Remove single-view assumption from material library (#117486)

* Remove single-view assumption from material library

* one widget

Author: goderbauer

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

@@ -1358,9 +1358,9 @@ class _DropdownButtonState<T> extends State<DropdownButton<T>> with WidgetsBindi
   Orientation _getOrientation(BuildContext context) {
     Orientation? result = MediaQuery.maybeOrientationOf(context);
     if (result == null) {
-      // If there's no MediaQuery, then use the window aspect to determine
+      // If there's no MediaQuery, then use the view aspect to determine
       // orientation.
-      final Size size = WidgetsBinding.instance.window.physicalSize;
+      final Size size = View.of(context).physicalSize;
       result = size.width > size.height ? Orientation.landscape : Orientation.portrait;
     }
     return result;

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

@@ -2053,7 +2053,7 @@ class _HourMinuteTextFieldState extends State<_HourMinuteTextField> with Restora
     // If screen reader is in use, make the hint text say hours/minutes.
     // Otherwise, remove the hint text when focused because the centered cursor
     // appears odd above the hint text.
-    final String? hintText = MediaQuery.accessibleNavigationOf(context) || WidgetsBinding.instance.window.semanticsEnabled
+    final String? hintText = MediaQuery.accessibleNavigationOf(context) || View.of(context).platformDispatcher.semanticsEnabled
         ? widget.semanticHintText
         : (focusNode.hasFocus ? null : _formattedValue);
 

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

@@ -117,7 +117,9 @@ abstract class WidgetsBindingObserver {
   ///   @override
   ///   void initState() {
   ///     super.initState();
-  ///     _lastSize = WidgetsBinding.instance.window.physicalSize;
+  ///     // [View.of] exposes the view from `WidgetsBinding.instance.platformDispatcher.views`
+  ///     // into which this widget is drawn.
+  ///     _lastSize = View.of(context).physicalSize;
   ///     WidgetsBinding.instance.addObserver(this);
   ///   }
   ///
@@ -129,7 +131,7 @@ abstract class WidgetsBindingObserver {
   ///
   ///   @override
   ///   void didChangeMetrics() {
-  ///     setState(() { _lastSize = WidgetsBinding.instance.window.physicalSize; });
+  ///     setState(() { _lastSize = View.of(context).physicalSize; });
   ///   }
   ///
   ///   @override
@@ -186,7 +188,7 @@ abstract class WidgetsBindingObserver {
   ///
   ///   @override
   ///   void didChangeTextScaleFactor() {
-  ///     setState(() { _lastTextScaleFactor = WidgetsBinding.instance.window.textScaleFactor; });
+  ///     setState(() { _lastTextScaleFactor = WidgetsBinding.instance.platformDispatcher.textScaleFactor; });
   ///   }
   ///
   ///   @override