api: Bring stream-color int parsing out to the "crunchy shell"

Author: chrisbobbe

lib/api/model/model.dart

@@ -319,7 +319,16 @@ class Subscription {
   final bool isMuted;
   // final bool? inHomeView; // deprecated; ignore
 
-  final String color;
+  /// As an int that dart:ui's Color constructor will take:
+  ///   <https://api.flutter.dev/flutter/dart-ui/Color/Color.html>
+  @JsonKey(readValue: _readColor)
+  final int color;
+
+  static Object? _readColor(Map json, String key) {
+    final str = (json[key] as String);
+    assert(RegExp(r'^#[0-9a-f]{6}$').hasMatch(str));
+    return 0xff000000 | int.parse(str.substring(1), radix: 16);
+  }
 
   Subscription({
     required this.streamId,

lib/api/model/model.g.dart

@@ -485,13 +485,6 @@ class _UnreadMarker extends StatelessWidget {
   }
 }
 
-Color colorForStream(Subscription? subscription) {
-  final color = subscription?.color;
-  if (color == null) return const Color(0x00c2c2c2);
-  assert(RegExp(r'^#[0-9a-f]{6}$').hasMatch(color));
-  return Color(0xff000000 | int.parse(color.substring(1), radix: 16));
-}
-
 class StreamTopicRecipientHeader extends StatelessWidget {
   const StreamTopicRecipientHeader({super.key, required this.message});
 
@@ -506,7 +499,7 @@ class StreamTopicRecipientHeader extends StatelessWidget {
     final topic = message.subject;
 
     final subscription = store.subscriptions[message.streamId];
-    final streamColor = colorForStream(subscription);
+    final streamColor = Color(subscription?.color ?? 0x00c2c2c2);
     final contrastingColor =
       ThemeData.estimateBrightnessForColor(streamColor) == Brightness.dark
         ? Colors.white

lib/widgets/message_list.dart

@@ -65,6 +65,20 @@ void main() {
     });
   });
 
+  group('Subscription', () {
+    test('converts color to int', () {
+      Subscription subWithColor(String color) {
+        return Subscription.fromJson(
+          deepToJson(eg.subscription(stream: eg.stream())) as Map<String, dynamic>
+            ..['color'] = color,
+        );
+      }
+      check(subWithColor('#e79ab5').color).equals(0xffe79ab5);
+      check(subWithColor('#ffffff').color).equals(0xffffffff);
+      check(subWithColor('#000000').color).equals(0xff000000);
+    });
+  });
+
   group('Message', () {
     test('no crash on unrecognized flag', () {
       final m1 = Message.fromJson(

test/api/model/model_test.dart

@@ -134,7 +134,7 @@ Subscription subscription({
   String? emailAddress,
   bool? isMuted,
   bool? isWebPublic,
-  String? color,
+  int? color,
   int? streamPostPolicy,
   int? messageRetentionDays,
   bool? historyPublicToSubscribers,
@@ -158,7 +158,7 @@ Subscription subscription({
     emailAddress: emailAddress ?? '[email protected]', // TODO generate example data
     isMuted: isMuted ?? true,
     isWebPublic: isWebPublic ?? true,
-    color: color ?? '#e79ab5',
+    color: color ?? 0xffe79ab5,
     streamPostPolicy: streamPostPolicy ?? 1,
     messageRetentionDays: messageRetentionDays ?? 365,
     historyPublicToSubscribers: historyPublicToSubscribers ?? true,