Fix selection menu not showing after clear (#37042)

This allows the text selection menu to be shown after deleting all text in a text field.

packages/flutter/lib/src/widgets/editable_text.dart

@@ -1061,7 +1061,7 @@ class EditableTextState extends State<EditableText> with AutomaticKeepAliveClien
       return;
     }
     if (value.text != _value.text) {
-      _hideSelectionOverlayIfNeeded();
+      hideToolbar();
       _showCaretOnScreen();
       if (widget.obscureText && value.text.length == _value.text.length + 1) {
         _obscureShowCharTicksPending = _kObscureShowLatestCharCursorTicks;
@@ -1300,11 +1300,6 @@ class EditableTextState extends State<EditableText> with AutomaticKeepAliveClien
     }
   }
 
-  void _hideSelectionOverlayIfNeeded() {
-    _selectionOverlay?.hide();
-    _selectionOverlay = null;
-  }
-
   void _updateOrDisposeSelectionOverlayIfNeeded() {
     if (_selectionOverlay != null) {
       if (_hasFocus) {
@@ -1323,7 +1318,8 @@ class EditableTextState extends State<EditableText> with AutomaticKeepAliveClien
     // EditableWidget, not just changes triggered by user gestures.
     requestKeyboard();
 
-    _hideSelectionOverlayIfNeeded();
+    _selectionOverlay?.hide();
+    _selectionOverlay = null;
 
     if (widget.selectionControls != null) {
       _selectionOverlay = TextSelectionOverlay(

packages/flutter/test/widgets/editable_text_test.dart

@@ -16,7 +16,7 @@ import 'package:flutter/foundation.dart';
 import 'editable_text_utils.dart';
 import 'semantics_tester.dart';
 
-final TextEditingController controller = TextEditingController();
+TextEditingController controller;
 final FocusNode focusNode = FocusNode(debugLabel: 'EditableText Node');
 final FocusScopeNode focusScopeNode = FocusScopeNode(debugLabel: 'EditableText Scope Node');
 const TextStyle textStyle = TextStyle();
@@ -29,6 +29,12 @@ enum HandlePositionInViewport {
 void main() {
   setUp(() {
     debugResetSemanticsIdCounter();
+    controller = TextEditingController();
+  });
+
+  tearDown(() {
+    controller.dispose();
+    controller = null;
   });
 
   // Tests that the desired keyboard action button is requested.
@@ -528,7 +534,7 @@ void main() {
         equals('TextInputAction.done'));
   });
 
-  testWidgets('can only show toolbar when there is text and a selection', (WidgetTester tester) async {
+  testWidgets('can show toolbar when there is text and a selection', (WidgetTester tester) async {
     await tester.pumpWidget(
       MaterialApp(
         home: EditableText(
@@ -545,17 +551,12 @@ void main() {
     final EditableTextState state =
         tester.state<EditableTextState>(find.byType(EditableText));
 
+    // Can't show the toolbar when there's no focus.
     expect(state.showToolbar(), false);
     await tester.pump();
     expect(find.text('PASTE'), findsNothing);
 
-    controller.text = 'blah';
+    // Can show the toolbar when focused even though there's no text.
-    await tester.pump();
-    expect(state.showToolbar(), false);
-    await tester.pump();
-    expect(find.text('PASTE'), findsNothing);
-
-    // Select something. Doesn't really matter what.
     state.renderEditable.selectWordsInRange(
       from: const Offset(0, 0),
       cause: SelectionChangedCause.tap,
@@ -564,6 +565,58 @@ void main() {
     expect(state.showToolbar(), true);
     await tester.pump();
     expect(find.text('PASTE'), findsOneWidget);
+
+    // Hide the menu again.
+    state.hideToolbar();
+    await tester.pump();
+    expect(find.text('PASTE'), findsNothing);
+
+    // Can show the menu with text and a selection.
+    controller.text = 'blah';
+    await tester.pump();
+    expect(state.showToolbar(), true);
+    await tester.pump();
+    expect(find.text('PASTE'), findsOneWidget);
+  });
+
+  testWidgets('can show the toolbar after clearing all text', (WidgetTester tester) async {
+    // Regression test for https://github.com/flutter/flutter/issues/35998.
+    await tester.pumpWidget(
+      MaterialApp(
+        home: EditableText(
+          backgroundCursorColor: Colors.grey,
+          controller: controller,
+          focusNode: focusNode,
+          style: textStyle,
+          cursorColor: cursorColor,
+          selectionControls: materialTextSelectionControls,
+        ),
+      ),
+    );
+
+    final EditableTextState state =
+        tester.state<EditableTextState>(find.byType(EditableText));
+
+    // Add text and an empty selection.
+    controller.text = 'blah';
+    await tester.pump();
+    state.renderEditable.selectWordsInRange(
+      from: const Offset(0, 0),
+      cause: SelectionChangedCause.tap,
+    );
+    await tester.pump();
+
+    // Clear the text and selection.
+    expect(find.text('PASTE'), findsNothing);
+    state.updateEditingValue(const TextEditingValue(
+      text: '',
+    ));
+    await tester.pump();
+
+    // Should be able to show the toolbar.
+    expect(state.showToolbar(), true);
+    await tester.pump();
+    expect(find.text('PASTE'), findsOneWidget);
   });
 
   testWidgets('Fires onChanged when text changes via TextSelectionOverlay', (WidgetTester tester) async {