Line data    Source code

       1             : // Copyright 2023 The terCAD team. All rights reserved.
       2             : // Use of this source code is governed by a CC BY-NC-ND 4.0 license that can be found in the LICENSE file.
       3             : 
       4             : import 'package:app_finance/charts/painter/gauge_painter.dart';
       5             : import 'package:flutter/material.dart';
       6             : 
       7             : class GaugeLinearPainter extends GaugePainter {
       8           0 :   GaugeLinearPainter({
       9             :     required super.value,
      10             :     required super.max,
      11             :     required super.min,
      12             :     super.color = Colors.grey,
      13           0 :   }) : super(fontSize: 9);
      14             : 
      15           0 :   @override
      16             :   void paint(Canvas canvas, Size size) {
      17             :     const indent = 2.0;
      18           0 :     final height = size.height / 2;
      19           0 :     final xStart = 0.10 * size.width;
      20           0 :     _drawRect(canvas, size, const Offset(0, indent), Offset(xStart, height), Colors.red.shade900);
      21           0 :     final xMiddle = 0.35 * size.width;
      22           0 :     _drawRect(canvas, size, Offset(xStart + indent, indent), Offset(xMiddle, height), Colors.orange);
      23           0 :     _drawRect(canvas, size, Offset(xMiddle + indent, indent), Offset(size.width, height), Colors.green.shade500);
      24             : 
      25           0 :     final paint = Paint()
      26           0 :       ..color = color
      27           0 :       ..strokeWidth = 2
      28           0 :       ..style = PaintingStyle.fill;
      29           0 :     final spread = size.width / threshold - 1;
      30           0 :     final step = (max - min) / spread;
      31           0 :     fnZero(double _, TextPainter __) => 0.0;
      32           0 :     for (double i = 0; i < spread; i += 1) {
      33           0 :       final pos = Offset(i * threshold + 3, size.height - 3);
      34           0 :       canvas.drawCircle(pos, 2.0, paint);
      35           0 :       paintText(
      36           0 :           canvas, size, fnZero, Offset(pos.dx + 6, size.height / 2 + 2), '${(min + step * i).toStringAsFixed(2)}%');
      37             :     }
      38             : 
      39           0 :     final pos = value * size.width;
      40           0 :     final strokePath = Path()
      41           0 :       ..moveTo(pos - 6, 0)
      42           0 :       ..lineTo(pos, size.height / 2 + 2)
      43           0 :       ..lineTo(pos + 6, 0);
      44           0 :     canvas.drawPath(strokePath, paint..invertColors = true);
      45           0 :     final path = Path()
      46           0 :       ..moveTo(pos - 3, 0)
      47           0 :       ..lineTo(pos, size.height / 3)
      48           0 :       ..lineTo(pos + 3, 0);
      49           0 :     canvas.drawPath(path, paint..invertColors = false);
      50             :   }
      51             : 
      52           0 :   void _drawRect(Canvas canvas, Size size, Offset start, Offset end, Color color) {
      53           0 :     final paint = Paint()
      54           0 :       ..color = color
      55           0 :       ..style = PaintingStyle.fill;
      56           0 :     canvas.drawRect(Rect.fromPoints(start, end), paint);
      57             :   }
      58             : }