 pub fn drop() {
     let ide = IDE.with(RefCell::take);
-    if let Some(Ok(ide)) = &ide {
+    if let Some(Ok(ide)) = ide {
         //TODO[ao] #6420 We should not do this, but somehow the `dom` field in the scene is
         // leaking.
         ide.ensogl_app.display.default_scene.dom.root.remove();
-    }
+        // The presenter need to be dropped first, so all visible components should hide themselves
-    mem::drop(ide);
+        // and be pushed to the garbage collector before we clear it.
+        mem::drop(ide.presenter);
+        //TODO[ao] As widgets which are garbage-collected may (and ofter do) keep references to
+        // [`Application`] or [`World`], we need to force dropping them. This is not an ideal
+        // solution, but the garbage collector will be removed soon anyway - see
+        // https://github.com/enso-org/enso/issues/6850#issuecomment-1576754037
+        ide.ensogl_app.display.force_garbage_drop();
+        mem::drop(ide.ensogl_app)
+    };
     EXECUTOR.with(RefCell::take);
     leak_detector::TRACKED_OBJECTS.with(|objects| {
         let objects = objects.borrow();

app/gui/src/presenter/graph/visualization.rs

@@ -12,7 +12,6 @@ use crate::presenter::graph::AstNodeId;
 use crate::presenter::graph::ViewNodeId;
 
 use enso_frp as frp;
-use ensogl::application::View;
 use ide_view as view;
 use ide_view::graph_editor::component::node as node_view;
 use ide_view::graph_editor::component::visualization as visualization_view;
@@ -181,7 +180,6 @@ impl Visualization {
             state,
         });
 
-        let app = &view.app().frp;
         frp::extend! { network
             eval view.visualization_shown (((node, metadata)) model.visualization_shown(*node, metadata.clone()));
             eval view.visualization_hidden ((node) model.visualization_hidden(*node));
@@ -196,8 +194,7 @@ impl Visualization {
 
             view.set_visualization_data <+ set_data;
             view.set_error_visualization_data <+ error_update;
-            view.disable_visualization <+ visualization_failure._0();
+            view.visualization_update_failed <+ visualization_failure;
-            app.show_notification <+ visualization_failure._1();
 
             eval_ view.visualization_registry_reload_requested (model.load_visualizations());
         }

app/gui/view/component-browser/component-list-panel/breadcrumbs/src/lib.rs

@@ -492,10 +492,6 @@ impl ensogl_core::application::View for Breadcrumbs {
         Self::new(app)
     }
 
-    fn app(&self) -> &Application {
-        self.widget.app()
-    }
-
     fn default_shortcuts() -> Vec<Shortcut> {
         use ensogl_core::application::shortcut::ActionType::*;
         [(Press, "shift enter", "move_up"), (Press, "ctrl shift enter", "move_down")]

app/gui/view/component-browser/component-list-panel/src/lib.rs

@@ -246,7 +246,6 @@ pub struct Model {
 
 impl Model {
     fn new(app: &Application) -> Self {
-        let app = app.clone_ref();
         let scene = &app.display.default_scene;
         let display_object = display::object::Instance::new();
 
@@ -256,7 +255,7 @@ impl Model {
         let grid = app.new_view::<grid::View>();
         display_object.add_child(&grid);
 
-        let section_navigator = SectionNavigator::new(&app);
+        let section_navigator = SectionNavigator::new(app);
         display_object.add_child(&section_navigator);
 
         let breadcrumbs = app.new_view::<breadcrumbs::Breadcrumbs>();

app/gui/view/graph-editor/src/component/breadcrumbs.rs

@@ -132,6 +132,7 @@ pub struct BreadcrumbsModel {
     /// A container for all the breadcrumbs after project name. This contained and all its
     /// breadcrumbs are moved when project name component is resized.
     breadcrumbs_container: display::object::Instance,
+    // Required for creating new breadcrumbs
     app:                   Application,
     breadcrumbs:           Rc<RefCell<Vec<Breadcrumb>>>,
     frp_inputs:            FrpInputs,

app/gui/view/graph-editor/src/component/breadcrumbs/project_name.rs

@@ -127,7 +127,6 @@ impl Animations {
 #[derive(Debug, Clone, CloneRef)]
 #[allow(missing_docs)]
 struct ProjectNameModel {
-    app:            Application,
     display_object: display::object::Instance,
     view:           background::View,
     style:          StyleWatch,
@@ -138,7 +137,6 @@ struct ProjectNameModel {
 impl ProjectNameModel {
     /// Constructor.
     fn new(app: &Application) -> Self {
-        let app = app.clone_ref();
         let scene = &app.display.default_scene;
         let display_object = display::object::Instance::new();
         // FIXME : StyleWatch is unsuitable here, as it was designed as an internal tool for shape
@@ -160,7 +158,7 @@ impl ProjectNameModel {
         scene.layers.panel.add(&view);
 
         let project_name = default();
-        Self { app, display_object, view, style, text_field, project_name }.init()
+        Self { display_object, view, style, text_field, project_name }.init()
     }
 
     /// Compute the width of the ProjectName view.
@@ -423,12 +421,10 @@ impl View for ProjectName {
     fn label() -> &'static str {
         "ProjectName"
     }
+
     fn new(app: &Application) -> Self {
         ProjectName::new(app)
     }
-    fn app(&self) -> &Application {
-        &self.model.app
-    }
 
     fn default_shortcuts() -> Vec<shortcut::Shortcut> {
         use shortcut::ActionType::*;

app/gui/view/graph-editor/src/component/node.rs

@@ -402,6 +402,7 @@ impl Deref for Node {
 #[derive(Clone, CloneRef, Debug)]
 #[allow(missing_docs)]
 pub struct NodeModel {
+    // Required for switching the node to a different layer
     pub app:                 Application,
     pub display_object:      display::object::Instance,
     pub background:          Background,

app/gui/view/graph-editor/src/component/node/input/area.rs

@@ -133,7 +133,6 @@ impl From<node::Expression> for Expression {
 /// Internal model of the port area.
 #[derive(Debug)]
 pub struct Model {
-    app:             Application,
     display_object:  display::object::Instance,
     edit_mode_label: text::Text,
     expression:      RefCell<Expression>,
@@ -152,17 +151,16 @@ impl Model {
     /// Constructor.
     #[profile(Debug)]
     pub fn new(app: &Application) -> Self {
-        let app = app.clone_ref();
         let display_object = display::object::Instance::new_named("input");
 
         let edit_mode_label = app.new_view::<text::Text>();
         let expression = default();
         let styles = StyleWatch::new(&app.display.default_scene.style_sheet);
         let styles_frp = StyleWatchFrp::new(&app.display.default_scene.style_sheet);
-        let widget_tree = widget::Tree::new(&app);
+        let widget_tree = widget::Tree::new(app);
         with_context(|ctx| ctx.layers.widget.add(&widget_tree));
-        Self { app, display_object, edit_mode_label, expression, styles, styles_frp, widget_tree }
+        Self { display_object, edit_mode_label, expression, styles, styles_frp, widget_tree }
-            .init()
+            .init(app)
     }
 
