♻️ Separate AssetPickerDelegate (#315)

Author: AlexV525

lib/src/delegates/asset_picker_delegate.dart

@@ -0,0 +1,280 @@
+///
+/// [Author] Alex (https://github.com/AlexV525)
+/// [Date] 2022/05/05 11:25
+///
+// ignore_for_file: deprecated_member_use
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:photo_manager/photo_manager.dart';
+
+import '../constants/config.dart';
+import '../constants/constants.dart';
+import '../internal/methods.dart';
+import '../internal/singleton.dart';
+import '../provider/asset_picker_provider.dart';
+import '../widget/asset_picker.dart';
+import '../widget/asset_picker_page_route.dart';
+import 'asset_picker_builder_delegate.dart';
+
+class AssetPickerDelegate {
+  const AssetPickerDelegate();
+
+  /// {@template wechat_assets_picker.delegates.AssetPickerDelegate.permissionCheck}
+  /// Request the current [PermissionState] of required permissions.
+  /// 请求所需权限的 [PermissionState]。
+  ///
+  /// Throws a [StateError] when the state is not [PermissionState.authorized]
+  /// or [PermissionState.limited],
+  /// which means the picker can not perform further actions.
+  /// 当权限状态不是 [PermissionState.authorized] 或 [PermissionState.limited] 时，
+  /// 将抛出 [StateError]，此时选择器无法执行其他操作。
+  ///
+  /// See also:
+  ///  * [PermissionState] which defined all states of required permissions.
+  /// {@endtemplate}
+  Future<PermissionState> permissionCheck() async {
+    final PermissionState _ps = await PhotoManager.requestPermissionExtend();
+    if (_ps != PermissionState.authorized && _ps != PermissionState.limited) {
+      throw StateError('Permission state error with $_ps.');
+    }
+    return _ps;
+  }
+
+  /// {@template wechat_assets_picker.delegates.AssetPickerDelegate.pickAssets}
+  /// Pick assets with the given [pickerConfig].
+  /// 根据给定的 [pickerConfig] 选择资源。
+  ///
+  /// Set [useRootNavigator] to determine
+  /// whether the picker route should use the root [Navigator].
+  /// 使用 [useRootNavigator] 来控制选择器的路由是否使用最顶层的 [Navigator]。
+  ///
+  /// By extending the [AssetPickerPageRoute], users can customize the route
+  /// and use it with the [pageRouteBuilder].
+  /// 继承 [AssetPickerPageRoute] 可以自定义路由，
+  /// 并且通过 [pageRouteBuilder] 进行使用。
+  ///
+  /// See also:
+  ///  * [AssetPickerConfig] which holds all configurations for basic picking.
+  ///  * [DefaultAssetPickerProvider] which is the default provider that
+  ///    manages assets during the picking process.
+  ///  * [DefaultAssetPickerBuilderDelegate] which is the default builder that
+  ///    builds all widgets during the picking process.
+  /// {@endtemplate}
+  Future<List<AssetEntity>?> pickAssets(
+    BuildContext context, {
+    AssetPickerConfig pickerConfig = const AssetPickerConfig(),
+    bool useRootNavigator = true,
+    AssetPickerPageRouteBuilder<List<AssetEntity>>? pageRouteBuilder,
+  }) async {
+    final PermissionState _ps = await permissionCheck();
+    final DefaultAssetPickerProvider provider = DefaultAssetPickerProvider(
+      maxAssets: pickerConfig.maxAssets,
+      pageSize: pickerConfig.pageSize,
+      pathThumbnailSize: pickerConfig.pathThumbnailSize,
+      selectedAssets: pickerConfig.selectedAssets,
+      requestType: pickerConfig.requestType,
+      sortPathDelegate: pickerConfig.sortPathDelegate,
+      filterOptions: pickerConfig.filterOptions,
+    );
+    final Widget picker = AssetPicker<AssetEntity, AssetPathEntity>(
+      key: Singleton.pickerKey,
+      builder: DefaultAssetPickerBuilderDelegate(
+        provider: provider,
+        initialPermission: _ps,
+        gridCount: pickerConfig.gridCount,
+        pickerTheme: pickerConfig.pickerTheme,
+        gridThumbnailSize: pickerConfig.gridThumbnailSize,
+        previewThumbnailSize: pickerConfig.previewThumbnailSize,
+        specialPickerType: pickerConfig.specialPickerType,
+        specialItemPosition: pickerConfig.specialItemPosition,
+        specialItemBuilder: pickerConfig.specialItemBuilder,
+        loadingIndicatorBuilder: pickerConfig.loadingIndicatorBuilder,
+        selectPredicate: pickerConfig.selectPredicate,
+        shouldRevertGrid: pickerConfig.shouldRevertGrid,
+        limitedPermissionOverlayPredicate:
+            pickerConfig.limitedPermissionOverlayPredicate,
+        pathNameBuilder: pickerConfig.pathNameBuilder,
+        textDelegate: pickerConfig.textDelegate,
+        themeColor: pickerConfig.themeColor,
+        locale: Localizations.maybeLocaleOf(context),
+      ),
+    );
+    final List<AssetEntity>? result = await Navigator.of(
+      context,
+      rootNavigator: useRootNavigator,
+    ).push<List<AssetEntity>>(
+      pageRouteBuilder?.call(picker) ??
