fis_lib_measure/lib/view/standard_line/calibration_gesture.dart

import 'package:fis_measure/interfaces/process/standard_line/calibration.dart';
import 'package:fis_measure/interfaces/process/workspace/point_info.dart';
import 'package:fis_measure/values/colors.dart';
import 'package:fis_measure/view/cursor.dart';
import 'package:flutter/material.dart';

/// 参考校准线手势画布
class StandardLineCalibrationGesture extends StatefulWidget {
  const StandardLineCalibrationGesture(this.controller, {Key? key})
      : super(key: key);

  final IStandardLineCalibrationController controller;

  @override
  State<StandardLineCalibrationGesture> createState() => _GestureState();
}

class _GestureState extends State<StandardLineCalibrationGesture> {
  // ignore: constant_identifier_names
  static const C_CURSOR_SIZE = 16.0;
  Offset position = Offset.zero;

  @override
  Widget build(BuildContext context) {
    final controller = widget.controller;
    return MouseRegion(
      cursor: SystemMouseCursors.none,
      onHover: (event) {
        setState(() {
          _updatePosition(event.localPosition);
          controller.executeGesturePoint(
            event.localPosition,
            PointInfoType.mouseMove,
          );
        });
      },
      child: GestureDetector(
        onTapDown: (details) {
          controller.executeGesturePoint(
            details.localPosition,
            PointInfoType.mouseDown,
          );
        },
        onTapUp: (details) {
          controller.executeGesturePoint(
            details.localPosition,
            PointInfoType.mouseUp,
          );
        },
        child: Stack(
          children: [
            Positioned(
              // top: position.dy - 16,
              // left: position.dx - 16,
              top: position.dy,
              left: position.dx,
              child: const MeasureCursor(
                type: MeasureCursorType.cursor01,
                size: C_CURSOR_SIZE,
                color: MeasureColors.Primary,
              ),
            ),
          ],
        ),
      ),
    );
  }

  void _updatePosition(Offset offset) {
    const side = C_CURSOR_SIZE / 2;
    double dx = offset.dx - side;
    double dy = offset.dy - side;
    if (dx < 0) dx = 0;
    if (dy < 0) dy = 0;
    position = Offset(dx, dy);
  }
}