feat(cap-detect): show top 3 dominant colors + mixed average

lib/main.dart

@@ -435,6 +435,7 @@ class _MosaicHomePageState extends State<MosaicHomePage>
       detected = {
         'dominantColor': fallbackColor,
         'averageColor': fallbackColor,
+        'topDominantColors': [fallbackColor],
         'usedFallback': true,
         'circleX': imageW / 2,
         'circleY': imageH / 2,
@@ -1290,6 +1291,7 @@ class _CapPhotoReviewPageState extends State<_CapPhotoReviewPage> {
 
   late Color _dominantColor;
   late Color _averageColor;
+  late List<Color> _topDominantColors;
   late Uint8List _previewBytes;
   late bool _usedFallback;
   late double _imageW;
@@ -1310,6 +1312,10 @@ class _CapPhotoReviewPageState extends State<_CapPhotoReviewPage> {
     final detected = widget.detected;
     _dominantColor = Color(detected['dominantColor'] as int);
     _averageColor = Color(detected['averageColor'] as int);
+    _topDominantColors = ((detected['topDominantColors'] as List?) ??
+            [detected['dominantColor']])
+        .map((e) => Color(e as int))
+        .toList(growable: false);
     _previewBytes = detected['previewPng'] as Uint8List;
     _usedFallback = detected['usedFallback'] as bool? ?? false;
     _imageW = (detected['imageW'] as num).toDouble();
@@ -1385,6 +1391,10 @@ class _CapPhotoReviewPageState extends State<_CapPhotoReviewPage> {
       if (localToken != _recalcToken) return;
       _dominantColor = Color(adjusted['dominantColor'] as int);
       _averageColor = Color(adjusted['averageColor'] as int);
+      _topDominantColors = ((adjusted['topDominantColors'] as List?) ??
+              [adjusted['dominantColor']])
+          .map((e) => Color(e as int))
+          .toList(growable: false);
       _previewBytes = adjusted['previewPng'] as Uint8List;
       _selected = _mode == ColorExtractionMode.dominant
           ? _dominantColor
@@ -1398,6 +1408,7 @@ class _CapPhotoReviewPageState extends State<_CapPhotoReviewPage> {
       const fallback = Colors.orange;
       _dominantColor = fallback;
       _averageColor = fallback;
+      _topDominantColors = [fallback];
       _selected = fallback;
       _hexCtrl.text = _colorToHexStatic(_selected);
     }
@@ -1478,6 +1489,39 @@ class _CapPhotoReviewPageState extends State<_CapPhotoReviewPage> {
                 setState(() {});
               },
             ),
+            const SizedBox(height: 8),
+            Text(
+              'Dominante Farben (Anteil) + Durchschnitt:',
+              style: Theme.of(context).textTheme.bodySmall,
+            ),
+            const SizedBox(height: 6),
+            Wrap(
+              spacing: 8,
+              runSpacing: 8,
+              children: [
+                for (int i = 0; i < _topDominantColors.length; i++)
+                  _ColorPickChip(
+                    label: 'D${i + 1}',
+                    color: _topDominantColors[i],
+                    onTap: () {
+                      setState(() {
+                        _selected = _topDominantColors[i];
+                        _hexCtrl.text = _colorToHexStatic(_selected);
+                      });
+                    },
+                  ),
+                _ColorPickChip(
+                  label: 'Mix',
+                  color: _averageColor,
+                  onTap: () {
+                    setState(() {
+                      _selected = _averageColor;
+                      _hexCtrl.text = _colorToHexStatic(_selected);
+                    });
+                  },
+                ),
+              ],
+            ),
             Slider(
               value: _circleR,
               min: 0.08,
@@ -1568,6 +1612,50 @@ String _colorToHexStatic(Color color) {
   return '#${color.toARGB32().toRadixString(16).substring(2).toUpperCase()}';
 }
 
+class _ColorPickChip extends StatelessWidget {
+  final String label;
+  final Color color;
+  final VoidCallback onTap;
+
+  const _ColorPickChip({
+    required this.label,
+    required this.color,
+    required this.onTap,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    return InkWell(
+      borderRadius: BorderRadius.circular(20),
+      onTap: onTap,
+      child: Container(
+        padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 6),
+        decoration: BoxDecoration(
+          color: Colors.white.withValues(alpha: 0.65),
+          borderRadius: BorderRadius.circular(20),
+          border: Border.all(color: Colors.black12),
+        ),
+        child: Row(
+          mainAxisSize: MainAxisSize.min,
+          children: [
+            Container(
+              width: 16,
+              height: 16,
+              decoration: BoxDecoration(
+                color: color,
+                borderRadius: BorderRadius.circular(5),
+                border: Border.all(color: Colors.black26),
+              ),
+            ),
+            const SizedBox(width: 6),
+            Text(label),
+          ],
+        ),
+      ),
+    );
+  }
+}
+
 class _AeroBackgroundAccents extends StatelessWidget {
   const _AeroBackgroundAccents();
 
