emoji_reaction [nfc]: Make EmojiReactionTheme.{light,dark} static finals

Like we did for MessageListTheme in the previous commit and
DesignVariables in dcc8123.

Author: chrisbobbe

lib/widgets/emoji_reaction.dart

@@ -16,38 +16,36 @@ import 'theme.dart';
 
 /// Emoji-reaction styles that differ between light and dark themes.
 class EmojiReactionTheme extends ThemeExtension<EmojiReactionTheme> {
-  EmojiReactionTheme.light() :
-    this._(
-      bgSelected: Colors.white,
-
-      // TODO shadow effect, following web, which uses `box-shadow: inset`:
-      //   https://developer.mozilla.org/en-US/docs/Web/CSS/box-shadow#inset
-      //   Needs Flutter support for something like that:
-      //     https://github.com/flutter/flutter/issues/18636
-      //     https://github.com/flutter/flutter/issues/52999
-      //   Until then use a solid color; a much-lightened version of the shadow color.
-      //   Also adapt by making [borderUnselected] more transparent, so we'll
-      //   want to check that against web when implementing the shadow.
-      bgUnselected: const HSLColor.fromAHSL(0.08, 210, 0.50, 0.875).toColor(),
-
-      borderSelected: Colors.black.withValues(alpha: 0.45),
-
-      // TODO see TODO on [bgUnselected] about shadow effect
-      borderUnselected: Colors.black.withValues(alpha: 0.05),
-
-      textSelected: const HSLColor.fromAHSL(1, 210, 0.20, 0.20).toColor(),
-      textUnselected: const HSLColor.fromAHSL(1, 210, 0.20, 0.25).toColor(),
-    );
-
-  EmojiReactionTheme.dark() :
-    this._(
-      bgSelected: Colors.black.withValues(alpha: 0.8),
-      bgUnselected: Colors.black.withValues(alpha: 0.3),
-      borderSelected: Colors.white.withValues(alpha: 0.75),
-      borderUnselected: Colors.white.withValues(alpha: 0.15),
-      textSelected: Colors.white.withValues(alpha: 0.85),
-      textUnselected: Colors.white.withValues(alpha: 0.75),
-    );
+  static final light = EmojiReactionTheme._(
+    bgSelected: Colors.white,
+
+    // TODO shadow effect, following web, which uses `box-shadow: inset`:
+    //   https://developer.mozilla.org/en-US/docs/Web/CSS/box-shadow#inset
+    //   Needs Flutter support for something like that:
+    //     https://github.com/flutter/flutter/issues/18636
+    //     https://github.com/flutter/flutter/issues/52999
+    //   Until then use a solid color; a much-lightened version of the shadow color.
+    //   Also adapt by making [borderUnselected] more transparent, so we'll
+    //   want to check that against web when implementing the shadow.
+    bgUnselected: const HSLColor.fromAHSL(0.08, 210, 0.50, 0.875).toColor(),
+
+    borderSelected: Colors.black.withValues(alpha: 0.45),
+
+    // TODO see TODO on [bgUnselected] about shadow effect
+    borderUnselected: Colors.black.withValues(alpha: 0.05),
+
+    textSelected: const HSLColor.fromAHSL(1, 210, 0.20, 0.20).toColor(),
+    textUnselected: const HSLColor.fromAHSL(1, 210, 0.20, 0.25).toColor(),
+  );
+
+  static final dark = EmojiReactionTheme._(
+    bgSelected: Colors.black.withValues(alpha: 0.8),
+    bgUnselected: Colors.black.withValues(alpha: 0.3),
+    borderSelected: Colors.white.withValues(alpha: 0.75),
+    borderUnselected: Colors.white.withValues(alpha: 0.15),
+    textSelected: Colors.white.withValues(alpha: 0.85),
+    textUnselected: Colors.white.withValues(alpha: 0.75),
+  );
 
   EmojiReactionTheme._({
     required this.bgSelected,

lib/widgets/theme.dart

@@ -30,7 +30,7 @@ ThemeData zulipThemeData(BuildContext context) {
       themeExtensions = [
         ContentTheme.light(context),
         designVariables,
-        EmojiReactionTheme.light(),
+        EmojiReactionTheme.light,
         MessageListTheme.light,
       ];
     }
@@ -39,7 +39,7 @@ ThemeData zulipThemeData(BuildContext context) {
       themeExtensions = [
         ContentTheme.dark(context),
         designVariables,
-        EmojiReactionTheme.dark(),
+        EmojiReactionTheme.dark,
         MessageListTheme.dark,
       ];
     }

test/widgets/emoji_reaction_test.dart

@@ -251,25 +251,25 @@ void main() {
     }
 
     check(backgroundColor('smile')).isNotNull()
-      .isSameColorAs(EmojiReactionTheme.light().bgSelected);
+      .isSameColorAs(EmojiReactionTheme.light.bgSelected);
     check(backgroundColor('tada')).isNotNull()
-      .isSameColorAs(EmojiReactionTheme.light().bgUnselected);
+      .isSameColorAs(EmojiReactionTheme.light.bgUnselected);
 
     tester.platformDispatcher.platformBrightnessTestValue = Brightness.dark;
     await tester.pump();
 
     await tester.pump(kThemeAnimationDuration * 0.4);
-    final expectedLerped = EmojiReactionTheme.light().lerp(EmojiReactionTheme.dark(), 0.4);
+    final expectedLerped = EmojiReactionTheme.light.lerp(EmojiReactionTheme.dark, 0.4);
     check(backgroundColor('smile')).isNotNull()
       .isSameColorAs(expectedLerped.bgSelected);
     check(backgroundColor('tada')).isNotNull()
       .isSameColorAs(expectedLerped.bgUnselected);
 
     await tester.pump(kThemeAnimationDuration * 0.6);
     check(backgroundColor('smile')).isNotNull()
-      .isSameColorAs(EmojiReactionTheme.dark().bgSelected);
+      .isSameColorAs(EmojiReactionTheme.dark.bgSelected);
     check(backgroundColor('tada')).isNotNull()
-      .isSameColorAs(EmojiReactionTheme.dark().bgUnselected);
+      .isSameColorAs(EmojiReactionTheme.dark.bgUnselected);
   });
 
   testWidgets('use emoji font', (tester) async {