add dimension box

lib/widget/dimension_box.dart

@@ -0,0 +1,164 @@
+import 'dart:math';
+import 'package:flutter/material.dart';
+
+class DimensionBox extends StatelessWidget {
+  final double length;
+  final double width;
+  final double height;
+
+  DimensionBox({
+    Key key,
+    this.length,
+    this.width,
+    this.height,
+  }) : super(key: key);
+
+  Widget build(BuildContext context) {
+    return CustomPaint(
+      size: Size.infinite,
+      painter:
+          DimensionBoxPainter(length: length, width: width, height: height),
+    );
+  }
+}
+
+class DimensionBoxPainter extends CustomPainter {
+  final double avatarRadius = 10;
+  final double length;
+  final double width;
+  final double height;
+
+  DimensionBoxPainter({this.length, this.width, this.height});
+
+  //3
+  final Color color = Colors.blueAccent;
+
+  //4
+  @override
+  void paint(Canvas canvas, Size size) {
+    final shapeBounds =
+        Rect.fromLTWH(0, 0, size.width, size.height - avatarRadius);
+
+    final centerAvatar = Offset(shapeBounds.center.dx, shapeBounds.bottom);
+    final avatarBounds =
+        Rect.fromCircle(center: centerAvatar, radius: avatarRadius).inflate(6);
+    _drawBackground(canvas, shapeBounds, avatarBounds);
+
+    final curvedShapeBounds = Rect.fromLTRB(
+      shapeBounds.left,
+      shapeBounds.top + shapeBounds.height * 0.35,
+      shapeBounds.right,
+      shapeBounds.bottom,
+    );
+    // _drawCurvedShape(canvas, curvedShapeBounds, avatarBounds);
+
+    _drawCube(
+        canvas, shapeBounds, length * 10, width * 10, height * 10, Colors.teal);
+  }
+
+  void _drawBackground(Canvas canvas, Rect shapeBounds, Rect avatarBounds) {
+    //1
+    final paint = Paint()..color = Colors.amberAccent;
+
+    //2
+    final backgroundPath = Path()
+      ..moveTo(shapeBounds.left, shapeBounds.top) //3
+      ..lineTo(shapeBounds.bottomLeft.dx, shapeBounds.bottomLeft.dy) //4
+      // ..arcTo(avatarBounds, -pi, pi, false) //5
+      ..lineTo(shapeBounds.bottomRight.dx, shapeBounds.bottomRight.dy) //6
+      ..lineTo(shapeBounds.topRight.dx, shapeBounds.topRight.dy) //7
+      ..close(); //8
+
+    //9
+    canvas.drawPath(backgroundPath, paint);
+  }
+
+  void _drawCurvedShape(Canvas canvas, Rect bounds, Rect avatarBounds) {
+    final paint = Paint()..color = Colors.amber;
+    final handlePoint = Offset(bounds.left + (bounds.width * 0.25), bounds.top);
+    final curvePath = Path()
+      ..moveTo(bounds.bottomLeft.dx, bounds.bottomLeft.dy) //4
+      ..arcTo(avatarBounds, -pi, pi, false) //5
+      ..lineTo(bounds.bottomRight.dx, bounds.bottomRight.dy) //6
+      ..lineTo(bounds.topRight.dx, bounds.topRight.dy) //7
+      ..quadraticBezierTo(handlePoint.dx, handlePoint.dy, bounds.bottomLeft.dx,
+          bounds.bottomLeft.dy) //8
+      ..close(); //9
+
+    canvas.drawPath(curvePath, paint);
+  }
+
+  void _drawCube(Canvas canvas, Rect shapeBounds, double wx, double wy,
+      double h, Color color) {
+    //1
+    final paintLeft = Paint()..color = Color(0xff838357);
+    paintLeft.strokeJoin = StrokeJoin.round;
+
+    double x = shapeBounds.bottomCenter.dx;
+    double y = shapeBounds.bottomCenter.dy * 0.9;
+
+    final leftFacePath = Path()
+      ..moveTo(x, y)
+      ..lineTo(x - wx, y - wx * 0.5)
+      ..lineTo(x - wx, y - h - wx * 0.5)
+      ..lineTo(x, y - h * 1)
+      ..close();
+    canvas.drawPath(leftFacePath, paintLeft);
+
+    final paintRight = Paint()..color = Color(0xff6f6f49);
+    paintRight.strokeJoin = StrokeJoin.round;
+    final rightFacePath = Path()
+      ..moveTo(x, y)
+      ..lineTo(x + wy, y - wy * 0.5)
+      ..lineTo(x + wy, y - h - wy * 0.5)
+      ..lineTo(x, y - h * 1)
+      ..close();
+    canvas.drawPath(rightFacePath, paintRight);
+
+    final paintTop = Paint()..color = Color(0xff989865);
+    paintTop.strokeJoin = StrokeJoin.round;
+    final topFacePath = Path()
+      ..moveTo(x, y - h)
+      ..lineTo(x - wx, y - h - wx * 0.5)
+      ..lineTo(x - wx + wy, y - h - (wx * 0.5 + wy * 0.5))
+      ..lineTo(x + wy, y - h - wy * 0.5)
+      ..close();
+    canvas.drawPath(topFacePath, paintTop);
+
+    _drawText("length\n${length.toInt()}\"", canvas,
+        shapeBounds.bottomCenter.dx - 100, shapeBounds.bottomCenter.dy - 40);
+    _drawText("width\n${width.toInt()}\"", canvas,
+        shapeBounds.bottomCenter.dx + 100, shapeBounds.bottomCenter.dy - 40);
+    _drawText(
+        "height\n${height.toInt()}\"",
+        canvas,
+        shapeBounds.bottomCenter.dx,
+        shapeBounds.bottomCenter.dy - (h > 30 ? h / 2 : h) * 1.2);
+  }
+
+  _drawText(String text, Canvas canvas, double x, y) {
+    final textStyle = TextStyle(
+      color: Colors.white,
+      fontSize: 16,
+    );
+    final textSpan = TextSpan(
+      text: text,
+      style: textStyle,
+    );
+    final textPainter = TextPainter(
+        text: textSpan,
+        textDirection: TextDirection.ltr,
+        textAlign: TextAlign.center);
+    textPainter.layout(
+      minWidth: 0,
+      maxWidth: 50,
+    );
+    final offset = Offset(x, y);
+    textPainter.paint(canvas, offset);
+  }
+
+  @override
+  bool shouldRepaint(DimensionBoxPainter oldDelegate) {
+    return color != oldDelegate.color;
+  }
+}