Custom height parameters for DataTable header and data rows (#33535)

* Custom dataRowHeight for DataTable and PaginatedDataTable

* Custom headingRowHeight for DataTable and PaginatedDataTable

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

@@ -262,6 +262,8 @@ class DataTable extends StatelessWidget {
     this.sortColumnIndex,
     this.sortAscending = true,
     this.onSelectAll,
+    this.dataRowHeight = 48.0,
+    this.headingRowHeight = 56.0,
     this.horizontalMargin = 24.0,
     this.columnSpacing = 56.0,
     @required this.rows,
@@ -269,6 +271,8 @@ class DataTable extends StatelessWidget {
        assert(columns.isNotEmpty),
        assert(sortColumnIndex == null || (sortColumnIndex >= 0 && sortColumnIndex < columns.length)),
        assert(sortAscending != null),
+       assert(dataRowHeight != null),
+       assert(headingRowHeight != null),
        assert(horizontalMargin != null),
        assert(columnSpacing != null),
        assert(rows != null),
@@ -315,6 +319,16 @@ class DataTable extends StatelessWidget {
   /// row is selectable.
   final ValueSetter<bool> onSelectAll;
 
+  /// The height of each row (excluding the row that contains column headings).
+  ///
+  /// This value defaults to 48.0 to adhere to the Material Design specifications.
+  final double dataRowHeight;
+
+  /// The height of the heading row.
+  ///
+  /// This value defaults to 56.0 to adhere to the Material Design specifications.
+  final double headingRowHeight;
+
   /// The horizontal margin between the edges of the table and the content
   /// in the first and last cells of each row.
   ///
@@ -330,7 +344,9 @@ class DataTable extends StatelessWidget {
   final double columnSpacing;
 
   /// The data to show in each row (excluding the row that contains
-  /// the column headings). Must be non-null, but may be empty.
+  /// the column headings).
+  ///
+  /// Must be non-null, but may be empty.
   final List<DataRow> rows;
 
   // Set by the constructor to the index of the only Column that is
@@ -367,8 +383,6 @@ class DataTable extends StatelessWidget {
     }
   }
 
-  static const double _headingRowHeight = 56.0;
-  static const double _dataRowHeight = 48.0;
   static const double _sortArrowPadding = 2.0;
   static const double _headingFontSize = 12.0;
   static const Duration _sortArrowAnimationDuration = Duration(milliseconds: 150);
@@ -430,14 +444,14 @@ class DataTable extends StatelessWidget {
     }
     label = Container(
       padding: padding,
-      height: _headingRowHeight,
+      height: headingRowHeight,
       alignment: numeric ? Alignment.centerRight : AlignmentDirectional.centerStart,
       child: AnimatedDefaultTextStyle(
         style: TextStyle(
           // TODO(ianh): font family should match Theme; see https://github.com/flutter/flutter/issues/3116
           fontWeight: FontWeight.w500,
           fontSize: _headingFontSize,
-          height: math.min(1.0, _headingRowHeight / _headingFontSize),
+          height: math.min(1.0, headingRowHeight / _headingFontSize),
           color: (Theme.of(context).brightness == Brightness.light)
             ? ((onSort != null && sorted) ? Colors.black87 : Colors.black54)
             : ((onSort != null && sorted) ? Colors.white : Colors.white70),
@@ -483,7 +497,7 @@ class DataTable extends StatelessWidget {
     }
     label = Container(
       padding: padding,
-      height: _dataRowHeight,
+      height: dataRowHeight,
       alignment: numeric ? Alignment.centerRight : AlignmentDirectional.centerStart,
       child: DefaultTextStyle(
         style: TextStyle(

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

@@ -70,6 +70,8 @@ class PaginatedDataTable extends StatefulWidget {
     this.sortColumnIndex,
     this.sortAscending = true,
     this.onSelectAll,
+    this.dataRowHeight = 48.0,
+    this.headingRowHeight = 56.0,
     this.horizontalMargin = 24.0,
     this.columnSpacing = 56.0,
     this.initialFirstRowIndex = 0,
@@ -85,6 +87,8 @@ class PaginatedDataTable extends StatefulWidget {
        assert(columns.isNotEmpty),
        assert(sortColumnIndex == null || (sortColumnIndex >= 0 && sortColumnIndex < columns.length)),
        assert(sortAscending != null),
+       assert(dataRowHeight != null),
+       assert(headingRowHeight != null),
        assert(horizontalMargin != null),
        assert(columnSpacing != null),
        assert(rowsPerPage != null),
@@ -135,6 +139,16 @@ class PaginatedDataTable extends StatefulWidget {
   /// See [DataTable.onSelectAll].
   final ValueSetter<bool> onSelectAll;
 
