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.gr,
  });

  Graphs gr;
  final double rad = 7;
  final double width = 4;
  final Color col = Colors.black;
  final double aboveHeight = 5;
  double circleRad = 100;
  final TextStyle textStyle = const TextStyle(
    color: Colors.black,
    fontSize: 21,
  );

  void drawLine(Canvas canvas, Offset p1, Offset p2) {
    Paint p = Paint();
    p.color = col;
    p.strokeWidth = width - 2;
    canvas.drawLine(p1, p2, p);
  }

  void drawDot(Canvas canvas, Offset p1) {
    var p = Paint();
    p.color = Colors.yellow.shade900;
    p.strokeWidth = width;
    canvas.drawCircle(p1, rad, p);
  }

  void drawSelfConnect(Canvas canvas, Offset p1) {
    var p = Paint();
    p.color = col;
    p.strokeWidth = width - 2;
    p.style = PaintingStyle.stroke;
    canvas.drawCircle(Offset(p1.dx + rad + 20, p1.dy), rad + 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 drawAboveText(Canvas canvas, Offset size, String s) {
    var textPainter = _getTextPainter(s);
    textPainter.layout();
    textPainter.paint(
        canvas,
        Offset((size.dx - textPainter.width),
            (size.dy - textPainter.height) - aboveHeight));
  }

  Graphs getGraph() {
    List<Dot> d = <Dot>[];
    d.add(Dot.fromTwoLists("1", [2, 3], [1, 1]));
    d.add(Dot.fromTwoLists("2", [1, 3], [1, 1]));
    d.add(Dot.fromTwoLists("3", [1, 2], [1, 1]));
    d.add(Dot.fromTwoLists("Name1", [], []));
    d.add(Dot.fromTwoLists("Name2", [], []));
    return Graphs.fromList("1", d, false, false);
  }

  int getHighInputConnections() {
    if (gr.getDots().length <= 3) return -1;
    int higest = -1;
    for (var i in gr.getDots()) {
      if (i.getL().length > higest) higest = i.num;
    }
    /*gr.getDots().forEach((element) {
      if (element.getL().length > higest) {
        higest = element.num;
      }
    });*/
    return higest;
  }

  Map<int, Offset> getDotPos(int dotsAm, Size size, [int? exclude]) {
    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 drawLowArrow(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 = width - 1;

    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: 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 = width - 1;

    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 + 60,
        (from.dy + to.dy) / length + 0, 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 (gr.getDoubleSidedBool()) {
            if (d > i.num) {
              drawLowArrow(canvas, size, beg!, off[d]!, false);
              if (gr.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 (gr.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 (gr.getUseLengthBool()) {
              drawDotNames(
                  canvas,
                  Offset((off[d]!.dx + beg.dx) / 2, (off[d]!.dy + beg.dy) / 2),
                  i.getL()[d].toString());
            }
          }
        }
      }
    }
  }

  @override
  void paint(Canvas canvas, Size size) {
    if (size.width > size.height) {
      circleRad = size.height / 3;
    } else {
      circleRad = size.width / 3;
    }
    //var paint = Paint();
    //drawLine(canvas, Offset(0, size.height / 2),
    //Offset(size.width, size.height / 2));

    //gr = getGraph();
    //int higest = getHighConnections();
    //if (higest > -1) {
    var off = getDotPos(gr.getDotAmount(), size); //, higest);
    //off[higest] = Offset(size.width / 2, size.height / 2);
    for (int i in off.keys) {
      drawDot(canvas, off[i]!);
      drawDotNames(canvas, off[i]!, "${gr.getDots()[i - 1].getName()}:[${i}]");
    }
    //var g = gr.getNoRepeatDots();
    //print(g);
    var g = gr.getDots();
    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));
    //}
  }

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

  /*void _drawTextAt(String txt, Offset position, Canvas canvas) {
    final textPainter = getTextPainter(txt);
    textPainter.layout(minWidth: 0, maxWidth: 0);
    Offset drawPosition =
        Offset(position.dx, position.dy - (textPainter.height / 2));
    textPainter.paint(canvas, drawPosition);
  }*/
}

