feat: filter keybind help (#1832)

* feat: filter keybind help

refs #1825

* fix: recognize shifted slash in keybind help

---------

Co-authored-by: Ogulcan Celik <ogulcancelik@gmail.com>

5 files changed, 272 insertions, 11 deletions

diff --git a/src/app/input/mod.rs b/src/app/input/mod.rs
index 16713222..f304cde6 100644
--- a/src/app/input/mod.rs
+++ b/src/app/input/mod.rs
@@ -49,7 +49,8 @@ mod terminal;
 pub(crate) use self::{
     modal::{
         handle_global_menu_key, handle_keybind_help_key, handle_navigator_key,
-        insert_navigator_search_text, insert_rename_input_text, open_new_workspace_dialog,
+        insert_keybind_help_query_text, insert_navigator_search_text, insert_rename_input_text,
+        open_new_workspace_dialog,
     },
     navigate::{
         terminal_direct_indexed_navigation_action, terminal_direct_non_indexed_navigation_action,
@@ -109,7 +110,7 @@ impl App {
                 }
                 Mode::Settings => self.handle_settings_key(key_event),
                 Mode::GlobalMenu => handle_global_menu_key(&mut self.state, key_event),
-                Mode::KeybindHelp => handle_keybind_help_key(&mut self.state, key_event),
+                Mode::KeybindHelp => handle_keybind_help_key(&mut self.state, key),
                 Mode::Navigator => {
                     handle_navigator_key(&mut self.state, &self.terminal_runtimes, key_event)
                 }
@@ -172,6 +173,13 @@ impl App {
                 insert_navigator_search_text(&mut self.state, &self.terminal_runtimes, text);
                 true
             }
+            Mode::KeybindHelp => {
+                if !self.state.keybind_help.search_focused {
+                    return false;
+                }
+                insert_keybind_help_query_text(&mut self.state, text);
+                true
+            }
             Mode::Copy => {
                 let Some(prompt) = self
                     .state
@@ -653,6 +661,7 @@ pub(crate) fn modal_paste_target_active(state: &AppState) -> bool {
             .as_ref()
             .is_some_and(|open| open.search_focused),
         Mode::Navigator => state.navigator.search_focused,
+        Mode::KeybindHelp => state.keybind_help.search_focused,
         Mode::Copy => state
             .copy_mode
             .as_ref()
@@ -858,6 +867,21 @@ mod tests {
     }
 
     #[tokio::test]
+    async fn paste_routes_to_keybind_help_query_only_when_searching() {
+        let mut app = test_app();
+        app.state.mode = Mode::KeybindHelp;
+        app.handle_paste("ignored".into()).await;
+        assert!(app.state.keybind_help.query.is_empty());
+
+        app.state.keybind_help.search_focused = true;
+        app.state.keybind_help.scroll = 3;
+        app.handle_paste("work\nspace".into()).await;
+
+        assert_eq!(app.state.keybind_help.query, "workspace");
+        assert_eq!(app.state.keybind_help.scroll, 0);
+    }
+
+    #[tokio::test]
     async fn paste_routes_to_new_linked_worktree_input() {
         let mut app = test_app();
         app.state.mode = Mode::NewLinkedWorktree;
@@ -922,6 +946,12 @@ mod tests {
         state.navigator.search_focused = true;
         assert!(modal_paste_target_active(&state));
 
+        state.mode = Mode::KeybindHelp;
+        state.keybind_help.search_focused = false;
+        assert!(!modal_paste_target_active(&state));
+        state.keybind_help.search_focused = true;
+        assert!(modal_paste_target_active(&state));
+
         state.mode = Mode::ConfirmClose;
         assert!(!modal_paste_target_active(&state));
     }
diff --git a/src/app/input/modal.rs b/src/app/input/modal.rs
index dc126b40..d8a14602 100644
--- a/src/app/input/modal.rs
+++ b/src/app/input/modal.rs
@@ -101,6 +101,8 @@ pub(super) fn open_global_menu(state: &mut AppState) {
 
 pub(super) fn open_keybind_help(state: &mut AppState) {
     state.keybind_help.scroll = 0;
+    state.keybind_help.query.clear();
+    state.keybind_help.search_focused = false;
     state.mode = Mode::KeybindHelp;
 }
 
@@ -284,7 +286,56 @@ pub(crate) fn insert_navigator_search_text(
     state.select_first_navigator_match_from(terminal_runtimes);
 }
 
