ops-console v1.0.2 (versionCode 8) 源码入库

lib/widgets/region_picker.dart

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+import 'package:flutter/material.dart';
+
+import '../data/region_data.dart';
+
+/// 省→市→区三级联动结果。
+class RegionResult {
+  const RegionResult({
+    required this.provinceCode,
+    required this.provinceName,
+    required this.cityCode,
+    required this.cityName,
+    required this.districtCode,
+    required this.districtName,
+  });
+
+  final String provinceCode;
+  final String provinceName;
+  final String cityCode;
+  final String cityName;
+  final String districtCode;
+  final String districtName;
+
+  /// 拼接展示文本（省名+市名+区名）。
+  String get label =>
+      '$provinceName$cityName$districtName';
+}
+
+/// 省→市→区三级联动底部弹起选择器。
+///
+/// 数据源统一来自 [RegionData]（已加载的 `province.json`）。
+/// 返回 [RegionResult]（含 code 与 name）；用户取消时弹出 null。
+class RegionPicker extends StatefulWidget {
+  const RegionPicker({
+    super.key,
+    this.initialProvinceCode,
+    this.initialCityCode,
+    this.initialDistrictCode,
+  });
+
+  final String? initialProvinceCode;
+  final String? initialCityCode;
+  final String? initialDistrictCode;
+
+  /// 打开选择器底部弹窗，返回所选 [RegionResult] 或 null。
+  static Future<RegionResult?> show({
+    required BuildContext context,
+    String? initialProvinceCode,
+    String? initialCityCode,
+    String? initialDistrictCode,
+  }) {
+    return showModalBottomSheet<RegionResult>(
+          useSafeArea: true,
+      context: context,
+      isScrollControlled: true,
+      builder: (ctx) => RegionPicker(
+        initialProvinceCode: initialProvinceCode,
+        initialCityCode: initialCityCode,
+        initialDistrictCode: initialDistrictCode,
+      ),
+    );
+  }
+
+  @override
+  State<RegionPicker> createState() => _RegionPickerState();
+}
+
+class _RegionPickerState extends State<RegionPicker> {
+  final RegionData _region = RegionData.instance;
+
+  /// 当前选中层级：0=省 1=市 2=区。
+  int _level = 0;
+  String? _provinceCode;
+  String? _cityCode;
+  String? _districtCode;
+
+  @override
+  void initState() {
+    super.initState();
+    _provinceCode = widget.initialProvinceCode;
+    _cityCode = widget.initialCityCode;
+    _districtCode = widget.initialDistrictCode;
+    // 若已带初始省，直接进入市层级以便快速定位。
+    if (_provinceCode != null && _provinceCode!.isNotEmpty) {
+      _level = 1;
+      if (_cityCode != null && _cityCode!.isNotEmpty) {
+        _level = 2;
+      }
+    }
+  }
+
+  List<RegionNode> get _currentList {
+    switch (_level) {
+      case 0:
+        return _region.provinces;
+      case 1:
+        return _region.citiesOf(_provinceCode ?? '');
+      case 2:
+        return _region.districtsOf(
+          _provinceCode ?? '',
+          _cityCode ?? '',
+        );
+      default:
+        return const [];
+    }
+  }
+
+  String _levelTitle() {
+    switch (_level) {
+      case 0:
+        return '选择省份';
+      case 1:
+        return '选择城市';
+      case 2:
+        return '选择区县';
+      default:
+        return '选择地区';
+    }
+  }
+
+  void _onSelect(RegionNode node) {
+    if (_level == 0) {
+      setState(() {
+        _provinceCode = node.code;
+        _cityCode = null;
+        _districtCode = null;
+        _level = 1;
+      });
+    } else if (_level == 1) {
+      setState(() {
+        _cityCode = node.code;
+        _districtCode = null;
+        _level = 2;
+      });
+    } else {
+      final provinceName = _region.nameOf(_provinceCode ?? '');
+      final cityName = _region.nameOf(_cityCode ?? '');
+      Navigator.pop(
+        context,
+        RegionResult(
+          provinceCode: _provinceCode ?? '',
+          provinceName: provinceName,
+          cityCode: _cityCode ?? '',
+          cityName: cityName,
+          districtCode: node.code,
+          districtName: node.name,
+        ),
+      );
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final nodes = _currentList;
+    return Container(
+      height: MediaQuery.of(context).size.height * 0.6,
+      padding: const EdgeInsets.only(top: 8),
+      child: Column(
+        children: [
+          Row(
+            children: [
+              const SizedBox(width: 16),
+              Expanded(
+                child: Text(
+                  _levelTitle(),
+                  style: Theme.of(context)
+                      .textTheme
+                      .titleMedium
+                      ?.copyWith(fontWeight: FontWeight.bold),
+                ),
+              ),
+              if (_level > 0)
+                TextButton(
+                  onPressed: () => setState(() => _level--),
+                  child: const Text('上一级'),
+                ),
+              const SizedBox(width: 8),
+            ],
+          ),
+          const Divider(height: 1),
+          Expanded(
+            child: ListView.separated(
+              itemCount: nodes.length,
+              separatorBuilder: (_, __) => const Divider(height: 1),
+              itemBuilder: (context, index) {
+                final node = nodes[index];
+                final isSelected = _isSelected(node);
+                return ListTile(
+                  title: Text(node.name),
+                  trailing: isSelected
+                      ? Icon(Icons.check,
+                          color: Theme.of(context).colorScheme.primary)
+                      : const Icon(Icons.chevron_right),
+                  onTap: () => _onSelect(node),
+                );
+              },
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+
+  bool _isSelected(RegionNode node) {
+    if (_level == 0) return node.code == _provinceCode;
+    if (_level == 1) return node.code == _cityCode;
+    return node.code == _districtCode;
+  }
+}