     /// React to edit mode change. Shows and hides appropriate child views according to current
@@ -183,19 +181,24 @@ impl Model {
     }
 
     #[profile(Debug)]
-    fn init(self) -> Self {
+    fn init(self, app: &Application) -> Self {
         // TODO: Depth sorting of labels to in front of the mouse pointer. Temporary solution.
         //   It needs to be more flexible once we have proper depth management.
         //   See https://www.pivotaltracker.com/story/show/183567632.
-        let scene = &self.app.display.default_scene;
+        let scene = &app.display.default_scene;
         self.set_label_layer(&scene.layers.label);
 
         let text_color = self.styles.get_color(theme::graph_editor::node::text);
 
         self.edit_mode_label.set_single_line_mode(true);
-        self.edit_mode_label.disable_command("cursor_move_up");
+
-        self.edit_mode_label.disable_command("cursor_move_down");
+        app.commands.set_command_enabled(&self.edit_mode_label, "cursor_move_up", false);
-        self.edit_mode_label.disable_command("add_cursor_at_mouse_position");
+        app.commands.set_command_enabled(&self.edit_mode_label, "cursor_move_down", false);
+        app.commands.set_command_enabled(
+            &self.edit_mode_label,
+            "add_cursor_at_mouse_position",
+            false,
+        );
         self.edit_mode_label.set_property_default(text_color);
         self.edit_mode_label.set_property_default(text::Size(TEXT_SIZE));
         self.edit_mode_label.remove_all_cursors();

app/gui/view/graph-editor/src/component/node/input/widget/single_choice.rs

@@ -400,6 +400,7 @@ fn entry_for_current_value(
 /// is minimal, as the actual dropdown view is not created.
 #[derive(Debug)]
 struct LazyDropdown {
+    // Required for lazy initialization
     app: ensogl::application::Application,
     set_all_entries: frp::Any<Vec<Choice>>,
     set_selected_entries: frp::Any<HashSet<Choice>>,

app/gui/view/graph-editor/src/component/node/output/area.rs

@@ -156,7 +156,6 @@ impl Model {
     /// Constructor.
     #[profile(Debug)]
     pub fn new(app: &Application, frp: &Frp) -> Self {
-        let app = app.clone_ref();
         let display_object = display::object::Instance::new_named("output");
         let ports = display::object::Instance::new();
         let port_models = default();
@@ -169,7 +168,7 @@ impl Model {
         display_object.add_child(&label);
         display_object.add_child(&ports);
         Self {
-            app,
+            app: app.clone_ref(),
             display_object,
             ports,
             port_models,
@@ -180,21 +179,21 @@ impl Model {
             styles_frp,
             frp,
         }
-        .init()
+        .init(app)
     }
 
     #[profile(Debug)]
-    fn init(self) -> Self {
+    fn init(self, app: &Application) -> Self {
         // FIXME[WD]: Depth sorting of labels to in front of the mouse pointer. Temporary solution.
         // It needs to be more flexible once we have proper depth management.
-        let scene = &self.app.display.default_scene;
+        let scene = &app.display.default_scene;
         scene.layers.main.remove(&self.label);
         self.label.add_to_scene_layer(&scene.layers.label);
 
         let text_color = self.styles.get_color(theme::graph_editor::node::text);
         self.label.set_single_line_mode(true);
-        self.label.disable_command("cursor_move_up");
+        app.commands.set_command_enabled(&self.label, "cursor_move_up", false);
-        self.label.disable_command("cursor_move_down");
+        app.commands.set_command_enabled(&self.label, "cursor_move_up", false);
         self.label.set_property_default(text_color);
         self.label.set_property_default(text::Size(input::area::TEXT_SIZE));
         self.label.remove_all_cursors();

app/gui/view/graph-editor/src/lib.rs

@@ -658,6 +658,8 @@ ensogl::define_endpoints_2! {
         set_error_visualization_data ((NodeId, visualization::Data)),
         enable_visualization         (NodeId),
         disable_visualization        (NodeId),
+        /// Inform Graph Editor that attaching or updating visualization has resulted in error.
+        visualization_update_failed  ((NodeId, String)),
 
         /// Remove from visualization registry all non-default visualizations.
         reset_visualization_registry (),
@@ -760,6 +762,7 @@ ensogl::define_endpoints_2! {
         is_fs_visualization_displayed           (bool),
         visualization_preprocessor_changed      ((NodeId,PreprocessorConfiguration)),
         visualization_registry_reload_requested (),
+        visualization_update_error              ((NodeId, String)),
 
         widgets_requested                       (NodeId, ast::Id, ast::Id),
         request_import                          (ImString),
@@ -1802,6 +1805,7 @@ impl GraphEditorModelWithNetwork {
 #[allow(missing_docs)] // FIXME[everyone] Public-facing API should be documented.
 pub struct GraphEditorModel {
     pub display_object: display::object::Instance,
+    // Required for dynamically creating nodes and edges.
     pub app: Application,
     pub breadcrumbs: component::Breadcrumbs,
     pub cursor: cursor::Cursor,
@@ -2713,10 +2717,6 @@ impl application::View for GraphEditor {
         new_graph_editor(app)
     }
 
-    fn app(&self) -> &Application {
-        &self.model.app
-    }
-
     fn default_shortcuts() -> Vec<application::shortcut::Shortcut> {
         use crate::shortcuts::SHORTCUTS;
         SHORTCUTS.iter().map(|(a, b, c, d)| Self::self_shortcut_when(*a, *c, *d, *b)).collect()
@@ -3520,7 +3520,8 @@ fn new_graph_editor(app: &Application) -> GraphEditor {
     viz_enable_by_press <= viz_tgt_nodes.gate_not(&viz_tgt_nodes_all_on);
     viz_enable <- any(viz_enable_by_press,inputs.enable_visualization);
     viz_disable_by_press <= viz_tgt_nodes.gate(&viz_tgt_nodes_all_on);
-    viz_disable <- any(viz_disable_by_press,inputs.disable_visualization);
+    viz_update_failed <- inputs.visualization_update_failed._0();
+    viz_disable <- any(viz_disable_by_press, inputs.disable_visualization, viz_update_failed);
     viz_preview_disable <= viz_tgt_nodes_off.sample(&viz_preview_mode_end);
     viz_fullscreen_on <= viz_open_fs_ev.map(f_!(model.nodes.last_selected()));
 
