fis_lib_measure/lib/view/gesture/cross_position_indicator.dart

import 'package:fis_measure/values/colors.dart';
import 'package:fis_measure/view/gesture/positioned_cursor.dart';
import 'package:fis_measure/view/gesture/positioned_touch_cursor.dart';
import 'package:flutter/material.dart';
import 'package:get/get.dart';
import 'package:path_drawing/path_drawing.dart';

class CrossIndicator extends StatefulWidget {
  const CrossIndicator({Key? key, required this.areaRegion}) : super(key: key);
  final Rect areaRegion;

  @override
  State<StatefulWidget> createState() => CrossIndicatorState();
}

class CrossIndicatorState extends State<CrossIndicator> {
  final mouseState = Get.find<IMouseState>();
  CrossIndicatorStyle indicatorStyle = CrossIndicatorStyle.nomal;

  @override
  void initState() {
    mouseState.mousePositionChanged.addListener(mousePositionChanged);
    mouseState.crossIndicatorStyleChanged
        .addListener(_crossIndicatorStyleChanged);
    super.initState();
  }

  @override
  void dispose() {
    mouseState.mousePositionChanged.removeListener(mousePositionChanged);
    mouseState.crossIndicatorStyleChanged
        .removeListener(_crossIndicatorStyleChanged);
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    final position = mouseState.mousePosition;
    if (position == null) return Container();
    return Positioned(
      top: widget.areaRegion.top,
      width: widget.areaRegion.width,
      height: widget.areaRegion.height,
      child: RepaintBoundary(
        child: CustomPaint(
            painter: _CrossIndicatorPainter(
                color: MeasureColors.Primary,
                centerOffset:
                    Offset(position.dx, position.dy - widget.areaRegion.top),
                style: indicatorStyle)),
      ),
    );
  }

  void mousePositionChanged(Object sender, dynamic e) {
    onUpdate();
  }

  void _crossIndicatorStyleChanged(Object sender, dynamic e) {
    setState(() {
      indicatorStyle = e;
    });
  }

  void onUpdate() {
    setState(() {});
  }
}

class MobileCrossIndicator extends StatefulWidget {
  const MobileCrossIndicator({Key? key, required this.areaRegion})
      : super(key: key);
  final Rect areaRegion;

  @override
  State<StatefulWidget> createState() => MobileCrossIndicatorState();
}

class MobileCrossIndicatorState extends State<MobileCrossIndicator> {
  final touchState = Get.find<ITouchPointState>();
  CrossIndicatorStyle indicatorStyle = CrossIndicatorStyle.nomal;

  @override
  void initState() {
    touchState.mousePositionChanged.addListener(mousePositionChanged);
    touchState.crossIndicatorStyleChanged
        .addListener(_crossIndicatorStyleChanged);
    super.initState();
  }

  @override
  void dispose() {
    touchState.mousePositionChanged.removeListener(mousePositionChanged);
    touchState.crossIndicatorStyleChanged
        .removeListener(_crossIndicatorStyleChanged);
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    final position = touchState.touchPosition;
    if (position == null) return Container();
    final centerOffset = position + touchState.touchOffset;
    return Positioned(
      top: widget.areaRegion.top,
      width: widget.areaRegion.width,
      height: widget.areaRegion.height,
      child: RepaintBoundary(
        child: CustomPaint(
            painter: _CrossIndicatorPainter(
                strokeWidth: 1,
                color: MeasureColors.ActiveCaliper,
                centerOffset: Offset(
                    centerOffset.dx, centerOffset.dy - widget.areaRegion.top),
                style: indicatorStyle)),
      ),
    );
  }

  void mousePositionChanged(Object sender, dynamic e) {
    onUpdate();
  }

  void _crossIndicatorStyleChanged(Object sender, dynamic e) {
    setState(() {
      indicatorStyle = e;
    });
  }

  void onUpdate() {
    setState(() {});
  }
}

class _CrossIndicatorPainter extends CustomPainter {
  const _CrossIndicatorPainter(
      {this.color,
      this.strokeWidth,
      this.centerOffset,
      this.style = CrossIndicatorStyle.nomal});
  final Color? color;
  final double? strokeWidth;
  final Offset? centerOffset;
  final CrossIndicatorStyle style;

  @override
  void paint(Canvas canvas, Size size) {
    final paint = Paint()
      ..color = color ?? const Color.fromARGB(255, 255, 255, 0)
      ..strokeWidth = strokeWidth ?? 2
      ..style = PaintingStyle.stroke
      ..isAntiAlias = false;
    final center = centerOffset ?? Offset(size.width / 2, size.height / 2);
    //绘制十字点路径
    final path = Path();

    switch (style) {
      case CrossIndicatorStyle.nomal:
        path
          ..moveTo(center.dx, 0)
          ..lineTo(center.dx, size.height)
          ..moveTo(0, center.dy)
          ..lineTo(size.width, center.dy);
        break;
      case CrossIndicatorStyle.vertical:
        path
          ..moveTo(center.dx, 0)
          ..lineTo(center.dx, size.height);
        break;
      case CrossIndicatorStyle.horizontal:
        path
          ..moveTo(0, center.dy)
          ..lineTo(size.width, center.dy);
        break;
    }
    canvas.drawPath(
        dashPath(
          path,
          dashArray: CircularIntervalList<double>([5, 10]),
        ),
        paint);
  }

  @override
  bool shouldRepaint(covariant _CrossIndicatorPainter oldDelegate) {
    return oldDelegate.color != color ||
        oldDelegate.centerOffset != centerOffset ||
        oldDelegate.style != style;
  }
}

enum CrossIndicatorStyle {
  ///标准状态
  nomal,
  //仅横指示线
  horizontal,
  //仅纵指示线
  vertical,
}