Drop redundant `ToggleButtonsStateManager` instances (#1305)

simplistic_editor/lib/main.dart

@@ -310,13 +310,7 @@ class _MyHomePageState extends State<MyHomePage> {
                   child: Row(
                     mainAxisAlignment: MainAxisAlignment.center,
                     children: [
-                      ToggleButtonsStateManager(
+                      Builder(builder: (innerContext) {
-                        isToggleButtonsSelected: _isSelected,
-                        updateToggleButtonsStateOnButtonPressed:
-                            _updateToggleButtonsStateOnButtonPressed,
-                        updateToggleButtonStateOnSelectionChanged:
-                            _updateToggleButtonsStateOnSelectionChanged,
-                        child: Builder(builder: (innerContext) {
                         final ToggleButtonsStateManager manager =
                             ToggleButtonsStateManager.of(innerContext);
 
@@ -331,8 +325,8 @@ class _MyHomePageState extends State<MyHomePage> {
                             manager.toggleButtonsState
                                 .contains(ToggleButtonsState.underline),
                           ],
-                            onPressed: (index) => manager
+                          onPressed: (index) =>
-                                .updateToggleButtonsOnButtonPressed(index),
+                              manager.updateToggleButtonsOnButtonPressed(index),
                           children: const [
                             Icon(Icons.format_bold),
                             Icon(Icons.format_italic),
@@ -340,19 +334,12 @@ class _MyHomePageState extends State<MyHomePage> {
                           ],
                         );
                       }),
-                      ),
                     ],
                   ),
                 ),
                 Expanded(
                   child: Padding(
                     padding: const EdgeInsets.symmetric(horizontal: 35.0),
-                    child: ToggleButtonsStateManager(
-                      isToggleButtonsSelected: _isSelected,
-                      updateToggleButtonsStateOnButtonPressed:
-                          _updateToggleButtonsStateOnButtonPressed,
-                      updateToggleButtonStateOnSelectionChanged:
-                          _updateToggleButtonsStateOnSelectionChanged,
                     child: TextEditingDeltaHistoryManager(
                       history: _textEditingDeltaHistory,
                       updateHistoryOnInput: _updateTextEditingDeltaHistory,
@@ -365,7 +352,6 @@ class _MyHomePageState extends State<MyHomePage> {
                     ),
                   ),
                 ),
-                ),
                 Expanded(
                   child: Column(
                     children: [