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:material_ui/material_ui.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              : }