Wire up logic for thinking animation

Co-authored-by: Danilo Leal <daniloleal09@gmail.com>

crates/agent_ui/src/acp/entry_view_state.rs

@@ -6,7 +6,7 @@ use agent2::HistoryStore;
 use collections::HashMap;
 use editor::{Editor, EditorMode, MinimapVisibility};
 use gpui::{
-    AnyEntity, App, AppContext as _, Entity, EntityId, EventEmitter, Focusable,
+    AnyEntity, App, AppContext as _, Entity, EntityId, EventEmitter, Focusable, ScrollHandle,
     TextStyleRefinement, WeakEntity, Window,
 };
 use language::language_settings::SoftWrap;
@@ -154,10 +154,22 @@ impl EntryViewState {
                     });
                 }
             }
-            AgentThreadEntry::AssistantMessage(_) => {
-                if index == self.entries.len() {
-                    self.entries.push(Entry::empty())
-                }
+            AgentThreadEntry::AssistantMessage(message) => {
+                let entry = if let Some(Entry::AssistantMessage(entry)) =
+                    self.entries.get_mut(index)
+                {
+                    entry
+                } else {
+                    self.set_entry(
+                        index,
+                        Entry::AssistantMessage(AssistantMessageEntry::default()),
+                    );
+                    let Some(Entry::AssistantMessage(entry)) = self.entries.get_mut(index) else {
+                        unreachable!()
+                    };
+                    entry
+                };
+                entry.sync(message);
             }
         };
     }
@@ -177,7 +189,7 @@ impl EntryViewState {
     pub fn settings_changed(&mut self, cx: &mut App) {
         for entry in self.entries.iter() {
             match entry {
-                Entry::UserMessage { .. } => {}
+                Entry::UserMessage { .. } | Entry::AssistantMessage { .. } => {}
                 Entry::Content(response_views) => {
                     for view in response_views.values() {
                         if let Ok(diff_editor) = view.clone().downcast::<Editor>() {
@@ -208,9 +220,29 @@ pub enum ViewEvent {
     MessageEditorEvent(Entity<MessageEditor>, MessageEditorEvent),
 }
 
+#[derive(Default, Debug)]
+pub struct AssistantMessageEntry {
+    scroll_handles_by_chunk_index: HashMap<usize, ScrollHandle>,
+}
+
+impl AssistantMessageEntry {
+    pub fn scroll_handle_for_chunk(&self, ix: usize) -> Option<ScrollHandle> {
+        self.scroll_handles_by_chunk_index.get(&ix).cloned()
+    }
+
+    pub fn sync(&mut self, message: &acp_thread::AssistantMessage) {
+        if let Some(acp_thread::AssistantMessageChunk::Thought { .. }) = message.chunks.last() {
+            let ix = message.chunks.len() - 1;
+            let handle = self.scroll_handles_by_chunk_index.entry(ix).or_default();
+            handle.scroll_to_bottom();
+        }
+    }
+}
+
 #[derive(Debug)]
 pub enum Entry {
     UserMessage(Entity<MessageEditor>),
+    AssistantMessage(AssistantMessageEntry),
     Content(HashMap<EntityId, AnyEntity>),
 }
 
@@ -218,7 +250,7 @@ impl Entry {
     pub fn message_editor(&self) -> Option<&Entity<MessageEditor>> {
         match self {
             Self::UserMessage(editor) => Some(editor),
-            Entry::Content(_) => None,
+            Self::AssistantMessage(_) | Self::Content(_) => None,
         }
     }
 
@@ -239,6 +271,16 @@ impl Entry {
             .map(|entity| entity.downcast::<TerminalView>().unwrap())
     }
 
+    pub fn scroll_handle_for_assistant_message_chunk(
+        &self,
+        chunk_ix: usize,
+    ) -> Option<ScrollHandle> {
+        match self {
+            Self::AssistantMessage(message) => message.scroll_handle_for_chunk(chunk_ix),
+            Self::UserMessage(_) | Self::Content(_) => None,
+        }
+    }
+
     fn content_map(&self) -> Option<&HashMap<EntityId, AnyEntity>> {
         match self {
             Self::Content(map) => Some(map),
@@ -254,7 +296,7 @@ impl Entry {
     pub fn has_content(&self) -> bool {
         match self {
             Self::Content(map) => !map.is_empty(),
-            Self::UserMessage(_) => false,
+            Self::UserMessage(_) | Self::AssistantMessage(_) => false,
         }
     }
 }

crates/agent_ui/src/acp/thread_view.rs

@@ -1615,9 +1615,15 @@ impl AcpThreadView {
         let card_header_id = SharedString::from("inner-card-header");
         let key = (entry_ix, chunk_ix);
         let is_open = self.expanded_thinking_blocks.contains(&key);
+        let scroll_handle = self
+            .entry_view_state
+            .read(cx)
+            .entry(entry_ix)
+            .and_then(|entry| entry.scroll_handle_for_assistant_message_chunk(chunk_ix));
 
         v_flex()
-            // .debug_bg_cyan()
+            .border_1()
+            .border_color(cx.theme().colors().border)
             .child(
                 h_flex()
                     .id(header_id)
@@ -1631,11 +1637,9 @@ impl AcpThreadView {
                             .h(window.line_height())
                             .gap_1p5()
                             .child(
-                                // div().debug_bg_magenta().child(
                                 Icon::new(IconName::ToolThink)
                                     .size(IconSize::Small)
                                     .color(Color::Muted),
-                                // ),
                             )
                             .child(
                                 div()
@@ -1671,8 +1675,8 @@ impl AcpThreadView {
                         }
                     })),
             )
-            .when(is_open, |this| {
-                this.child(
+            .map(|this| {
+                this.child(if is_open {
                     div()
                         .relative()
                         .mt_1p5()
@@ -1684,8 +1688,44 @@ impl AcpThreadView {
                         .child(self.render_markdown(
                             chunk,
                             default_markdown_style(false, false, window, cx),
-                        )),
-                )
+                        ))
+                } else {
+                    let editor_bg = cx.theme().colors().editor_background;
+                    let gradient_overlay = div()
+                        .rounded_b_lg()
+                        .h_full()
+                        .absolute()
+                        .w_full()
+                        .bottom_0()
+                        .left_0()
+                        .bg(linear_gradient(
+                            180.,
+                            linear_color_stop(editor_bg, 1.),
+                            linear_color_stop(editor_bg.opacity(0.2), 0.),
+                        ));
+
+                    div()
+                        .relative()
+                        .bg(editor_bg)
+                        .rounded_b_lg()
+                        .mt_2()
+                        .pl_4()
+                        .child(
+                            div()
+                                .id(("thinking-content", chunk_ix))
+                                .max_h_20()
+                                .when_some(scroll_handle, |this, scroll_handle| {
+                                    this.track_scroll(&scroll_handle)
+                                })
+                                .text_ui_sm(cx)
+                                .overflow_hidden()
+                                .child(self.render_markdown(
+                                    chunk,
+                                    default_markdown_style(false, false, window, cx),
+                                )),
+                        )
+                        .child(gradient_overlay)
+                })
             })
             .into_any_element()
     }