Feature/stacked panel dual plot

qa.sh

@@ -399,6 +399,51 @@ assert_not_contains "J/picky-esc2"  "Space toggle"
 
 quit
 
+# ── Suite J2: Dual-panel plot mode ─────────────────────────────────────────────
+echo ""
+echo "=== Suite J2: Dual-panel plot mode ==="
+
+start_app "tests/fixtures/orders.csv"
+
+# J2-1: assign total_amount to panel 1 (pre-selected by p), quantity to panel 2
+send "lllllllll"          # total_amount (col 9)
+send "p" 0.25             # PlotPickY: total_amount pre-selected in y_cols
+assert_contains "J2/picky-mode" "P1"  # status bar shows P1/P2 labels
+
+key Left 0.15
+key Left 0.15             # navigate to quantity (col 7)
+send "2" 0.25             # toggle quantity into y2_cols (panel 2)
+assert_contains "J2/p2-assigned" "quantity"  # quantity appears in P2 status
+
+# J2-2: guard: pressing 2 again on quantity removes it from y2 (toggle off)
+# navigate back to total_amount — pressing 2 on it (the only y1 col) must be a no-op
+send "ll"                 # back to total_amount (col 9)
+send "2" 0.15             # this would drain y_cols — must be refused
+assert_contains "J2/drain-guard" "total_amount"  # total_amount still in P1
+
+# J2-3: re-navigate to quantity, ensure it is still in P2 (guard didn't corrupt state)
+key Left 0.15
+key Left 0.15             # back to quantity
+assert_contains "J2/p2-intact" "quantity"
+
+# J2-4: press i to plot against row index
+send "i" 0.40
+assert_contains "J2/panel1-title" "total_amount"   # panel 1 chart title
+assert_contains "J2/panel2-title" "quantity"       # panel 2 chart title
+
+# J2-5: t cycles Line → Bar only (no Histogram) in dual mode
+send "t" 0.25
+assert_contains     "J2/dual-bar"     "Bar"
+assert_not_contains "J2/dual-no-hist" "Histogram"
+send "t" 0.25
+assert_contains     "J2/dual-line"    "Line"
+
+esc
+sleep 0.15
+assert_contains "J2/dual-exit" "order_id"
+
+quit
+
 # ── Suite K: Help popup ────────────────────────────────────────────────────────
 echo ""
 echo "=== Suite K: Help popup ==="

src/app.rs

@@ -23,6 +23,7 @@ pub struct ColumnProfile {
     pub count: usize,
     pub null_count: usize,
     pub unique: usize,
+    pub sum: Option<f64>,
     pub min: String,
     pub max: String,
     pub mean: Option<f64>,
@@ -69,6 +70,7 @@ pub enum AggFunc {
 #[derive(Default, Clone)]
 pub struct ColumnStats {
     pub count: usize,
+    pub sum: Option<f64>,
     pub min: String,
     pub max: String,
     pub mean: Option<f64>,
@@ -112,6 +114,7 @@ pub struct GroupByState {
 #[derive(Default)]
 pub struct PlotState {
     pub y_cols: Vec<usize>,
+    pub y2_cols: Vec<usize>,
     pub x_col: Option<usize>,
     pub plot_type: PlotType,
 }
@@ -705,12 +708,14 @@ impl App {
             .ok()
             .map(|s| s.value().to_string())
             .unwrap_or_default();
-        let (mean, median) = series
-            .as_series()
+        let s = series.as_series();
+        let sum = s.as_ref().and_then(|s| s.sum::<f64>().ok());
+        let (mean, median) = s
             .map(|s| (s.mean(), s.median()))
             .unwrap_or((None, None));
         ColumnStats {
             count,
+            sum,
             min,
             max,
             mean,
@@ -890,14 +895,17 @@ impl App {
                     .ok()
                     .map(|s| s.value().to_string())
                     .unwrap_or_default();
-                let mean = col.as_series().and_then(|s| s.mean());
-                let median = col.as_series().and_then(|s| s.median());
+                let s = col.as_series();
+                let sum = s.as_ref().and_then(|s| s.sum::<f64>().ok());
+                let mean = s.as_ref().and_then(|s| s.mean());
+                let median = s.and_then(|s| s.median());
                 ColumnProfile {
                     name,
                     dtype,
                     count,
                     null_count,
                     unique,
+                    sum,
                     min,
                     max,
                     mean,
@@ -939,6 +947,15 @@ impl App {
             });
     }
 
