Enhance Tabs (#5496)

* improve how `ElevatedButton` handles style

* initial commit

* docs

* update .pre-commit-config.yaml

* update Taskfile.yml

* updates

* use a custom `TabController` | remove `initial_index` in favor of `selected_index`

* examples

* fix tests

* make `get_event_field_type` protected

* move `get_event_field_type` to module level

* Tabs inherits from AdaptiveControl

* revert: Tabs inherits from AdaptiveControl

* `GestureDetector` example

* Fix for FletPageDisconnectedException

* conditional creation of ButtonStyle

* fix tests

---------

Co-authored-by: Feodor Fitsner <[email protected]>

Author: ndonkoHenri

packages/flet/lib/src/controls/button.dart

@@ -88,7 +88,8 @@ class _ButtonControlState extends State<ButtonControl> with FletStoreMixin {
 
     var theme = Theme.of(context);
 
-    var style = widget.control.getButtonStyle("style", Theme.of(context),
+    var style = parseButtonStyle(
+        widget.control.internals?["style"], Theme.of(context),
         defaultForegroundColor: widget.control
             .getColor("color", context, theme.colorScheme.primary)!,
         defaultBackgroundColor: widget.control