CHANGELOG.md

@@ -8,13 +8,22 @@ and the project aims to follow [Semantic Versioning](https://semver.org/).
 ## [Unreleased]
 
 ### Added
-- **Source-code slides** — a dark "code sheet" with per-language syntax
-  highlighting, stored as a fenced code block.
-- **Charts** — bar, line, and pie chart slides. Data is entered in an in-app grid
-  or imported from CSV; the spec is stored as JSON in a ```chart block. Data can
-  stay inline or be linked to a CSV in a separate `data/` directory. Rendered
-  natively in-app (preview, presenter, PDF, PPTX) and as self-contained SVG in
-  the HTML export.
+- **Source-code slides** — a "code sheet" with per-language syntax highlighting,
+  stored as a fenced code block. Background and text colours are part of the style
+  profile, with a syntax-colouring toggle; turning it off renders the block in a
+  single colour (e.g. green on black for a CRT-terminal look).
+- **Charts** — bar, line, pie, and **spider/radar** chart slides. Data is entered
+  in an in-app grid or imported from CSV; the spec is stored as JSON in a ```chart
+  block. Data can stay inline or be linked to a CSV in a separate `data/`
+  directory. Rendered natively in-app (preview, presenter, PDF, PPTX) and as
+  self-contained SVG in the HTML export.
+  - Optional **min/max**: horizontal reference lines on bar/line charts, or a
+    fixed scale on spider/radar charts shown as a small legend beside the figure.
+  - **Legend hover** highlights the matching series (or pie slice). Line-chart
+    tooltips attach to the dot under the cursor (showing every overlapping dot),
+    and spider/radar points show a tooltip on hover too.
+- **Custom theme colours** — every style-profile colour can be entered as a custom
+  hex value in addition to the presets.
 - **Per-slide TLP classification** — each slide can carry its own Traffic Light
   Protocol level; slides classified stricter than the level the deck is shown at
   are withheld when presenting and exporting.

README.md

@@ -9,8 +9,8 @@ Built with Flutter for macOS, Windows, and Linux.
 ## Features
 
 - **Structured slide editors** — dedicated editors per slide type: title, bullets, two-column bullets, bullets + image, single/two images, quote, table, section divider, image-only, video, audio, source code, charts, and free-form Markdown.
-- **Source-code slides** — a dark "code sheet" with syntax highlighting per language, stored as a fenced code block.
-- **Charts** — bar, line, and pie charts rendered natively (preview, presenter, PDF, PPTX) and as self-contained SVG in the HTML export. Data is entered in an in-app grid or imported from CSV; the spec is stored as JSON in the Markdown, with optional linking to a CSV kept in a tidy `data/` directory.
+- **Source-code slides** — a "code sheet" with per-language syntax highlighting, stored as a fenced code block. Background and text colours come from the style profile, with an optional syntax-colouring toggle (turn it off for a single-colour, CRT-terminal look).
+- **Charts** — bar, line, pie, and spider/radar charts rendered natively (preview, presenter, PDF, PPTX) and as self-contained SVG in the HTML export. Data is entered in an in-app grid or imported from CSV; the spec is stored as JSON in the Markdown, with optional linking to a CSV kept in a tidy `data/` directory. Optional min/max draw reference lines (bar/line) or fix the scale (radar); legend hover highlights a series, and line tooltips pick the dot under the cursor.
 - **Live preview** — see each slide rendered as you edit, with inline Markdown, footers, and TLP (Traffic Light Protocol) marking. Free-Markdown slides render fenced code with syntax highlighting and `$…$` / `$$…$$` LaTeX math.
 - **Traffic Light Protocol** — a deck-wide classification plus an optional **per-slide TLP level**; slides classified stricter than the level the deck is shown at are automatically withheld, both when presenting and exporting.
 - **Fullscreen presenter** — keyboard-driven navigation, presenter view, blank screen, auto-advance, and a slide-grid overview.
@@ -20,7 +20,7 @@ Built with Flutter for macOS, Windows, and Linux.
 - **Import / export** — round-trips Marp Markdown, imports existing slides, and exports to PDF, PPTX (with speaker notes), and a self-contained offline HTML deck (code highlighting, math, charts, and mermaid diagrams render in the browser). Decks are saved as a self-contained package with copied assets.
 - **Productivity** — find & replace, slide finder, undo/redo, skip-slide state, multi-select with bulk copy-to-another-deck / delete / skip, and tabbed multi-deck editing. `Ctrl/Cmd+O` opens, `Ctrl/Cmd+S` saves.
 - **Crash recovery** — automatic snapshots so work survives an unexpected exit.
-- **Theming** — customizable deck style profiles and app appearance (including a dark interface), a bundled Marp CSS theme (`assets/themes/ocideck.css`), and a bundled EB Garamond font (no network fetch).
+- **Theming** — customizable deck style profiles (deck and source-code colours via presets or custom hex, fonts, logo, footer) and app appearance (including a dark interface), a bundled Marp CSS theme (`assets/themes/ocideck.css`), and a bundled EB Garamond font (no network fetch).
 - **Localized** — Dutch, English, Italian, German, French, Spanish, Frisian, and Papiamento.
 