+    pub fn is_typing(&self) -> bool {
+        match self.mode {
+            Mode::Search | Mode::Filter => true,
+            Mode::ColumnsView => self.columns_view.searching,
+            Mode::UniqueValues => self.unique_values.searching,
+            _ => false,
+        }
+    }
+
     pub fn plot_type_label(&self) -> &str {
         match self.plot.plot_type {
             PlotType::Line => "Line",

src/app_tests.rs

@@ -659,6 +659,10 @@ mod plot_tests {
     }
 
     fn toggle_y_col(app: &mut App, col: usize) {
+        // mutual exclusion: remove from y2_cols if present
+        if let Some(pos) = app.plot.y2_cols.iter().position(|&c| c == col) {
+            app.plot.y2_cols.remove(pos);
+        }
         if let Some(pos) = app.plot.y_cols.iter().position(|&c| c == col) {
             app.plot.y_cols.remove(pos);
         } else {
@@ -709,6 +713,131 @@ mod plot_tests {
         toggle_y_col(&mut app, 0);
         assert_eq!(app.plot.y_cols, vec![2]);
     }
+
+    #[test]
+    fn test_plot_state_default_y2_cols_empty() {
+        let state = PlotState::default();
+        assert!(state.y2_cols.is_empty());
+    }
+
+    fn toggle_y2_col(app: &mut App, col: usize) {
+        // mutual exclusion: remove from y_cols if present
+        if let Some(pos) = app.plot.y_cols.iter().position(|&c| c == col) {
+            app.plot.y_cols.remove(pos);
+        }
+        // toggle in y2_cols
+        if let Some(pos) = app.plot.y2_cols.iter().position(|&c| c == col) {
+            app.plot.y2_cols.remove(pos);
+        } else {
+            app.plot.y2_cols.push(col);
+        }
+    }
+
+    #[test]
+    fn test_toggle_y2_col_adds_to_y2() {
+        let df = df! { "a" => [1i32], "b" => [2i32] }.unwrap();
+        let mut app = App::new(df, "test.csv".to_string(), crate::theme::default_theme());
+        toggle_y2_col(&mut app, 1);
+        assert_eq!(app.plot.y2_cols, vec![1]);
+        assert!(app.plot.y_cols.is_empty());
+    }
+
+    #[test]
+    fn test_toggle_y2_col_removes_from_y1_if_present() {
+        let df = df! { "a" => [1i32], "b" => [2i32] }.unwrap();
+        let mut app = App::new(df, "test.csv".to_string(), crate::theme::default_theme());
+        app.plot.y_cols = vec![1];
+        toggle_y2_col(&mut app, 1);
+        assert_eq!(app.plot.y2_cols, vec![1]);
+        assert!(
+            app.plot.y_cols.is_empty(),
+            "col should be removed from y_cols"
+        );
+    }
+
+    #[test]
+    fn test_toggle_y2_col_removes_if_already_in_y2() {
+        let df = df! { "a" => [1i32], "b" => [2i32] }.unwrap();
+        let mut app = App::new(df, "test.csv".to_string(), crate::theme::default_theme());
+        app.plot.y2_cols = vec![1];
+        toggle_y2_col(&mut app, 1);
+        assert!(app.plot.y2_cols.is_empty());
+    }
+
+    #[test]
+    fn test_toggle_y1_col_removes_from_y2_if_present() {
+        let df = df! { "a" => [1i32], "b" => [2i32] }.unwrap();
+        let mut app = App::new(df, "test.csv".to_string(), crate::theme::default_theme());
+        app.plot.y2_cols = vec![0];
+        toggle_y_col(&mut app, 0);
+        assert_eq!(app.plot.y_cols, vec![0]);
+        assert!(
+            app.plot.y2_cols.is_empty(),
+            "col should be removed from y2_cols"
+        );
+    }
+}
+
+mod is_typing_tests {
+    use super::*;
+
+    fn make_app() -> App {
+        let df = df! { "a" => [1i32], "b" => [2i32] }.unwrap();
+        App::new(df, "test.csv".to_string(), crate::theme::default_theme())
+    }
+
+    #[test]
+    fn test_normal_mode_not_typing() {
+        let mut app = make_app();
+        app.mode = Mode::Normal;
+        assert!(!app.is_typing());
+    }
+
+    #[test]
+    fn test_search_mode_is_typing() {
+        let mut app = make_app();
+        app.mode = Mode::Search;
+        assert!(app.is_typing());
+    }
+
+    #[test]
+    fn test_filter_mode_is_typing() {
+        let mut app = make_app();
+        app.mode = Mode::Filter;
+        assert!(app.is_typing());
+    }
+
+    #[test]
+    fn test_columns_view_not_searching_not_typing() {
+        let mut app = make_app();
+        app.mode = Mode::ColumnsView;
+        app.columns_view.searching = false;
+        assert!(!app.is_typing());
+    }
+
+    #[test]
+    fn test_columns_view_searching_is_typing() {
+        let mut app = make_app();
+        app.mode = Mode::ColumnsView;
+        app.columns_view.searching = true;
+        assert!(app.is_typing());
+    }
+
+    #[test]
+    fn test_unique_values_not_searching_not_typing() {
+        let mut app = make_app();
+        app.mode = Mode::UniqueValues;
+        app.unique_values.searching = false;
+        assert!(!app.is_typing());
+    }
+
+    #[test]
+    fn test_unique_values_searching_is_typing() {
+        let mut app = make_app();
+        app.mode = Mode::UniqueValues;
+        app.unique_values.searching = true;
+        assert!(app.is_typing());
+    }
 }
 
