Implement loading spinner for visualisations.

CHANGELOG.md

@@ -143,6 +143,7 @@
   belongs to the node.][6487].
 - [List Editor Widget][6470]. Now you can edit lists by clicking buttons on
   nodes or by dragging the elements.
+- [Visualisations now show a loading spinner while waiting on data.][6512].
 - [Fixed text visualisations which were being cut off at the last line.][6421]
 - [Fixed a bug where, when scrolling or dragging on a full-screen visualization,
   the view of the graph changed as well.][6530]
@@ -216,6 +217,7 @@
 [6487]: https://github.com/enso-org/enso/pull/6487
 [6341]: https://github.com/enso-org/enso/pull/6341
 [6470]: https://github.com/enso-org/enso/pull/6470
+[6512]: https://github.com/enso-org/enso/pull/6512
 
 #### Enso Standard Library
 

app/gui/view/documentation/src/lib.rs

@@ -188,7 +188,7 @@ impl Model {
     }
 
     /// Load an HTML file into the documentation view when user is waiting for data to be received.
-    /// TODO(#184315201): This should be replaced with a EnsoGL spinner.
+    /// TODO(#5214): This should be replaced with a EnsoGL spinner.
     fn load_waiting_screen(&self) {
         let spinner = include_str!("../assets/spinner.html");
         self.inner_dom.dom().set_inner_html(spinner)

app/gui/view/graph-editor/src/component/visualization/container.rs

@@ -20,6 +20,7 @@ use crate::visualization;
 use action_bar::ActionBar;
 use enso_frp as frp;
 use ensogl::application::Application;
+use ensogl::data::color::Rgba;
 use ensogl::display;
 use ensogl::display::scene;
 use ensogl::display::scene::Scene;
@@ -162,10 +163,11 @@ ensogl::define_endpoints! {
 pub struct View {
     display_object: display::object::Instance,
 
-    background:     background::View,
-    overlay:        overlay::View,
-    background_dom: DomSymbol,
-    scene:          Scene,
+    background:      background::View,
+    overlay:         overlay::View,
+    background_dom:  DomSymbol,
+    scene:           Scene,
+    loading_spinner: ensogl_component::spinner::View,
 }
 
 impl View {
@@ -176,16 +178,38 @@ impl View {
         let overlay = overlay::View::new();
         display_object.add_child(&background);
         display_object.add_child(&overlay);
+        let div = web::document.create_div_or_panic();
+        let background_dom = DomSymbol::new(&div);
+        display_object.add_child(&background_dom);
+        let loading_spinner = ensogl_component::spinner::View::new();
 
         ensogl::shapes_order_dependencies! {
             scene => {
                 background -> overlay;
+                background -> ensogl_component::spinner;
             }
         };
 
+        Self { display_object, background, overlay, background_dom, scene, loading_spinner }.init()
+    }
+
+    fn set_layer(&self, layer: visualization::Layer) {
+        layer.apply_for_html_component(&self.scene, &self.background_dom);
+    }
+
+    fn show_waiting_screen(&self) {
+        self.add_child(&self.loading_spinner);
+    }
+
+    fn disable_waiting_screen(&self) {
+        self.loading_spinner.unset_parent();
+    }
+
+    fn init_background(&self) {
+        let background = &self.background_dom;
         // FIXME : StyleWatch is unsuitable here, as it was designed as an internal tool for shape
         // system (#795)
-        let styles = StyleWatch::new(&scene.style_sheet);
+        let styles = StyleWatch::new(&self.scene.style_sheet);
         let bg_color =
             styles.get_color(ensogl_hardcoded_theme::graph_editor::visualization::background);
         let bg_hex = format!(
@@ -196,29 +220,29 @@ impl View {
             bg_color.alpha
         );
 
-        let div = web::document.create_div_or_panic();
-        let background_dom = DomSymbol::new(&div);
         // TODO : We added a HTML background to the `View`, because "shape" background was
         // overlapping the JS visualization. This should be further investigated
         // while fixing rust visualization displaying. (#796)
-        background_dom.dom().set_style_or_warn("width", "0");
-        background_dom.dom().set_style_or_warn("height", "0");
-        background_dom.dom().set_style_or_warn("z-index", "1");
-        background_dom.dom().set_style_or_warn("overflow-y", "auto");
-        background_dom.dom().set_style_or_warn("overflow-x", "auto");
-        background_dom.dom().set_style_or_warn("background", bg_hex);
-        background_dom.dom().set_style_or_warn("border-radius", "14px");
-        shadow::add_to_dom_element(&background_dom, &styles);
-        display_object.add_child(&background_dom);
-
-        Self { display_object, background, overlay, background_dom, scene }.init()
+        background.dom().set_style_or_warn("width", "0");
+        background.dom().set_style_or_warn("height", "0");
+        background.dom().set_style_or_warn("z-index", "1");
+        background.dom().set_style_or_warn("overflow-y", "auto");
+        background.dom().set_style_or_warn("overflow-x", "auto");
+        background.dom().set_style_or_warn("background", bg_hex);
+        background.dom().set_style_or_warn("border-radius", "14px");
+        shadow::add_to_dom_element(background, &styles);
     }
 
-    fn set_layer(&self, layer: visualization::Layer) {
-        layer.apply_for_html_component(&self.scene, &self.background_dom);
+    fn init_spinner(&self) {
+        let spinner = &self.loading_spinner;
+        spinner.scale.set(5.0);
+        spinner.rgba.set(Rgba::black().into())
     }
 
     fn init(self) -> Self {
+        self.init_background();
+        self.init_spinner();
+        self.show_waiting_screen();
         self.set_layer(visualization::Layer::Default);
         self.scene.layers.viz.add(&self);
         self
@@ -300,6 +324,8 @@ impl ContainerModel {
         // FIXME: These 2 lines fix a bug with display objects visible on stage.
         self.set_visibility(true);
         self.set_visibility(false);
+
+        self.view.show_waiting_screen();
         self
     }
 