 ## Requirements

docs/FILE_FORMAT.md

@@ -135,6 +135,9 @@ JSON heeft deze velden (met standaardwaarden):
 | `titleBackgroundColor` | `#1C2B47` | Achtergrond titelslide. |
 | `titleTextColor` | `#FFFFFF` | Tekst op titel-/sectieslide. |
 | `sectionBackgroundColor` | `#2E7D64` | Achtergrond sectieslide. |
+| `codeBackgroundColor` | `#282C34` | Achtergrond van broncode-slides. |
+| `codeTextColor` | `#ABB2BF` | Tekstkleur van broncode-slides. |
+| `codeHighlightSyntax` | `true` | Syntaxkleuring aan/uit. Uit = alles in één kleur (bijv. groen op zwart voor een CRT-look). |
 | `logoPath` | `null` | Pad naar logo (relatief in `logos/`). |
 | `logoPosition` | `bottom-right` | `top-left`/`top-right`/`bottom-left`/`bottom-right`. |
 | `logoSize` | `96` | Logogrootte in px. |
@@ -314,15 +317,31 @@ openen wordt die weer ingelezen.
 ````markdown
 ```chart
 {
-  "type": "bar",            // bar | line | pie
+  "type": "bar",            // bar | line | pie | radar
   "title": "Omzet",
   "source": "data/omzet.csv",  // optioneel; anders inline x/series
   "x": ["Q1", "Q2"],
-  "series": [ { "name": "2025", "data": [10, 14] } ]
+  "rowColors": ["#003399", "#FFCC00"],  // optioneel; kleur per label (cirkel/radar)
+  "minBound": 0,            // optioneel; niet bij pie
+  "maxBound": 20,           // optioneel; niet bij pie
+  "series": [ { "name": "2025", "data": [10, 14], "color": "#2563EB" } ]
 }
 ```
 ````
 
+Velden:
+
+- `type` — `bar`, `line`, `pie` of `radar` (spider). Standaard `bar`.
+- `x` — labels; bij `pie`/`radar` zijn dit de segmenten/assen (radar heeft er
+  minstens drie nodig).
+- `series` — genoemde reeksen met `data` (uitgelijnd op `x`) en optioneel een
+  `color` (hex). `pie` toont maximaal de eerste twee reeksen.
+- `rowColors` — optionele kleur per label (gebruikt door `pie`/`radar`).
+- `minBound` / `maxBound` — optioneel en alleen voor niet-`pie`. Bij `bar`/`line`
+  zijn het horizontale **referentielijnen**; bij `radar` bepalen ze de **schaal**
+  (binnenste/buitenste ring) met een gelijkmatige verdeling. Worden weggelaten
+  bij `pie`.
+
 ### Afbeeldingsgrootte (`imageSize`)
 Eén integer-veld met typeafhankelijke betekenis: bij `image`/`title`/`quote` het
 achtergrond-percentage (`![bg N%]`), bij `split` de paneelbreedte (geklemd

docs/USER_GUIDE.md

@@ -20,8 +20,9 @@ Marp tools.
 