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));
/*
  /// Draw a double sided arrow.
  path = Path();
  path.moveTo(size.width * 0.25, size.height * 0.2);
  path.relativeCubicTo(0, 0, size.width * 0.25, 50, size.width * 0.5, 0);
  path = ArrowPath.make(path: path, isDoubleSided: true);
  canvas.drawPath(path, paint..color = Colors.cyan);

  textSpan = const TextSpan(
    text: 'Double sided arrow',
    style: TextStyle(color: Colors.cyan),
  );
  textPainter = TextPainter(
    text: textSpan,
    textAlign: TextAlign.center,
    textDirection: TextDirection.ltr,
  );
  textPainter.layout(minWidth: size.width);
  textPainter.paint(canvas, Offset(0, size.height * 0.16));

  /// Use complex path.
  path = Path();
  path.moveTo(size.width * 0.25, size.height * 0.3);
  path.relativeCubicTo(0, 0, size.width * 0.25, 0, size.width * 0.5, 50);
  path.relativeCubicTo(0, 0, -size.width * 0.25, 50, -size.width * 0.5, 50);
  //path.relativeCubicTo(0, 0, size.width * 0.125, 10, size.width * 0.25, -10);
  path = ArrowPath.make(path: path, isDoubleSided: true);
  canvas.drawPath(path, paint..color = Colors.blue);

  textSpan = const TextSpan(
    text: 'Complex path',
    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 * 0.28));

  /// Draw several arrows on the same path.
  path = Path();
  path.moveTo(size.width * 0.25, size.height * 0.53);
  path.relativeCubicTo(0, 0, size.width * 0.25, 50, size.width * 0.5, 50);
  path = ArrowPath.make(path: path);
  path.relativeCubicTo(0, 0, -size.width * 0.25, 0, -size.width * 0.5, 50);
  path = ArrowPath.make(path: path);
  Path subPath = Path();
  subPath.moveTo(size.width * 0.375, size.height * 0.53 + 100);
  subPath.relativeCubicTo(0, 0, size.width * 0.125, 10, size.width * 0.25, -10);
  subPath = ArrowPath.make(path: subPath, isDoubleSided: true);
  path.addPath(subPath, Offset.zero);
  canvas.drawPath(path, paint..color = Colors.cyan);

  textSpan = const TextSpan(
    text: 'Several arrows on the same path',
    style: TextStyle(color: Colors.cyan),
  );
  textPainter = TextPainter(
    text: textSpan,
    textAlign: TextAlign.center,
    textDirection: TextDirection.ltr,
  );
  textPainter.layout(minWidth: size.width);
  textPainter.paint(canvas, Offset(0, size.height * 0.49));

  /// Adjusted
  path = Path();
  path.moveTo(size.width * 0.1, size.height * 0.8);
  path.relativeCubicTo(0, 0, size.width * 0.3, 50, size.width * 0.25, 75);
  path = ArrowPath.make(path: path, isAdjusted: true);
  canvas.drawPath(path, paint..color = Colors.blue);

  textSpan = const TextSpan(
    text: 'Adjusted',
    style: TextStyle(color: Colors.blue),
  );
  textPainter = TextPainter(
    text: textSpan,
    textAlign: TextAlign.left,
    textDirection: TextDirection.ltr,
  );
  textPainter.layout();
  textPainter.paint(canvas, Offset(size.width * 0.2, size.height * 0.77));

  /// Non adjusted.
  path = Path();
  path.moveTo(size.width * 0.6, size.height * 0.8);
  path.relativeCubicTo(0, 0, size.width * 0.3, 50, size.width * 0.25, 75);
  path = ArrowPath.make(path: path, isAdjusted: false);
  canvas.drawPath(path, paint..color = Colors.blue);

  textSpan = const TextSpan(
    text: 'Non adjusted',
    style: TextStyle(color: Colors.blue),
  );
  textPainter = TextPainter(
    text: textSpan,
    textAlign: TextAlign.left,
    textDirection: TextDirection.ltr,
  );
  textPainter.layout();
  textPainter.paint(canvas, Offset(size.width * 0.65, size.height * 0.77));*/
}