@@ -3544,6 +3545,8 @@ fn new_graph_editor(app: &Application) -> GraphEditor {
 
     out.is_fs_visualization_displayed <+ out.visualization_fullscreen.map(Option::is_some);
 
+    out.visualization_update_error <+ inputs.visualization_update_failed;
+
 
     // === Register Visualization ===
 

app/gui/view/src/code_editor.rs

@@ -155,10 +155,6 @@ impl application::View for View {
         Self::new(app)
     }
 
-    fn app(&self) -> &Application {
-        self.model.app()
-    }
-
     fn default_shortcuts() -> Vec<shortcut::Shortcut> {
         use shortcut::ActionType::*;
         [(Press, "ctrl `", "toggle"), (Press, "escape", "hide")]

app/gui/view/src/project.rs

@@ -143,7 +143,6 @@ ensogl::define_endpoints! {
 
 #[derive(Clone, CloneRef, Debug)]
 struct Model {
-    app:                  Application,
     display_object:       display::object::Instance,
     project_view_top_bar: ProjectViewTopBar,
     graph_editor:         Rc<GraphEditor>,
@@ -175,10 +174,8 @@ impl Model {
         display_object.add_child(&project_view_top_bar);
         display_object.remove_child(&searcher);
 
-        let app = app.clone_ref();
         let graph_editor = Rc::new(graph_editor);
         Self {
-            app,
             display_object,
             project_view_top_bar,
             graph_editor,
@@ -411,6 +408,7 @@ impl View {
             graph.set_navigator_disabled <+ disable_navigation;
 
             model.popup.set_label <+ graph.model.breadcrumbs.project_name_error;
+            model.popup.set_label <+ graph.visualization_update_error._1();
             graph.set_read_only <+ frp.set_read_only;
             graph.set_debug_mode <+ frp.source.debug_mode;
 
@@ -722,10 +720,6 @@ impl application::View for View {
         View::new(app)
     }
 
-    fn app(&self) -> &Application {
-        &self.model.app
-    }
-
     fn default_shortcuts() -> Vec<application::shortcut::Shortcut> {
         use shortcut::ActionType::*;
         [

app/gui/view/src/project/project_view_top_bar/window_control_buttons.rs

@@ -44,7 +44,6 @@ mod shape {
 /// An internal model of Status Bar component
 #[derive(Clone, CloneRef, Debug)]
 pub struct Model {
-    app:            Application,
     display_object: display::object::Instance,
     shape:          shape::View,
     close:          close::View,
@@ -54,7 +53,6 @@ pub struct Model {
 impl Model {
     /// Constructor.
     pub fn new(app: &Application) -> Self {
-        let app = app.clone_ref();
         let display_object = display::object::Instance::new_named("WindowControlButtons");
 
         ensogl::shapes_order_dependencies! {
@@ -63,10 +61,10 @@ impl Model {
                 shape -> fullscreen::shape;
             }
         };
-        let close = close::View::new(&app);
+        let close = close::View::new(app);
         display_object.add_child(&close);
 
-        let fullscreen = fullscreen::View::new(&app);
+        let fullscreen = fullscreen::View::new(app);
         display_object.add_child(&fullscreen);
 
         let shape = shape::View::new();
@@ -74,7 +72,7 @@ impl Model {
 
         app.display.default_scene.layers.panel.add(&display_object);
 
-        Self { app, display_object, shape, close, fullscreen }
+        Self { display_object, shape, close, fullscreen }
     }
 
     /// Updates positions of the buttons and sizes of the mouse area.
@@ -190,10 +188,8 @@ impl application::View for View {
     fn label() -> &'static str {
         "TopButtons"
     }
+
     fn new(app: &Application) -> Self {
         View::new(app)
     }
-    fn app(&self) -> &Application {
-        &self.model.app
-    }
 }

app/gui/view/src/root.rs

@@ -33,13 +33,14 @@ enum State {
 /// visibility.
 #[derive(Clone, CloneRef, Debug)]
 pub struct Model {
+    // Required for creating project view dynamically
     app:            Application,
     display_object: display::object::Instance,
     state:          Rc<CloneCell<State>>,
     status_bar:     crate::status_bar::View,
     welcome_view:   crate::welcome_screen::View,
     project_view:   Rc<CloneCell<Option<crate::project::View>>>,
-    frp:            Frp,
+    frp_outputs:    FrpOutputsSource,
 }
 
 impl Model {
@@ -53,9 +54,9 @@ impl Model {
         let welcome_view = app.new_view::<crate::welcome_screen::View>();
         let project_view = Rc::new(CloneCell::new(None));
         display_object.add_child(&welcome_view);
-        let frp = frp.clone_ref();
+        let frp_outputs = frp.output.source.clone_ref();
 
-        Self { app, display_object, state, status_bar, welcome_view, project_view, frp }
+        Self { app, display_object, state, status_bar, welcome_view, project_view, frp_outputs }
     }
 
     /// Switch displayed view from Project View to Welcome Screen. Project View will not be
@@ -84,18 +85,18 @@ impl Model {
 
     fn init_project_view(&self) {
         if self.project_view.get().is_none() {
-            let network = &self.frp.network;
             let view = self.app.new_view::<crate::project::View>();
+            let network = &view.network;
             let project_list_frp = &view.project_list().frp;
             let status_bar = &self.status_bar;
             let display_object = &self.display_object;
-            frp::new_bridge_network! { [network, view.network] project_bridge
+            frp::extend! { network
                 fs_vis_shown <- view.fullscreen_visualization_shown.on_true();
                 fs_vis_hidden <- view.fullscreen_visualization_shown.on_false();
                 eval fs_vis_shown ((_) status_bar.unset_parent());
                 eval fs_vis_hidden ([display_object, status_bar](_) display_object.add_child(&status_bar));
 
