VisualDensity should not reduce ButtonStyleButton horizontal padding (#79680)

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

@@ -312,14 +312,15 @@ class _ButtonStyleState extends State<ButtonStyleButton> with TickerProviderStat
       }
     }
 
-    final EdgeInsetsGeometry padding = resolvedPadding!.add(
-      EdgeInsets.only(
-        left: densityAdjustment.dx,
-        top: densityAdjustment.dy,
-        right: densityAdjustment.dx,
-        bottom: densityAdjustment.dy,
-      ),
-    ).clamp(EdgeInsets.zero, EdgeInsetsGeometry.infinity);
+    // Per the Material Design team: don't allow the VisualDensity
+    // adjustment to reduce the width of the left/right padding. If we
+    // did, VisualDensity.compact, the default for desktop/web, would
+    // reduce the horizontal padding to zero.
+    final double dy = densityAdjustment.dy;
+    final double dx = math.max(0, densityAdjustment.dx);
+    final EdgeInsetsGeometry padding = resolvedPadding!
+      .add(EdgeInsets.fromLTRB(dx, dy, dx, dy))
+      .clamp(EdgeInsets.zero, EdgeInsetsGeometry.infinity);
 
     // If an opaque button's background is becoming translucent while its
     // elevation is changing, change the elevation first. Material implicitly

packages/flutter/test/material/elevated_button_test.dart

@@ -649,7 +649,7 @@ void main() {
     await buildTest(const VisualDensity(horizontal: -3.0, vertical: -3.0));
     await tester.pumpAndSettle();
     childRect = tester.getRect(find.byKey(childKey));
-    expect(box.size, equals(const Size(108, 100)));
+    expect(box.size, equals(const Size(132, 100)));
     expect(childRect, equals(const Rect.fromLTRB(350, 250, 450, 350)));
 
     await buildTest(VisualDensity.standard, useText: true);
@@ -667,7 +667,7 @@ void main() {
     await buildTest(const VisualDensity(horizontal: -3.0, vertical: -3.0), useText: true);
     await tester.pumpAndSettle();
     childRect = tester.getRect(find.byKey(childKey));
-    expect(box.size, equals(const Size(76, 36)));
+    expect(box.size, equals(const Size(88, 36)));
     expect(childRect, equals(const Rect.fromLTRB(372.0, 293.0, 428.0, 307.0)));
   });
 

packages/flutter/test/material/outlined_button_test.dart

@@ -956,7 +956,7 @@ void main() {
     await buildTest(const VisualDensity(horizontal: -3.0, vertical: -3.0));
     await tester.pumpAndSettle();
     childRect = tester.getRect(find.byKey(childKey));
-    expect(box.size, equals(const Size(108, 100)));
+    expect(box.size, equals(const Size(132, 100)));
     expect(childRect, equals(const Rect.fromLTRB(350, 250, 450, 350)));
 
     await buildTest(VisualDensity.standard, useText: true);
@@ -974,7 +974,7 @@ void main() {
     await buildTest(const VisualDensity(horizontal: -3.0, vertical: -3.0), useText: true);
     await tester.pumpAndSettle();
     childRect = tester.getRect(find.byKey(childKey));
-    expect(box.size, equals(const Size(64, 36)));
+    expect(box.size, equals(const Size(88, 36)));
     expect(childRect, equals(const Rect.fromLTRB(372.0, 293.0, 428.0, 307.0)));
   });
 

packages/flutter/test/material/text_button_test.dart

@@ -739,7 +739,7 @@ void main() {
     await buildTest(const VisualDensity(horizontal: -3.0, vertical: -3.0));
     await tester.pumpAndSettle();
     childRect = tester.getRect(find.byKey(childKey));
-    expect(box.size, equals(const Size(100, 100)));
+    expect(box.size, equals(const Size(116, 100)));
     expect(childRect, equals(const Rect.fromLTRB(350, 250, 450, 350)));
 
