Dashboard webview hybrid composition support

lib/widgets/tb_app_bar.dart

@@ -12,13 +12,14 @@ class TbAppBar extends TbContextWidget<TbAppBar, _TbAppBarState> implements Pref
   final Widget? title;
   final List<Widget>? actions;
   final double? elevation;
+  final Color? shadowColor;
   final bool showLoadingIndicator;
 
   @override
   final Size preferredSize;
 
   TbAppBar(TbContext tbContext, {this.leading, this.title, this.actions, this.elevation = 8,
-                                 this.showLoadingIndicator = false}) :
+                                 this.shadowColor, this.showLoadingIndicator = false}) :
     preferredSize = Size.fromHeight(kToolbarHeight + (showLoadingIndicator ? 4 : 0)),
     super(tbContext);
 
@@ -68,7 +69,7 @@ class _TbAppBarState extends TbContextState<TbAppBar, _TbAppBarState> {
       title: widget.title,
       actions: widget.actions,
       elevation: widget.elevation,
-      shadowColor: Color(0xFFFFFFFF).withAlpha(150),
+      shadowColor: widget.shadowColor ?? Color(0xFFFFFFFF).withAlpha(150),
     );
   }
 }

lib/widgets/two_value_listenable_builder.dart

@@ -0,0 +1,33 @@
+import 'package:flutter/foundation.dart';
+import 'package:flutter/widgets.dart';
+
+class TwoValueListenableBuilder<A, B> extends StatelessWidget {
+  TwoValueListenableBuilder(
+      {
+        Key? key,
+        required this.firstValueListenable,
+        required this.secondValueListenable,
+        required this.builder,
+        this.child,
+      }) : super(key: key);
+
+  final ValueListenable<A> firstValueListenable;
+  final ValueListenable<B> secondValueListenable;
+  final Widget? child;
+  final Widget Function(BuildContext context, A a, B b, Widget? child) builder;
+
+  @override
+  Widget build(BuildContext context) {
+    return ValueListenableBuilder<A>(
+      valueListenable: firstValueListenable,
+      builder: (_, a, __) {
+        return ValueListenableBuilder<B>(
+          valueListenable: secondValueListenable,
+          builder: (context, b, __) {
+            return builder(context, a, b, child);
+          },
+        );
+      },
+    );
+  }
+}