refactor: extract file-tree key handling into key_actions module (#2042)

* refactor: extract file-tree key handling into key_actions module

* refactor: simplify file_tree_key with early Esc return and let-else binding

* fix: address review comments on file-tree key_actions refactor

Restore file_tree_visible guard, remove stale KeyActionResult docs, unify format string style.

crates/tui/src/tui/key_actions.rs

@@ -0,0 +1,56 @@
+//! Keyboard event action handlers extracted from `ui.rs`.
+//!
+//! Each function handles a focused subset of keyboard input so the
+//! main event loop stays lean.
+
+use crossterm::event::{KeyCode, KeyEvent};
+
+use super::app::App;
+
+// ── File-tree key handling ───────────────────────────────────────
+
+/// Handle keyboard input when the file-tree pane is visible.
+///
+/// Returns `true` when the key was consumed (caller should `continue`).
+pub fn handle_file_tree_key(app: &mut App, key: &KeyEvent) -> bool {
+    // Guard: do not intercept keys when the file-tree pane is not visible.
+    if !app.file_tree_visible {
+        return false;
+    }
+
+    // Esc closes the tree even when entries are still loading.
+    if key.code == KeyCode::Esc && app.file_tree.is_some() {
+        app.file_tree = None;
+        app.status_message = Some("File tree closed".to_string());
+        app.needs_redraw = true;
+        return true;
+    }
+
+    let Some(file_tree) = app.file_tree.as_mut() else {
+        return false;
+    };
+
+    match key.code {
+        KeyCode::Up => {
+            file_tree.cursor_up();
+            app.needs_redraw = true;
+            true
+        }
+        KeyCode::Down => {
+            file_tree.cursor_down();
+            app.needs_redraw = true;
+            true
+        }
+        KeyCode::Enter => {
+            if let Some(rel_path) = file_tree.activate() {
+                let path_str = rel_path.to_string_lossy().to_string();
+                app.status_message = Some(format!("Attached @{path_str}"));
+                app.insert_str(&format!("@{path_str} "));
+            } else {
+                app.needs_redraw = true;
+            }
+            true
+        }
+        _ => false,
+    }
+}

crates/tui/src/tui/mod.rs

@@ -35,6 +35,7 @@ pub mod footer_ui;
 pub mod format_helpers;
 pub mod frame_rate_limiter;
 pub mod history;
+pub mod key_actions;
 pub mod key_shortcuts;
 pub mod keybindings;
 pub mod live_transcript;

crates/tui/src/tui/ui.rs

@@ -106,6 +106,8 @@ use crate::tui::views::subagent_view_agents;
 use crate::tui::vim_mode;
 use crate::tui::workspace_context;
 
+use super::key_actions;
+
 use super::app::{
     App, AppAction, AppMode, OnboardingState, QueuedMessage, ReasoningEffort, SidebarFocus,
     StatusToastLevel, SubmitDisposition, TaskPanelEntry, TuiOptions,
@@ -2772,47 +2774,9 @@ async fn run_event_loop(
                 continue;
             }
 
-            // File-tree navigation: intercept keys when the file-tree pane is
-            // visible so Up/Down/Enter/Esc operate on the tree rather than
-            // falling through to composer or modal handlers.
-            if app.file_tree_visible {
-                match key.code {
-                    KeyCode::Up => {
-                        if let Some(state) = app.file_tree.as_mut() {
-                            state.cursor_up();
-                        }
-                        app.needs_redraw = true;
-                        continue;
-                    }
-                    KeyCode::Down => {
-                        if let Some(state) = app.file_tree.as_mut() {
-                            state.cursor_down();
-                        }
-                        app.needs_redraw = true;
-                        continue;
-                    }
-                    KeyCode::Enter => {
-                        if let Some(state) = app.file_tree.as_mut() {
-                            if let Some(rel_path) = state.activate() {
-                                // Insert @path into the composer.
-                                let path_str = rel_path.to_string_lossy().to_string();
-                                app.status_message = Some(format!("Attached @{path_str}"));
-                                app.insert_str(&format!("@{path_str} "));
-                            } else {
-                                // Directory was expanded/collapsed; rebuild.
-                                app.needs_redraw = true;
-                            }
-                        }
-                        continue;
-                    }
-                    KeyCode::Esc => {
-                        app.file_tree = None;
-                        app.status_message = Some("File tree closed".to_string());
-                        app.needs_redraw = true;
-                        continue;
-                    }
-                    _ => {}
-                }
+            // File-tree navigation: delegated to key_actions module.
+            if key_actions::handle_file_tree_key(app, &key) {
+                continue;
             }
 
             if app.is_history_search_active() {