@@ -2186,9 +2274,11 @@ Map<String, dynamic> _generateMosaicIsolate(Map<String, dynamic> request) {
 Map<String, dynamic> _extractCapFromPhotoIsolate(Uint8List sourceBytes) {
   final decoded = img.decodeImage(sourceBytes);
   if (decoded == null) {
+    final fallback = Colors.orange.toARGB32();
     return {
-      'dominantColor': Colors.orange.toARGB32(),
+      'dominantColor': fallback,
-      'averageColor': Colors.orange.toARGB32(),
+      'averageColor': fallback,
+      'topDominantColors': [fallback],
       'usedFallback': true,
       'circleX': 0.5,
       'circleY': 0.5,
@@ -2233,6 +2323,7 @@ Map<String, dynamic> _extractCapFromPhotoIsolate(Uint8List sourceBytes) {
   return {
     'dominantColor': stats.dominantArgb,
     'averageColor': stats.averageArgb,
+    'topDominantColors': stats.topDominantArgbs,
     'usedFallback': usedFallback,
     'circleX': upscaledCircle.cx,
     'circleY': upscaledCircle.cy,
@@ -2248,9 +2339,11 @@ Map<String, dynamic> _extractCapFromAdjustedCircleIsolate(
   final sourceBytes = request['sourceBytes'] as Uint8List;
   final decoded = img.decodeImage(sourceBytes);
   if (decoded == null) {
+    final fallback = Colors.orange.toARGB32();
     return {
-      'dominantColor': Colors.orange.toARGB32(),
+      'dominantColor': fallback,
-      'averageColor': Colors.orange.toARGB32(),
+      'averageColor': fallback,
+      'topDominantColors': [fallback],
       'previewPng': Uint8List.fromList(
           img.encodePng(img.Image(width: 1, height: 1), level: 1)),
     };
@@ -2296,6 +2389,7 @@ Map<String, dynamic> _extractCapFromAdjustedCircleIsolate(
   return {
     'dominantColor': stats.dominantArgb,
     'averageColor': stats.averageArgb,
+    'topDominantColors': stats.topDominantArgbs,
     'previewPng': Uint8List.fromList(img.encodePng(preview, level: 1)),
   };
 }
@@ -2445,7 +2539,11 @@ _CapColorStats _sampleCapColors(img.Image image, _DetectedCircle circle) {
 
   if (samples.isEmpty) {
     final fallback = const Color(0xFFFF9800).toARGB32();
-    return _CapColorStats(averageArgb: fallback, dominantArgb: fallback);
+    return _CapColorStats(
+      averageArgb: fallback,
+      dominantArgb: fallback,
+      topDominantArgbs: [fallback],
+    );
   }
 
   final lumValues = samples.map((s) => s.luminance).toList()..sort();
@@ -2461,9 +2559,14 @@ _CapColorStats _sampleCapColors(img.Image image, _DetectedCircle circle) {
   final usable = filtered.isEmpty ? samples : filtered;
 
   final avg = _weightedAverage(usable);
-  final dominant = _weightedDominant(usable);
+  final topDominant = _weightedDominantTop(usable, 3);
+  final dominant = topDominant.first;
 
-  return _CapColorStats(averageArgb: avg, dominantArgb: dominant);
+  return _CapColorStats(
+    averageArgb: avg,
+    dominantArgb: dominant,
+    topDominantArgbs: topDominant,
+  );
 }
 
 void _drawCircle(img.Image image, double cx, double cy, double r) {
@@ -2499,8 +2602,13 @@ class _DetectedCircle {
 class _CapColorStats {
   final int averageArgb;
   final int dominantArgb;
+  final List<int> topDominantArgbs;
 
-  const _CapColorStats({required this.averageArgb, required this.dominantArgb});
+  const _CapColorStats({
+    required this.averageArgb,
+    required this.dominantArgb,
+    required this.topDominantArgbs,
+  });
 }
 
 class _ColorSample {
@@ -2561,7 +2669,7 @@ int _weightedAverage(List<_ColorSample> samples) {
   ).toARGB32();
 }
 
-int _weightedDominant(List<_ColorSample> samples) {
+List<int> _weightedDominantTop(List<_ColorSample> samples, int count) {
   final bins = <int, _WeightedRgb>{};
   for (final s in samples) {
     final hsv = _rgbToHsv(s.r, s.g, s.b);
@@ -2573,18 +2681,25 @@ int _weightedDominant(List<_ColorSample> samples) {
     bucket.add(s, s.weight);
   }
 
-  _WeightedRgb? best;
+  if (bins.isEmpty) return [_weightedAverage(samples)];
-  for (final b in bins.values) {
-    if (best == null || b.weight > best.weight) best = b;
-  }
-  if (best == null || best.weight <= 0) return _weightedAverage(samples);
 
+  final sorted = bins.values.toList()
+    ..sort((a, b) => b.weight.compareTo(a.weight));
+
+  final take = math.max(1, math.min(count, sorted.length));
+  return sorted.take(take).map((b) {
+    if (b.weight <= 0) return _weightedAverage(samples);
     return Color.fromARGB(
       255,
-    (best.r / best.weight).round().clamp(0, 255),
+      (b.r / b.weight).round().clamp(0, 255),
-    (best.g / best.weight).round().clamp(0, 255),
+      (b.g / b.weight).round().clamp(0, 255),
-    (best.b / best.weight).round().clamp(0, 255),
+      (b.b / b.weight).round().clamp(0, 255),
     ).toARGB32();
+  }).toList(growable: false);
+}
+
+int _weightedDominant(List<_ColorSample> samples) {
+  return _weightedDominantTop(samples, 1).first;
 }
 
 List<double> _rgbToHsv(int r, int g, int b) {