+  /// The height of each row (excluding the row that contains column headings).
+  ///
+  /// This value is optional and defaults to 48.0 if not specified.
+  final double dataRowHeight;
+
+  /// The height of the heading row.
+  ///
+  /// This value is optional and defaults to 56.0 if not specified.
+  final double headingRowHeight;
+
   /// The horizontal margin between the edges of the table and the content
   /// in the first and last cells of each row.
   ///
@@ -448,6 +462,8 @@ class PaginatedDataTableState extends State<PaginatedDataTable> {
               sortColumnIndex: widget.sortColumnIndex,
               sortAscending: widget.sortAscending,
               onSelectAll: widget.onSelectAll,
+              dataRowHeight: widget.dataRowHeight,
+              headingRowHeight: widget.headingRowHeight,
               horizontalMargin: widget.horizontalMargin,
               columnSpacing: widget.columnSpacing,
               rows: _getRows(_firstRowIndex, widget.rowsPerPage),

packages/flutter/test/material/data_table_test.dart

@@ -267,6 +267,123 @@ void main() {
     expect(tester.takeException(), isNull);
   });
 
+  testWidgets('DataTable custom row height', (WidgetTester tester) async {
+    Widget buildCustomTable({
+      int sortColumnIndex,
+      bool sortAscending = true,
+      double dataRowHeight = 48.0,
+      double headingRowHeight = 56.0,
+    }) {
+      return DataTable(
+        sortColumnIndex: sortColumnIndex,
+        sortAscending: sortAscending,
+        onSelectAll: (bool value) {},
+        dataRowHeight: dataRowHeight,
+        headingRowHeight: headingRowHeight,
+        columns: <DataColumn>[
+          const DataColumn(
+            label: Text('Name'),
+            tooltip: 'Name',
+          ),
+          DataColumn(
+            label: const Text('Calories'),
+            tooltip: 'Calories',
+            numeric: true,
+            onSort: (int columnIndex, bool ascending) {},
+          ),
+        ],
+        rows: kDesserts.map<DataRow>((Dessert dessert) {
+          return DataRow(
+            key: Key(dessert.name),
+            onSelectChanged: (bool selected) {},
+            cells: <DataCell>[
+              DataCell(
+                Text(dessert.name),
+              ),
+              DataCell(
+                Text('${dessert.calories}'),
+                showEditIcon: true,
+                onTap: () {},
+              ),
+            ],
+          );
+        }).toList(),
+      );
+    }
+
+    // DEFAULT VALUES
+    await tester.pumpWidget(MaterialApp(
+      home: Material(
+        child: DataTable(
+          onSelectAll: (bool value) {},
+          columns: <DataColumn>[
+            const DataColumn(
+              label: Text('Name'),
+              tooltip: 'Name',
+            ),
+            DataColumn(
+              label: const Text('Calories'),
+              tooltip: 'Calories',
+              numeric: true,
+              onSort: (int columnIndex, bool ascending) {},
+            ),
+          ],
+          rows: kDesserts.map<DataRow>((Dessert dessert) {
+            return DataRow(
+              key: Key(dessert.name),
+              onSelectChanged: (bool selected) {},
+              cells: <DataCell>[
+                DataCell(
+                  Text(dessert.name),
+                ),
+                DataCell(
+                  Text('${dessert.calories}'),
+                  showEditIcon: true,
+                  onTap: () {},
+                ),
+              ],
+            );
+          }).toList(),
+        ),
+      ),
+    ));
+    expect(tester.renderObject<RenderBox>(
+      find.widgetWithText(Container, 'Name')
+    ).size.height, 56.0); // This is the header row height
+    expect(tester.renderObject<RenderBox>(
+      find.widgetWithText(Container, 'Frozen yogurt')
+    ).size.height, 48.0); // This is the data row height
+
+    // CUSTOM VALUES
+    await tester.pumpWidget(MaterialApp(
+      home: Material(child: buildCustomTable(headingRowHeight: 48.0)),
+    ));
+    expect(tester.renderObject<RenderBox>(
+      find.widgetWithText(Container, 'Name')
+    ).size.height, 48.0);
+
+    await tester.pumpWidget(MaterialApp(
+      home: Material(child: buildCustomTable(headingRowHeight: 64.0)),
+    ));
+    expect(tester.renderObject<RenderBox>(
+      find.widgetWithText(Container, 'Name')
+    ).size.height, 64.0);
+
+    await tester.pumpWidget(MaterialApp(
+      home: Material(child: buildCustomTable(dataRowHeight: 30.0)),
+    ));
+    expect(tester.renderObject<RenderBox>(
+      find.widgetWithText(Container, 'Frozen yogurt')
+    ).size.height, 30.0);
+
+    await tester.pumpWidget(MaterialApp(
+      home: Material(child: buildCustomTable(dataRowHeight: 56.0)),
+    ));
+    expect(tester.renderObject<RenderBox>(
+      find.widgetWithText(Container, 'Frozen yogurt')
+    ).size.height, 56.0);
+  });
+
   testWidgets('DataTable custom horizontal padding - checkbox', (WidgetTester tester) async {
     const double _defaultHorizontalMargin = 24.0;
     const double _defaultColumnSpacing = 56.0;

