Minor cleanup to new UI

pkgs/sketch_pad/lib/console.dart

@@ -50,8 +50,11 @@ class _ConsoleWidgetState extends State<ConsoleWidget> {
         color: theme.scaffoldBackgroundColor,
         border: widget.showDivider
             ? Border(
-                top: Divider.createBorderSide(context,
-                    width: 8.0, color: theme.colorScheme.surface))
+                top: Divider.createBorderSide(
+                context,
+                width: 8.0,
+                color: theme.colorScheme.surface,
+              ))
             : null,
       ),
       padding: const EdgeInsets.all(denseSpacing),
@@ -99,11 +102,13 @@ class _ConsoleWidgetState extends State<ConsoleWidget> {
 
   void _scrollToEnd() {
     WidgetsBinding.instance.addPostFrameCallback((timeStamp) {
-      scrollController?.animateTo(
-        scrollController!.position.maxScrollExtent,
-        duration: animationDelay,
-        curve: animationCurve,
-      );
+      if (scrollController case final scrollController?) {
+        scrollController.animateTo(
+          scrollController.position.maxScrollExtent,
+          duration: animationDelay,
+          curve: animationCurve,
+        );
+      }
     });
   }
 }

pkgs/sketch_pad/lib/editor/editor.dart

@@ -37,7 +37,7 @@ web.Element _codeMirrorFactory(int viewId) {
 
   codeMirrorInstance = CodeMirror(
       div,
-      <String, dynamic>{
+      <String, Object>{
         'lineNumbers': true,
         'lineWrapping': true,
         'mode': 'dart',

pkgs/sketch_pad/lib/execution/execution.dart

@@ -15,7 +15,7 @@ import 'frame.dart';
 const String _viewType = 'dartpad-execution';
 
 bool _viewFactoryInitialized = false;
-ExecutionService? executionServiceInstance;
+ExecutionService? _executionServiceInstance;
 
 final Key _elementViewKey = UniqueKey();
 
@@ -37,7 +37,7 @@ web.Element _iFrameFactory(int viewId) {
     ..style.width = '100%'
     ..style.height = '100%';
 
-  executionServiceInstance = ExecutionServiceImpl(frame);
+  _executionServiceInstance = ExecutionServiceImpl(frame);
 
   return frame;
 }
@@ -74,7 +74,8 @@ class _ExecutionWidgetState extends State<ExecutionWidget> {
         key: _elementViewKey,
         viewType: _viewType,
         onPlatformViewCreated: (int id) {
-          widget.appServices.registerExecutionService(executionServiceInstance);
+          widget.appServices
+              .registerExecutionService(_executionServiceInstance);
         },
       ),
     );

pkgs/sketch_pad/lib/execution/frame.dart

@@ -143,14 +143,14 @@ require(["dartpad_main", "dart_sdk"], function(dartpad_main, dart_sdk) {
 
   /// Destroy and reload the iframe.
   Future<void> _reset() {
-    if (_frame.parentElement != null) {
+    if (_frame.parentElement case final parentElement?) {
       _readyCompleter = Completer();
 
       final clone = _frame.clone(false) as web.HTMLIFrameElement;
       clone.src = _frameSrc;
 
-      _frame.parentElement!.appendChild(clone);
-      _frame.parentElement!.removeChild(_frame);
+      parentElement.appendChild(clone);
+      parentElement.removeChild(_frame);
       _frame = clone;
     }
 
@@ -162,29 +162,30 @@ require(["dartpad_main", "dart_sdk"], function(dartpad_main, dart_sdk) {
 
   void _initListener() {
     web.window.addEventListener(
-        'message',
-        (web.Event event) {
-          if (event is web.MessageEvent) {
-            final data = event.data.dartify() as Map<Object?, Object?>;
-            if (data['sender'] != 'frame') {
-              return;
-            }
-            final type = data['type'] as String?;
-
-            if (type == 'stderr') {
-              // Ignore any exceptions before the iframe has completed
-              // initialization.
-              if (_readyCompleter.isCompleted) {
-                _stdoutController.add(data['message'] as String);
-              }
-            } else if (type == 'ready' && !_readyCompleter.isCompleted) {
-              _readyCompleter.complete();
-            } else if (data['message'] != null) {
+      'message',
+      (web.Event event) {
+        if (event is web.MessageEvent) {
+          final data = event.data.dartify();
+          if (data is! Map<Object?, Object?> || data['sender'] != 'frame') {
+            return;
+          }
+          final type = data['type'] as String?;
+
+          if (type == 'stderr') {
+            // Ignore any exceptions before the iframe has completed
+            // initialization.
+            if (_readyCompleter.isCompleted) {
               _stdoutController.add(data['message'] as String);
             }
+          } else if (type == 'ready' && !_readyCompleter.isCompleted) {
+            _readyCompleter.complete();
+          } else if (data['message'] != null) {
+            _stdoutController.add(data['message'] as String);
           }
-        }.toJS,
-        false.toJS);
+        }
+      }.toJS,
+      false.toJS,
+    );
   }
 }
 

pkgs/sketch_pad/lib/flutter_samples.dart

@@ -5,20 +5,21 @@
 import 'package:http/http.dart' as http;
 
 class FlutterSampleLoader {
-  final http.Client client = http.Client();
+  final http.Client _client = http.Client();
 
