add structure

lib/face/smile_painter.dart

@@ -0,0 +1,138 @@
+import 'dart:ui' as ui show Image;
+import 'dart:math' as Math;
+import 'package:firebase_ml_vision/firebase_ml_vision.dart';
+import 'package:flutter/material.dart';
+
+class FacePaint extends CustomPaint {
+  final CustomPainter painter;
+
+  FacePaint({this.painter}) : super(painter: painter);
+}
+
+class SmilePainter extends CustomPainter {
+  final ui.Image image;
+  final List<Face> faces;
+
+  SmilePainter(this.image, this.faces);
+
+  @override
+  void paint(Canvas canvas, Size size) {
+    if (image != null) {
+      canvas.drawImage(image, Offset.zero, Paint());
+    }
+
+    final paintRectStyle = Paint()
+      ..color = Colors.red
+      ..strokeWidth = 30.0
+      ..style = PaintingStyle.stroke;
+
+    //Draw Body
+    final paint = Paint()..color = Colors.yellow;
+
+    for (var i = 0; i < faces.length; i++) {
+      final radius =
+          Math.min(faces[i].boundingBox.width, faces[i].boundingBox.height) / 2;
+      final center = faces[i].boundingBox.center;
+      final smilePaint = Paint()
+        ..style = PaintingStyle.stroke
+        ..strokeWidth = radius / 8;
+      canvas.drawRect(faces[i].boundingBox, paintRectStyle);
+      canvas.drawCircle(center, radius, paint);
+      canvas.drawArc(
+          Rect.fromCircle(
+              center: center.translate(0, radius / 8), radius: radius / 2),
+          0,
+          Math.pi,
+          false,
+          smilePaint);
+      //Draw the eyes
+      canvas.drawCircle(Offset(center.dx - radius / 2, center.dy - radius / 2),
+          radius / 8, Paint());
+      canvas.drawCircle(Offset(center.dx + radius / 2, center.dy - radius / 2),
+          radius / 8, Paint());
+    }
+  }
+
+  @override
+  bool shouldRepaint(SmilePainter oldDelegate) {
+    return image != oldDelegate.image || faces != oldDelegate.faces;
+  }
+}
+
+class SmilePainterLiveCamera extends CustomPainter {
+  final Size imageSize;
+  final List<Face> faces;
+
+  SmilePainterLiveCamera(this.imageSize, this.faces);
+
+  @override
+  void paint(Canvas canvas, Size size) {
+//    final paintRectStyle = Paint()
+//      ..color = Colors.red
+//      ..strokeWidth = 10.0
+//      ..style = PaintingStyle.stroke;
+
+    final paint = Paint()..color = Colors.yellow;
+
+    for (var i = 0; i < faces.length; i++) {
+      //Scale rect to image size
+      final rect = _scaleRect(
+        rect: faces[i].boundingBox,
+        imageSize: imageSize,
+        widgetSize: size,
+      );
+
+      //Radius for smile circle
+      final radius = Math.min(rect.width, rect.height) / 2;
+
+      //Center of face rect
+      final Offset center = rect.center;
+
+      final smilePaint = Paint()
+        ..style = PaintingStyle.stroke
+        ..strokeWidth = radius / 8;
+
+      //Draw rect border
+      //canvas.drawRect(rect, paintRectStyle);
+
+      //Draw body
+      canvas.drawCircle(center, radius, paint);
+
+      //Draw mouth
+      canvas.drawArc(
+          Rect.fromCircle(
+              center: center.translate(0, radius / 8), radius: radius / 2),
+          0,
+          Math.pi,
+          false,
+          smilePaint);
+
+      //Draw the eyes
+      canvas.drawCircle(Offset(center.dx - radius / 2, center.dy - radius / 2),
+          radius / 8, Paint());
+      canvas.drawCircle(Offset(center.dx + radius / 2, center.dy - radius / 2),
+          radius / 8, Paint());
+    }
+  }
+
+  @override
+  bool shouldRepaint(SmilePainterLiveCamera oldDelegate) {
+    return imageSize != oldDelegate.imageSize || faces != oldDelegate.faces;
+  }
+}
+
+Rect _scaleRect({
+  @required Rect rect,
+  @required Size imageSize,
+  @required Size widgetSize,
+}) {
+  final double scaleX = widgetSize.width / imageSize.width;
+  final double scaleY = widgetSize.height / imageSize.height;
+
+  return Rect.fromLTRB(
+    rect.left.toDouble() * scaleX,
+    rect.top.toDouble() * scaleY,
+    rect.right.toDouble() * scaleX,
+    rect.bottom.toDouble() * scaleY,
+  );
+}