-pub(crate) fn handle_keybind_help_key(state: &mut AppState, key: KeyEvent) {
+pub(crate) fn insert_keybind_help_query_text(state: &mut AppState, text: &str) {
+    if !state.keybind_help.search_focused {
+        return;
+    }
+    state
+        .keybind_help
+        .query
+        .extend(text.chars().filter(|ch| !ch.is_control()));
+    state.keybind_help.scroll = 0;
+}
+
+pub(super) fn keybind_help_back(state: &mut AppState) {
+    if state.keybind_help.search_focused {
+        state.keybind_help.query.clear();
+        state.keybind_help.search_focused = false;
+        state.keybind_help.scroll = 0;
+    } else {
+        leave_modal(state);
+    }
+}
+
+pub(crate) fn handle_keybind_help_key(state: &mut AppState, key: TerminalKey) {
+    if state.keybind_help.search_focused {
+        let text_char = keybind_help_text_char(key);
+        match key.code {
+            KeyCode::Up => state.scroll_keybind_help(-1),
+            KeyCode::Down => state.scroll_keybind_help(1),
+            KeyCode::PageUp => state.scroll_keybind_help(-8),
+            KeyCode::PageDown => state.scroll_keybind_help(8),
+            KeyCode::Home => state.keybind_help.scroll = 0,
+            KeyCode::End => state.keybind_help.scroll = state.keybind_help_max_scroll(),
+            KeyCode::Backspace => {
+                state.keybind_help.query.pop();
+                state.keybind_help.scroll = 0;
+            }
+            KeyCode::Char('u') if key.modifiers == KeyModifiers::CONTROL => {
+                state.keybind_help.query.clear();
+                state.keybind_help.scroll = 0;
+            }
+            KeyCode::Esc => keybind_help_back(state),
+            KeyCode::Enter => leave_modal(state),
+            _ => {
+                if let Some(character) = text_char {
+                    insert_keybind_help_query_text(state, &character.to_string());
+                }
+            }
+        }
+        return;
+    }
+
     match key.code {
         KeyCode::Up | KeyCode::Char('k') => state.scroll_keybind_help(-1),
         KeyCode::Down | KeyCode::Char('j') => state.scroll_keybind_help(1),
@@ -292,11 +343,30 @@ pub(crate) fn handle_keybind_help_key(state: &mut AppState, key: KeyEvent) {
         KeyCode::PageDown => state.scroll_keybind_help(8),
         KeyCode::Home => state.keybind_help.scroll = 0,
         KeyCode::End => state.keybind_help.scroll = state.keybind_help_max_scroll(),
-        KeyCode::Esc | KeyCode::Enter | KeyCode::Char('?') => leave_modal(state),
+        _ if keybind_help_text_char(key) == Some('/') => {
+            state.keybind_help.search_focused = true;
+            state.keybind_help.scroll = 0;
+        }
+        KeyCode::Esc => keybind_help_back(state),
+        KeyCode::Enter => leave_modal(state),
+        _ if keybind_help_text_char(key) == Some('?') => leave_modal(state),
         _ => {}
     }
 }
 
+fn keybind_help_text_char(key: TerminalKey) -> Option<char> {
+    if !key.modifiers.difference(KeyModifiers::SHIFT).is_empty() {
+        return None;
+    }
+    if let Some(character) = key.shifted_codepoint.and_then(char::from_u32) {
+        return Some(character);
+    }
+    let KeyCode::Char(character) = key.code else {
+        return None;
+    };
+    Some(character)
+}
+
 pub(super) fn open_rename_workspace(
     state: &mut AppState,
     terminal_runtimes: &crate::terminal::TerminalRuntimeRegistry,
@@ -1655,6 +1725,136 @@ mod tests {
     }
 