-                self.frp.source.selected_project <+ project_list_frp.selected_project;
+                self.frp_outputs.selected_project <+ project_list_frp.selected_project;
             }
             self.project_view.set(Some(view));
         }
@@ -203,8 +204,4 @@ impl application::View for View {
     fn new(app: &Application) -> Self {
         Self::new(app)
     }
-
-    fn app(&self) -> &Application {
-        &self.model.app
-    }
 }

app/gui/view/src/searcher.rs

@@ -107,7 +107,6 @@ pub type Entry = list_view::entry::GlyphHighlightedLabel;
 
 #[derive(Clone, CloneRef, Debug)]
 struct Model {
-    app:            Application,
     display_object: display::object::Instance,
     list:           ListView<Entry>,
     documentation:  documentation::View,
@@ -117,11 +116,10 @@ struct Model {
 impl Model {
     fn new(app: &Application) -> Self {
         let scene = &app.display.default_scene;
-        let app = app.clone_ref();
         let display_object = display::object::Instance::new();
         let list = app.new_view::<ListView<Entry>>();
         list.deprecated_focus();
-        let documentation = documentation::View::new(&app);
+        let documentation = documentation::View::new(app);
         let doc_provider = default();
         scene.layers.node_searcher.add(&list);
         display_object.add_child(&documentation);
@@ -137,7 +135,7 @@ impl Model {
         list.set_x(ACTION_LIST_X);
         documentation.set_x(DOCUMENTATION_X);
         documentation.set_y(-action_list_gap);
-        Self { app, display_object, list, documentation, doc_provider }
+        Self { display_object, list, documentation, doc_provider }
     }
 
     fn set_height(&self, h: f32) {
@@ -287,12 +285,11 @@ impl application::View for View {
     fn label() -> &'static str {
         "Searcher"
     }
+
     fn new(app: &Application) -> Self {
         Self::new(app)
     }
-    fn app(&self) -> &Application {
+
-        &self.model.app
-    }
     fn default_shortcuts() -> Vec<shortcut::Shortcut> {
         use shortcut::ActionType::*;
         [(Press, "tab", "use_as_suggestion")]

app/gui/view/welcome-screen/src/lib.rs

@@ -116,7 +116,6 @@ static STYLESHEET: &str = include_str!("../style.css");
 /// Model of Welcome Screen that generates HTML DOM elements.
 #[derive(Clone, CloneRef, Debug)]
 pub struct Model {
-    application:    Application,
     dom:            DomSymbol,
     display_object: display::object::Instance,
     side_menu:      SideMenu,
@@ -126,7 +125,6 @@ pub struct Model {
 impl Model {
     /// Constructor. `frp` is used to set up event handlers on buttons.
     pub fn new(app: &Application) -> Self {
-        let application = app.clone_ref();
         let display_object = display::object::Instance::new();
 
         let side_menu = SideMenu::new();
@@ -141,7 +139,7 @@ impl Model {
         style.set_inner_html(STYLESHEET);
         dom.append_or_warn(&style);
 
-        Self { application, dom, display_object, side_menu, template_cards }
+        Self { dom, display_object, side_menu, template_cards }
     }
 
     fn create_dom(side_menu: &SideMenu, template_cards: &TemplateCards) -> DomSymbol {
@@ -258,8 +256,4 @@ impl application::View for View {
     fn new(app: &Application) -> Self {
         Self::new(app)
     }
-
-    fn app(&self) -> &Application {
-        &self.model.application
-    }
 }

lib/rust/ensogl/component/button/src/lib.rs

@@ -203,19 +203,17 @@ pub mod shape {
 #[derivative(Clone(bound = ""))]
 #[allow(missing_docs)]
 pub struct Model<S: Shape> {
-    app:            Application,
     display_object: display::object::Instance,
     shape:          ShapeView<S>,
 }
 
 impl<Shape: ButtonShape> Model<Shape> {
     /// Construct a button's model.
-    pub fn new(app: &Application) -> Self {
+    pub fn new(_app: &Application) -> Self {
-        let app = app.clone_ref();
         let display_object = display::object::Instance::new();
         let shape = ShapeView::new();
         display_object.add_child(&shape);
-        Self { app, display_object, shape }
+        Self { display_object, shape }
     }
 
     /// Set the background (i.e. the circle) color.

lib/rust/ensogl/component/flame-graph/src/block.rs

@@ -95,7 +95,6 @@ impl component::Frp<Model> for Frp {
 
 #[derive(Clone, CloneRef, Debug)]
 pub struct Model {
-    app:            Application,
     background:     background::View,
     label:          Rc<RefCell<Option<text::Text>>>,
     display_object: display::object::Instance,
@@ -115,8 +114,7 @@ impl component::Model for Model {
         display_object.add_child(&background);
         scene.layers.tooltip.add(&background);
 
-        let app = app.clone_ref();
+        Model { background, label, display_object }
-        Model { app, background, label, display_object }
     }
 }
 

lib/rust/ensogl/component/flame-graph/src/lib.rs

@@ -114,6 +114,7 @@ pub struct FlameGraph {
     blocks:         Vec<Block>,
     marks:          Vec<Mark>,
     origin_x:       f64,
+    // Required for dynamically adding blocks.
     app:            Application,
 }
 

lib/rust/ensogl/component/flame-graph/src/mark.rs

@@ -98,7 +98,6 @@ impl component::Frp<Model> for Frp {
 
 #[derive(Clone, CloneRef, Debug)]
 pub struct Model {
-    app:            Application,
     background:     background::View,
     label:          Rc<RefCell<Option<text::Text>>>,
     display_object: display::object::Instance,
@@ -118,8 +117,7 @@ impl component::Model for Model {
         display_object.add_child(&background);
         scene.layers.tooltip.add(&background);
 
-        let app = app.clone_ref();
+        Model { background, label, display_object }
-        Model { app, background, label, display_object }
     }
 }
 

lib/rust/ensogl/component/grid-view/src/entry/visible.rs

@@ -59,6 +59,7 @@ impl<E: display::Object> display::Object for VisibleEntry<E> {
 #[derive(CloneRef, Debug, Derivative)]
 #[derivative(Clone(bound = ""))]
 pub struct CreationCtx<EntryParams> {
+    // Required for dynamically creating entries.
     pub app:                   Application,
     pub network:               frp::WeakNetwork,
     pub set_entry_size:        frp::Stream<Vector2>,

lib/rust/ensogl/component/grid-view/src/lib.rs

@@ -688,10 +688,6 @@ impl<E: Entry> application::View for GridView<E> {
         GridView::<E>::new(app)
     }
 
