feat: add elevation and centerTitle to ThreadHeader and ChannelListHeader

packages/stream_chat_flutter/lib/src/channel_header.dart

@@ -170,7 +170,7 @@ class ChannelHeader extends StatelessWidget implements PreferredSizeWidget {
                     ),
                   ),
                 ],
-            centerTitle: _getEffectiveCenterTitle(theme),
+            centerTitle: centerTitle,
             title: InkWell(
               onTap: onTitleTap,
               child: SizedBox(
@@ -202,24 +202,4 @@ class ChannelHeader extends StatelessWidget implements PreferredSizeWidget {
 
   @override
   final Size preferredSize;
-
-  /// Returns the effective center title for the current theme and platform.
-  ///
-  /// This code is aligned with the [AppBar]'s [AppBar.centerTitle].
-  bool _getEffectiveCenterTitle(ThemeData theme) {
-    if (centerTitle != null) return centerTitle!;
-    if (theme.appBarTheme.centerTitle != null) {
-      return theme.appBarTheme.centerTitle!;
-    }
-    switch (theme.platform) {
-      case TargetPlatform.android:
-      case TargetPlatform.fuchsia:
-      case TargetPlatform.linux:
-      case TargetPlatform.windows:
-        return false;
-      case TargetPlatform.iOS:
-      case TargetPlatform.macOS:
-        return actions == null || actions!.length < 2;
-    }
-  }
 }

packages/stream_chat_flutter/lib/src/channel_list_header.dart

@@ -56,9 +56,11 @@ class ChannelListHeader extends StatelessWidget implements PreferredSizeWidget {
     this.showConnectionStateTile = false,
     this.preNavigationCallback,
     this.subtitle,
+    this.centerTitle,
     this.leading,
     this.actions,
     this.backgroundColor,
+    this.elevation,
   }) : super(key: key);
 
   /// Pass this if you don't have a [StreamChatClient] in your widget tree.
@@ -83,6 +85,9 @@ class ChannelListHeader extends StatelessWidget implements PreferredSizeWidget {
   /// Subtitle widget
   final Widget? subtitle;
 
+  /// Whether the title should be centered
+  final bool? centerTitle;
+
   /// Leading widget
   /// By default it shows the logged in user avatar
   final Widget? leading;
@@ -94,6 +99,9 @@ class ChannelListHeader extends StatelessWidget implements PreferredSizeWidget {
   /// The background color for this [ChannelListHeader].
   final Color? backgroundColor;
 
+  /// The elevation for this [ChannelListHeader].
+  final double? elevation;
+
   @override
   Widget build(BuildContext context) {
     final _client = client ?? StreamChat.of(context).client;
@@ -128,10 +136,10 @@ class ChannelListHeader extends StatelessWidget implements PreferredSizeWidget {
             systemOverlayStyle: theme.brightness == Brightness.dark
                 ? SystemUiOverlayStyle.light
                 : SystemUiOverlayStyle.dark,
-            elevation: 1,
+            elevation: elevation ?? 1,
             backgroundColor:
                 backgroundColor ?? channelListHeaderThemeData.color,
-            centerTitle: true,
+            centerTitle: centerTitle,
             leading: leading ??
                 Center(
                   child: user != null

packages/stream_chat_flutter/lib/src/thread_header.dart

@@ -65,11 +65,13 @@ class ThreadHeader extends StatelessWidget implements PreferredSizeWidget {
     this.onBackPressed,
     this.title,
     this.subtitle,
+    this.centerTitle,
     this.leading,
     this.actions,
     this.onTitleTap,
     this.showTypingIndicator = true,
     this.backgroundColor,
+    this.elevation,
   })  : preferredSize = const Size.fromHeight(kToolbarHeight),
         super(key: key);
 
@@ -92,6 +94,9 @@ class ThreadHeader extends StatelessWidget implements PreferredSizeWidget {
   /// Subtitle widget
   final Widget? subtitle;
 
+  /// Whether the title should be centered
+  final bool? centerTitle;
+
   /// Leading widget
   final Widget? leading;
 
@@ -105,6 +110,9 @@ class ThreadHeader extends StatelessWidget implements PreferredSizeWidget {
   /// The background color of this [ThreadHeader].
   final Color? backgroundColor;
 
+  /// The elevation for this [ThreadHeader].
+  final double? elevation;
+
   @override
   Widget build(BuildContext context) {
     final channelHeaderTheme = ChannelHeaderTheme.of(context);
@@ -134,7 +142,7 @@ class ThreadHeader extends StatelessWidget implements PreferredSizeWidget {
       systemOverlayStyle: theme.brightness == Brightness.dark
           ? SystemUiOverlayStyle.light
           : SystemUiOverlayStyle.dark,
-      elevation: 1,
+      elevation: elevation ?? 1,
       leading: leading ??
           (showBackButton
               ? StreamBackButton(
@@ -144,7 +152,7 @@ class ThreadHeader extends StatelessWidget implements PreferredSizeWidget {
                 )
               : const SizedBox()),
       backgroundColor: backgroundColor ?? channelHeaderTheme.color,
-      centerTitle: true,
+      centerTitle: centerTitle,
       actions: actions,
       title: InkWell(
         onTap: onTitleTap,