     #[test]
+    fn keybind_help_slash_focuses_filter_and_preserves_vim_scroll() {
+        let mut state = state_with_workspaces(&["test"]);
+        state.keybind_help.query = "stale".into();
+        state.keybind_help.search_focused = true;
+        state.view.terminal_area = Rect::new(0, 0, 100, 30);
+
+        open_keybind_help(&mut state);
+        handle_keybind_help_key(
+            &mut state,
+            TerminalKey::new(KeyCode::Char('j'), KeyModifiers::empty()),
+        );
+        assert_eq!(state.keybind_help.scroll, 1);
+        handle_keybind_help_key(
+            &mut state,
+            TerminalKey::new(KeyCode::Char('k'), KeyModifiers::empty()),
+        );
+        assert_eq!(state.keybind_help.scroll, 0);
+
+        handle_keybind_help_key(
+            &mut state,
+            TerminalKey::new(KeyCode::Char('w'), KeyModifiers::empty()),
+        );
+        assert!(state.keybind_help.query.is_empty());
+
+        handle_keybind_help_key(
+            &mut state,
+            TerminalKey::new(KeyCode::Char('/'), KeyModifiers::empty()),
+        );
+        for character in "work".chars() {
+            state.keybind_help.scroll = 2;
+            handle_keybind_help_key(
+                &mut state,
+                TerminalKey::new(KeyCode::Char(character), KeyModifiers::empty()),
+            );
+        }
+
+        assert!(state.keybind_help.search_focused);
+        assert_eq!(state.keybind_help.query, "work");
+        assert_eq!(state.keybind_help.scroll, 0);
+    }
+
+    #[test]
+    fn keybind_help_query_supports_backspace_clear_and_sanitized_paste() {
+        let mut state = state_with_workspaces(&["test"]);
+        open_keybind_help(&mut state);
+        handle_keybind_help_key(
+            &mut state,
+            TerminalKey::new(KeyCode::Char('/'), KeyModifiers::empty()),
+        );
+
+        insert_keybind_help_query_text(&mut state, "work\nspace");
+        assert_eq!(state.keybind_help.query, "workspace");
+
+        handle_keybind_help_key(
+            &mut state,
+            TerminalKey::new(KeyCode::Backspace, KeyModifiers::empty()),
+        );
+        assert_eq!(state.keybind_help.query, "workspac");
+
+        handle_keybind_help_key(
+            &mut state,
+            TerminalKey::new(KeyCode::Char('u'), KeyModifiers::CONTROL),
+        );
+        assert!(state.keybind_help.query.is_empty());
+    }
+
+    #[test]
+    fn keybind_help_escape_leaves_search_before_closing() {
+        let mut state = state_with_workspaces(&["test"]);
+        open_keybind_help(&mut state);
+        state.keybind_help.search_focused = true;
+        state.keybind_help.query = "work".into();
+
+        handle_keybind_help_key(
+            &mut state,
+            TerminalKey::new(KeyCode::Esc, KeyModifiers::empty()),
+        );
+        assert_eq!(state.mode, Mode::KeybindHelp);
+        assert!(!state.keybind_help.search_focused);
+        assert!(state.keybind_help.query.is_empty());
+
+        handle_keybind_help_key(
+            &mut state,
+            TerminalKey::new(KeyCode::Esc, KeyModifiers::empty()),
+        );
+        assert_eq!(state.mode, Mode::Terminal);
+    }
+
+    #[test]
+    fn enhanced_shifted_slash_focuses_keybind_help_filter() {
+        let mut state = state_with_workspaces(&["test"]);
+        open_keybind_help(&mut state);
+
+        handle_keybind_help_key(
+            &mut state,
+            TerminalKey::new(KeyCode::Char('7'), KeyModifiers::SHIFT)
+                .with_shifted_codepoint('/' as u32),
+        );
+
+        assert!(state.keybind_help.search_focused);
+    }
+
+    #[test]
+    fn enhanced_shifted_question_mark_closes_keybind_help_when_not_searching() {
+        let mut state = state_with_workspaces(&["test"]);
+        open_keybind_help(&mut state);
+
+        handle_keybind_help_key(
+            &mut state,
+            TerminalKey::new(KeyCode::Char('/'), KeyModifiers::SHIFT)
+                .with_shifted_codepoint('?' as u32),
+        );
+
+        assert_eq!(state.mode, Mode::Terminal);
+
+        open_keybind_help(&mut state);
+        handle_keybind_help_key(
+            &mut state,
+            TerminalKey::new(KeyCode::Char('/'), KeyModifiers::empty()),
+        );
+        handle_keybind_help_key(
+            &mut state,
+            TerminalKey::new(KeyCode::Char('/'), KeyModifiers::SHIFT)
+                .with_shifted_codepoint('?' as u32),
+        );
+
+        assert_eq!(state.keybind_help.query, "?");
+    }
+
+    #[test]
     fn navigator_search_accepts_pasted_text_when_focused() {
         let mut state = state_with_workspaces(&["alpha", "beta"]);
         let terminal_runtimes = crate::terminal::TerminalRuntimeRegistry::new();
diff --git a/src/app/input/overlays.rs b/src/app/input/overlays.rs
index e9cf3139..58f2ef71 100644
--- a/src/app/input/overlays.rs
+++ b/src/app/input/overlays.rs
@@ -10,7 +10,7 @@ use crate::app::{
 };
 
 use super::{
-    modal::{leave_modal, modal_action_from_buttons, ModalAction},
+    modal::{keybind_help_back, leave_modal, modal_action_from_buttons, ModalAction},
     ScrollbarClickTarget,
 };
 