-    fn app(&self) -> &Application {
-        self.widget.app()
-    }
-
     fn default_shortcuts() -> Vec<application::shortcut::Shortcut> {
         use application::shortcut::ActionType::*;
         [

lib/rust/ensogl/component/gui/src/component.rs

@@ -144,10 +144,6 @@ where
         ComponentView::new(app)
     }
 
-    fn app(&self) -> &Application {
-        self.widget.app()
-    }
-
     fn default_shortcuts() -> Vec<shortcut::Shortcut> {
         F::default_shortcuts()
     }

lib/rust/ensogl/component/label/src/lib.rs

@@ -59,8 +59,7 @@ struct Model {
 }
 
 impl Model {
-    fn new(app: Application) -> Self {
+    fn new(app: &Application) -> Self {
-        let app = app.clone_ref();
         let scene = &app.display.default_scene;
         let display_object = display::object::Instance::new();
         let label = app.new_view::<text::Text>();
@@ -144,7 +143,7 @@ impl Label {
     /// Constructor.
     pub fn new(app: &Application) -> Self {
         let frp = Rc::new(Frp::new());
-        let model = Rc::new(Model::new(app.clone_ref()));
+        let model = Rc::new(Model::new(app));
         Label { model, frp }.init()
     }
 

lib/rust/ensogl/component/list-view/src/entry/list.rs

@@ -66,6 +66,7 @@ pub type List<E> = ListData<E, <E as Entry>::Params>;
 #[derivative(Clone(bound = ""))]
 #[clone_ref(bound = "E:CloneRef")]
 pub struct ListData<E, P> {
+    // Required for dynamically creating new entries.
     app:            Application,
     display_object: display::object::Instance,
     entries:        Rc<RefCell<Vec<DisplayedEntry<E>>>>,

lib/rust/ensogl/component/list-view/src/lib.rs

@@ -124,7 +124,6 @@ impl Default for JumpTarget {
 /// The Model of Select Component.
 #[derive(Clone, CloneRef, Debug)]
 struct Model<E: Entry> {
-    app:            Application,
     entries:        entry::List<E>,
     selection:      Selection,
     background:     Rectangle,
@@ -134,10 +133,9 @@ struct Model<E: Entry> {
 
 impl<E: Entry> Model<E> {
     fn new(app: &Application) -> Self {
-        let app = app.clone_ref();
         let display_object = display::object::Instance::new();
         let scrolled_area = display::object::Instance::new();
-        let entries = entry::List::new(&app);
+        let entries = entry::List::new(app);
         let background = Rectangle();
         background.set_border_color(color::Rgba::transparent());
         let selection = Selection::default();
@@ -146,7 +144,7 @@ impl<E: Entry> Model<E> {
         display_object.add_child(&scrolled_area);
         scrolled_area.add_child(&entries);
         scrolled_area.add_child(&selection);
-        Model { app, entries, selection, background, scrolled_area, display_object }
+        Model { entries, selection, background, scrolled_area, display_object }
     }
 
     /// Update the displayed entries list when _view_ has changed - the list was scrolled or
@@ -438,7 +436,7 @@ where E::Model: Default
 
             // === Selected Entry ===
 
-            eval frp.source.focused([frp](f) if !f { frp.deselect_entries.emit(()) } );
+            frp.deselect_entries <+ frp.focused.on_false();
 
             frp.source.selected_entry <+ frp.select_entry;
             frp.source.selected_entry <+ frp.output.chosen_entry;
@@ -636,12 +634,11 @@ impl<E: Entry> application::View for ListView<E> {
     fn label() -> &'static str {
         "ListView"
     }
+
     fn new(app: &Application) -> Self {
         ListView::new(app)
     }
-    fn app(&self) -> &Application {
+
-        &self.model.app
-    }
     fn default_shortcuts() -> Vec<shortcut::Shortcut> {
         use shortcut::ActionType::*;
         [

lib/rust/ensogl/component/scroll-area/src/lib.rs

@@ -367,18 +367,14 @@ impl ScrollArea {
                     (0.0..=size.x).contains(&local_pos.x) && (-size.y..=0.0).contains(&local_pos.y)
                 }));
             hovering <- hovering.sampler();
+            let on_scroll = model.display_object.on_event::<mouse::Wheel>();
+            on_scroll_when_hovering <- on_scroll.gate(&hovering);
+            model.h_scrollbar.scroll_by <+ on_scroll_when_hovering
+                .map(|event| event.delta_x() as f32);
+            model.v_scrollbar.scroll_by <+ on_scroll_when_hovering
+                .map(|event| event.delta_y() as f32);
         }
 
-        let mouse_manager = &mouse.mouse_manager;
-        let scroll_handler = f!([model](event: &mouse::Wheel)
-            if hovering.value() {
-                model.h_scrollbar.scroll_by(event.delta_x() as f32);
-                model.v_scrollbar.scroll_by(event.delta_y() as f32);
-            }
-        );
-        let scroll_handler_handle = mouse_manager.on_wheel.add(scroll_handler);
-        network.store(&scroll_handler_handle);
-
 
         ScrollArea { model, frp }
     }

lib/rust/ensogl/component/scrollbar/src/lib.rs

@@ -115,7 +115,7 @@ impl Frp {
             resize <- frp.set_length.map(|&length| Vector2::new(length,WIDTH));
         }
 
-        let base_frp = selector::Frp::new(model, style, network, resize.clone(), mouse);
+        let base_frp = selector::Frp::new(app, model, style, network, resize.clone(), mouse);
 
         model.use_track_handles(false);
         model.set_track_corner_round(true);
@@ -358,22 +358,17 @@ pub struct Scrollbar {
     /// Public FRP api of the Component.
     pub frp: Rc<Frp>,
     model:   Rc<Model>,
-    /// Reference to the application the Component belongs to. Generally required for implementing
-    /// `application::View` and initialising the `Model` and `Frp` and thus provided by the
-    /// `Component`.
-    pub app: Application,
 }
 
 impl Scrollbar {
     /// Constructor.
     pub fn new(app: &Application) -> Self {
-        let app = app.clone_ref();
+        let model = Rc::new(Model::new(app));
-        let model = Rc::new(Model::new(&app));
         let frp = Frp::default();
         let style = StyleWatchFrp::new(&app.display.default_scene.style_sheet);
-        frp.init(&app, &model, &style);
+        frp.init(app, &model, &style);
         let frp = Rc::new(frp);
-        Self { frp, model, app }
+        Self { frp, model }
     }
 }
 
