added scrimColor property in Scaffold widget (#31025)

AUTHORS

@@ -39,3 +39,4 @@ Marco Scannadinari <m@scannadinari.co.uk>
 Frederik Schweiger <mail@flschweiger.net>
 Martin Staadecker <machstg@gmail.com>
 Igor Katsuba <katsuba.igor@gmail.com>
+Diego Velásquez <diego.velasquez.lopez@gmail.com>

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

@@ -181,6 +181,7 @@ class DrawerController extends StatefulWidget {
     @required this.alignment,
     this.drawerCallback,
     this.dragStartBehavior = DragStartBehavior.start,
+    this.scrimColor = Colors.black54,
   }) : assert(child != null),
        assert(dragStartBehavior != null),
        assert(alignment != null),
@@ -220,6 +221,11 @@ class DrawerController extends StatefulWidget {
   /// {@endtemplate}
   final DragStartBehavior dragStartBehavior;
 
+  /// The color to use for the scrim that obscures primary content while a drawer is open.
+  ///
+  /// By default, the color is [Colors.black54]
+  final Color scrimColor;
+
   @override
   DrawerControllerState createState() => DrawerControllerState();
 }
@@ -231,6 +237,7 @@ class DrawerControllerState extends State<DrawerController> with SingleTickerPro
   @override
   void initState() {
     super.initState();
+    _color = ColorTween(begin: Colors.transparent, end: widget.scrimColor);
     _controller = AnimationController(duration: _kBaseSettleDuration, vsync: this)
       ..addListener(_animationChanged)
       ..addStatusListener(_animationStatusChanged);
@@ -379,7 +386,7 @@ class DrawerControllerState extends State<DrawerController> with SingleTickerPro
       widget.drawerCallback(false);
   }
 
-  final ColorTween _color = ColorTween(begin: Colors.transparent, end: Colors.black54);
+  ColorTween _color;
   final GlobalKey _gestureDetectorKey = GlobalKey();
 
   AlignmentDirectional get _drawerOuterAlignment {

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

@@ -904,6 +904,7 @@ class Scaffold extends StatefulWidget {
     this.primary = true,
     this.drawerDragStartBehavior = DragStartBehavior.start,
     this.extendBody = false,
+    this.drawerScrimColor = Colors.black54,
   }) : assert(primary != null),
        assert(extendBody != null),
        assert(drawerDragStartBehavior != null),
@@ -994,6 +995,11 @@ class Scaffold extends StatefulWidget {
   /// Typically a [Drawer].
   final Widget endDrawer;
 
+  /// The color to use for the scrim that obscures primary content while a drawer is open.
+  ///
+  /// By default, the color is [Colors.black54]
+  final Color drawerScrimColor;
+
   /// The color of the [Material] widget that underlies the entire Scaffold.
   ///
   /// The theme's [ThemeData.scaffoldBackgroundColor] by default.
@@ -1906,6 +1912,7 @@ class ScaffoldState extends State<Scaffold> with TickerProviderStateMixin {
           child: widget.endDrawer,
           drawerCallback: _endDrawerOpenedCallback,
           dragStartBehavior: widget.drawerDragStartBehavior,
+          scrimColor: widget.drawerScrimColor,
         ),
         _ScaffoldSlot.endDrawer,
         // remove the side padding from the side we're not touching
@@ -1928,6 +1935,7 @@ class ScaffoldState extends State<Scaffold> with TickerProviderStateMixin {
           child: widget.drawer,
           drawerCallback: _drawerOpenedCallback,
           dragStartBehavior: widget.drawerDragStartBehavior,
+          scrimColor: widget.drawerScrimColor,
         ),
         _ScaffoldSlot.drawer,
         // remove the side padding from the side we're not touching

packages/flutter/test/material/drawer_test.dart

@@ -106,4 +106,32 @@ void main() {
 
     semantics.dispose();
   });
+
+  testWidgets('Drawer scrimDrawerColor test', (WidgetTester tester) async {
+
+    await tester.pumpWidget(
+      MaterialApp(
+        home: Scaffold(
+          drawerScrimColor: const Color(0xFF323232),
+          drawer: Drawer(),
+        ),
+      ),
+    );
+
+    final ScaffoldState state = tester.firstState(find.byType(Scaffold));
+    state.openDrawer();
+
+    await tester.pump();
+    await tester.pump(const Duration(seconds: 1));
+
+    final Container container = tester.widget<Container>(find.descendant(
+      of: find.byType(Scaffold),
+      matching: find.byType(Container),
+      ).first,
+    );
+
+    final BoxDecoration decoration = container.decoration;
+    expect(decoration.color, const Color(0xFF323232));
+    expect(decoration.shape,  BoxShape.rectangle);
+  });
 }