Show hovered cursors less flickerily (#4242)

Conrad Irwin created 2 years ago

Now when hovering on a cursor it'll stay around for 2 seconds

Release Notes:

- Improved hovering over collaborators' cursors.

Change summary

crates/editor/src/editor.rs  |  8 +++++---
crates/editor/src/element.rs | 25 +++++++++++++++++++------
2 files changed, 24 insertions(+), 9 deletions(-)

Detailed changes

crates/editor/src/editor.rs

@@ -126,6 +126,7 @@ const MAX_LINE_LEN: usize = 1024;
 const MIN_NAVIGATION_HISTORY_ROW_DELTA: i64 = 10;
 const MAX_SELECTION_HISTORY_LEN: usize = 1024;
 const COPILOT_DEBOUNCE_TIMEOUT: Duration = Duration::from_millis(75);
+pub(crate) const CURSORS_VISIBLE_FOR: Duration = Duration::from_millis(2000);
 #[doc(hidden)]
 pub const CODE_ACTIONS_DEBOUNCE_TIMEOUT: Duration = Duration::from_millis(250);
 #[doc(hidden)]
@@ -369,7 +370,7 @@ pub struct Editor {
     collaboration_hub: Option<Box<dyn CollaborationHub>>,
     blink_manager: Model<BlinkManager>,
     show_cursor_names: bool,
-    hovered_cursor: Option<HoveredCursor>,
+    hovered_cursors: HashMap<HoveredCursor, Task<()>>,
     pub show_local_selections: bool,
     mode: EditorMode,
     show_gutter: bool,
@@ -463,6 +464,7 @@ enum SelectionHistoryMode {
     Redoing,
 }
 
+#[derive(Clone, PartialEq, Eq, Hash)]
 struct HoveredCursor {
     replica_id: u16,
     selection_id: usize,
@@ -1440,7 +1442,7 @@ impl Editor {
             gutter_width: Default::default(),
             style: None,
             show_cursor_names: false,
-            hovered_cursor: Default::default(),
+            hovered_cursors: Default::default(),
             editor_actions: Default::default(),
             show_copilot_suggestions: mode == EditorMode::Full,
             _subscriptions: vec![
@@ -3741,7 +3743,7 @@ impl Editor {
         self.show_cursor_names = true;
         cx.notify();
         cx.spawn(|this, mut cx| async move {
-            cx.background_executor().timer(Duration::from_secs(3)).await;
+            cx.background_executor().timer(CURSORS_VISIBLE_FOR).await;
             this.update(&mut cx, |this, cx| {
                 this.show_cursor_names = false;
                 cx.notify()

crates/editor/src/element.rs

@@ -17,8 +17,8 @@ use crate::{
     mouse_context_menu,
     scroll::scroll_amount::ScrollAmount,
     CursorShape, DisplayPoint, Editor, EditorMode, EditorSettings, EditorSnapshot, EditorStyle,
-    HalfPageDown, HalfPageUp, LineDown, LineUp, OpenExcerpts, PageDown, PageUp, Point, SelectPhase,
-    Selection, SoftWrap, ToPoint, MAX_LINE_LEN,
+    HalfPageDown, HalfPageUp, HoveredCursor, LineDown, LineUp, OpenExcerpts, PageDown, PageUp,
+    Point, SelectPhase, Selection, SoftWrap, ToPoint, CURSORS_VISIBLE_FOR, MAX_LINE_LEN,
 };
 use anyhow::Result;
 use collections::{BTreeMap, HashMap};
@@ -612,13 +612,24 @@ impl EditorElement {
                 .anchor_at(range.end.to_point(&snapshot.display_snapshot), Bias::Right);
 
         let Some(selection) = snapshot.remote_selections_in_range(&range, hub, cx).next() else {
-            editor.hovered_cursor.take();
             return;
         };
-        editor.hovered_cursor.replace(crate::HoveredCursor {
+        let key = crate::HoveredCursor {
             replica_id: selection.replica_id,
             selection_id: selection.selection.id,
-        });
+        };
+        editor.hovered_cursors.insert(
+            key.clone(),
+            cx.spawn(|editor, mut cx| async move {
+                cx.background_executor().timer(CURSORS_VISIBLE_FOR).await;
+                editor
+                    .update(&mut cx, |editor, cx| {
+                        editor.hovered_cursors.remove(&key);
+                        cx.notify();
+                    })
+                    .ok();
+            }),
+        );
         cx.notify()
     }
 
@@ -1986,7 +1997,9 @@ impl EditorElement {
                     if Some(selection.peer_id) == editor.leader_peer_id {
                         continue;
                     }
-                    let is_shown = editor.show_cursor_names || editor.hovered_cursor.as_ref().is_some_and(|c| c.replica_id == selection.replica_id && c.selection_id == selection.selection.id);
+                    let key = HoveredCursor{replica_id: selection.replica_id, selection_id: selection.selection.id};
+
+                    let is_shown = editor.show_cursor_names || editor.hovered_cursors.contains_key(&key);
 
                     remote_selections
                         .entry(selection.replica_id)