 Add a slide and pick a type: **title**, **section** divider, **bullets**, **two
 bullet columns**, **bullets + image**, **two images**, **large image**, **video**,
-**audio**, **quote**, **table**, **source code**, **chart**, and **free Markdown**.
-Each type has a dedicated editor on the left and a live preview on the right.
+**audio**, **quote**, **table**, **source code**, **chart** (bar, line, pie, or
+spider/radar), and **free Markdown**. Each type has a dedicated editor on the left
+and a live preview on the right.
 
 Text fields support inline Markdown (`**bold**`, `*italic*`, `` `code` ``,
 `[links](…)`). Free-Markdown slides also render fenced code with syntax
@@ -30,19 +31,30 @@ highlighting and `$…$` / `$$…$$` LaTeX math.
 ### Source-code slides
 
 Choose a programming language for syntax highlighting (or "plain text") and paste
-your code. It renders as a dark "code sheet". Stored as a fenced code block in the
-Markdown.
+your code. It renders as a "code sheet" whose background and text colour come from
+the active **style profile**. Turn **syntax colouring** off to show the whole block
+in a single colour — e.g. bright green on black for a classic CRT-terminal look.
+Stored as a fenced code block in the Markdown.
 
 ### Charts
 
-Pick a type (**bar**, **line**, **pie**) and a title, then enter data in the grid:
-the first column is the labels, each further column is a named series. Use **Row**
-and **Series** to add data; the small ✕ removes a row/column.
+Pick a type (**bar**, **line**, **pie**, or **spider/radar**) and a title, then
+enter data in the grid: the first column is the labels, each further column is a
+named series. Use **Row** and **Series** to add data; the small ✕ removes a
+row/column. Each series and (for pie/radar) each label can be given its own colour.
 
 - **CSV import** — click **CSV importeren**. You can either keep the data **in the
   slide** (inline) or store it **as a CSV file**. A linked CSV lives in the deck's
   `data/` directory and stays the source of truth (edit it in a spreadsheet); the
   grid then shows it read-only until you **Ontkoppelen** (unlink).
+- **Min/max** (optional, bar/line/radar) — on bar and line charts these draw
+  horizontal **reference lines**; on a spider/radar chart they fix the **scale**
+  (centre to outer ring), shown as evenly spaced values in a small legend beside
+  the chart. Leave them empty to scale automatically.
+- **Reading values** — hovering a legend entry highlights its series (or pie
+  slice). On a line chart the tooltip belongs to the dot under the cursor and
+  shows every overlapping dot at once; on a spider/radar chart hovering a point
+  shows its value in a tooltip too.
 - Charts render in the preview, presenter, PDF, and PPTX, and as inline SVG in the
   HTML export.
 
@@ -100,8 +112,10 @@ Export to:
 
 ## Theming and language
 
-- **Style profiles** control deck colours, fonts, logo, and footer. The bundled
-  Marp theme is `assets/themes/ocideck.css`.
+- **Style profiles** control deck colours (including the source-code background and
+  text, with an optional syntax-colouring toggle), fonts, logo, and footer. Every
+  colour can be picked from the presets or entered as a custom hex value. The
+  bundled Marp theme is `assets/themes/ocideck.css`.
 - **App appearance** (including a dark interface) is configurable in settings.
 - The interface is available in Dutch, English, Italian, German, French, Spanish,
   Frisian, and Papiamento.