@@ -400,10 +395,8 @@ impl application::View for Scrollbar {
     fn label() -> &'static str {
         "Scrollbar"
     }
+
     fn new(app: &Application) -> Self {
         Scrollbar::new(app)
     }
-    fn app(&self) -> &Application {
-        &self.app
-    }
 }

lib/rust/ensogl/component/selector/src/decimal_aligned.rs

@@ -100,18 +100,16 @@ impl display::Object for Model {
 pub struct FloatLabel {
     pub frp: Rc<Frp>,
     model:   Rc<Model>,
-    app:     Application,
 }
 
 impl FloatLabel {
     /// Constructor.
     pub fn new(app: &Application) -> Self {
-        let app = app.clone_ref();
+        let model = Rc::new(Model::new(app));
-        let model = Rc::new(Model::new(&app));
         let frp = Frp::default();
         frp.init(&model);
         let frp = Rc::new(frp);
-        Self { frp, model, app }
+        Self { frp, model }
     }
 }
 

lib/rust/ensogl/component/selector/src/frp.rs

@@ -9,6 +9,7 @@ use crate::shape::shape_is_dragged;
 use enso_frp as frp;
 use enso_frp::io::Mouse_DEPRECATED;
 use enso_frp::Network;
+use ensogl_core::application::Application;
 use ensogl_core::display::object::ObjectOps;
 use ensogl_core::display::shape::StyleWatchFrp;
 use ensogl_hardcoded_theme as theme;
@@ -69,6 +70,7 @@ pub struct Frp {
 impl Frp {
     /// Create and initialize the FRP.
     pub fn new(
+        app: &Application,
         model: &Model,
         style: &StyleWatchFrp,
         network: &Network,
@@ -76,7 +78,7 @@ impl Frp {
         mouse: &Mouse_DEPRECATED,
     ) -> Frp {
         let net = &network;
-        let scene = &model.app.display.default_scene;
+        let scene = &app.display.default_scene;
         let shadow = shadow::frp_from_style(style, theme::shadow);
         let text_size = style.get_number(theme::text::size);
 

lib/rust/ensogl/component/selector/src/lib.rs

@@ -77,22 +77,17 @@ pub struct NumberPicker {
     /// Public FRP api of the Component.
     pub frp: Rc<number::Frp>,
     model:   Rc<Model>,
-    /// Reference to the application the Component belongs to. Generally required for implementing
-    /// `application::View` and initialising the `Model` and `Frp` and thus provided by the
-    /// `Component`.
-    pub app: Application,
 }
 
 impl NumberPicker {
     /// Constructor.
     pub fn new(app: &Application) -> Self {
-        let app = app.clone_ref();
+        let model = Rc::new(Model::new(app));
-        let model = Rc::new(Model::new(&app));
         let frp = number::Frp::default();
         let style = StyleWatchFrp::new(&app.display.default_scene.style_sheet);
-        frp.init(&app, &model, &style);
+        frp.init(app, &model, &style);
         let frp = Rc::new(frp);
-        Self { frp, model, app }
+        Self { frp, model }
     }
 }
 
@@ -119,12 +114,10 @@ impl application::View for NumberPicker {
     fn label() -> &'static str {
         "NumberPicker"
     }
+
     fn new(app: &Application) -> Self {
         NumberPicker::new(app)
     }
-    fn app(&self) -> &Application {
-        &self.app
-    }
 }
 
 
@@ -147,22 +140,17 @@ pub struct NumberRangePicker {
     /// Public FRP api of the Component.
     pub frp: Rc<range::Frp>,
     model:   Rc<Model>,
-    /// Reference to the application the Component belongs to. Generally required for implementing
-    /// `application::View` and initialising the `Model` and `Frp` and thus provided by the
-    /// `Component`.
-    pub app: Application,
 }
 
 impl NumberRangePicker {
     /// Constructor.
     pub fn new(app: &Application) -> Self {
-        let app = app.clone_ref();
+        let model = Rc::new(Model::new(app));
-        let model = Rc::new(Model::new(&app));
         let frp = range::Frp::default();
         let style = StyleWatchFrp::new(&app.display.default_scene.style_sheet);
-        frp.init(&app, &model, &style);
+        frp.init(app, &model, &style);
         let frp = Rc::new(frp);
-        Self { frp, model, app }
+        Self { frp, model }
     }
 }
 
@@ -189,10 +177,8 @@ impl application::View for NumberRangePicker {
     fn label() -> &'static str {
         "RangePicker"
     }
+
     fn new(app: &Application) -> Self {
         NumberRangePicker::new(app)
     }
-    fn app(&self) -> &Application {
-        &self.app
-    }
 }

lib/rust/ensogl/component/selector/src/model.rs

@@ -70,8 +70,6 @@ pub struct Model {
     background_left_corner_roundness: Rc<Cell<bool>>,
     background_right_corner_roundness: Rc<Cell<bool>>,
     padding: Rc<Cell<f32>>,
-
-    pub app: Application,
 }
 
 #[allow(missing_docs)]
@@ -95,7 +93,6 @@ impl Model {
         let background_right_corner_roundness = default();
         let padding = default();
 
-        let app = app.clone_ref();
         let scene = &app.display.default_scene;
 
         root.add_child(&label);
@@ -134,7 +131,6 @@ impl Model {
             background_left_corner_roundness,
             background_right_corner_roundness,
             padding,
-            app,
         }
     }
 

lib/rust/ensogl/component/selector/src/number.rs

@@ -49,7 +49,8 @@ impl Frp {
 
         model.show_background(true);
 
-        let base_frp = super::Frp::new(model, style, network, frp.resize.clone().into(), mouse);
+        let base_frp =
+            super::Frp::new(app, model, style, network, frp.resize.clone().into(), mouse);
 
         let background_click = relative_shape_down_position(network, scene, &model.background);
         let track_click = relative_shape_down_position(network, scene, &model.track);

lib/rust/ensogl/component/selector/src/range.rs

@@ -44,7 +44,8 @@ impl Frp {
         let scene = &app.display.default_scene;
         let mouse = &scene.mouse.frp_deprecated;
 
