Fix Tooltip obscured by keyboard (#103339)

packages/flutter/lib/src/material/tooltip.dart

@@ -841,6 +841,7 @@ class _TooltipOverlay extends StatelessWidget {
       );
     }
     return Positioned.fill(
+      bottom: MediaQuery.maybeOf(context)?.viewInsets.bottom ?? 0.0,
       child: CustomSingleChildLayout(
         delegate: _TooltipPositionDelegate(
           target: target,

packages/flutter/test/material/tooltip_test.dart

@@ -489,6 +489,61 @@ void main() {
     expect(tip.localToGlobal(tip.size.bottomRight(Offset.zero)).dy, equals(324.0));
   });
 
+  testWidgets('Tooltip should be fully visible when MediaQuery.viewInsets > 0', (WidgetTester tester) async {
+    // Regression test for https://github.com/flutter/flutter/issues/23666
+    Widget materialAppWithViewInsets(double viewInsetsHeight) {
+      final Widget scaffold = Scaffold(
+        body: const TextField(),
+        floatingActionButton: FloatingActionButton(
+          tooltip: tooltipText,
+          onPressed: () { /* do nothing */ },
+          child: const Icon(Icons.add),
+        ),
+      );
+      return MediaQuery.fromWindow(
+        child: MediaQuery(
+          data: MediaQueryData(
+            viewInsets: EdgeInsets.only(bottom: viewInsetsHeight),
+          ),
+          child: MaterialApp(
+            useInheritedMediaQuery: true,
+            home: scaffold,
+          ),
+        ),
+      );
+    }
+
+    // Start with MediaQuery.viewInsets.bottom = 0
+    await tester.pumpWidget(materialAppWithViewInsets(0));
+
+    // Show FAB tooltip
+    final Finder fabFinder = find.byType(FloatingActionButton);
+    await tester.longPress(fabFinder);
+    await tester.pump(const Duration(milliseconds: 500));
+    expect(find.byType(Tooltip), findsOneWidget);
+
+    // FAB tooltip should be above FAB
+    RenderBox tip = tester.renderObject(_findTooltipContainer(tooltipText));
+    Offset fabTopRight = tester.getTopRight(fabFinder);
+    Offset tooltipTopRight = tip.localToGlobal(tip.size.topRight(Offset.zero));
+    expect(tooltipTopRight.dy < fabTopRight.dy, true);
+
+    // Simulate Keyboard opening (MediaQuery.viewInsets.bottom = 300))
+    await tester.pumpWidget(materialAppWithViewInsets(300));
+    await tester.pumpAndSettle();
+
+    // Show FAB tooltip
+    await tester.longPress(fabFinder);
+    await tester.pump(const Duration(milliseconds: 500));
+    expect(find.byType(Tooltip), findsOneWidget);
+
+    // FAB tooltip should still be above FAB
+    tip = tester.renderObject(_findTooltipContainer(tooltipText));
+    fabTopRight = tester.getTopRight(fabFinder);
+    tooltipTopRight = tip.localToGlobal(tip.size.topRight(Offset.zero));
+    expect(tooltipTopRight.dy < fabTopRight.dy, true);
+  });
+
   testWidgets('Custom tooltip margin', (WidgetTester tester) async {
     const double customMarginValue = 10.0;
     final GlobalKey<TooltipState> tooltipKey = GlobalKey<TooltipState>();