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/interface/ohlc_data.dart';
       5             : import 'package:app_finance/charts/painter/abstract_painter.dart';
       6             : import 'package:flutter/material.dart';
       7             : 
       8             : class OhlcChartPainter extends AbstractPainter {
       9             :   final List<OhlcData> data;
      10             :   final Color color;
      11             : 
      12           0 :   OhlcChartPainter({
      13             :     required super.indent,
      14             :     required this.data,
      15             :     required this.color,
      16             :     super.size,
      17             :     super.xMax = 1.0,
      18             :     super.xMin = 0.0,
      19             :     super.yMax = 1.0,
      20             :   });
      21             : 
      22           0 :   @override
      23             :   void paint(Canvas canvas, Size size) {
      24           0 :     if (data.isEmpty) {
      25             :       return;
      26             :     }
      27           0 :     size = this.size ?? size;
      28           0 :     for (int i = 0; i < data.length; i++) {
      29           0 :       _drawLine(canvas, size, data[i]);
      30           0 :       _drawRectangle(canvas, size, data[i]);
      31             :     }
      32             :   }
      33             : 
      34           0 :   _drawRectangle(Canvas canvas, Size size, OhlcData value) {
      35           0 :     final paint = Paint()
      36           0 :       ..color = value.open > value.close ? Colors.red : Colors.blue
      37           0 :       ..style = PaintingStyle.fill
      38           0 :       ..strokeWidth = 1;
      39           0 :     final time = value.date.millisecondsSinceEpoch.toDouble() - msDay * 8;
      40           0 :     final rect = Rect.fromPoints(
      41           0 :       getValue(Offset(time - msDay * 1.5, value.open), size),
      42           0 :       getValue(Offset(time + msDay * 1.5, value.close), size),
      43             :     );
      44           0 :     canvas.drawRect(rect, paint);
      45             :   }
      46             : 
      47           0 :   _drawLine(Canvas canvas, Size size, OhlcData value) {
      48           0 :     final line = Paint()
      49           0 :       ..color = color
      50           0 :       ..style = PaintingStyle.stroke
      51           0 :       ..strokeWidth = 1;
      52           0 :     final time = value.date.millisecondsSinceEpoch.toDouble() - msDay * 8;
      53           0 :     canvas.drawLine(getValue(Offset(time, value.low), size), getValue(Offset(time, value.high), size), line);
      54             :   }
      55             : }