theme [nfc]: Extract starColor to DesignVariables.

Signed-off-by: Zixuan James Li <[email protected]>

Author: PIG208

lib/widgets/message_list.dart

@@ -896,12 +896,10 @@ class MessageWithPossibleSender extends StatelessWidget {
 
   final MessageListMessageItem item;
 
-  // TODO(#95) unchanged in dark theme?
-  static final _starColor = const HSLColor.fromAHSL(0.5, 47, 1, 0.41).toColor();
-
   @override
   Widget build(BuildContext context) {
     final store = PerAccountStoreWidget.of(context);
+    final theme = DesignVariables.of(context);
 
     final message = item.message;
     final sender = store.users[message.senderId];
@@ -980,7 +978,7 @@ class MessageWithPossibleSender extends StatelessWidget {
                 // Design from Figma at:
                 //   https://www.figma.com/file/1JTNtYo9memgW7vV6d0ygq/Zulip-Mobile?node-id=813%3A28817&mode=dev .
                 ? Padding(padding: const EdgeInsets.only(top: 4),
-                    child: Icon(ZulipIcons.star_filled, size: 16, color: _starColor))
+                    child: Icon(ZulipIcons.star_filled, size: 16, color: theme.starColor))
                 : null),
           ]),
         ])));

lib/widgets/theme.dart

@@ -81,7 +81,8 @@ class DesignVariables extends ThemeExtension<DesignVariables> {
     borderBar = const Color(0x33000000),
     icon = const Color(0xff666699),
     title = const Color(0xff1a1a1a),
-    streamColorSwatches = StreamColorSwatches.light;
+    streamColorSwatches = StreamColorSwatches.light,
+    starColor = const HSLColor.fromAHSL(0.5, 47, 1, 0.41).toColor();
 
   DesignVariables._({
     required this.bgMain,
@@ -90,6 +91,7 @@ class DesignVariables extends ThemeExtension<DesignVariables> {
     required this.icon,
     required this.title,
     required this.streamColorSwatches,
+    required this.starColor,
   });
 
   /// The [DesignVariables] from the context's active theme.
@@ -111,6 +113,9 @@ class DesignVariables extends ThemeExtension<DesignVariables> {
   // Not exactly from the Figma design, but from Vlad anyway.
   final StreamColorSwatches streamColorSwatches;
 
+  // Not named variables in Figma; taken from older Figma drafts, or elsewhere.
+  final Color starColor;
+
   @override
   DesignVariables copyWith({
     Color? bgMain,
@@ -119,6 +124,7 @@ class DesignVariables extends ThemeExtension<DesignVariables> {
     Color? icon,
     Color? title,
     StreamColorSwatches? streamColorSwatches,
+    Color? starColor,
   }) {
     return DesignVariables._(
       bgMain: bgMain ?? this.bgMain,
@@ -127,6 +133,7 @@ class DesignVariables extends ThemeExtension<DesignVariables> {
       icon: icon ?? this.icon,
       title: title ?? this.title,
       streamColorSwatches: streamColorSwatches ?? this.streamColorSwatches,
+      starColor: starColor ?? this.starColor,
     );
   }
 
@@ -142,6 +149,7 @@ class DesignVariables extends ThemeExtension<DesignVariables> {
       icon: Color.lerp(icon, other.icon, t)!,
       title: Color.lerp(title, other.title, t)!,
       streamColorSwatches: StreamColorSwatches.lerp(streamColorSwatches, other.streamColorSwatches, t),
+      starColor: Color.lerp(starColor, other.starColor, t)!,
     );
   }
 }