   Future<String> loadFlutterSample({
     required String sampleId,
     String? channel,
   }) async {
     // There are only two hosted versions of the docs: master/main and stable.
-    final sampleUrl = switch (channel) {
-      'master' => 'https://main-api.flutter.dev/snippets/$sampleId.dart',
-      'main' => 'https://main-api.flutter.dev/snippets/$sampleId.dart',
-      _ => 'https://api.flutter.dev/snippets/$sampleId.dart',
+    final sampleUrlAuthority = switch (channel) {
+      'master' || 'main' => 'main-api.flutter.dev',
+      _ => 'api.flutter.dev',
     };
 
-    final response = await client.get(Uri.parse(sampleUrl));
+    final sampleUrl = Uri.https(sampleUrlAuthority, '/snippets/$sampleId.dart');
+
+    final response = await _client.get(sampleUrl);
 
     if (response.statusCode != 200) {
       throw Exception('Unable to load sample '
@@ -29,6 +30,6 @@ class FlutterSampleLoader {
   }
 
   void dispose() {
-    client.close();
+    _client.close();
   }
 }

pkgs/sketch_pad/lib/gists.dart

@@ -8,22 +8,22 @@ import 'package:collection/collection.dart';
 import 'package:http/http.dart' as http;
 
 class GistLoader {
-  final http.Client client = http.Client();
+  final http.Client _client = http.Client();
 
   Future<Gist> load(String gistId) async {
     final response =
-        await client.get(Uri.parse('https://api.github.com/gists/$gistId'));
+        await _client.get(Uri.https('api.github.com', '/gists/$gistId'));
 
     if (response.statusCode != 200) {
       throw Exception('Unable to load gist '
           '(${response.statusCode} ${response.reasonPhrase}})');
     }
 
-    return Gist.fromJson(jsonDecode(response.body) as Map<String, dynamic>);
+    return Gist.fromJson(jsonDecode(response.body) as Map<String, Object?>);
   }
 
   void dispose() {
-    client.close();
+    _client.close();
   }
 }
 
@@ -40,7 +40,7 @@ class Gist {
     required this.files,
   });
 
-  factory Gist.fromJson(Map<String, dynamic> json) {
+  factory Gist.fromJson(Map<String, Object?> json) {
 /* {
   "id": "d3bd83918d21b6d5f778bdc69c3d36d6",
   "description": "Fibonacci",
@@ -65,25 +65,22 @@ class Gist {
     }
   },
 } */
-    final owner = json['owner'] as Map<String, dynamic>;
-    final files = json['files'] as Map<String, dynamic>;
+    final owner = json['owner'] as Map<String, Object?>;
+    final files = json['files'] as Map<String, Object?>;
 
     return Gist(
       id: json['id'] as String,
       description: json['description'] as String?,
       owner: owner['login'] as String?,
       files: files.values
-          .cast<Map<String, dynamic>>()
+          .cast<Map<String, Object?>>()
           .map(GistFile.fromJson)
-          .toList(),
+          .toList(growable: false),
     );
   }
 
-  String? get mainDartSource {
-    return files
-        .firstWhereOrNull((file) => file.fileName == 'main.dart')
-        ?.content;
-  }
+  String? get mainDartSource =>
+      files.firstWhereOrNull((file) => file.fileName == 'main.dart')?.content;
 }
 
 class GistFile {
@@ -99,7 +96,7 @@ class GistFile {
     required this.content,
   });
 
-  factory GistFile.fromJson(Map<String, dynamic> json) {
+  factory GistFile.fromJson(Map<String, Object?> json) {
     return GistFile(
       fileName: json['filename'] as String,
       truncated: json['truncated'] as bool,

pkgs/sketch_pad/lib/keys.dart

@@ -38,14 +38,13 @@ final ShortcutActivator quickFixKeyActivator = SingleActivator(
   control: _nonMac,
 );
 
-// map of key activator names
-
-final List<(String, ShortcutActivator)> keyBindings = [
-  ('Code completion', codeCompletionKeyActivator),
-  ('Find', findKeyActivator),
-  ('Find next', findNextKeyActivator),
-  ('Quick fixes', quickFixKeyActivator),
-  ('Reload', reloadKeyActivator),
+/// Key binding names and activators.
+final List<({String keyName, ShortcutActivator activator})> keyBindings = [
+  (keyName: 'Code completion', activator: codeCompletionKeyActivator),
+  (keyName: 'Find', activator: findKeyActivator),
+  (keyName: 'Find next', activator: findNextKeyActivator),
+  (keyName: 'Quick fixes', activator: quickFixKeyActivator),
+  (keyName: 'Reload', activator: reloadKeyActivator),
 ];
 
 extension SingleActivatorExtension on SingleActivator {
@@ -60,10 +59,11 @@ extension SingleActivatorExtension on SingleActivator {
 
     return Container(
       decoration: BoxDecoration(
-          border: Border.fromBorderSide(
-            Divider.createBorderSide(context, width: 1.0, color: subtleColor),
-          ),
-          borderRadius: const BorderRadius.all(Radius.circular(4))),
+        border: Border.fromBorderSide(
+          Divider.createBorderSide(context, width: 1.0, color: subtleColor),
+        ),
+        borderRadius: const BorderRadius.all(Radius.circular(4)),
+      ),
       padding: const EdgeInsets.symmetric(
         vertical: 2,
         horizontal: 6,