feat(ui_kit-ui_components): Modify the theme resolver to utilize the theme helper and streamline the logic

packages/wyatt_ui_components/lib/src/core/utils/theme_helper.dart

@@ -0,0 +1,49 @@
+// Copyright (C) 2023 WYATT GROUP
+// Please see the AUTHORS file for details.
+//
+// super program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// any later version.
+//
+// super program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with super program. If not, see <https://www.gnu.org/licenses/>.
+
+/// A helper class for getting theme elements.
+abstract class ThemeHelper {
+  /// Gets a theme element from a list of styles.
+  /// Styles are checked in order, and the first one that passes the
+  /// [valueValidator] is returned.
+  /// Style elements are transformed using the [transform] function.
+  ///
+  /// [styles]: A list of styles that need to be checked.
+  /// [transform]: A function that transforms each style element
+  /// to a [T] type.
+  /// [valueValidator]: An optional validation function that
+  /// determines if a style element is valid.
+  /// [combine]: A function that combines two [P] type objects to create
+  /// a new object.
+
+  static T? getThemeElement<P, T>(
+    List<P?>? styles, {
+    required T? Function(P?)? transform,
+    bool? Function(P?)? valueValidator,
+    P? Function(P?, P?)? combine,
+  }) {
+    final Iterable<P?>? validStyles = styles?.where(
+      (element) => valueValidator?.call(element) ?? (element != null),
+    );
+    return (validStyles?.isNotEmpty ?? false)
+        ? transform?.call(
+            validStyles?.reduce(
+              (value, element) => combine?.call(value, element) ?? value,
+            ),
+          )
+        : null;
+  }
+}

packages/wyatt_ui_components/lib/src/core/utils/theme_resolver.dart

@@ -15,6 +15,7 @@
 // along with this program. If not, see <https://www.gnu.org/licenses/>.
 
 import 'package:flutter/material.dart';
+import 'package:wyatt_ui_components/src/core/utils/theme_helper.dart';
 import 'package:wyatt_ui_components/src/domain/entities/theme_style.dart';
 
 /// {@template theme_resolver}
@@ -38,52 +39,35 @@ abstract class ThemeResolver<S extends ThemeStyle<S>, T, E> {
   S? Function(BuildContext context, {E? extra}) get customStyleFn;
 
   /// Compute default value from Flutter Theme or with hardcoded values.
-  S computeDefaultValue(BuildContext context, {E? extra});
-
-  S? computeExtensionValueFn(
-    BuildContext context,
-    T themeExtension, {
+  S computeDefaultValue(
+    BuildContext context, {
     E? extra,
   });
 
-  /// Compute values from the extension if found
-  S? _computeExtensionValue(
-    BuildContext context, {
+  /// Compute extension value from custom component extension.
+  S? computeExtensionValueFn(
+    BuildContext context,
+    T? themeExtension, {
     E? extra,
-  }) {
-    final themeExtension = Theme.of(context).extension<T>();
-    if (themeExtension != null) {
-      return computeExtensionValueFn(
-        context,
-        themeExtension,
-        extra: extra,
-      );
-    }
-    return null;
-  }
-
-  /// Compute custom value
-  S? _computeCustomValue(
-    BuildContext context, {
-    E? extra,
-  }) {
-    final customStyle = customStyleFn(
-      context,
-      extra: extra,
-    );
-    if (customStyle != null) {
-      return customStyle;
-    }
-    return null;
-  }
+  });
 
   /// Choose most suitable style for a given context.
   S negotiate(BuildContext context, {E? extra}) {
-    S style = computeDefaultValue(context, extra: extra);
-    style =
-        style.mergeWith(_computeExtensionValue(context, extra: extra)) ?? style;
-    style =
-        style.mergeWith(_computeCustomValue(context, extra: extra)) ?? style;
-    return style;
+    final style = computeDefaultValue(context, extra: extra);
+    return ThemeHelper.getThemeElement<S, S>(
+          [
+            style,
+            computeExtensionValueFn(
+              context,
+              Theme.of(context).extension<T>(),
+              extra: extra,
+            ),
+            // _computeExtensionValue(context, extra: extra),
+            customStyleFn(context, extra: extra)
+          ],
+          transform: (value) => value,
+          combine: (value, element) => value?.mergeWith(element),
+        ) ??
+        style;
   }
 }

packages/wyatt_ui_components/lib/src/core/utils/utils.dart

@@ -16,4 +16,5 @@
 
 export 'multi_color.dart';
 export 'text_wrapper.dart';
+export 'theme_helper.dart';
 export 'theme_resolver.dart';