lib/services/marp_html_service.dart

@@ -480,12 +480,19 @@ class MarpHtmlService {
       );
     }
 
-    // Scale labels up the top spoke: lo at the centre, hi at the outer ring.
-    for (var k = 0; k <= ticks; k++) {
+    // Scale legend on the right: hi at the top down to lo at the bottom, so the
+    // figure itself stays clean.
+    final legendX = cx + radius + 30;
+    for (var k = ticks; k >= 0; k--) {
       final value = lo + span * k / ticks;
-      final y = cy - radius * k / ticks;
-      b.write(
-        '<text x="${cx + 6}" y="${y - 2}" font-size="11" '
+      final y = (cy - radius) + (2 * radius) * (ticks - k) / ticks;
+      b
+        ..write(
+          '<line x1="$legendX" y1="$y" x2="${legendX + 8}" y2="$y" '
+          'stroke="#cbd5e1" stroke-width="1"/>',
+        )
+        ..write(
+          '<text x="${legendX + 12}" y="${y + 4}" font-size="12" '
           'fill="#94a3b8">${_num(value)}</text>',
         );
     }

lib/widgets/slides/slide_preview.dart

@@ -2212,6 +2212,10 @@ class _ChartPreviewState extends State<_ChartPreview> {
   /// slice (category) index for pie charts. Null when nothing is hovered.
   int? _hovered;
 
+  /// The radar vertex under the pointer, used to draw its tooltip. Null when not
+  /// hovering a point.
+  ({int series, int entry, double value, Offset offset})? _radarTouch;
+
   void _setHover(int? index) {
     if (_hovered != index) setState(() => _hovered = index);
   }
@@ -2894,27 +2898,25 @@ class _ChartPreviewState extends State<_ChartPreview> {
     }
     final grid = textColor.withValues(alpha: 0.18);
     final scale = radarScale(spec);
-    final bg = _hexColor(profile.slideBackgroundColor);
 
     return Padding(
-      padding: EdgeInsets.symmetric(horizontal: w * 0.06, vertical: w * 0.012),
+      padding: EdgeInsets.symmetric(horizontal: w * 0.03, vertical: w * 0.012),
       child: LayoutBuilder(
         builder: (context, constraints) {
-          // A square keeps fl_chart's centre/radius predictable so the tick
-          // labels we overlay line up exactly with its grid rings.
-          final side = math.min(constraints.maxWidth, constraints.maxHeight);
-          final centerOffset = side / 2;
-          final radius = centerOffset * 0.8; // matches RadarChartPainter
-          final tickStyle = _applyFont(
-            font,
-            TextStyle(
-              fontSize: w * 0.012 * _labelScale,
-              color: textColor.withValues(alpha: 0.6),
-              fontWeight: FontWeight.w600,
-            ),
+          // Reserve a slim column on the right for the scale legend, then keep
+          // the chart square so fl_chart's centre/radius stay predictable.
+          final legendWidth = w * 0.075;
+          final available = constraints.maxWidth - legendWidth - w * 0.02;
+          final side = math.max(
+            0.0,
+            math.min(available, constraints.maxHeight),
           );
 
