the_paint/lib/grid.dart

import 'dart:async';
import 'dart:math';
import 'package:flutter/material.dart';
import 'package:grpc/grpc_web.dart';

import 'package:cyclop/cyclop.dart';

import 'src/color_ref.dart';
import 'src/connection/ws.dart';
import 'src/widget/square.dart';

class TransformationsDemo extends StatefulWidget {
  const TransformationsDemo({Key? key}) : super(key: key);

  @override
  State<TransformationsDemo> createState() => _TransformationsDemoState();
}

class _TransformationsDemoState extends State<TransformationsDemo>
    with TickerProviderStateMixin {
  final GlobalKey _targetKey = GlobalKey();
  final Map<Point<int>, Widget> elements = <Point<int>, Widget>{};
  Set<Color> swatches = Colors.primaries.map((e) => Color(e.value)).toSet();
  final double minScale = 2;
  final ColorRef cc = ColorRef(Colors.blueGrey);

  final TransformationController _transformationController =
      TransformationController();
  Animation<Matrix4>? _animationReset;
  late AnimationController _controllerReset;
  Matrix4? _homeMatrix;

  final channel = GrpcWebClientChannel.xhr(Uri.parse('http://localhost:8080'));

  @override
  void initState() {
    super.initState();
    WebRTCChannels().connect((x) {});
  }

  @override
  Widget build(BuildContext context) {
    // The scene is drawn by a CustomPaint, but user interaction is handled by
    // the InteractiveViewer parent widget.
    return Scaffold(
      backgroundColor: Theme.of(context).colorScheme.primary,
      // appBar: AppBar(
      //   automaticallyImplyLeading: false,
      //   title: const Text('title'),
      // ),
      body: Container(
        color: Colors.white,
        child: LayoutBuilder(
          builder: (context, constraints) {
            // Start the first render, start the scene centered in the viewport.
            if (_homeMatrix == null) {
              _homeMatrix = Matrix4.identity() * minScale
                ..translate(0, 0);
              _transformationController.value = _homeMatrix!;
              createComponentMap();
            }

            return ClipRect(
              child: MouseRegion(
                cursor: SystemMouseCursors.click,
                child: GestureDetector(
                  behavior: HitTestBehavior.opaque,
                  // onTapUp: _onTapUp,
                  child: InteractiveViewer(
                    constrained: false,
                    key: _targetKey,
                    transformationController: _transformationController,
                    boundaryMargin: const EdgeInsets.all(0),
                    minScale: minScale,
                    maxScale: 30,
                    // onInteractionStart: _onScaleStart,
                    onInteractionUpdate: _onInteractionUpdate,
                    onInteractionEnd: _onInteractionEnd,
                    child: SizedBox(
                      width: 256 * 90,
                      height: 256 * 53,
                      child: GridPaper(
                        child: Stack(children: elements.values.toList()),
                      ),
                    ),
                  ),
                ),
              ),
            );
          },
        ),
      ),
      // persistentFooterButtons: [],
      floatingActionButton: ColorButton(
        darkMode: true,
        key: const Key('c2'),
        color: cc.getColor(),
        boxShape: BoxShape.circle,
        swatches: swatches,
        size: 64,
        config: const ColorPickerConfig(
          enableOpacity: false,
          enableLibrary: true,
        ),
        onColorChanged: (value) => setState(() {
          cc.setColor(value);
        }),
        onSwatchesChanged: (newSwatches) =>
            setState(() => swatches = newSwatches),
      ),
    );
  }

  @override
  void dispose() {
    // _controllerReset.dispose();
    super.dispose();
  }

  void _onInteractionUpdate(ScaleUpdateDetails details) => _onUpdate();
  void _onInteractionEnd(ScaleEndDetails details) {
    _onUpdate();
    Timer(const Duration(milliseconds: 250), () => _onUpdate());
    Timer(const Duration(milliseconds: 500), () => _onUpdate());
  }

  void _onUpdate() {
    setState(() {
      createComponentMap();
    });
  }

  void createComponentMap() {
    var bounds = MediaQuery.of(context).size;

    var topLeft =
        _transformationController.toScene(bounds.topLeft(Offset.zero));
    var bottomRight =
        _transformationController.toScene(bounds.bottomRight(Offset.zero));

    var newSet = <Point<int>>{};

    var rec = Rectangle<int>.fromPoints(
        _offsetToIndex(topLeft), _offsetToIndex(bottomRight));
    for (var i = rec.left; i <= rec.right; i++) {
      for (var j = rec.top; j <= rec.bottom; j++) {
        newSet.add(Point<int>(i, j));
      }
    }

    final oldKeys = Set.from(elements.keys);
    final newPoints = newSet.difference(oldKeys);
    final disposePoints = oldKeys.difference(newSet);

    for (var point in newPoints) {
      elements[point] = Container(
          key: Key(point.toString()),
          margin: EdgeInsets.only(left: 256.0 * point.x, top: 256.0 * point.y),
          child: Stack(children: [
            CustomPaint(
              painter: OpenPainter(point),
            ),
            Text(point.toString()),
            SquareComponent(color: cc, tile: point, key: Key(point.toString())),
          ])
          // child: SquareComponent(point, cc),
          );
    }

    for (var point in disposePoints) {
      elements.remove(point);
    }
  }
}

Point<int> _offsetToIndex(Offset offset) {
  offset = offset / 256.0;
  var x = offset.dx.floor();
  var y = offset.dy.floor();
  if (x < 0) x = 0;
  if (y < 0) y = 0;
  return Point<int>(x, y);
}

class OpenPainter extends CustomPainter {
  Point<int> point;

  OpenPainter(Point<int> this.point);

  @override
  void paint(Canvas canvas, Size size) {
    var paint1 = Paint()
      ..color = Color.fromARGB(
        100,
        ((point.x * point.y * 7) % 64) * 4,
        ((point.x * 10039) % 64) * 4,
        ((point.y * 10061) % 64) * 4,
      )
      ..style = PaintingStyle.fill;
    canvas.drawRect(const Offset(0, 0) & const Size(256, 256), paint1);
  }

  @override
  bool shouldRepaint(CustomPainter oldDelegate) => true;
}