fix: NavigationBarDestination.selected_icon renders wrongly when set to a Control

CHANGELOG.md

@@ -29,6 +29,7 @@
 * Fix `Page.on_resize` and `Page.on_media_change` not firing after mobile orientation changes ([#6457](https://github.com/flet-dev/flet/issues/6457), [#6423](https://github.com/flet-dev/flet/pull/6423)) by @ndonkoHenri.
 * Fix `flet pack` desktop packaging so Windows and Linux bundles include the expected client archive, and Windows taskbar pins point to the packed app instead of the cached `flet.exe` ([#5151](https://github.com/flet-dev/flet/issues/5151), [#6403](https://github.com/flet-dev/flet/pull/6403)) by @ndonkoHenri.
 * Fix environment variable priority in `flet build` template: inherit from `Platform.environment` and use `putIfAbsent` for FLET_* variables so pre-set system env vars are not overwritten ([#6394](https://github.com/flet-dev/flet/pull/6394)) by @Bahtya.
+* Fix `NavigationBarDestination.selected_icon` rendering wrongly when provided as an `Icon` control ([#6460](https://github.com/flet-dev/flet/issues/6460), [#6468](https://github.com/flet-dev/flet/pull/6468)) by @ndonkoHenri.
 * Fix 3- and 4-digit hex color shorthand (e.g. `#c00`, `#fc00`) rendering as invisible by expanding them to their full 6/8-digit forms ([#6419](https://github.com/flet-dev/flet/issues/6419), [#6421](https://github.com/flet-dev/flet/pull/6421)) by @ndonkoHenri.
 * Fix `LineChart` (and other charts) silently dropping custom `ChartAxisLabel` entries whose `value` matched a tick only after floating-point rounding (e.g. `0.1`, `0.2`, `0.3`) by switching label lookup to a tolerance-based comparison scaled to the axis interval ([#6445](https://github.com/flet-dev/flet/issues/6445), [#6459](https://github.com/flet-dev/flet/pull/6459)) by @KangZhaoKui.
 

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

@@ -2,7 +2,6 @@ import 'package:flutter/material.dart';
 
 import '../extensions/control.dart';
 import '../models/control.dart';
-import '../utils/icons.dart';
 import '../utils/numbers.dart';
 import 'base_controls.dart';
 
@@ -15,14 +14,13 @@ class NavigationBarDestinationControl extends StatelessWidget {
   Widget build(BuildContext context) {
     debugPrint("NavigationBarDestination build: ${control.id}");
 
-    var selectedIcon = control.getIconData("selected_icon");
     var child = NavigationDestination(
-        enabled: !control.disabled,
-        tooltip: !control.disabled ? control.getString("tooltip") : null,
-        icon: control.buildIconOrWidget("icon")!,
-        selectedIcon: control.buildWidget("selected_icon") ??
-            (selectedIcon != null ? Icon(selectedIcon) : null),
-        label: control.getString("label", "")!);
+      enabled: !control.disabled,
+      tooltip: !control.disabled ? control.getString("tooltip") : null,
+      icon: control.buildIconOrWidget("icon")!,
+      selectedIcon: control.buildIconOrWidget("selected_icon"),
+      label: control.getString("label", "")!,
+    );
 
     return BaseControl(control: control, child: child);
   }

sdk/python/packages/flet/integration_tests/controls/material/test_navigation_bar.py

@@ -16,15 +16,16 @@ async def test_basic(flet_app: ftt.FletTestApp, request):
     await flet_app.assert_control_screenshot(
         request.node.name,
         ft.NavigationBar(
+            selected_index=2,
             destinations=[
                 ft.NavigationBarDestination(icon=ft.Icons.EXPLORE, label="Explore"),
                 ft.NavigationBarDestination(icon=ft.Icons.COMMUTE, label="Commute"),
                 ft.NavigationBarDestination(
                     icon=ft.Icons.BOOKMARK_BORDER,
-                    selected_icon=ft.Icons.BOOKMARK,
+                    selected_icon=ft.Icon(ft.Icons.BOOKMARK),
                     label="Favorites",
                 ),
-            ]
+            ],
         ),
     )