Graphs_dart/flutter/lib/curve_painter.dart

import 'package:arrow_path/arrow_path.dart';
import 'package:graphs/src/graph.dart';
import 'package:flutter/material.dart';
import 'dart:math';

class CurvePainter extends CustomPainter {
  CurvePainter({
    Key? key,
    required this.graphData,
    required this.bfsPath,
    required this.start,
    required this.end,
    required this.dfsAccessTable,
  });

  List<int>? bfsPath;
  List<bool>? dfsAccessTable;
  int? start;
  int? end;
  Graphs graphData;
  final double _dotRad = 6;
  final double _lineWidth = 1.5;
  final Color _lineColor = Colors.black;
  final double _aboveHeight = 5;
  double _circleRad = 100;
  final TextStyle _textStyle = TextStyle(
    color: Colors.red.shade900,
    decorationColor: Colors.green.shade900,
    decorationThickness: 10,
    decorationStyle: TextDecorationStyle.dashed,
    fontSize: 20,
  );
  Map<int, Offset> _off = <int, Offset>{};
  void _drawLine(Canvas canvas, Offset p1, Offset p2) {
    Paint p = Paint();
    p.color = _lineColor;
    p.strokeWidth = _lineWidth;
    canvas.drawLine(p1, p2, p);
  }

  void _drawDot(Canvas canvas, Offset p1, [double plusRad = 0, Color? col]) {
    col ??= Colors.yellow.shade900;
    var p = Paint();
    p.color = col;
    p.strokeWidth = _lineWidth + 2;
    canvas.drawCircle(p1, _dotRad + plusRad, p);
  }

  void _drawSelfConnect(Canvas canvas, Offset p1) {
    var p = Paint();
    p.color = _lineColor;
    p.strokeWidth = _lineWidth;
    p.style = PaintingStyle.stroke;
    canvas.drawCircle(Offset(p1.dx + _dotRad + 20, p1.dy), _dotRad + 20, p);
  }

  TextSpan _getTextSpan(String s) => TextSpan(text: s, style: _textStyle);
  TextPainter _getTextPainter(String s) => TextPainter(
      text: _getTextSpan(s),
      textDirection: TextDirection.ltr,
      textAlign: TextAlign.center);

  void _drawDotNames(Canvas canvas, Offset place, String s) {
    var textPainter = _getTextPainter(s);
    textPainter.layout();
    textPainter.paint(
        canvas,
        Offset((place.dx - textPainter.width),
            (place.dy - textPainter.height) - _aboveHeight));
  }

  void _drawDotNum(Canvas canvas, Offset size, String s) {
    var textPainter = TextPainter(
        text: TextSpan(
            text: s,
            style: const TextStyle(
              color: Colors.black,
              fontSize: 17,
            )),
        textDirection: TextDirection.ltr,
        textAlign: TextAlign.center);
    textPainter.layout();
    textPainter.paint(
        canvas,
        Offset((size.dx - textPainter.width) + 25,
            (size.dy - textPainter.height) + _aboveHeight + 30));
  }

  int _getHighInputConnections() {
    if (graphData.getDots().length != 1 && graphData.getDots().length <= 3) {
      return -1;
    }
    int higest = -1;
    for (var i in graphData.getDots()) {
      if (i.getL().length > higest) higest = i.num;
    }
    return higest;
  }

  Map<int, Offset> _getDotPos(int dotsAm, Size size) {
    Map<int, Offset> off = <int, Offset>{};
    var width = size.width / 2;
    var height = size.height / 2;
    int add = 0;
    int h = _getHighInputConnections();
    for (int i = 0; i < dotsAm; i++) {
      if ((i + 1) != h) {
        double x =
            cos(2 * pi * (i - add) / (dotsAm - add)) * _circleRad + width;
        double y =
            sin(2 * pi * (i - add) / (dotsAm - add)) * _circleRad + height;

        off[i + 1] = Offset(x, y);
      } else if ((i + 1) == h) {
        off[i + 1] = Offset(width + 2, height - 2);
        add = 1;
        h = 0;
      } else {
        print("GetDotPos error");
      }
      //print(off.length);
    }

    //print(off);
    return off;
  }

  void _drawHArrow(Canvas canvas, Size size, Offset from, Offset to,
      [bool doubleSided = false]) {
    Path path;

    // The arrows usually looks better with rounded caps.
    Paint paint = Paint()
      ..color = Colors.black
      ..style = PaintingStyle.stroke
      ..strokeCap = StrokeCap.round
      ..strokeJoin = StrokeJoin.round
      ..strokeWidth = _lineWidth;

    var length = sqrt((to.dx - from.dx) * (to.dx - from.dx) +
        (to.dy - from.dy) * (to.dy - from.dy));

    /// Draw a single arrow.
    path = Path();
    path.moveTo(from.dx, from.dy);
    path.relativeCubicTo(
        0,
        0,
        -(from.dx + to.dx + length) / (length) - 40,
        -(from.dy + to.dy + length) / (length) - 40,
        to.dx - from.dx,
        to.dy - from.dy);
    path =
        ArrowPath.make(path: path, isDoubleSided: doubleSided, tipLength: 16);
    canvas.drawPath(path, paint);
  }

  void _drawHighArrow(Canvas canvas, Size size, Offset from, Offset to,
      [bool doubleSided = false]) {
    Path path;

    // The arrows usually looks better with rounded caps.
    Paint paint = Paint()
      ..color = Colors.black
      ..style = PaintingStyle.stroke
      ..strokeCap = StrokeCap.round
      ..strokeJoin = StrokeJoin.round
      ..strokeWidth = _lineWidth;

    var length = sqrt((to.dx - from.dx) * (to.dx - from.dx) +
        (to.dy - from.dy) * (to.dy - from.dy));

