Fix duplicate egui id in the stream trees (rerun-io#8229)

Co-authored-by: Emil Ernerfeldt <[email protected]>

crates/viewer/re_time_panel/src/lib.rs

@@ -547,8 +547,11 @@ impl TimePanel {
                     ui.scroll_with_delta(Vec2::Y * time_area_response.drag_delta().y);
                 }
 
-                // Show "/" on top?
-                let show_root = true;
+                // Show "/" on top only for recording streams, because the `/` entity in blueprint
+                // is always empty, so it's just lost space. This works around an issue where the
+                // selection/hover state of the `/` entity is wrongly synchronized between both
+                // stores, due to `Item::*` not tracking stores for entity paths.
+                let show_root = self.source == TimePanelSource::Recording;
 
                 if show_root {
                     self.show_tree(
@@ -632,7 +635,12 @@ impl TimePanel {
 
         // Globally unique id - should only be one of these in view at one time.
         // We do this so that we can support "collapse/expand all" command.
-        let id = egui::Id::new(CollapseScope::StreamsTree.entity(tree.path.clone()));
+        let id = egui::Id::new(match self.source {
+            TimePanelSource::Recording => CollapseScope::StreamsTree.entity(tree.path.clone()),
+            TimePanelSource::Blueprint => {
+                CollapseScope::BlueprintStreamsTree.entity(tree.path.clone())
+            }
+        });
 
         let list_item::ShowCollapsingResponse {
             item_response: response,

crates/viewer/re_viewer_context/src/collapsed_id.rs

@@ -9,11 +9,15 @@ use crate::{ContainerId, SpaceViewId};
 
 /// The various scopes for which we want to track collapsed state.
 #[derive(Debug, Clone, Copy, Hash)]
+#[allow(clippy::enum_variant_names)]
 pub enum CollapseScope {
     /// Stream tree from the time panel
     StreamsTree,
 
-    /// Blueprint tree from the blueprint panel
+    /// The stream tree from the blueprint debug time panel
+    BlueprintStreamsTree,
+
+    /// Blueprint tree from the blueprint panel (left panel)
     BlueprintTree,
 }