packages/flutter/test/material/paginated_data_table_test.dart

@@ -296,6 +296,86 @@ void main() {
     expect(find.text('Rows per page:'), findsOneWidget);
     expect(tester.getTopLeft(find.text('Rows per page:')).dx, 18.0); // 14 padding in the footer row, 4 padding from the card
   });
+  testWidgets('PaginatedDataTable custom row height', (WidgetTester tester) async {
+    final TestDataSource source = TestDataSource();
+
+    Widget buildCustomHeightPaginatedTable({
+      double dataRowHeight = 48.0,
+      double headingRowHeight = 56.0,
+    }) {
+      return PaginatedDataTable(
+        header: const Text('Test table'),
+        source: source,
+        rowsPerPage: 2,
+        availableRowsPerPage: const <int>[
+          2, 4, 8, 16,
+        ],
+        onRowsPerPageChanged: (int rowsPerPage) {},
+        onPageChanged: (int rowIndex) {},
+        columns: const <DataColumn>[
+          DataColumn(label: Text('Name')),
+          DataColumn(label: Text('Calories'), numeric: true),
+          DataColumn(label: Text('Generation')),
+        ],
+        dataRowHeight: dataRowHeight,
+        headingRowHeight: headingRowHeight,
+      );
+    }
+
+    // DEFAULT VALUES
+    await tester.pumpWidget(MaterialApp(
+      home: PaginatedDataTable(
+        header: const Text('Test table'),
+        source: source,
+        rowsPerPage: 2,
+        availableRowsPerPage: const <int>[
+          2, 4, 8, 16,
+        ],
+        onRowsPerPageChanged: (int rowsPerPage) {},
+        onPageChanged: (int rowIndex) {},
+        columns: const <DataColumn>[
+          DataColumn(label: Text('Name')),
+          DataColumn(label: Text('Calories'), numeric: true),
+          DataColumn(label: Text('Generation')),
+        ],
+      ),
+    ));
+    expect(tester.renderObject<RenderBox>(
+      find.widgetWithText(Container, 'Name').first
+    ).size.height, 56.0); // This is the header row height
+    expect(tester.renderObject<RenderBox>(
+      find.widgetWithText(Container, 'Frozen yogurt (0)').first
+    ).size.height, 48.0); // This is the data row height
+
+    // CUSTOM VALUES
+    await tester.pumpWidget(MaterialApp(
+      home: Material(child: buildCustomHeightPaginatedTable(headingRowHeight: 48.0)),
+    ));
+    expect(tester.renderObject<RenderBox>(
+      find.widgetWithText(Container, 'Name').first
+    ).size.height, 48.0);
+
+    await tester.pumpWidget(MaterialApp(
+      home: Material(child: buildCustomHeightPaginatedTable(headingRowHeight: 64.0)),
+    ));
+    expect(tester.renderObject<RenderBox>(
+      find.widgetWithText(Container, 'Name').first
+    ).size.height, 64.0);
+
+    await tester.pumpWidget(MaterialApp(
+      home: Material(child: buildCustomHeightPaginatedTable(dataRowHeight: 30.0)),
+    ));
+    expect(tester.renderObject<RenderBox>(
+      find.widgetWithText(Container, 'Frozen yogurt (0)').first
+    ).size.height, 30.0);
+
+    await tester.pumpWidget(MaterialApp(
+      home: Material(child: buildCustomHeightPaginatedTable(dataRowHeight: 56.0)),
+    ));
+    expect(tester.renderObject<RenderBox>(
+      find.widgetWithText(Container, 'Frozen yogurt (0)').first
+    ).size.height, 56.0);
+  });
 
   testWidgets('PaginatedDataTable custom horizontal padding - checkbox', (WidgetTester tester) async {
     const double _defaultHorizontalMargin = 24.0;