@@ -409,6 +435,7 @@ impl ContainerModel {
             self.view.background.radius.set(CORNER_RADIUS);
             self.view.overlay.set_size(size);
             self.view.background.set_size(size + 2.0 * Vector2(PADDING, PADDING));
+            self.view.loading_spinner.set_size(size + 2.0 * Vector2(PADDING, PADDING));
             dom.set_style_or_warn("width", format!("{}px", size[0]));
             dom.set_style_or_warn("height", format!("{}px", size[1]));
             bg_dom.set_style_or_warn("width", "0");
@@ -584,9 +611,17 @@ impl Container {
                 }
                 vis_definition.clone()
             }));
+
+
+        // === Visualisation Loading Spinner ===
+
+        eval_ frp.source.visualisation ( model.view.show_waiting_screen() );
+        eval_ frp.set_data ( model.view.disable_waiting_screen() );
+
         }
 
 
+
         // === Selecting Visualization ===
 
         frp::extend! { network

lib/rust/ensogl/component/Cargo.toml

@@ -23,3 +23,4 @@ ensogl-shadow = { path = "shadow" }
 ensogl-text = { path = "text" }
 ensogl-tooltip = { path = "tooltip" }
 ensogl-toggle-button = { path = "toggle-button" }
+ensogl-spinner = { path = "spinner" }

lib/rust/ensogl/component/spinner/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "ensogl-spinner"
+version = "0.1.0"
+authors = ["Enso Team <[email protected]>"]
+edition = "2021"
+
+[lib]
+crate-type = ["rlib", "cdylib"]
+
+[dependencies]
+enso-frp = { path = "../../../frp" }
+enso-prelude = { path = "../../../prelude" }
+enso-shapely = { path = "../../../shapely" }
+enso-types = { path = "../../../types" }
+ensogl-core = { path = "../../core" }

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

@@ -0,0 +1,58 @@
+//! An animated spinner component that can be used to indicate that a process
+//! is running.
+
+use ensogl_core::display::shape::*;
+use ensogl_core::prelude::*;
+
+use ensogl_core::display::IntoGlsl;
+
+
+
+// ===============
+// === Spinner ===
+// ===============
+
+const ANIMATION_SPEED: f32 = 0.001;
+const SHAPE_RADIUS: f32 = 1.0;
+const SHAPE_OFFSET: f32 = 2.0;
+const ANIMATION_OFFSET_MS: f32 = 100.0;
+
+/// Convert a time value to an alpha value for the spinner animation. The
+/// animation is a sine wave that oscillates between 0 and 1.
+fn time_to_alpha<F1: Into<Var<f32>>, F2: Into<Var<f32>>, F3: Into<Var<f32>>>(
+    time: F1,
+    offset: F2,
+    scale: F3,
+) -> Var<f32> {
+    let time = time.into();
+    let offset = offset.into();
+    let scale = scale.into();
+    Var::from(0.5) + ((time + offset) * scale).sin() / 2.0
+}
+
+ensogl_core::shape! {
+    alignment = center;
+    (style: Style, scale: f32, rgba: Vector4<f32>) {
+        let time = &Var::<f32>::from("input_time");
+        let radius = (&scale * SHAPE_RADIUS).px();
+        let offset = (&scale * (SHAPE_RADIUS * 2.0 + SHAPE_OFFSET)).px();
+        let dot1 = Circle(&radius).translate_x(-&offset);
+        let dot2 = Circle(&radius);
+        let dot3 = Circle(&radius).translate_x(offset);
+        let dot3_anim_start = 0.0;
+        let dot2_anim_start = dot3_anim_start + ANIMATION_OFFSET_MS;
+        let dot1_anim_start = dot2_anim_start + ANIMATION_OFFSET_MS;
+        let dot1_alpha = rgba.w() * time_to_alpha(time, dot1_anim_start, ANIMATION_SPEED);
+        let dot2_alpha = rgba.w() * time_to_alpha(time, dot2_anim_start, ANIMATION_SPEED);
+        let dot3_alpha = rgba.w() * time_to_alpha(time, dot3_anim_start, ANIMATION_SPEED);
+        let rgb = rgba.xyz();
+        let color1 = format!("srgba({}.x,{}.y,{}.z,{})", rgb, rgb, rgb, dot1_alpha.glsl());
+        let color2 = format!("srgba({}.x,{}.y,{}.z,{})", rgb, rgb, rgb, dot2_alpha.glsl());
+        let color3 = format!("srgba({}.x,{}.y,{}.z,{})", rgb, rgb, rgb, dot3_alpha.glsl());
+        let dot1 = dot1.fill(color1);
+        let dot2 = dot2.fill(color2);
+        let dot3 = dot3.fill(color3);
+        let shape = dot1 + dot2 + dot3;
+        shape.into()
+    }
+}

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

@@ -24,6 +24,7 @@ pub use ensogl_scroll_area as scroll_area;
 pub use ensogl_scrollbar as scrollbar;
 pub use ensogl_selector as selector;
 pub use ensogl_shadow as shadow;
+pub use ensogl_spinner as spinner;
 pub use ensogl_text as text;
 pub use ensogl_toggle_button as toggle_button;
 pub use ensogl_tooltip as tooltip;