msglist: Add MessageListTheme.streamRecipientHeaderChevronRight

The dark-theme variant is copied from the web app.

Author: chrisbobbe

lib/widgets/message_list.dart

@@ -32,6 +32,7 @@ class MessageListTheme extends ThemeExtension<MessageListTheme> {
  dmRecipientHeaderBg: const HSLColor.fromAHSL(1, 46, 0.35, 0.93).toColor(),
  recipientHeaderText: const HSLColor.fromAHSL(1, 0, 0, 0.15).toColor(),
  streamMessageBgDefault: Colors.white,
+ streamRecipientHeaderChevronRight: Colors.black.withOpacity(0.3),
 
  // From the Figma mockup at:
  // https://www.figma.com/file/1JTNtYo9memgW7vV6d0ygq/Zulip-Mobile?node-id=132-9684
@@ -53,6 +54,7 @@ class MessageListTheme extends ThemeExtension<MessageListTheme> {
  dmRecipientHeaderBg: const HSLColor.fromAHSL(1, 46, 0.15, 0.2).toColor(),
  recipientHeaderText: const HSLColor.fromAHSL(0.8, 0, 0, 1).toColor(),
  streamMessageBgDefault: const HSLColor.fromAHSL(1, 0, 0, 0.15).toColor(),
+ streamRecipientHeaderChevronRight: Colors.white.withOpacity(0.3),
 
  // 0.75 opacity from here:
  // https://www.figma.com/design/1JTNtYo9memgW7vV6d0ygq/Zulip-Mobile?node-id=807-33998&m=dev
@@ -72,6 +74,7 @@ class MessageListTheme extends ThemeExtension<MessageListTheme> {
  required this.dmRecipientHeaderBg,
  required this.recipientHeaderText,
  required this.streamMessageBgDefault,
+ required this.streamRecipientHeaderChevronRight,
  required this.unreadMarker,
  required this.unreadMarkerGap,
  required this.unsubscribedStreamRecipientHeaderBg,
@@ -91,6 +94,7 @@ class MessageListTheme extends ThemeExtension<MessageListTheme> {
  final Color dmRecipientHeaderBg;
  final Color recipientHeaderText;
  final Color streamMessageBgDefault;
+ final Color streamRecipientHeaderChevronRight;
  final Color unreadMarker;
  final Color unreadMarkerGap;
  final Color unsubscribedStreamRecipientHeaderBg;
@@ -101,6 +105,7 @@ class MessageListTheme extends ThemeExtension<MessageListTheme> {
  Color? dmRecipientHeaderBg,
  Color? recipientHeaderText,
  Color? streamMessageBgDefault,
+ Color? streamRecipientHeaderChevronRight,
  Color? unreadMarker,
  Color? unreadMarkerGap,
  Color? unsubscribedStreamRecipientHeaderBg,
@@ -110,6 +115,7 @@ class MessageListTheme extends ThemeExtension<MessageListTheme> {
  dmRecipientHeaderBg: dmRecipientHeaderBg ?? this.dmRecipientHeaderBg,
  recipientHeaderText: recipientHeaderText ?? this.recipientHeaderText,
  streamMessageBgDefault: streamMessageBgDefault ?? this.streamMessageBgDefault,
+ streamRecipientHeaderChevronRight: streamRecipientHeaderChevronRight ?? this.streamRecipientHeaderChevronRight,
  unreadMarker: unreadMarker ?? this.unreadMarker,
  unreadMarkerGap: unreadMarkerGap ?? this.unreadMarkerGap,
  unsubscribedStreamRecipientHeaderBg: unsubscribedStreamRecipientHeaderBg ?? this.unsubscribedStreamRecipientHeaderBg,
@@ -126,6 +132,7 @@ class MessageListTheme extends ThemeExtension<MessageListTheme> {
  dmRecipientHeaderBg: Color.lerp(streamMessageBgDefault, other.dmRecipientHeaderBg, t)!,
  recipientHeaderText: Color.lerp(recipientHeaderText, other.recipientHeaderText, t)!,
  streamMessageBgDefault: Color.lerp(streamMessageBgDefault, other.streamMessageBgDefault, t)!,
+ streamRecipientHeaderChevronRight: Color.lerp(streamRecipientHeaderChevronRight, other.streamRecipientHeaderChevronRight, t)!,
  unreadMarker: Color.lerp(unreadMarker, other.unreadMarker, t)!,
  unreadMarkerGap: Color.lerp(unreadMarkerGap, other.unreadMarkerGap, t)!,
  unsubscribedStreamRecipientHeaderBg: Color.lerp(unsubscribedStreamRecipientHeaderBg, other.unsubscribedStreamRecipientHeaderBg, t)!,
@@ -886,7 +893,7 @@ class StreamMessageRecipientHeader extends StatelessWidget {
  // Icon is 16px wide here so horizontal padding is 1px.
  padding: const EdgeInsets.symmetric(horizontal: 1),
  child: Icon(size: 16,
- color: Colors.black.withOpacity(0.3),
+ color: messageListTheme.streamRecipientHeaderChevronRight,
  ZulipIcons.chevron_right)),
  ]));
  }