-          return Center(
+          return Row(
+            crossAxisAlignment: CrossAxisAlignment.center,
+            children: [
+              Expanded(
+                child: Center(
                   child: SizedBox(
                     width: side,
                     height: side,
@@ -2929,7 +2931,8 @@ class _ChartPreviewState extends State<_ChartPreview> {
                                     dataEntries: [
                                       for (var xi = 0; xi < spec.x.length; xi++)
                                         RadarEntry(
-                                    value: xi < spec.series[si].data.length
+                                          value:
+                                              xi < spec.series[si].data.length
                                               ? spec.series[si].data[xi]
                                               : 0,
                                         ),
@@ -2942,15 +2945,19 @@ class _ChartPreviewState extends State<_ChartPreview> {
                                       spec.series[si],
                                       si,
                                     ),
-                              borderWidth: w * (_hovered == si ? 0.0055 : 0.0035),
-                              entryRadius: w * (_hovered == si ? 0.006 : 0.004),
+                                    borderWidth:
+                                        w * (_hovered == si ? 0.0055 : 0.0035),
+                                    entryRadius:
+                                        w * (_hovered == si ? 0.006 : 0.004),
                                   ),
-                          // Invisible anchor pinning the scale to [lo, hi] so the
-                          // rings — and our labels — represent a fixed scale.
+                                // Invisible anchor pinning the scale to [lo, hi]
+                                // so the rings represent a fixed scale.
                                 RadarDataSet(
                                   dataEntries: [
                                     for (var xi = 0; xi < spec.x.length; xi++)
-                                RadarEntry(value: xi == 0 ? scale.hi : scale.lo),
+                                      RadarEntry(
+                                        value: xi == 0 ? scale.hi : scale.lo,
+                                      ),
                                   ],
                                   fillColor: Colors.transparent,
                                   borderColor: Colors.transparent,
@@ -2965,8 +2972,8 @@ class _ChartPreviewState extends State<_ChartPreview> {
                               tickBorderData: BorderSide(color: grid, width: 1),
                               tickCount: scale.ticks,
                               isMinValueAtCenter: true,
-                        // Hide fl_chart's own ring numbers; we draw labelled
-                        // ticks ourselves so any min/max scale reads correctly.
+                              // The scale now lives in a side legend, so hide
+                              // fl_chart's in-chart ring numbers.
                               ticksTextStyle: const TextStyle(
                                 color: Colors.transparent,
                                 fontSize: 0.001,
@@ -2985,39 +2992,150 @@ class _ChartPreviewState extends State<_ChartPreview> {
                                       : FontWeight.w500,
                                 ),
                               ),
-                        radarTouchData: RadarTouchData(enabled: false),
+                              radarTouchData: RadarTouchData(
+                                enabled: true,
+                                touchSpotThreshold: (w * 0.02).clamp(8.0, 24.0)
+                                    .toDouble(),
+                                mouseCursorResolver: (event, response) =>
+                                    _radarSpotFrom(response, spec) == null
+                                    ? SystemMouseCursors.basic
+                                    : SystemMouseCursors.click,
+                                touchCallback: (event, response) {
+                                  final next =
+                                      event.isInterestedForInteractions
+                                      ? _radarSpotFrom(response, spec)
+                                      : null;
+                                  if (next != _radarTouch) {
+                                    setState(() => _radarTouch = next);
+                                  }
+                                },
+                              ),
                             ),
                             duration: Duration.zero,
                           ),
                         ),
-                  // Evenly spaced scale labels up the top spoke: lo at centre,