 mod parse_operator_tests {

src/browser/events.rs

@@ -57,8 +57,11 @@ pub fn run_browser_app(
                 continue;
             }
 
-            // T (uppercase) opens the picker.
-            if key.code == event::KeyCode::Char('T') {
+            // T (uppercase) opens the picker — but not when the viewer is accepting text input
+            // (Search, Filter, ColumnsView/UniqueValues in search sub-mode).
+            let viewer_typing = app.focus == Focus::Viewer
+                && app.viewer.as_ref().map(|v| v.is_typing()).unwrap_or(false);
+            if key.code == event::KeyCode::Char('T') && !viewer_typing {
                 app.picker = Some(crate::theme_picker::ThemePicker::open(app.theme));
                 continue;
             }

src/events.rs

@@ -90,6 +90,7 @@ pub(crate) fn dispatch_viewer_key(app: &mut App, key: &event::KeyEvent) {
             event::KeyCode::Char('=') => app.autofit_all_columns(),
             event::KeyCode::Char('p') if !app.df.is_empty() => {
                 app.plot.y_cols.clear();
+                app.plot.y2_cols.clear();
                 if let Some(col) = app.state.selected_column() {
                     app.plot.y_cols.push(col);
                 }
@@ -150,13 +151,34 @@ pub(crate) fn dispatch_viewer_key(app: &mut App, key: &event::KeyEvent) {
             event::KeyCode::Right | event::KeyCode::Char('l') => app.select_next_column(),
             event::KeyCode::Char(' ') => {
                 if let Some(col) = app.state.selected_column() {
+                    // mutual exclusion: remove from y2 if present
+                    if let Some(pos) = app.plot.y2_cols.iter().position(|&c| c == col) {
+                        app.plot.y2_cols.remove(pos);
+                    }
                     if let Some(pos) = app.plot.y_cols.iter().position(|&c| c == col) {
                         app.plot.y_cols.remove(pos);
                     } else {
                         app.plot.y_cols.push(col);
                     }
                 }
             }
+            event::KeyCode::Char('2') => {
+                if let Some(col) = app.state.selected_column() {
+                    // refuse if this would leave y_cols empty
+                    let already_in_y1 = app.plot.y_cols.contains(&col);
+                    let would_drain_y1 = already_in_y1 && app.plot.y_cols.len() == 1;
+                    if !would_drain_y1 {
+                        if let Some(pos) = app.plot.y_cols.iter().position(|&c| c == col) {
+                            app.plot.y_cols.remove(pos);
+                        }
+                        if let Some(pos) = app.plot.y2_cols.iter().position(|&c| c == col) {
+                            app.plot.y2_cols.remove(pos);
+                        } else {
+                            app.plot.y2_cols.push(col);
+                        }
+                    }
+                }
+            }
             event::KeyCode::Enter if !app.plot.y_cols.is_empty() => {
                 app.mode = Mode::PlotPickX;
             }
@@ -166,6 +188,7 @@ pub(crate) fn dispatch_viewer_key(app: &mut App, key: &event::KeyEvent) {
             }
             event::KeyCode::Esc => {
                 app.plot.y_cols.clear();
+                app.plot.y2_cols.clear();
                 app.mode = Mode::Normal;
             }
             _ => {}
@@ -184,7 +207,7 @@ pub(crate) fn dispatch_viewer_key(app: &mut App, key: &event::KeyEvent) {
         },
         Mode::Plot => match key.code {
             event::KeyCode::Char('t') => {
-                app.plot.plot_type = if app.plot.y_cols.len() > 1 {
+                app.plot.plot_type = if app.plot.y_cols.len() > 1 || !app.plot.y2_cols.is_empty() {
                     match app.plot.plot_type {
                         PlotType::Line => PlotType::Bar,
                         _ => PlotType::Line,