    /// Draw a single arrow.
    path = Path();
    path.moveTo(from.dx, from.dy);
    path.relativeCubicTo(
        0,
        0,
        (from.dx + to.dx) / (length * 2) + 40,
        (from.dy + to.dy) / (length * 2) + 40,
        to.dx - from.dx,
        to.dy - from.dy);
    path = ArrowPath.make(
        path: path,
        isDoubleSided: doubleSided,
        tipLength: 13,
        isAdjusted: false);
    canvas.drawPath(path, paint);
  }

  void _drawConnections(
      Canvas canvas, Size size, List<Dot> dots, Map<int, Offset> off) {
    for (var i in dots) {
      var list = i.getL();
      var beg = off[i.num];
      for (var d in list.keys) {
        if (d == i.num) {
          _drawSelfConnect(canvas, off[d]!);
        } else {
          if (graphData.getDoubleSidedBool()) {
            if (d > i.num) {
              _drawHArrow(canvas, size, beg!, off[d]!, false);
              if (graphData.getUseLengthBool()) {
                _drawDotNames(
                    canvas,
                    Offset((off[d]!.dx + beg.dx) / 2 - 18,
                        (off[d]!.dy + beg.dy) / 2 - 18),
                    i.getL()[d].toString());
              }
            } else {
              _drawHighArrow(canvas, size, beg!, off[d]!, false);
              if (graphData.getUseLengthBool()) {
                _drawDotNames(
                    canvas,
                    Offset((off[d]!.dx + beg.dx) / 2 + 30,
                        (off[d]!.dy + beg.dy) / 2 + 30),
                    i.getL()[d].toString());
              }
            }
          } else {
            _drawLine(canvas, beg!, off[d]!);
            if (graphData.getUseLengthBool()) {
              _drawDotNames(
                  canvas,
                  Offset((off[d]!.dx + beg.dx) / 2, (off[d]!.dy + beg.dy) / 2),
                  i.getL()[d].toString());
            }
          }
        }
      }
    }
  }

  void _drawBFS(Canvas canvas) {
    if (bfsPath != null) {
      for (int i = 0; i < bfsPath!.length; i++) {
        _drawDot(canvas, _off[bfsPath![i]]!, 8, Colors.yellow);
      }
      _drawDot(canvas, _off[start]!, 9, Colors.green);
      _drawDot(canvas, _off[end]!, 7, Colors.red.shade200);
      for (int i = 0; i < bfsPath!.length; i++) {
        _drawDotNum(canvas, _off[bfsPath![i]]!, "bfs: №${i + 1}");
      }
    }
  }

  void _drawDFS(Canvas canvas) {
    if (dfsAccessTable != null) {
      for (int i = 0; i < dfsAccessTable!.length; i++) {
        if (dfsAccessTable![i]) {
          _drawDot(canvas, _off[i + 1]!, 8, Colors.green.shade500);
          _drawDotNum(canvas, _off[i + 1]!, "dfs: visible");
        } else {
          _drawDot(canvas, _off[i + 1]!, 7, Colors.red.shade500);
          _drawDotNum(canvas, _off[i + 1]!, "dfs: not visible");
        }
      }
      _drawDot(canvas, _off[start]!, 9, Colors.green.shade900);
    }
  }

  @override
  void paint(Canvas canvas, Size size) {
    if (size.width > size.height) {
      _circleRad = size.height / 3;
    } else {
      _circleRad = size.width / 3;
    }

    _off = _getDotPos(graphData.getDotAmount(), size); //, higest);
    for (int i in _off.keys) {
      _drawDot(canvas, _off[i]!);
      //drawDotNames(canvas, off[i]!, "${graphData.getDots()[i - 1].getName()}:[$i]");
    }

    var g = graphData.getDots();
    _drawBFS(canvas);
    _drawDFS(canvas);
    _drawConnections(canvas, size, g, _off);
    //pringArr(canvas, size);
    //drawArrow(canvas, Offset(size.width / 2, size.height / 2),
    //   Offset(size.width / 2 + 50, size.height / 2 + 200));
    //}

    for (int i in _off.keys) {
      //drawDot(canvas, off[i]!);
      _drawDotNames(
          canvas, _off[i]!, "${graphData.getDots()[i - 1].getName()}:[$i]");
    }
  }

  @override
  bool shouldRepaint(CustomPainter oldDelegate) {
    return true;
  }
}

/*void _pringArr(Canvas canvas, Size size) {
  TextSpan textSpan;
  TextPainter textPainter;
  Path path;

  // The arrows usually looks better with rounded caps.
  Paint paint = Paint()
    ..color = Colors.black
    ..style = PaintingStyle.stroke
    ..strokeCap = StrokeCap.round
    ..strokeJoin = StrokeJoin.round
    ..strokeWidth = 3.0;

  /// Draw a single arrow.
  path = Path();
  path.moveTo(size.width * 0.25, size.height * 0.10);
  path.relativeCubicTo(0, 0, size.width * 0.25, 50, size.width * 0.5, 0);
  path = ArrowPath.make(path: path);
  canvas.drawPath(path, paint..color = Colors.blue);

  textSpan = const TextSpan(
    text: 'Single arrow',
    style: TextStyle(color: Colors.blue),
  );
  textPainter = TextPainter(
    text: textSpan,
    textAlign: TextAlign.center,
    textDirection: TextDirection.ltr,
  );
  textPainter.layout(minWidth: size.width);
  textPainter.paint(canvas, Offset(0, size.height * 0.06));
}*/