From 0ff0affb3a9db746f6335846236f69ee24445f1a Mon Sep 17 00:00:00 2001
From: Aman Verma <verma1090aman@gmail.com>
Date: Tue, 10 May 2022 02:04:07 +0530
Subject: [PATCH] Expose controller for PaginatedDataTable (#100005)

---
 .../src/material/paginated_data_table.dart    | 16 +++-
 .../material/paginated_data_table_test.dart   | 82 +++++++++++++++++++
 2 files changed, 97 insertions(+), 1 deletion(-)

diff --git a/packages/flutter/lib/src/material/paginated_data_table.dart b/packages/flutter/lib/src/material/paginated_data_table.dart
index f79abdbab4..82070fe900 100644
--- a/packages/flutter/lib/src/material/paginated_data_table.dart
+++ b/packages/flutter/lib/src/material/paginated_data_table.dart
@@ -86,6 +86,8 @@ class PaginatedDataTable extends StatefulWidget {
     this.arrowHeadColor,
     required this.source,
     this.checkboxHorizontalMargin,
+    this.controller,
+    this.primary,
   }) : assert(actions == null || (actions != null && header != null)),
        assert(columns != null),
        assert(dragStartBehavior != null),
@@ -105,7 +107,11 @@ class PaginatedDataTable extends StatefulWidget {
            assert(availableRowsPerPage != null && availableRowsPerPage.contains(rowsPerPage));
          return true;
        }()),
-       assert(source != null);
+       assert(source != null),
+       assert(!(controller != null && (primary ?? false)),
+          'Primary ScrollViews obtain their ScrollController via inheritance from a PrimaryScrollController widget. '
+          'You cannot both set primary to true and pass an explicit controller.',
+       );
 
   /// The table card's optional header.
   ///
@@ -237,6 +243,12 @@ class PaginatedDataTable extends StatefulWidget {
   /// Defines the color of the arrow heads in the footer.
   final Color? arrowHeadColor;
 
+  /// {@macro flutter.widgets.scroll_view.controller}
+  final ScrollController? controller;
+
+  /// {@macro flutter.widgets.scroll_view.primary}
+  final bool? primary;
+
   @override
   PaginatedDataTableState createState() => PaginatedDataTableState();
 }
@@ -501,6 +513,8 @@ class PaginatedDataTableState extends State<PaginatedDataTable> {
                 ),
               SingleChildScrollView(
                 scrollDirection: Axis.horizontal,
+                primary: widget.primary,
+                controller: widget.controller,
                 dragStartBehavior: widget.dragStartBehavior,
                 child: ConstrainedBox(
                   constraints: BoxConstraints(minWidth: constraints.minWidth),
diff --git a/packages/flutter/test/material/paginated_data_table_test.dart b/packages/flutter/test/material/paginated_data_table_test.dart
index 43c5ce0711..2c148d8edf 100644
--- a/packages/flutter/test/material/paginated_data_table_test.dart
+++ b/packages/flutter/test/material/paginated_data_table_test.dart
@@ -398,6 +398,7 @@ 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();
 
@@ -1043,4 +1044,85 @@ void main() {
     await tester.pumpWidget(buildFrame(overflowBar));
     expect(headerX, tester.getTopLeft(find.byType(ElevatedButton)).dx);
   });
+
+  testWidgets('PaginatedDataTable can be scrolled using ScrollController', (WidgetTester tester) async {
+    final TestDataSource source = TestDataSource();
+    final ScrollController scrollController = ScrollController();
+
+    Widget buildTable(TestDataSource source) {
+      return Align(
+        alignment: Alignment.topLeft,
+        child: SizedBox(
+          width: 100,
+          child: PaginatedDataTable(
+            controller: scrollController,
+            header: const Text('Test table'),
+            source: source,
+            rowsPerPage: 2,
+            columns: const <DataColumn>[
+              DataColumn(
+                label: Text('Name'),
+                tooltip: 'Name',
+              ),
+              DataColumn(
+                label: Text('Calories'),
+                tooltip: 'Calories',
+                numeric: true,
+              ),
+              DataColumn(
+                label: Text('Generation'),
+                tooltip: 'Generation',
+              ),
+            ],
+          ),
+        ),
+      );
+    }
+
+    await tester.pumpWidget(MaterialApp(
+      home: buildTable(source),
+    ));
+
+    // DataTable uses provided ScrollController
+    final Scrollable bodyScrollView = tester.widget(find.byType(Scrollable).first);
+    expect(bodyScrollView.controller, scrollController);
+
+    expect(scrollController.offset, 0.0);
+    scrollController.jumpTo(50.0);
+    await tester.pumpAndSettle();
+
+    expect(scrollController.offset, 50.0);
+  });
+
+  testWidgets('PaginatedDataTable uses PrimaryScrollController when primary ', (WidgetTester tester) async {
+    final ScrollController primaryScrollController = ScrollController();
+    final TestDataSource source = TestDataSource();
+
+    await tester.pumpWidget(
+      MaterialApp(
+        home: PrimaryScrollController(
+          controller: primaryScrollController,
+          child: PaginatedDataTable(
+            primary: true,
+            header: const Text('Test table'),
+            source: source,
+            rowsPerPage: 2,
+            columns: const <DataColumn>[
+              DataColumn(label: Text('Name')),
+              DataColumn(label: Text('Calories'), numeric: true),
+              DataColumn(label: Text('Generation')),
+            ],
+          ),
+        ),
+      )
+    );
+
+    // DataTable uses primaryScrollController
+    final Scrollable bodyScrollView = tester.widget(find.byType(Scrollable).first);
+    expect(bodyScrollView.controller, primaryScrollController);
+
+    // Footer does not use primaryScrollController
+    final Scrollable footerScrollView = tester.widget(find.byType(Scrollable).last);
+    expect(footerScrollView.controller, null);
+  });
 }