[Material] Add contentPadding property to SwitchListTile (#38709)

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

@@ -279,6 +279,7 @@ class SwitchListTile extends StatelessWidget {
     this.subtitle,
     this.isThreeLine = false,
     this.dense,
+    this.contentPadding,
     this.secondary,
     this.selected = false,
   }) : _switchListTileType = _SwitchListTileType.material,
@@ -310,6 +311,7 @@ class SwitchListTile extends StatelessWidget {
     this.subtitle,
     this.isThreeLine = false,
     this.dense,
+    this.contentPadding,
     this.secondary,
     this.selected = false,
   }) : _switchListTileType = _SwitchListTileType.adaptive,
@@ -409,6 +411,15 @@ class SwitchListTile extends StatelessWidget {
   /// If this property is null then its value is based on [ListTileTheme.dense].
   final bool dense;
 
+  /// The tile's internal padding.
+  ///
+  /// Insets a [SwitchListTile]'s contents: its [title], [subtitle],
+  /// [secondary], and [Switch] widgets.
+  ///
+  /// If null, [ListTile]'s default of `EdgeInsets.symmetric(horizontal: 16.0)`
+  /// is used.
+  final EdgeInsetsGeometry contentPadding;
+
   /// Whether to render icons and text in the [activeColor].
   ///
   /// No effort is made to automatically coordinate the [selected] state and the
@@ -462,6 +473,7 @@ class SwitchListTile extends StatelessWidget {
           trailing: control,
           isThreeLine: isThreeLine,
           dense: dense,
+          contentPadding: contentPadding,
           enabled: onChanged != null,
           onTap: onChanged != null ? () { onChanged(!value); } : null,
           selected: selected,

packages/flutter/test/material/switch_list_tile_test.dart

@@ -100,4 +100,45 @@ void main() {
     await tester.tap(find.byType(SwitchListTile));
     expect(value, isFalse);
   });
+
+  testWidgets('SwitchListTile contentPadding', (WidgetTester tester) async {
+    Widget buildFrame(TextDirection textDirection) {
+      return MediaQuery(
+        data: const MediaQueryData(
+          padding: EdgeInsets.zero,
+          textScaleFactor: 1.0,
+        ),
+        child: Directionality(
+          textDirection: textDirection,
+          child: Material(
+            child: Container(
+              alignment: Alignment.topLeft,
+              child: SwitchListTile(
+                contentPadding: const EdgeInsetsDirectional.only(
+                  start: 10.0,
+                  end: 20.0,
+                  top: 30.0,
+                  bottom: 40.0,
+                ),
+                secondary: const Text('L'),
+                title: const Text('title'),
+                value: true,
+                onChanged: (bool selected) {},
+              ),
+            ),
+          ),
+        ),
+      );
+    }
+
+    await tester.pumpWidget(buildFrame(TextDirection.ltr));
+
+    expect(tester.getTopLeft(find.text('L')).dx, 10.0); // contentPadding.start = 10
+    expect(tester.getTopRight(find.byType(Switch)).dx, 780.0); // 800 - contentPadding.end
+
+    await tester.pumpWidget(buildFrame(TextDirection.rtl));
+
+    expect(tester.getTopLeft(find.byType(Switch)).dx, 20.0); // contentPadding.end = 20
+    expect(tester.getTopRight(find.text('L')).dx, 790.0); // 800 - contentPadding.start
+  });
 }