+          AssetPickerPageRoute<List<AssetEntity>>(builder: (_) => picker),
+    );
+    return result;
+  }
+
+  /// {@template wechat_assets_picker.delegates.AssetPickerDelegate.pickAssetsWithDelegate}
+  /// Pick assets with the given [delegate].
+  /// 根据给定的 [delegate] 选择资源。
+  ///
+  /// Set [useRootNavigator] to determine
+  /// whether the picker route should use the root [Navigator].
+  /// 使用 [useRootNavigator] 来控制选择器的路由是否使用最顶层的 [Navigator]。
+  ///
+  /// By extending the [AssetPickerPageRoute], users can customize the route
+  /// and use it with the [pageRouteBuilder].
+  /// 继承 [AssetPickerPageRoute] 可以自定义路由，
+  /// 并且通过 [pageRouteBuilder] 进行使用。
+  ///
+  /// See also:
+  ///  * [AssetPickerBuilderDelegate] for how to customize/override widgets
+  ///    during the picking process.
+  /// {@endtemplate}
+  Future<List<Asset>?> pickAssetsWithDelegate<Asset, Path,
+      PickerProvider extends AssetPickerProvider<Asset, Path>>(
+    BuildContext context, {
+    required AssetPickerBuilderDelegate<Asset, Path> delegate,
+    bool useRootNavigator = true,
+    AssetPickerPageRouteBuilder<List<Asset>>? pageRouteBuilder,
+  }) async {
+    await permissionCheck();
+    final Widget picker = AssetPicker<Asset, Path>(
+      key: Singleton.pickerKey,
+      builder: delegate,
+    );
+    final List<Asset>? result = await Navigator.of(
+      context,
+      rootNavigator: useRootNavigator,
+    ).push<List<Asset>>(
+      pageRouteBuilder?.call(picker) ??
+          AssetPickerPageRoute<List<Asset>>(builder: (_) => picker),
+    );
+    return result;
+  }
+
+  /// {@template wechat_assets_picker.delegates.AssetPickerDelegate.registerObserve}
+  /// Register observe callback with assets changes.
+  /// 注册资源（图库）变化的监听回调
+  /// @{endtemplate}
+  void registerObserve([ValueChanged<MethodCall>? callback]) {
+    if (callback == null) {
+      return;
+    }
+    try {
+      PhotoManager.addChangeCallback(callback);
+      PhotoManager.startChangeNotify();
+    } catch (e) {
+      realDebugPrint('Error when registering assets callback: $e');
+    }
+  }
+
+  /// {@template wechat_assets_picker.delegates.AssetPickerDelegate.unregisterObserve}
+  /// Unregister the observation callback with assets changes.
+  /// 取消注册资源（图库）变化的监听回调
+  /// @{endtemplate}
+  void unregisterObserve([ValueChanged<MethodCall>? callback]) {
+    if (callback == null) {
+      return;
+    }
+    try {
+      PhotoManager.removeChangeCallback(callback);
+      PhotoManager.stopChangeNotify();
+    } catch (e) {
+      realDebugPrint('Error when unregistering assets callback: $e');
+    }
+  }
+
+  /// {@template wechat_assets_picker.delegates.AssetPickerDelegate.themeData}
+  /// Build a [ThemeData] with the given [themeColor] for the picker.
