chore: Update flutter version for code analysis and fix linter issues. (#737)

Author: panmari

.github/workflows/code-analysis.yml

@@ -24,7 +24,7 @@ jobs:
           distribution: temurin
       - uses: subosito/[email protected]
         with:
-          flutter-version: '3.24.0'
+          flutter-version: '3.27.3'
           cache: true
 
       - name: Install dependencies for google_ml_kit

packages/example/lib/activity_indicator/activity_indicator.dart

@@ -43,7 +43,7 @@ class LoadingIndicator extends StatelessWidget {
   Widget build(BuildContext context) {
     return Container(
         padding: EdgeInsets.all(16),
-        color: Colors.black.withOpacity(0.8),
+        color: Colors.black.withAlpha(204),
         child: Column(
             mainAxisAlignment: MainAxisAlignment.center,
             mainAxisSize: MainAxisSize.min,

packages/example/lib/vision_detector_views/camera_view.dart

@@ -364,7 +364,9 @@ class _CameraViewState extends State<CameraView> {
     // * bgra8888 for iOS
     if (format == null ||
         (Platform.isAndroid && format != InputImageFormat.nv21) ||
-        (Platform.isIOS && format != InputImageFormat.bgra8888)) return null;
+        (Platform.isIOS && format != InputImageFormat.bgra8888)) {
+      return null;
+    }
 
     // since format is constraint to nv21 or bgra8888, both only have one plane
     if (image.planes.length != 1) return null;

packages/example/lib/vision_detector_views/painters/segmentation_painter.dart

@@ -44,7 +44,7 @@ class SegmentationPainter extends CustomPainter {
         ).round();
 
         final double opacity = confidences[(y * width) + x] * 0.5;
-        paint.color = color.withOpacity(opacity);
+        paint.color = color.withAlpha((opacity * 255).round());
         canvas.drawCircle(Offset(tx.toDouble(), ty.toDouble()), 2, paint);
       }
     }

packages/example/lib/vision_detector_views/painters/subject_segmentation_painter.dart

@@ -52,7 +52,7 @@ class SubjectSegmentationPainter extends CustomPainter {
               .round();
 
           final double opacity = confidences[(y * subjectWidth) + x] * 0.5;
-          paint.color = color.withOpacity(opacity);
+          paint.color = color.withAlpha((opacity * 255).round());
           canvas.drawCircle(Offset(tx.toDouble(), ty.toDouble()), 2, paint);
         }
       }