-        let base_frp = super::Frp::new(model, style, network, frp.resize.clone().into(), mouse);
+        let base_frp =
+            super::Frp::new(app, model, style, network, frp.resize.clone().into(), mouse);
 
         model.use_track_handles(true);
         model.show_background(true);

lib/rust/ensogl/component/sequence-diagram/src/lib.rs

@@ -89,6 +89,7 @@ impl component::Frp<Model> for Frp {
 /// Internal model of the SequenceDiagram.
 #[derive(Clone, CloneRef, Debug)]
 pub struct Model {
+    // Required for dynamically creating new lines.
     app:            Application,
     display_object: display::object::Instance,
     actor_lines:    Rc<RefCell<Vec<LabeledLine>>>,

lib/rust/ensogl/component/slider/src/lib.rs

@@ -337,10 +337,6 @@ pub struct Slider {
     #[deref]
     pub frp: Frp,
     model:   Rc<Model>,
-    /// Reference to the application the component belongs to. Generally required for implementing
-    /// `application::View` and initialising the `Model` and `Frp` and thus provided by the
-    /// component.
-    pub app: Application,
 }
 
 impl Slider {
@@ -348,12 +344,11 @@ impl Slider {
     pub fn new(app: &Application) -> Self {
         let frp = Frp::new();
         let model = Rc::new(Model::new(app, frp.network()));
-        let app = app.clone_ref();
+        Self { frp, model }.init(app)
-        Self { frp, model, app }.init()
     }
 
-    fn init(self) -> Self {
+    fn init(self, app: &Application) -> Self {
-        self.init_value_update();
+        self.init_value_update(app);
         self.init_limit_handling();
         self.init_value_display();
 
@@ -367,13 +362,13 @@ impl Slider {
     }
 
     /// Initialize the slider value update FRP network.
-    fn init_value_update(&self) {
+    fn init_value_update(&self, app: &Application) {
         let network = self.frp.network();
         let frp = &self.frp;
         let input = &self.frp.input;
         let output = &self.frp.private.output;
         let model = &self.model;
-        let scene = &self.app.display.default_scene;
+        let scene = &app.display.default_scene;
         let mouse = &scene.mouse.frp_deprecated;
         let keyboard = &scene.keyboard.frp;
 
@@ -845,10 +840,6 @@ impl application::View for Slider {
         Self::new(app)
     }
 
-    fn app(&self) -> &Application {
-        &self.app
-    }
-
     fn default_shortcuts() -> Vec<shortcut::Shortcut> {
         use shortcut::ActionType::DoublePress;
         use shortcut::ActionType::Press;

lib/rust/ensogl/component/text/src/component/text.rs

@@ -1978,10 +1978,6 @@ impl application::View for Text {
         Text::new(app)
     }
 
-    fn app(&self) -> &Application {
-        &self.data.app
-    }
-
     fn default_shortcuts() -> Vec<shortcut::Shortcut> {
         use shortcut::ActionType::*;
         ([

lib/rust/ensogl/core/src/application.rs

@@ -76,15 +76,6 @@ pub struct ApplicationData {
     pub frp:       Frp,
 }
 
-impl ApplicationData {
-    /// Show or hide the system mouse cursor by setting the `cursor` CSS property of the `body`
-    /// element.
-    fn show_system_cursor(&self, show: bool) {
-        let style = if show { "auto" } else { "none" };
-        web::document.body_or_panic().set_style_or_warn("cursor", style);
-    }
-}
-
 impl Application {
     /// Constructor.
     pub fn new(dom: impl DomPath) -> Self {
@@ -94,7 +85,7 @@ impl Application {
         let commands = command::Registry::create();
         let shortcuts =
             shortcut::Registry::new(&scene.mouse.frp_deprecated, &scene.keyboard.frp, &commands);
-        let views = view::Registry::create(&display, &commands, &shortcuts);
+        let views = view::Registry::create(&commands, &shortcuts);
         let cursor = Cursor::new(&display.default_scene);
         display.add_child(&cursor);
         let frp = Frp::new();
@@ -106,20 +97,27 @@ impl Application {
 
     fn init(self) -> Self {
         let frp = &self.frp;
-        let data = &self.inner;
         let network = self.frp.network();
         enso_frp::extend! { network
             app_focused <- self.display.default_scene.frp.focused.on_change();
-            eval app_focused((t) data.show_system_cursor(!t));
+            eval app_focused([](t) Self::show_system_cursor(!t));
+            eval_ frp.private.input.show_system_cursor([] Self::show_system_cursor(true));
+            eval_ frp.private.input.hide_system_cursor([] Self::show_system_cursor(false));
+
             frp.private.output.tooltip <+ frp.private.input.set_tooltip;
-            eval_ frp.private.input.show_system_cursor(data.show_system_cursor(true));
-            eval_ frp.private.input.hide_system_cursor(data.show_system_cursor(false));
         }
         // We hide the system cursor to replace it with the EnsoGL-provided one.
         self.frp.hide_system_cursor();
         self
     }
 
+    /// Show or hide the system mouse cursor by setting the `cursor` CSS property of the `body`
+    /// element.
+    fn show_system_cursor(show: bool) {
+        let style = if show { "auto" } else { "none" };
+        web::document.body_or_panic().set_style_or_warn("cursor", style);
+    }
+
     /// Create a new instance of a view.
     pub fn new_view<T: View>(&self) -> T {
         self.views.new_view(self)

lib/rust/ensogl/core/src/application/command.rs

@@ -27,9 +27,6 @@ pub trait View: FrpNetworkProvider + DerefToCommandApi {
     /// Constructor.
     fn new(app: &Application) -> Self;
 
-    /// Application reference.
-    fn app(&self) -> &Application;
-
     /// Set of default shortcuts.
     fn default_shortcuts() -> Vec<Shortcut> {
         default()
@@ -58,24 +55,6 @@ pub trait View: FrpNetworkProvider + DerefToCommandApi {
             condition,
         )
     }
-
-    /// Disable the command in this component instance.
-    fn disable_command(&self, name: impl AsRef<str>)
-    where Self: Sized {
-        self.set_command_enabled(name, false)
-    }
-
-    /// Enable the command in this component instance.
-    fn enable_command(&self, name: impl AsRef<str>)
-    where Self: Sized {
-        self.set_command_enabled(name, true)
-    }
-
-    /// Set the command enable status in this component instance.
-    fn set_command_enabled(&self, name: impl AsRef<str>, enabled: bool)
-    where Self: Sized {
-        self.app().commands.set_command_enabled(self, name, enabled)
-    }
 }
 
 /// FRP Network provider. Used to check whether FRP bindings are still alive.
@@ -232,7 +211,7 @@ impl Registry {
     }
 
     /// Sets the command enable status for the provided component instance.
-    fn set_command_enabled<T: View>(&self, instance: &T, name: impl AsRef<str>, enabled: bool) {
+    pub fn set_command_enabled<T: View>(&self, instance: &T, name: impl AsRef<str>, enabled: bool) {
         self.with_command_mut(instance, name, |command| command.enabled = enabled)
     }
 }

lib/rust/ensogl/core/src/application/view.rs

@@ -2,8 +2,6 @@
 
 use crate::prelude::*;
 
