flutter_canvas_template_editor/lib/grid/grid_painter...

// Copyright (c) 2021 Razeware LLC
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
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// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
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// distribute, sublicense, create a derivative work, and/or sell copies of the
// Software in any work that is designed, intended, or marketed for pedagogical
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import 'package:flutter/material.dart';

class GridPainter extends CustomPainter {
  final double boxSize = 50;

  @override
  void paint(Canvas canvas, Size size) {
    final vLines = (size.width ~/ boxSize) + 1;
    final hLines = (size.height ~/ boxSize) + 1;

    final paint = Paint()
      ..strokeWidth = 1
      ..color = Colors.red
      ..style = PaintingStyle.stroke;

    final path = Path();

    // Draw vertical lines
    for (var i = 0; i < vLines; ++i) {
      final x = boxSize * i;
      path.moveTo(x, 0);
      path.relativeLineTo(0, size.height);
    }

    // Draw horizontal lines
    for (var i = 0; i < hLines; ++i) {
      final y = boxSize * i;
      path.moveTo(0, y);
      path.relativeLineTo(size.width, 0);
    }
    canvas.drawPath(path, paint);
  }

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