fis_lib_measure/lib/view/gesture/annotation/label_drag_target_pannel.dart

import 'package:fis_measure/interfaces/process/workspace/application.dart';
import 'package:fis_measure/interfaces/process/workspace/point_info.dart';
import 'package:flutter/material.dart';
import 'package:get/get.dart';

import '../positioned_cursor.dart';

/// 文本注释拖拽目标面板
class AnnotationLabelDragTargetPanel extends StatefulWidget {
  const AnnotationLabelDragTargetPanel({Key? key}) : super(key: key);

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

class _PanelState extends State<AnnotationLabelDragTargetPanel> {
  late final application = Get.find<IApplication>();

  @override
  void initState() {
    // TODO: implement initState
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Container(
      // color: Colors.green,
      child: DragTarget<String>(
        builder: (context, candidateData, rejectedData) {
          return Container(
            child: Stack(
              children: const [
                PositionedCursor(),
              ],
            ),
          );
        },
        onMove: (details) {
          _notifyPosition(context, details.offset, PointInfoType.mouseMove);
        },
        onAcceptWithDetails: (details) {
          _notifyPosition(context, details.offset, PointInfoType.mouseUp);
        },
      ),
    );
  }

  void _notifyPosition(
    BuildContext context,
    Offset offset,
    PointInfoType type,
  ) {
    final localOffset = _findLocalPosition(context, offset);
    application.createPointInfo(localOffset, type);
  }

  Offset _findLocalPosition(BuildContext context, Offset globalPosition) {
    final renderBox = context.findRenderObject() as RenderBox?;
    if (renderBox == null) return globalPosition;
    return renderBox.globalToLocal(globalPosition);
  }

  @override
  void dispose() {
    // TODO: implement dispose
    super.dispose();
  }
}