@@ -197,7 +197,7 @@ impl App {
                         .state
                         .keybind_help_close_button_at(mouse.column, mouse.row) =>
                 {
-                    leave_modal(&mut self.state);
+                    keybind_help_back(&mut self.state);
                 }
                 MouseEventKind::Down(MouseButton::Left) => {
                     if let Some(target) = self
@@ -739,6 +739,33 @@ mod tests {
     }
 
     #[test]
+    fn clicking_keybind_help_back_button_leaves_help_open() {
+        let mut app = app_for_mouse_test();
+        app.state.mode = Mode::KeybindHelp;
+        app.state.keybind_help.search_focused = true;
+        app.state.keybind_help.query = "work".into();
+
+        let rect = app.state.keybind_help_popup_rect();
+        let inner = Rect::new(
+            rect.x + 1,
+            rect.y + 1,
+            rect.width.saturating_sub(2),
+            rect.height.saturating_sub(2),
+        );
+        let back =
+            crate::ui::release_notes_close_button_rect(Rect::new(inner.x, inner.y, inner.width, 1));
+        app.handle_mouse(mouse(
+            MouseEventKind::Down(MouseButton::Left),
+            back.x,
+            back.y,
+        ));
+
+        assert_eq!(app.state.mode, Mode::KeybindHelp);
+        assert!(!app.state.keybind_help.search_focused);
+        assert!(app.state.keybind_help.query.is_empty());
+    }
+
+    #[test]
     fn onboarding_hover_does_not_change_selection() {
         let mut app = app_for_mouse_test();
         app.state.mode = Mode::Onboarding;
diff --git a/src/app/mod.rs b/src/app/mod.rs
index 30e1c949..6ca1d940 100644
--- a/src/app/mod.rs
+++ b/src/app/mod.rs
@@ -573,7 +573,7 @@ impl App {
                     preview: announcement.preview,
                 }
             }),
-            keybind_help: state::KeybindHelpState { scroll: 0 },
+            keybind_help: state::KeybindHelpState::default(),
             navigator: state::NavigatorState::default(),
             copy_mode: None,
             workspace_scroll: 0,
@@ -1771,7 +1771,7 @@ impl App {
                 self.handle_context_menu_key_via_api(key_event);
             }
             Mode::KeybindHelp => {
-                input::handle_keybind_help_key(&mut self.state, key_event);
+                input::handle_keybind_help_key(&mut self.state, key);
             }
             Mode::GlobalMenu => {
                 input::handle_global_menu_key(&mut self.state, key_event);
diff --git a/src/app/state.rs b/src/app/state.rs
index f8395cbd..b9e4ed70 100644
--- a/src/app/state.rs
+++ b/src/app/state.rs
@@ -821,8 +821,9 @@ impl Mode {
     /// `sync_prefix_input_source` (gated by `switch_ascii_input_source_in_prefix`) so multi-level
     /// prefix commands keep ASCII until they return to the terminal.
     ///
-    /// Known limitation: `Navigator`'s search box is also held on ASCII, since this `Mode`-level
-    /// predicate can't see `search_focused` (non-ASCII filtering there would need a runtime check).
+    /// Known limitation: the search boxes in `Navigator` and `KeybindHelp` are also held on ASCII,
+    /// since this `Mode`-level predicate can't see `search_focused` (non-ASCII filtering there
+    /// would need a runtime check).
     pub(crate) fn wants_ascii_input(self) -> bool {
         matches!(
             self,
@@ -1381,8 +1382,11 @@ pub struct ProductAnnouncementState {
     pub preview: bool,
 }
 
+#[derive(Default)]
 pub struct KeybindHelpState {
     pub scroll: u16,
+    pub query: String,
+    pub search_focused: bool,
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -1818,7 +1822,7 @@ impl AppState {
             name_input_replace_on_type: false,
             release_notes: None,
             product_announcement: None,
-            keybind_help: KeybindHelpState { scroll: 0 },
+            keybind_help: KeybindHelpState::default(),
             navigator: NavigatorState::default(),
             copy_mode: None,
             workspace_scroll: 0,