+  /// 为选择器构建基于 [themeColor] 的 [ThemeData]。
+  ///
+  /// If [themeColor] is null, the color will use the fallback
+  /// [defaultThemeColorWeChat] which is the default color in the WeChat design.
+  /// 如果 [themeColor] 为 null，主题色将回落使用 [defaultThemeColorWeChat]，
+  /// 即微信设计中的绿色主题色。
+  ///
+  /// Set [light] to true if pickers require a light version of the theme.
+  /// 设置 [light] 为 true 时可以获取浅色版本的主题。
+  /// {@endtemplate}
+  ThemeData themeData(Color? themeColor, {bool light = false}) {
+    themeColor ??= defaultThemeColorWeChat;
+    if (light) {
+      return ThemeData.light().copyWith(
+        primaryColor: Colors.grey[50],
+        primaryColorLight: Colors.grey[50],
+        primaryColorDark: Colors.grey[50],
+        canvasColor: Colors.grey[100],
+        scaffoldBackgroundColor: Colors.grey[50],
+        bottomAppBarColor: Colors.grey[50],
+        cardColor: Colors.grey[50],
+        highlightColor: Colors.transparent,
+        toggleableActiveColor: themeColor,
+        textSelectionTheme: TextSelectionThemeData(
+          cursorColor: themeColor,
+          selectionColor: themeColor.withAlpha(100),
+          selectionHandleColor: themeColor,
+        ),
+        indicatorColor: themeColor,
+        appBarTheme: const AppBarTheme(
+          systemOverlayStyle: SystemUiOverlayStyle(
+            statusBarBrightness: Brightness.light,
+            statusBarIconBrightness: Brightness.dark,
+          ),
+          elevation: 0,
+        ),
+        buttonTheme: ButtonThemeData(buttonColor: themeColor),
+        colorScheme: ColorScheme(
+          primary: Colors.grey[50]!,
+          primaryVariant: Colors.grey[50]!,
+          secondary: themeColor,
+          secondaryVariant: themeColor,
+          background: Colors.grey[50]!,
+          surface: Colors.grey[50]!,
+          brightness: Brightness.light,
+          error: const Color(0xffcf6679),
+          onPrimary: Colors.white,
+          onSecondary: Colors.white,
+          onSurface: Colors.black,
+          onBackground: Colors.black,
+          onError: Colors.white,
+        ),
+      );
+    }
+    return ThemeData.dark().copyWith(
+      primaryColor: Colors.grey[900],
+      primaryColorLight: Colors.grey[900],
+      primaryColorDark: Colors.grey[900],
+      canvasColor: Colors.grey[850],
+      scaffoldBackgroundColor: Colors.grey[900],
+      bottomAppBarColor: Colors.grey[900],
+      cardColor: Colors.grey[900],
+      highlightColor: Colors.transparent,
+      toggleableActiveColor: themeColor,
+      textSelectionTheme: TextSelectionThemeData(
+        cursorColor: themeColor,
+        selectionColor: themeColor.withAlpha(100),
+        selectionHandleColor: themeColor,
+      ),
+      indicatorColor: themeColor,
+      appBarTheme: const AppBarTheme(
+        systemOverlayStyle: SystemUiOverlayStyle(
+          statusBarBrightness: Brightness.dark,
+          statusBarIconBrightness: Brightness.light,
+        ),
+        elevation: 0,
+      ),
+      buttonTheme: ButtonThemeData(buttonColor: themeColor),
+      colorScheme: ColorScheme(
+        primary: Colors.grey[900]!,
+        primaryVariant: Colors.grey[900]!,
+        secondary: themeColor,
+        secondaryVariant: themeColor,
+        background: Colors.grey[900]!,
+        surface: Colors.grey[900]!,
+        brightness: Brightness.dark,
+        error: const Color(0xffcf6679),
+        onPrimary: Colors.black,
+        onSecondary: Colors.black,
+        onSurface: Colors.white,
+        onBackground: Colors.white,
+        onError: Colors.black,
+      ),
+    );
+  }
+}