-                  // hi at the outer ring, with equal steps between.
-                  for (var k = 0; k <= scale.ticks; k++)
-                    Positioned(
-                      left: centerOffset + w * 0.006,
-                      top:
-                          centerOffset -
-                          radius * k / scale.ticks -
-                          w * 0.01 * _labelScale,
+                        if (_radarTouch != null)
+                          _radarTooltip(spec, side, _radarTouch!),
+                      ],
+                    ),
+                  ),
+                ),
+              ),
+              SizedBox(
+                width: legendWidth,
+                child: _radarScaleLegend(scale, textColor),
+              ),
+            ],
+          );
+        },
+      ),
+    );
+  }
+
+  /// Extract the touched real-series vertex from a radar touch response,
+  /// ignoring the invisible scale anchor dataset.
+  ({int series, int entry, double value, Offset offset})? _radarSpotFrom(
+    RadarTouchResponse? response,
+    ChartSpec spec,
+  ) {
+    final spot = response?.touchedSpot;
+    if (spot == null) return null;
+    if (spot.touchedDataSetIndex < 0 ||
+        spot.touchedDataSetIndex >= spec.series.length) {
+      return null; // the anchor dataset, or out of range
+    }
+    return (
+      series: spot.touchedDataSetIndex,
+      entry: spot.touchedRadarEntryIndex,
+      value: spot.touchedRadarEntry.value,
+      offset: spot.offset,
+    );
+  }
+
+  /// A small floating tooltip for the hovered radar vertex, like the other
+  /// charts: the axis label, the series name and the value.
+  Widget _radarTooltip(
+    ChartSpec spec,
+    double side,
+    ({int series, int entry, double value, Offset offset}) touch,
+  ) {
+    final axis = touch.entry >= 0 && touch.entry < spec.x.length
+        ? spec.x[touch.entry]
+        : '';
+    final series = touch.series < spec.series.length
+        ? spec.series[touch.series].name
+        : '';
+    final label = series.isEmpty ? 'Reeks ${touch.series + 1}' : series;
+    final onLeftHalf = touch.offset.dx <= side / 2;
+    return Positioned(
+      left: onLeftHalf ? (touch.offset.dx + w * 0.012) : null,
+      right: onLeftHalf ? null : (side - touch.offset.dx + w * 0.012),
+      top: (touch.offset.dy - w * 0.03).clamp(0.0, math.max(0.0, side - 1)),
       child: IgnorePointer(
+        child: ConstrainedBox(
+          constraints: BoxConstraints(maxWidth: side * 0.6),
           child: Container(
             padding: EdgeInsets.symmetric(
-                            horizontal: w * 0.004,
+              horizontal: w * 0.012,
+              vertical: w * 0.006,
             ),
-                          color: bg.withValues(alpha: 0.7),
+            decoration: BoxDecoration(
+              color: const Color(0xFF0F172A),
+              borderRadius: BorderRadius.circular(w * 0.008),
+              boxShadow: const [
+                BoxShadow(color: Color(0x33000000), blurRadius: 6),
+              ],
+            ),
+            child: Text(
+              '${axis.isEmpty ? '' : '$axis\n'}$label: ${_fmtNum(touch.value)}',
+              maxLines: 3,
+              overflow: TextOverflow.ellipsis,
+              style: _tooltipStyle(),
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+
+  /// Vertical scale legend shown to the right of a radar chart: the tick values
+  /// from the outer ring (top) down to the centre (bottom), in a small font.
+  Widget _radarScaleLegend(
+    ({double lo, double hi, int ticks}) scale,
+    Color textColor,
+  ) {
+    final style = _applyFont(
+      font,
+      TextStyle(
+        fontSize: w * 0.012 * _labelScale,
+        color: textColor.withValues(alpha: 0.62),
+        fontWeight: FontWeight.w600,
+      ),
+    );
+    final tickColor = textColor.withValues(alpha: 0.3);
+    return Column(
+      mainAxisAlignment: MainAxisAlignment.center,
+      crossAxisAlignment: CrossAxisAlignment.start,
+      children: [
+        for (var k = scale.ticks; k >= 0; k--) ...[
+          if (k != scale.ticks) SizedBox(height: w * 0.018 * _labelScale),
+          Row(
+            mainAxisSize: MainAxisSize.min,
+            children: [
+              Container(width: w * 0.012, height: 1, color: tickColor),
+              SizedBox(width: w * 0.006),
+              Flexible(
                 child: Text(
                   _fmtNum(scale.lo + (scale.hi - scale.lo) * k / scale.ticks),
-                            style: tickStyle,
-                          ),
-                        ),
+                  style: style,
+                  maxLines: 1,
+                  overflow: TextOverflow.ellipsis,
                 ),
               ),
             ],
           ),
-            ),
-          );
-        },
-      ),
+        ],
+      ],
     );
   }
 

