Feat: Add opportunity to change CupertinoTextField suffix alignment (#154601)

Fixes #152482

Author: ziqq

packages/flutter/lib/src/cupertino/text_field.dart

@@ -239,6 +239,7 @@ class CupertinoTextField extends StatefulWidget {
     this.prefixMode = OverlayVisibilityMode.always,
     this.suffix,
     this.suffixMode = OverlayVisibilityMode.always,
+    this.crossAxisAlignment = CrossAxisAlignment.center,
     this.clearButtonMode = OverlayVisibilityMode.never,
     this.clearButtonSemanticLabel,
     TextInputType? keyboardType,
@@ -367,6 +368,7 @@ class CupertinoTextField extends StatefulWidget {
     this.prefixMode = OverlayVisibilityMode.always,
     this.suffix,
     this.suffixMode = OverlayVisibilityMode.always,
+    this.crossAxisAlignment = CrossAxisAlignment.center,
     this.clearButtonMode = OverlayVisibilityMode.never,
     this.clearButtonSemanticLabel,
     TextInputType? keyboardType,
@@ -516,6 +518,13 @@ class CupertinoTextField extends StatefulWidget {
   /// Has no effect when [suffix] is null.
   final OverlayVisibilityMode suffixMode;
 
+  /// Controls the vertical alignment of the [prefix] and the [suffix] widget in relation to content.
+  ///
+  /// Defaults to [CrossAxisAlignment.center].
+  ///
+  /// Has no effect when both the [prefix] and [suffix] are null.
+  final CrossAxisAlignment crossAxisAlignment;
+
   /// Show an iOS-style clear button to clear the current text entry.
   ///
   /// Can be made to appear depending on various text states of the
@@ -1213,28 +1222,31 @@ class _CupertinoTextFieldState extends State<CupertinoTextField> with Restoratio
           (true, true) => widget.suffix ?? _buildClearButton(),
           (false, true) => _buildClearButton(),
         };
-        return Row(children: <Widget>[
-          // Insert a prefix at the front if the prefix visibility mode matches
-          // the current text state.
-          if (prefixWidget != null) prefixWidget,
-          // In the middle part, stack the placeholder on top of the main EditableText
-          // if needed.
-          Expanded(
-            child: Stack(
-              // Ideally this should be baseline aligned. However that comes at
-              // the cost of the ability to compute the intrinsic dimensions of
-              // this widget.
-              // See also https://github.com/flutter/flutter/issues/13715.
-              alignment: AlignmentDirectional.center,
-              textDirection: widget.textDirection,
-              children: <Widget>[
-                if (placeholder != null) placeholder,
-                editableText,
-              ],
+        return Row(
+          crossAxisAlignment: widget.crossAxisAlignment,
+          children: <Widget>[
+            // Insert a prefix at the front if the prefix visibility mode matches
+            // the current text state.
+            if (prefixWidget != null) prefixWidget,
+            // In the middle part, stack the placeholder on top of the main EditableText
+            // if needed.
+            Expanded(
+              child: Stack(
+                // Ideally this should be baseline aligned. However that comes at
+                // the cost of the ability to compute the intrinsic dimensions of
+                // this widget.
+                // See also https://github.com/flutter/flutter/issues/13715.
+                alignment: AlignmentDirectional.center,
+                textDirection: widget.textDirection,
+                children: <Widget>[
+                  if (placeholder != null) placeholder,
+                  editableText,
+                ],
+              ),
             ),
-          ),
-          if (suffixWidget != null) suffixWidget
-        ]);
+            if (suffixWidget != null) suffixWidget,
+          ],
+        );
       },
     );
   }

packages/flutter/test/cupertino/text_field_test.dart

@@ -8067,6 +8067,73 @@ void main() {
     );
   });
 
+  testWidgets(
+    'CrossAxisAlignment start positions the prefix and suffix at the top of the field',
+    (WidgetTester tester) async {
+      await tester.pumpWidget(
+        const CupertinoApp(
+          home: Center(
+            child: CupertinoTextField(
+              padding: EdgeInsets.zero, // Preventing delta position.dy
+              prefix: Icon(CupertinoIcons.add),
+              suffix: Icon(CupertinoIcons.clear),
+              crossAxisAlignment: CrossAxisAlignment.start,
+            ),
+          ),
+        ),
+      );
+
+      final CupertinoTextField cupertinoTextField = tester.widget<CupertinoTextField>(
+        find.byType(CupertinoTextField),
+      );
+
+      expect(find.widgetWithIcon(CupertinoTextField, CupertinoIcons.clear), findsOneWidget);
+      expect(find.widgetWithIcon(CupertinoTextField, CupertinoIcons.add), findsOneWidget);
+      expect(cupertinoTextField.crossAxisAlignment, CrossAxisAlignment.start);
+
+      final double editableDy = tester.getTopLeft(find.byType(EditableText)).dy;
+      final double prefixDy = tester.getTopLeft(find.byIcon(CupertinoIcons.add)).dy;
+      final double suffixDy = tester.getTopLeft(find.byIcon(CupertinoIcons.clear)).dy;
+
+      expect(prefixDy, editableDy);
+      expect(suffixDy, editableDy);
+    },
+  );
+
+  testWidgets(
+    'CrossAxisAlignment end positions the prefix and suffix at the bottom of the field',
+    (WidgetTester tester) async {
+      await tester.pumpWidget(
+        const CupertinoApp(
+          home: Center(
+            child: CupertinoTextField(
+              padding: EdgeInsets.zero, // Preventing delta position.dy
+              prefix: SizedBox.square(dimension: 48, child: Icon(CupertinoIcons.add)),
+              suffix: SizedBox.square(dimension: 48, child: Icon(CupertinoIcons.clear)),
+              crossAxisAlignment: CrossAxisAlignment.end,
+            ),
+          ),
+        ),
+      );
+
+      final CupertinoTextField cupertinoTextField = tester.widget<CupertinoTextField>(
+        find.byType(CupertinoTextField),
+      );
+
+      expect(find.widgetWithIcon(CupertinoTextField, CupertinoIcons.clear), findsOneWidget);
+      expect(find.widgetWithIcon(CupertinoTextField, CupertinoIcons.add), findsOneWidget);
+      expect(cupertinoTextField.crossAxisAlignment, CrossAxisAlignment.end);
+
+
+      final double editableDy = tester.getTopLeft(find.byType(EditableText)).dy;
+      final double prefixDy = tester.getTopLeft(find.byIcon(CupertinoIcons.add)).dy;
+      final double suffixDy = tester.getTopLeft(find.byIcon(CupertinoIcons.clear)).dy;
+
+      expect(prefixDy, lessThan(editableDy));
+      expect(suffixDy, lessThan(editableDy));
+    },
+  );
+
   testWidgets('text selection style 1', (WidgetTester tester) async {
     final TextEditingController controller = TextEditingController(
       text: 'Atwater Peel Sherbrooke Bonaventure\nhi\nwassssup!',