Switch clients to ScrollGrid (#7752)

The only remaining client of ScrollableGrid (the old version) is Pesto,
which needs AppBar integration.

examples/flutter_gallery/lib/demo/grid_list_demo.dart

@@ -310,9 +310,6 @@ class GridListDemoState extends State<GridListDemo> {
     });
   }
 
-  // When the ScrollableGrid first appears we want the last row to only be
-  // partially visible, to help the user recognize that the grid is scrollable.
-  // The GridListDemoGridDelegate's tileHeightFactor is used for this.
   @override
   Widget build(BuildContext context) {
     final Orientation orientation = MediaQuery.of(context).orientation;

examples/flutter_gallery/lib/gallery/example_code.dart

@@ -203,14 +203,12 @@ class GridLists {
 // START gridlists
 // Creates a scrollable grid list with images
 // loaded from the web.
-new ScrollableGrid(
-  delegate: new FixedColumnCountGridDelegate(
-    columnCount: 3,
-    tileAspectRatio: 1.0,
-    padding: const EdgeInsets.all(4.0),
-    columnSpacing: 4.0,
-    rowSpacing: 4.0
-  ),
+new ScrollGrid.count(
+  crossAxisCount: 3,
+  childAspectRatio: 1.0,
+  padding: const EdgeInsets.all(4.0),
+  mainAxisSpacing: 4.0,
+  crossAxisSpacing: 4.0,
   children: <String>[
     'https://example.com/image-0.jpg',
     'https://example.com/image-1.jpg',
@@ -224,7 +222,7 @@ new ScrollableGrid(
       ),
       child: new Image.network(url, fit: ImageFit.cover)
     );
-  })
+  }).toList(),
 );
 // END
   }

examples/layers/widgets/media_query.dart

@@ -76,14 +76,14 @@ class AdaptiveContainer extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     if (MediaQuery.of(context).size.width < _kGridViewBreakpoint) {
-      return new ScrollableList(
+      return new ScrollView(
         itemExtent: _kListItemExtent,
-        children: names.map((String name) => new AdaptedListItem(name: name))
+        children: names.map((String name) => new AdaptedListItem(name: name)).toList(),
       );
     } else {
-      return new ScrollableGrid(
-        delegate: new MaxTileWidthGridDelegate(maxTileWidth: _kMaxTileWidth),
-        children: names.map((String name) => new AdaptedGridItem(name: name))
+      return new ScrollGrid.extent(
+        maxCrossAxisExtent: _kMaxTileWidth,
+        children: names.map((String name) => new AdaptedGridItem(name: name)).toList(),
       );
     }
   }

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

@@ -4,30 +4,41 @@
 
 import 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';
+import 'package:meta/meta.dart';
 
 /// A tile in a material design grid list.
 ///
-/// A grid list is a [ScrollableGrid] of tiles in a vertical and horizontal
+/// A grid list is a [ScrollGrid] of tiles in a vertical and horizontal
 /// array. Each tile typically contains some visually rich content (e.g., an
 /// image) together with a [GridTileBar] in either a [header] or a [footer].
 ///
 /// See also:
 ///
-///  * [ScrollableGrid]
-///  * [GridTileBar]
+///  * [ScrollGrid], which is a scrollable grid of tiles.
+///  * [GridTileBar], which is typically used in either the [header] or
+///    [footer].
 ///  * <https://material.google.com/components/grid-lists.html>
 class GridTile extends StatelessWidget {
   /// Creates a grid tile.
   ///
   /// Must have a child. Does not typically have both a header and a footer.
-  GridTile({ Key key, this.header, this.footer, @required this.child }) : super(key: key) {
+  GridTile({
+    Key key,
+    this.header,
+    this.footer,
+    @required this.child,
+  }) : super(key: key) {
     assert(child != null);
   }
 
   /// The widget to show over the top of this grid tile.
+  ///
+  /// Typically a [GridTileBar].
   final Widget header;
 
   /// The widget to show over the bottom of this grid tile.
+  ///
+  /// Typically a [GridTileBar].
   final Widget footer;
 
   /// The widget that fills the tile.

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

@@ -28,7 +28,7 @@ class ScrollView extends StatelessWidget {
     this.scrollDirection: Axis.vertical,
     this.initialScrollOffset: 0.0,
     this.itemExtent,
-    this.children,
+    this.children: const <Widget>[],
   }) : super(key: key);
 
   final EdgeInsets padding;
@@ -76,7 +76,7 @@ class ScrollGrid extends StatelessWidget {
     this.scrollDirection: Axis.vertical,
     this.initialScrollOffset: 0.0,
     this.gridDelegate,
-    this.children,
+    this.children: const <Widget>[],
   }) : super(key: key);
 
   ScrollGrid.count({
@@ -88,7 +88,7 @@ class ScrollGrid extends StatelessWidget {
     double mainAxisSpacing: 0.0,
     double crossAxisSpacing: 0.0,
     double childAspectRatio: 1.0,
-    this.children,
+    this.children: const <Widget>[],
   }) : gridDelegate = new SliverGridDelegateWithFixedCrossAxisCount(
     crossAxisCount: crossAxisCount,
     mainAxisSpacing: mainAxisSpacing,
@@ -105,7 +105,7 @@ class ScrollGrid extends StatelessWidget {
     double mainAxisSpacing: 0.0,
     double crossAxisSpacing: 0.0,
     double childAspectRatio: 1.0,
-    this.children,
+    this.children: const <Widget>[],
   }) : gridDelegate = new SliverGridDelegateWithMaxCrossAxisExtent(
     maxCrossAxisExtent: maxCrossAxisExtent,
     mainAxisSpacing: mainAxisSpacing,

packages/flutter/test/widgets/scrollable_grid_test.dart

@@ -7,30 +7,30 @@ import 'package:flutter/widgets.dart';
 import 'package:flutter/rendering.dart';
 
 void main() {
-  testWidgets('ScrollableGrid default control', (WidgetTester tester) async {
-    await tester.pumpWidget(new Center(child: new ScrollableGrid(
-      delegate: new FixedColumnCountGridDelegate(columnCount: 1),
-    )));
+  testWidgets('ScrollGrid default control', (WidgetTester tester) async {
+    await tester.pumpWidget(new Center(
+      child: new ScrollGrid.count(
+        crossAxisCount: 1,
+      ),
+    ));
   });
 
   // Tests https://github.com/flutter/flutter/issues/5522
-  testWidgets('ScrollableGrid displays correct children with nonzero padding', (WidgetTester tester) async {
+  testWidgets('ScrollGrid displays correct children with nonzero padding', (WidgetTester tester) async {
     final EdgeInsets padding = const EdgeInsets.fromLTRB(0.0, 100.0, 0.0, 0.0);
 
     Widget testWidget = new Align(
       child: new SizedBox(
         height: 800.0,
         width: 300.0,  // forces the grid children to be 300..300
-        child: new ScrollableGrid(
-          delegate: new FixedColumnCountGridDelegate(
-            columnCount: 1,
-            padding: padding
-          ),
+        child: new ScrollGrid.count(
+          crossAxisCount: 1,
+          padding: padding,
           children: new List<Widget>.generate(10, (int index) {
             return new Text('$index', key: new ValueKey<int>(index));
-          })
-        )
-      )
+          }).toList(),
+        ),
+      ),
     );
 
     await tester.pumpWidget(testWidget);