fix(chart): pass series index to data-table keys (#1150)

crates/chart/src/render/table.rs

@@ -70,7 +70,7 @@ pub(super) fn draw(ctx: &mut Ctx, chart: &Chart, data: &ChartData, plot: Bx, lay
         let y = top + (layout.headers as f32 + i as f32 + 0.5) * layout.row_height;
         let name_x = if settings.show_keys { x0 + 25.0 } else { x0 + 4.0 };
         if settings.show_keys {
-            let swatch = match plot_kind(chart, series) {
+            let swatch = match plot_kind(chart, series, i) {
                 ChartKind::Line | ChartKind::LineStacked => Swatch::Line,
                 ChartKind::LineMarkers => Swatch::LineMarker,
                 _ => Swatch::Box,

crates/chart/src/tests/data_table.rs

@@ -1,6 +1,35 @@
 use super::*;
 use gridcraft_model::ChartDataTable;
 
+#[test]
+fn combo_table_keys_use_each_series_index() {
+    let mut c = chart(ChartKind::Combo);
+    c.legend = LegendPos::None;
+    c.data_labels = false;
+    c.data_table = Some(ChartDataTable::default());
+    let mut d = sample(c.kind);
+    // The public renderer also accepts Combo series: the first defaults to columns, later ones to lines.
+    for s in &mut d.series {
+        s.kind = ChartKind::Combo;
+    }
+    let p = render(&c, &d, 900.0, 500.0, &ApproxMeasure);
+    assert_sane(&p, 900.0, 500.0);
+    let header_y = p
+        .iter()
+        .find_map(|p| match p {
+            Prim::Text { text, y, .. } if text == "Q1" => Some(*y),
+            _ => None,
+        })
+        .unwrap();
+    for (i, s) in d.series.iter().enumerate() {
+        let boxes = p.iter().filter(|p| matches!(p, Prim::Rect { y, fill: Some(f), .. } if *f == s.color && *y > header_y)).count();
+        let lines =
+            p.iter().filter(|p| matches!(p, Prim::Line { pts, color, .. } if *color == s.color && pts.iter().all(|p| p[1] > header_y))).count();
+        assert_eq!(boxes, usize::from(i == 0), "series {i}: column key");
+        assert_eq!(lines, usize::from(i > 0), "series {i}: line key");
+    }
+}
+
 #[test]
 fn tables_draw_source_values_for_every_supported_chart_kind() {
     for kind in ALL_KINDS {