[various] Prep for more const widgets

packages/flutter_adaptive_scaffold/example/lib/adaptive_layout_demo.dart

@@ -45,6 +45,8 @@ class MyHomePage extends StatelessWidget {
       children: <Widget>[
         const Divider(color: Colors.black),
         const SizedBox(height: 10),
+        // TODO(goderbauer): Make this const when this package requires Flutter 3.8 or later.
+        // ignore: prefer_const_constructors
         Row(
           children: const <Widget>[
             SizedBox(
@@ -150,6 +152,8 @@ class MyHomePage extends StatelessWidget {
             inAnimation: AdaptiveScaffold.leftOutIn,
             builder: (_) => AdaptiveScaffold.standardNavigationRail(
               extended: true,
+              // TODO(goderbauer): Make this const when this package requires Flutter 3.8 or later.
+              // ignore: prefer_const_constructors
               leading: Row(
                 mainAxisAlignment: MainAxisAlignment.spaceAround,
                 children: const <Widget>[

packages/flutter_adaptive_scaffold/example/lib/main.dart

@@ -409,6 +409,8 @@ class _LargeComposeIcon extends StatelessWidget {
       child: Column(children: <Widget>[
         Container(
           padding: const EdgeInsets.fromLTRB(6, 0, 0, 0),
+          // TODO(goderbauer): Make this const when this package requires Flutter 3.8 or later.
+          // ignore: prefer_const_constructors
           child: Row(
             mainAxisAlignment: MainAxisAlignment.spaceBetween,
             children: const <Widget>[
@@ -439,8 +441,12 @@ class _LargeComposeIcon extends StatelessWidget {
           ),
           width: 200,
           height: 50,
+          // TODO(goderbauer): Make this const when this package requires Flutter 3.8 or later.
+          // ignore: prefer_const_constructors
           child: Padding(
             padding: const EdgeInsets.fromLTRB(16.0, 0, 0, 0),
+            // TODO(goderbauer): Make this const when this package requires Flutter 3.8 or later.
+            // ignore: prefer_const_constructors
             child: Row(
               children: const <Widget>[
                 Icon(Icons.edit_outlined),

packages/flutter_markdown/test/list_test.dart

@@ -210,6 +210,8 @@ void defineTests() {
 
         await tester.pumpWidget(
           boilerplate(
+            // TODO(goderbauer): Make this const when this package requires Flutter 3.8 or later.
+            // ignore: prefer_const_constructors
             Column(
               children: const <Widget>[
                 MarkdownBody(fitContent: false, data: data),
@@ -233,6 +235,8 @@ void defineTests() {
 
         await tester.pumpWidget(
           boilerplate(
+            // TODO(goderbauer): Make this const when this package requires Flutter 3.8 or later.
+            // ignore: prefer_const_constructors
             Column(
               children: const <Widget>[
                 MarkdownBody(data: data),

packages/flutter_markdown/test/markdown_body_shrink_wrap_test.dart

@@ -15,17 +15,21 @@ void defineTests() {
       'Given a MarkdownBody with shrinkWrap=true '
       'Then it wraps its content',
       (WidgetTester tester) async {
-        await tester.pumpWidget(boilerplate(Stack(
-          children: const <Widget>[
-            Text('shrinkWrap=true'),
-            Align(
-              alignment: Alignment.bottomCenter,
-              child: MarkdownBody(
-                data: 'This is a [link](https://flutter.dev/)',
+        await tester.pumpWidget(boilerplate(
+          // TODO(goderbauer): Make this const when this package requires Flutter 3.8 or later.
+          // ignore: prefer_const_constructors
+          Stack(
+            children: const <Widget>[
+              Text('shrinkWrap=true'),
+              Align(
+                alignment: Alignment.bottomCenter,
+                child: MarkdownBody(
+                  data: 'This is a [link](https://flutter.dev/)',
+                ),
               ),
-            ),
-          ],
-        )));
+            ],
+          ),
+        ));
 
         final Rect stackRect = tester.getRect(find.byType(Stack));
         final Rect textRect = tester.getRect(find.byType(Text));
@@ -43,18 +47,22 @@ void defineTests() {
       'Given a MarkdownBody with shrinkWrap=false '
       'Then it expands to the maximum allowed height',
       (WidgetTester tester) async {
-        await tester.pumpWidget(boilerplate(Stack(
-          children: const <Widget>[
-            Text('shrinkWrap=false test'),
-            Align(
-              alignment: Alignment.bottomCenter,
-              child: MarkdownBody(
-                data: 'This is a [link](https://flutter.dev/)',
-                shrinkWrap: false,
+        await tester.pumpWidget(boilerplate(
+          // TODO(goderbauer): Make this const when this package requires Flutter 3.8 or later.
+          // ignore: prefer_const_constructors
+          Stack(
+            children: const <Widget>[
+              Text('shrinkWrap=false test'),
+              Align(
+                alignment: Alignment.bottomCenter,
+                child: MarkdownBody(
+                  data: 'This is a [link](https://flutter.dev/)',
+                  shrinkWrap: false,
+                ),
               ),
-            ),
-          ],
-        )));
+            ],
+          ),
+        ));
 
         final Rect stackRect = tester.getRect(find.byType(Stack));
         final Rect textRect = tester.getRect(find.byType(Text));

packages/rfw/example/remote/lib/main.dart

@@ -87,10 +87,18 @@ class _ExampleState extends State<Example> {
         },
       );
     } else {
+      // TODO(goderbauer): Make this const when this package requires Flutter 3.8 or later.
+      // ignore: prefer_const_constructors
       result = Material(
+        // TODO(goderbauer): Make this const when this package requires Flutter 3.8 or later.
+        // ignore: prefer_const_constructors
         child: SafeArea(
+          // TODO(goderbauer): Make this const when this package requires Flutter 3.8 or later.
+          // ignore: prefer_const_constructors
           child: Padding(
             padding: const EdgeInsets.all(20.0),
+            // TODO(goderbauer): Make this const when this package requires Flutter 3.8 or later.
+            // ignore: prefer_const_constructors
             child: Column(
               crossAxisAlignment: CrossAxisAlignment.stretch,
               children: const <Widget>[