-use crate::display::world::World;
-
 use super::command;
 use super::shortcut;
 use super::Application;
@@ -26,7 +24,6 @@ pub use command::View;
 #[derive(Debug, Clone, CloneRef)]
 #[allow(missing_docs)]
 pub struct Registry {
-    pub display:           World,
     pub command_registry:  command::Registry,
     pub shortcut_registry: shortcut::Registry,
     pub definitions:       Rc<RefCell<HashSet<String>>>,
@@ -35,15 +32,13 @@ pub struct Registry {
 impl Registry {
     /// Constructor.
     pub fn create(
-        display: &World,
         command_registry: &command::Registry,
         shortcut_registry: &shortcut::Registry,
     ) -> Self {
-        let display = display.clone_ref();
         let command_registry = command_registry.clone_ref();
         let shortcut_registry = shortcut_registry.clone_ref();
         let definitions = default();
-        Self { display, command_registry, shortcut_registry, definitions }
+        Self { command_registry, shortcut_registry, definitions }
     }
 
     /// View registration.

lib/rust/ensogl/core/src/display/garbage.rs

@@ -18,6 +18,14 @@ struct Garbage {
     before_mouse_events: Vec<Box<dyn Any>>,
 }
 
+impl Garbage {
+    fn collected_items_count(&self) -> usize {
+        self.before_pixel_sync.len()
+            + self.before_pixel_update.len()
+            + self.before_mouse_events.len()
+    }
+}
+
 
 /// The Garbage Collector
 ///
@@ -90,6 +98,14 @@ impl Collector {
         };
         drop(before_mouse_events);
     }
+
+    /// Immediately drop all collected garbage.
+    pub fn force_garbage_drop(&self) {
+        // Elements may add new objects on drop, thus we need to clear garbage in loop.
+        while self.garbage.borrow().collected_items_count() > 0 {
+            self.garbage.take();
+        }
+    }
 }
 
 

lib/rust/ensogl/core/src/display/world.rs

@@ -670,6 +670,13 @@ impl WorldData {
         self.garbage_collector.collect(object);
     }
 
+    /// Immediately drop the garbage.
+    ///
+    /// May be used to resolve dependence cycles if garbage keeps reference to [`World`].
+    pub fn force_garbage_drop(&self) {
+        self.garbage_collector.force_garbage_drop()
+    }
+
     /// Set the maximum frequency at which the pointer location will be checked, in terms of number
     /// of frames per check.
     pub fn set_pixel_read_period(&self, period: usize) {

lib/rust/ensogl/core/src/gui/component.rs

@@ -367,13 +367,6 @@ impl<Model: 'static, Frp: 'static> Widget<Model, Frp> {
     pub fn model(&self) -> &Model {
         &self.data.model
     }
-
-    /// Reference to the application the Widget belongs to. It's required for handling model and
-    /// FRP garbage collection, but also may be helpful when, for example, implementing
-    /// `application::View`.
-    pub fn app(&self) -> &Application {
-        &self.data.app
-    }
 }
 
 impl<Model: 'static, Frp: 'static> display::Object for Widget<Model, Frp> {

lib/rust/ensogl/examples/mouse-events/src/lib.rs

@@ -44,15 +44,13 @@ use ensogl_text_msdf::run_once_initialized;
 
 #[derive(Clone, CloneRef, Debug)]
 struct Model {
-    app:            Application,
     display_object: display::object::Instance,
     shape:          Rectangle,
     cover:          Rectangle,
 }
 
 impl Model {
-    fn new(app: &Application) -> Self {
+    fn new() -> Self {
-        let app = app.clone_ref();
         let display_object = display::object::Instance::new();
         let shape: Rectangle = default();
         shape.set_size(Vector2(300.0, 300.0));
@@ -68,7 +66,7 @@ impl Model {
         cover.set_corner_radius_max();
         cover.set_pointer_events(false);
         display_object.add_child(&cover);
-        Self { app, display_object, shape, cover }
+        Self { display_object, shape, cover }
     }
 }
 
@@ -99,9 +97,9 @@ struct View {
 
 impl View {
     /// Constructor.
-    pub fn new(app: &Application) -> Self {
+    pub fn new() -> Self {
         let frp = Frp::new();
-        let model = Model::new(app);
+        let model = Model::new();
         let network = &frp.network;
         frp::extend! { network
             trace model.shape.events_deprecated.mouse_up;
@@ -139,11 +137,9 @@ impl application::View for View {
     fn label() -> &'static str {
         "Circul"
     }
-    fn new(app: &Application) -> Self {
+
-        View::new(app)
+    fn new(_app: &Application) -> Self {
-    }
+        View::new()
-    fn app(&self) -> &Application {
-        &self.model.app
     }
 }
 

lib/rust/ensogl/examples/slider/src/lib.rs

@@ -232,16 +232,14 @@ impl FrpNetworkProvider for SliderCollection {
 struct SliderCollection {
     #[deref]
     frp:   Frp,
-    app:   Application,
     model: Model,
 }
 
 impl SliderCollection {
     fn new(app: &Application) -> Self {
         let frp = Frp::new();
-        let app = app.clone_ref();
+        let model = Model::new(app);
-        let model = Model::new(&app);
+        Self { frp, model }.init()
-        Self { frp, app, model }.init()
     }
 
     fn init(self) -> Self {
@@ -272,10 +270,6 @@ impl View for SliderCollection {
         Self::new(app)
     }
 
-    fn app(&self) -> &Application {
-        &self.app
-    }
-
     fn default_shortcuts() -> Vec<shortcut::Shortcut> {
         use shortcut::ActionType::Press;
         vec![

lib/rust/prelude/src/debug.rs

@@ -146,9 +146,9 @@ impl Drop for TraceCopies {
 /// A module containing an utility for detecting leaks.
 ///
 /// If you suspect a particular struct is leaking, i.e. its instances are still present when we
-/// expect them to be removed, you may add a [`Trace`] field to it. Then, at the point where we
+/// expect them to be removed, you may add a [`Trace`] field to it and call [`enable`]. Then, at
-/// expect all instances to be dropped, we may check the [`TRACKED_OBJECTS`] global variable, what
+/// the point where we expect all instances to be dropped, we may check the [`TRACKED_OBJECTS`]
-/// instances are still alive and their creation backtraces.
+/// global variable, what instances are still alive and their creation backtraces.
 pub mod leak_detector {
     use crate::*;