     await buildTest(VisualDensity.standard, useText: true);
@@ -757,7 +757,7 @@ void main() {
     await buildTest(const VisualDensity(horizontal: -3.0, vertical: -3.0), useText: true);
     await tester.pumpAndSettle();
     childRect = tester.getRect(find.byKey(childKey));
-    expect(box.size, equals(const Size(56, 36)));
+    expect(box.size, equals(const Size(72, 36)));
     expect(childRect, equals(const Rect.fromLTRB(372.0, 293.0, 428.0, 307.0)));
   });
 

packages/flutter/test/widgets/sliver_fill_remaining_test.dart

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'dart:math' as math;
+
 import 'package:flutter_test/flutter_test.dart';
 import 'package:flutter/material.dart';
 
@@ -322,10 +324,11 @@ void main() {
         expect(tester.getCenter(logo), Offset(400.0, 351.0 - density.vertical * 2.0));
 
         // Also check that the button alignment is true to expectations
+        // Buttons do not decrease their horizontal padding per the VisualDensity.
         final Finder button = find.byType(ElevatedButton);
         expect(
           tester.renderObject<RenderBox>(button).size,
-          Size(116.0 + density.horizontal * 8.0, 48.0 + density.vertical * 4.0),
+          Size(116.0 + math.max(0, density.horizontal) * 8.0, 48.0 + density.vertical * 4.0),
         );
         expect(tester.getBottomLeft(button).dy, equals(600.0));
         expect(tester.getCenter(button).dx, equals(400.0));
@@ -344,7 +347,8 @@ void main() {
         expect(tester.getCenter(logo).dy, lessThan(351.0));
         expect(
           tester.renderObject<RenderBox>(button).size,
-          Size(116.0 + density.horizontal * 8.0, 48.0 + density.vertical * 4.0),
+          // Buttons do not decrease their horizontal padding per the VisualDensity.
+          Size(116.0 + math.max(0, density.horizontal) * 8.0, 48.0 + density.vertical * 4.0),
         );
         expect(tester.getBottomLeft(button).dy, lessThan(600.0));
         expect(tester.getCenter(button).dx, equals(400.0));
@@ -592,10 +596,11 @@ void main() {
           expect(tester.getCenter(logo), Offset(400.0, 351.0 - density.vertical * 2.0));
 
           // Also check that the button alignment is true to expectations.
+          // Buttons do not decrease their horizontal padding per the VisualDensity.
           final Finder button = find.byType(ElevatedButton);
           expect(
             tester.renderObject<RenderBox>(button).size,
-            Size(116.0 + density.horizontal * 8.0, 48.0 + density.vertical * 4.0),
+            Size(116.0 + math.max(0, density.horizontal) * 8.0, 48.0 + density.vertical * 4.0),
           );
           expect(tester.getBottomLeft(button).dy, equals(600.0));
           expect(tester.getCenter(button).dx, equals(400.0));
@@ -616,7 +621,8 @@ void main() {
           expect(tester.getCenter(logo).dy, lessThan(351.0));
           expect(
             tester.renderObject<RenderBox>(button).size,
-            Size(116.0 + density.horizontal * 8.0, 48.0 + density.vertical * 4.0),
+            // Buttons do not decrease their horizontal padding per the VisualDensity.
+            Size(116.0 + math.max(0, density.horizontal) * 8.0, 48.0 + density.vertical * 4.0),
           );
           expect(tester.getBottomLeft(button).dy, equals(600.0));
           expect(tester.getCenter(button).dx, equals(400.0));
@@ -635,7 +641,8 @@ void main() {
           expect(tester.getCenter(logo), Offset(400.0, 351.0 - density.vertical * 2.0));
           expect(
             tester.renderObject<RenderBox>(button).size,
-            Size(116.0 + density.horizontal * 8.0, 48.0 + density.vertical * 4.0),
+            // Buttons do not decrease their horizontal padding per the VisualDensity.
+            Size(116.0 + math.max(0, density.horizontal) * 8.0, 48.0 + density.vertical * 4.0),
           );
           expect(tester.getBottomLeft(button).dy, equals(600.0));
           expect(tester.getCenter(button).dx, equals(400.0));