test/chart_preview_test.dart

@@ -189,8 +189,8 @@ void main() {
     // A crowded stack uses a smaller font than a single tooltip.
     final single = touch.touchTooltipData.getTooltipItems([spots.first]);
     expect(
-      items[0]!.textStyle!.fontSize!,
-      lessThan(single.single!.textStyle!.fontSize!),
+      items[0]!.textStyle.fontSize!,
+      lessThan(single.single!.textStyle.fontSize!),
     );
   });
 
@@ -324,12 +324,91 @@ void main() {
     final anchor = radar.data.dataSets.last.dataEntries.map((e) => e.value);
     expect(anchor.reduce((a, b) => a < b ? a : b), 0);
     expect(anchor.reduce((a, b) => a > b ? a : b), 10);
-    // Evenly spaced scale labels are drawn (0..10).
+    // The scale is shown in the side legend (0..10), not painted in the chart.
+    expect(radar.data.ticksTextStyle?.color, Colors.transparent);
     expect(find.text('0'), findsWidgets);
     expect(find.text('10'), findsOneWidget);
     expect(tester.takeException(), isNull);
   });
 
+  testWidgets('radar shows a tooltip for the hovered point', (tester) async {
+    const spec = ChartSpec(
+      type: ChartType.radar,
+      x: ['Snelheid', 'Kracht', 'Uithouding'],
+      series: [
+        ChartSeries(name: 'Alpha', data: [3, 4, 5]),
+        ChartSeries(name: 'Beta', data: [5, 2, 3]),
+      ],
+    );
+
+    await tester.pumpWidget(_host(spec));
+    await tester.pump();
+
+    final radar = tester.widget<RadarChart>(find.byType(RadarChart));
+    final touch = radar.data.radarTouchData;
+    expect(touch.enabled, isTrue);
+
+    // Simulate hovering the second axis of the Beta series.
+    final dataSet = radar.data.dataSets[1];
+    final entry = dataSet.dataEntries[1];
+    touch.touchCallback!(
+      const FlPointerHoverEvent(PointerHoverEvent()),
+      RadarTouchResponse(
+        touchLocation: const Offset(20, 20),
+        touchedSpot: RadarTouchedSpot(
+          dataSet,
+          1,
+          entry,
+          1,
+          const FlSpot(1, 2),
+          const Offset(20, 20),
+        ),
+      ),
+    );
+    await tester.pump();
+
+    expect(find.text('Kracht\nBeta: 2'), findsOneWidget);
+    expect(tester.takeException(), isNull);
+  });
+
+  testWidgets('radar ignores touches on the invisible scale anchor', (
+    tester,
+  ) async {
+    const spec = ChartSpec(
+      type: ChartType.radar,
+      x: ['A', 'B', 'C'],
+      series: [
+        ChartSeries(name: 'Alpha', data: [3, 4, 5]),
+      ],
+    );
+
+    await tester.pumpWidget(_host(spec));
+    await tester.pump();
+
+    final radar = tester.widget<RadarChart>(find.byType(RadarChart));
+    final anchorIndex = radar.data.dataSets.length - 1; // the anchor dataset
+    final anchor = radar.data.dataSets[anchorIndex];
+    radar.data.radarTouchData.touchCallback!(
+      const FlPointerHoverEvent(PointerHoverEvent()),
+      RadarTouchResponse(
+        touchLocation: Offset.zero,
+        touchedSpot: RadarTouchedSpot(
+          anchor,
+          anchorIndex,
+          anchor.dataEntries.first,
+          0,
+          const FlSpot(0, 0),
+          Offset.zero,
+        ),
+      ),
+    );
+    await tester.pump();
+
+    // No tooltip for the anchor: only the legend value "5" exists.
+    expect(find.textContaining(': '), findsNothing);
+    expect(tester.takeException(), isNull);
+  });
+
   testWidgets('radar chart asks for at least three labels', (tester) async {
     const spec = ChartSpec(
       type: ChartType.radar,