feat: add listHeaderBuilder

CHANGELOG.md

@@ -1,7 +1,7 @@
 ## 4.0.0
 
 - Add a serviceBuilder to the userstory configuration
-
+- Add a listHeaderBuilder for showing a header at the top of the list of posts in the timeline
 
 ## 3.0.1
 

packages/flutter_timeline_view/lib/src/config/timeline_options.dart

@@ -52,6 +52,7 @@ class TimelineOptions {
     this.maxContentLength,
     this.categorySelectorButtonBuilder,
     this.postOverviewButtonBuilder,
+    this.listHeaderBuilder,
     this.titleInputDecoration,
     this.contentInputDecoration,
   });
@@ -156,6 +157,11 @@ class TimelineOptions {
     String text,
   )? categorySelectorButtonBuilder;
 
+  /// This widgetbuilder is placed at the top of the list of posts and can be
+  ///  used to add custom elements
+  final Widget Function(BuildContext context, String? category)?
+      listHeaderBuilder;
+
   /// Builder for the post overview button
   /// on the timeline post overview screen
   final Widget Function(

packages/flutter_timeline_view/lib/src/screens/timeline_screen.dart

@@ -223,6 +223,9 @@ class _TimelineScreenState extends State<TimelineScreen> {
                 child: Column(
                   mainAxisSize: MainAxisSize.min,
                   children: [
+                    /// Add a optional custom header to the list of posts
+                    widget.options.listHeaderBuilder?.call(context, category) ??
+                        const SizedBox.shrink(),
                     ...posts.map(
                       (post) => Padding(
                         padding: widget.options.postPadding,