Reduce agent spinner GPU usage (#51756)

PuQing and Anthony Eid created 2 days ago

Closes #39532

## Summary

Move the long-running agent "generating" spinner into a dedicated
`GeneratingSpinner` view.

Previously, the generating state rendered `SpinnerLabel` inline as part
of the full thread view. This change keeps the same spinner styling, but
isolates it into its own small view so the animation no longer needs to
live directly inside the larger thread UI subtree while the agent is
running.

before:

<img width="398" height="448" alt="image"
src="https://github.com/user-attachments/assets/8a56c394-f7a6-4835-b877-fbc1500d2d03"
/>


after:

<img width="524" height="597" alt="image"
src="https://github.com/user-attachments/assets/bd2e5804-dba8-49c0-a421-7dc5ba600348"
/>


## Testing

- `cargo run -j 4 ~/Downloads/WorkSpace/zed/`
- `cargo check -p agent_ui`

Release Notes:

- Fixed high GPU usage from the agent panel's generating spinner while
an agent is running.

---------

Co-authored-by: Anthony Eid <[e-mail]>

Change summary

crates/agent_ui/src/conversation_view.rs             |  4 
crates/agent_ui/src/conversation_view/thread_view.rs | 56 ++++++++++++-
2 files changed, 53 insertions(+), 7 deletions(-)

Detailed changes

crates/agent_ui/src/conversation_view.rs

@@ -54,8 +54,8 @@ use theme_settings::AgentFontSize;
 use ui::{
     Callout, CircularProgress, CommonAnimationExt, ContextMenu, ContextMenuEntry, CopyButton,
     DecoratedIcon, DiffStat, Disclosure, Divider, DividerColor, IconDecoration, IconDecorationKind,
-    KeyBinding, PopoverMenu, PopoverMenuHandle, SpinnerLabel, TintColor, Tooltip, WithScrollbar,
-    prelude::*, right_click_menu,
+    KeyBinding, PopoverMenu, PopoverMenuHandle, TintColor, Tooltip, WithScrollbar, prelude::*,
+    right_click_menu,
 };
 use util::{ResultExt, size::format_file_size, time::duration_alt_display};
 use util::{debug_panic, defer};

crates/agent_ui/src/conversation_view/thread_view.rs

@@ -14,7 +14,7 @@ use gpui::{Corner, List};
 use heapless::Vec as ArrayVec;
 use language_model::{LanguageModelEffortLevel, Speed};
 use settings::update_settings_file;
-use ui::{ButtonLike, SplitButton, SplitButtonStyle, Tab};
+use ui::{ButtonLike, SpinnerLabel, SpinnerVariant, SplitButton, SplitButtonStyle, Tab};
 use workspace::SERIALIZATION_THROTTLE_TIME;
 
 use super::*;
@@ -164,6 +164,46 @@ impl ThreadFeedbackState {
     }
 }
 
+struct GeneratingSpinner {
+    variant: SpinnerVariant,
+}
+
+impl GeneratingSpinner {
+    fn new(variant: SpinnerVariant) -> Self {
+        Self { variant }
+    }
+}
+
+impl Render for GeneratingSpinner {
+    fn render(&mut self, _window: &mut Window, _cx: &mut Context<Self>) -> impl IntoElement {
+        SpinnerLabel::with_variant(self.variant).size(LabelSize::Small)
+    }
+}
+
+#[derive(IntoElement)]
+struct GeneratingSpinnerElement {
+    variant: SpinnerVariant,
+}
+
+impl GeneratingSpinnerElement {
+    fn new(variant: SpinnerVariant) -> Self {
+        Self { variant }
+    }
+}
+
+impl RenderOnce for GeneratingSpinnerElement {
+    fn render(self, window: &mut Window, cx: &mut App) -> impl IntoElement {
+        let id = match self.variant {
+            SpinnerVariant::Dots => "generating-spinner-view",
+            SpinnerVariant::Sand => "confirmation-spinner-view",
+            _ => "spinner-view",
+        };
+        window.with_id(id, |window| {
+            window.use_state(cx, |_, _| GeneratingSpinner::new(self.variant))
+        })
+    }
+}
+
 pub enum AcpThreadViewEvent {
     FirstSendRequested { content: Vec<acp::ContentBlock> },
     MessageSentOrQueued,
@@ -4275,10 +4315,10 @@ impl Render for TokenUsageTooltip {
 }
 
 impl ThreadView {
-    pub(crate) fn render_entries(&mut self, cx: &mut Context<Self>) -> List {
+    fn render_entries(&mut self, cx: &mut Context<Self>) -> List {
         list(
             self.list_state.clone(),
-            cx.processor(|this, index: usize, window, cx| {
+            cx.processor(move |this, index: usize, window, cx| {
                 let entries = this.thread.read(cx).entries();
                 if let Some(entry) = entries.get(index) {
                     this.render_entry(index, entries.len(), entry, window, cx)
@@ -5193,7 +5233,8 @@ impl ThreadView {
                     this.child(
                         h_flex()
                             .w_2()
-                            .child(SpinnerLabel::sand().size(LabelSize::Small)),
+                            .justify_center()
+                            .child(GeneratingSpinnerElement::new(SpinnerVariant::Sand)),
                     )
                     .child(
                         div().min_w(rems(8.)).child(
@@ -5205,7 +5246,12 @@ impl ThreadView {
                 } else if is_blocked_on_terminal_command {
                     this
                 } else {
-                    this.child(SpinnerLabel::new().size(LabelSize::Small))
+                    this.child(
+                        h_flex()
+                            .w_2()
+                            .justify_center()
+                            .child(GeneratingSpinnerElement::new(SpinnerVariant::Dots)),
+                    )
                 }
             })
             .when_some(elapsed_label, |this, elapsed| {