Only initialise visualisation chooser if it is used. (#6758)

Re-introduce a feature that was removed with #6638: only initialize visualization choosers when they are visible. This avoids initializing lots of invisible UI elements at the same time when opening a project.

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

@@ -569,10 +569,8 @@ impl Container {
             selected_definition <- action_bar.visualisation_selection.map(f!([registry](path)
                 path.as_ref().and_then(|path| registry.definition_from_path(path))
             ));
-            action_bar.hide_icons <+ selected_definition.constant(());
+            action_bar.set_vis_input_type <+ frp.set_vis_input_type;
             frp.source.vis_input_type <+ frp.set_vis_input_type;
-            let chooser = &model.action_bar.visualization_chooser();
-            chooser.frp.set_vis_input_type <+ frp.set_vis_input_type;
         }
 
 

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

@@ -7,6 +7,7 @@ use ensogl::display::traits::*;
 use crate::component::node;
 use crate::component::visualization;
 use crate::component::visualization::container::visualization_chooser::VisualizationChooser;
+use crate::data::enso;
 
 use enso_frp as frp;
 use enso_frp;
@@ -234,6 +235,7 @@ ensogl::define_endpoints! {
         show_icons                 (),
         hide_icons                 (),
         set_selected_visualization (Option<visualization::Path>),
+        set_vis_input_type         (Option<enso::Type>),
     }
 
     Output {
@@ -389,7 +391,11 @@ impl ActionBar {
             hide              <- any(mouse_out_no_menu,remote_click);
             eval_ hide (model.hide());
 
-            frp.source.visualisation_selection <+ visualization_chooser.chosen_entry;
+            // The action bar does not allow to deselect the visualisation, so we prohibit these
+            // events, which can occur on re-initialization.
+            has_selection <- visualization_chooser.chosen_entry.is_some();
+            frp.source.visualisation_selection
+                <+ visualization_chooser.chosen_entry.gate(&has_selection);
 
             let reset_position_icon = &model.icons.reset_position_icon.events_deprecated;
             let reset_position_icon_down = reset_position_icon.mouse_down_primary.clone_ref();
@@ -403,14 +409,29 @@ impl ActionBar {
 
             show_reset_icon <- bool(&reset_position_icon_down,start_dragging);
             eval show_reset_icon((visibility) model.icons.set_reset_icon_visibility(*visibility));
+
+
+           // === Visualisation Chooser ===
+
+            // Note: we only want to update the chooser if it is visible, or when it becomes
+            // visible. During startup we get the type information for every node, and propagate
+            // this information to the chooser. By delaying the creation of UI list elements until
+            // the chooser is visible, we can avoid creating a lot of UI elements that are never
+            // used.
+
+            visible <- any(&frp.show_icons, &any_component_over);
+            hidden <- any(&frp.hide_icons, &hide);
+
+            is_visible <- bool(&hidden, &visible);
+            on_show <- is_visible.on_change().on_true();
+
+            set_vis_input_while_visible <- frp.input.set_vis_input_type.gate(&is_visible);
+            set_vis_input_on_show       <- frp.input.set_vis_input_type.sample(&on_show);
+            set_vis_input <- any(&set_vis_input_while_visible, &set_vis_input_on_show).on_change();
+            visualization_chooser.input.set_vis_input_type <+ set_vis_input;
         }
         self
     }
-
-    /// Visualization Chooser component getter.
-    pub fn visualization_chooser(&self) -> &VisualizationChooser {
-        &self.model.visualization_chooser
-    }
 }
 
 impl display::Object for ActionBar {