Test DataTable (#7591)

This patch adds a basic test for the DataTable widget.

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

@@ -219,10 +219,11 @@ class DataCell {
 ///
 /// See also:
 ///
-///  * [DataColumn]
-///  * [DataRow]
-///  * [DataCell]
-///  * [PaginatedDataTable]
+///  * [DataColumn], which describes a column in the data table.
+///  * [DataRow], which contains the data for a row in the data table.
+///  * [DataCell], which contains the data for a single cell in the data table.
+///  * [PaginatedDataTable], which shows part of the data in a data table and
+///    provides controls for paging through the remainder of the data.
 ///  * <https://material.google.com/components/data-tables.html>
 class DataTable extends StatelessWidget {
   /// Creates a widget describing a data table.

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

@@ -22,8 +22,18 @@ import 'icons.dart';
 import 'progress_indicator.dart';
 import 'theme.dart';
 
-/// A wrapper for [DataTable] that obtains data lazily from a [DataTableSource]
-/// and displays it one page at a time. The widget is presented as a [Card].
+/// A material design data table that shows data using multiple pages.
+///
+/// A paginated data table shows [rowsPerPage] rows of data per page and
+/// provies controls for showing other pages.
+///
+/// Data is read lazily from from a [DataTableSource]. The widget is presented
+/// as a [Card].
+///
+/// See also:
+///
+///  * [DataTable], which is not paginated.
+///  * <https://material.io/guidelines/components/data-tables.html#data-tables-tables-within-cards>
 class PaginatedDataTable extends StatefulWidget {
   /// Creates a widget describing a paginated [DataTable] on a [Card].
   ///

packages/flutter/test/material/data_table_test.dart

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+class Dessert {
+  Dessert(this.name, this.calories, this.fat, this.carbs, this.protein, this.sodium, this.calcium, this.iron);
+
+  final String name;
+  final int calories;
+  final double fat;
+  final int carbs;
+  final double protein;
+  final int sodium;
+  final int calcium;
+  final int iron;
+}
+
+final List<Dessert> kDesserts = <Dessert>[
+  new Dessert('Frozen yogurt',                        159,  6.0,  24,  4.0,  87, 14,  1),
+  new Dessert('Ice cream sandwich',                   237,  9.0,  37,  4.3, 129,  8,  1),
+  new Dessert('Eclair',                               262, 16.0,  24,  6.0, 337,  6,  7),
+  new Dessert('Cupcake',                              305,  3.7,  67,  4.3, 413,  3,  8),
+  new Dessert('Gingerbread',                          356, 16.0,  49,  3.9, 327,  7, 16),
+  new Dessert('Jelly bean',                           375,  0.0,  94,  0.0,  50,  0,  0),
+  new Dessert('Lollipop',                             392,  0.2,  98,  0.0,  38,  0,  2),
+  new Dessert('Honeycomb',                            408,  3.2,  87,  6.5, 562,  0, 45),
+  new Dessert('Donut',                                452, 25.0,  51,  4.9, 326,  2, 22),
+  new Dessert('KitKat',                               518, 26.0,  65,  7.0,  54, 12,  6),
+];
+
+void main() {
+  testWidgets('DataTable control test', (WidgetTester tester) async {
+    List<String> log = <String>[];
+
+    Widget buildTable({ int sortColumnIndex, bool sortAscending: true }) {
+      return new DataTable(
+        sortColumnIndex: sortColumnIndex,
+        sortAscending: sortAscending,
+        onSelectAll: (bool value) {
+          log.add('select-all: $value');
+        },
+        columns: <DataColumn>[
+          new DataColumn(
+            label: new Text('Name'),
+            tooltip: 'Name',
+          ),
+          new DataColumn(
+            label: new Text('Calories'),
+            tooltip: 'Calories',
+            numeric: true,
+            onSort: (int columnIndex, bool ascending) {
+              log.add('column-sort: $columnIndex $ascending');
+            }
+          ),
+        ],
+        rows: kDesserts.map((Dessert dessert) {
+          return new DataRow(
+            key: new Key(dessert.name),
+            onSelectChanged: (bool selected) {
+              log.add('row-selected: ${dessert.name}');
+            },
+            cells: <DataCell>[
+              new DataCell(
+                new Text(dessert.name),
+              ),
+              new DataCell(
+                new Text('${dessert.calories}'),
+                showEditIcon: true,
+                onTap: () {
+                  log.add('cell-tap: ${dessert.calories}');
+                },
+              ),
+            ],
+          );
+        }).toList(),
+      );
+    }
+
+    await tester.pumpWidget(new MaterialApp(
+      home: new Material(child: buildTable())
+    ));
+
+    await tester.tap(find.byType(Checkbox).first);
+
+    expect(log, <String>['select-all: true']);
+    log.clear();
+
+    await tester.tap(find.text('Cupcake'));
+
+    expect(log, <String>['row-selected: Cupcake']);
+    log.clear();
+
+    await tester.tap(find.text('Calories'));
+
+    expect(log, <String>['column-sort: 1 true']);
+    log.clear();
+
+    await tester.pumpWidget(new MaterialApp(
+      home: new Material(child: buildTable(sortColumnIndex: 1))
+    ));
+    await tester.pumpUntilNoTransientCallbacks(const Duration(milliseconds: 200));
+    await tester.tap(find.text('Calories'));
+
+    expect(log, <String>['column-sort: 1 false']);
+    log.clear();
+
+    await tester.pumpWidget(new MaterialApp(
+      home: new Material(child: buildTable(sortColumnIndex: 1, sortAscending: false))
+    ));
+    await tester.pumpUntilNoTransientCallbacks(const Duration(milliseconds: 200));
+
+    await tester.tap(find.text('375'));
+
+    expect(log, <String>['cell-tap: 375']);
+    log.clear();
+
+    await tester.tap(find.byType(Checkbox).last);
+
+    expect(log, <String>['row-selected: KitKat']);
+    log.clear();
+  });
+}