Apply media padding to persistent footer buttons (#14512)

Applies left, right, and bottom media padding (e.g. iOS safe area
insets) around ButtonBar in the material scaffold
persistentFooterButtons.

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

@@ -916,17 +916,20 @@ class ScaffoldState extends State<Scaffold> with TickerProviderStateMixin {
           ),
           child: new SafeArea(
             child: new ButtonTheme.bar(
+              child: new SafeArea(
+                top: false,
                 child: new ButtonBar(
                   children: widget.persistentFooterButtons
                 ),
               ),
             ),
           ),
+        ),
         _ScaffoldSlot.persistentFooter,
         removeLeftPadding: false,
         removeTopPadding: true,
         removeRightPadding: false,
-        removeBottomPadding: widget.resizeToAvoidBottomPadding,
+        removeBottomPadding: false,
       );
     }
 

packages/flutter/test/material/scaffold_test.dart

@@ -346,6 +346,31 @@ void main() {
     expect(didPressButton, isTrue);
   });
 
+  testWidgets('Persistent bottom buttons apply media padding', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      new Directionality(
+        textDirection: TextDirection.ltr,
+        child: new MediaQuery(
+          data: const MediaQueryData(
+            padding: const EdgeInsets.fromLTRB(10.0, 20.0, 30.0, 40.0),
+          ),
+          child: new Scaffold(
+            body: new SingleChildScrollView(
+              child: new Container(
+                color: Colors.amber[500],
+                height: 5000.0,
+                child: const Text('body'),
+              ),
+            ),
+            persistentFooterButtons: <Widget>[const Placeholder()],
+          ),
+        ),
+      ),
+    );
+    expect(tester.getBottomLeft(find.byType(ButtonBar)), const Offset(10.0, 560.0));
+    expect(tester.getBottomRight(find.byType(ButtonBar)), const Offset(770.0, 560.0));
+  });
+
   group('back arrow', () {
     Future<Null> expectBackIcon(WidgetTester tester, TargetPlatform platform, IconData expectedIcon) async {
       final GlobalKey rootKey = new GlobalKey();
@@ -612,15 +637,15 @@ void main() {
     await tester.pump(const Duration(seconds: 1));
 
     expect(tester.getRect(find.byKey(appBar)), new Rect.fromLTRB(0.0, 0.0, 800.0, 43.0));
-    expect(tester.getRect(find.byKey(body)), new Rect.fromLTRB(0.0, 43.0, 800.0, 400.0));
-    expect(tester.getRect(find.byKey(floatingActionButton)), new Rect.fromLTRB(36.0, 307.0, 113.0, 384.0));
-    expect(tester.getRect(find.byKey(persistentFooterButton)), new Rect.fromLTRB(28.0, 417.0, 128.0, 507.0)); // Note: has 8px each top/bottom padding.
+    expect(tester.getRect(find.byKey(body)), new Rect.fromLTRB(0.0, 43.0, 800.0, 348.0));
+    expect(tester.getRect(find.byKey(floatingActionButton)), new Rect.fromLTRB(36.0, 255.0, 113.0, 332.0));
+    expect(tester.getRect(find.byKey(persistentFooterButton)), new Rect.fromLTRB(28.0, 357.0, 128.0, 447.0)); // Note: has 8px each top/bottom padding.
     expect(tester.getRect(find.byKey(drawer)), new Rect.fromLTRB(596.0, 0.0, 800.0, 600.0));
     expect(tester.getRect(find.byKey(bottomNavigationBar)), new Rect.fromLTRB(0.0, 515.0, 800.0, 600.0));
     expect(tester.getRect(find.byKey(insideAppBar)), new Rect.fromLTRB(20.0, 30.0, 750.0, 43.0));
-    expect(tester.getRect(find.byKey(insideBody)), new Rect.fromLTRB(20.0, 43.0, 750.0, 400.0));
-    expect(tester.getRect(find.byKey(insideFloatingActionButton)), new Rect.fromLTRB(36.0, 307.0, 113.0, 384.0));
-    expect(tester.getRect(find.byKey(insidePersistentFooterButton)), new Rect.fromLTRB(28.0, 417.0, 128.0, 507.0));
+    expect(tester.getRect(find.byKey(insideBody)), new Rect.fromLTRB(20.0, 43.0, 750.0, 348.0));
+    expect(tester.getRect(find.byKey(insideFloatingActionButton)), new Rect.fromLTRB(36.0, 255.0, 113.0, 332.0));
+    expect(tester.getRect(find.byKey(insidePersistentFooterButton)), new Rect.fromLTRB(28.0, 357.0, 128.0, 447.0));
     expect(tester.getRect(find.byKey(insideDrawer)), new Rect.fromLTRB(596.0, 30.0, 750.0, 540.0));
     expect(tester.getRect(find.byKey(insideBottomNavigationBar)), new Rect.fromLTRB(20.0, 515.0, 750.0, 540.0));
   });
@@ -702,12 +727,12 @@ void main() {
     expect(tester.getRect(find.byKey(appBar)), new Rect.fromLTRB(0.0, 0.0, 800.0, 43.0));
     expect(tester.getRect(find.byKey(body)), new Rect.fromLTRB(0.0, 43.0, 800.0, 400.0));
     expect(tester.getRect(find.byKey(floatingActionButton)), new Rect.fromLTRB(36.0, 307.0, 113.0, 384.0));
-    expect(tester.getRect(find.byKey(persistentFooterButton)), new Rect.fromLTRB(28.0, 502.0, 128.0, 592.0)); // Note: has 8px each top/bottom padding.
+    expect(tester.getRect(find.byKey(persistentFooterButton)), new Rect.fromLTRB(28.0, 442.0, 128.0, 532.0)); // Note: has 8px each top/bottom padding.
     expect(tester.getRect(find.byKey(drawer)), new Rect.fromLTRB(596.0, 0.0, 800.0, 600.0));
     expect(tester.getRect(find.byKey(insideAppBar)), new Rect.fromLTRB(20.0, 30.0, 750.0, 43.0));
     expect(tester.getRect(find.byKey(insideBody)), new Rect.fromLTRB(20.0, 43.0, 750.0, 400.0));
     expect(tester.getRect(find.byKey(insideFloatingActionButton)), new Rect.fromLTRB(36.0, 307.0, 113.0, 384.0));
-    expect(tester.getRect(find.byKey(insidePersistentFooterButton)), new Rect.fromLTRB(28.0, 502.0, 128.0, 592.0));
+    expect(tester.getRect(find.byKey(insidePersistentFooterButton)), new Rect.fromLTRB(28.0, 442.0, 128.0, 532.0));
     expect(tester.getRect(find.byKey(insideDrawer)), new Rect.fromLTRB(596.0, 30.0, 750.0, 540.0));
   });