[deep link] Update loading UI (#6732)

* 1

* lint

* 1

packages/devtools_app/lib/src/screens/deep_link_validation/deep_link_list_view.dart

diff --git a/packages/devtools_app/lib/src/screens/deep_link_validation/deep_link_list_view.dart b/packages/devtools_app/lib/src/screens/deep_link_validation/deep_link_list_view.dart
index bd14650..a04927d 100644
--- a/packages/devtools_app/lib/src/screens/deep_link_validation/deep_link_list_view.dart
+++ b/packages/devtools_app/lib/src/screens/deep_link_validation/deep_link_list_view.dart
@@ -89,7 +89,17 @@
         valueListenable: controller.allLinkDatasNotifier,
         builder: (context, linkDatas, _) {
           if (linkDatas == null) {
-            return const CenteredCircularProgressIndicator();
+            return Column(
+              mainAxisAlignment: MainAxisAlignment.center,
+              children: [
+                const CenteredCircularProgressIndicator(),
+                const SizedBox(height: densePadding),
+                Text(
+                  'Validating deep links...',
+                  style: Theme.of(context).subtleTextStyle,
+                ),
+              ],
+            );
           }
           if (displayOptions.showSplitScreen) {
             return Row(

packages/devtools_app/lib/src/screens/deep_link_validation/select_project_view.dart

diff --git a/packages/devtools_app/lib/src/screens/deep_link_validation/select_project_view.dart b/packages/devtools_app/lib/src/screens/deep_link_validation/select_project_view.dart
index d2c7dd8..13c2fe4 100644
--- a/packages/devtools_app/lib/src/screens/deep_link_validation/select_project_view.dart
+++ b/packages/devtools_app/lib/src/screens/deep_link_validation/select_project_view.dart
@@ -7,13 +7,14 @@
 
 import '../../shared/analytics/analytics.dart' as ga;
 import '../../shared/analytics/constants.dart' as gac;
-import '../../shared/common_widgets.dart';
 import '../../shared/directory_picker.dart';
 import '../../shared/server/server.dart' as server;
 import '../../shared/utils.dart';
 import 'deep_links_controller.dart';
 import 'deep_links_model.dart';
 
+const _kLinearProgressIndicatorWidth = 280.0;
+
 /// A view for selecting a Flutter project.
 class SelectProjectView extends StatefulWidget {
   const SelectProjectView({super.key});
@@ -24,7 +25,6 @@
 
 class _SelectProjectViewState extends State<SelectProjectView>
     with ProvidedControllerMixin<DeepLinksController, SelectProjectView> {
-  static const _kMessageSize = 24.0;
   bool _retrievingFlutterProject = false;
 
   @override
@@ -82,32 +82,46 @@
 
   @override
   Widget build(BuildContext context) {
-    Widget? child;
+    final theme = Theme.of(context);
     if (_retrievingFlutterProject) {
-      child = const CenteredCircularProgressIndicator(size: _kMessageSize);
-    } else {
-      child = Text(
-        'Pick a flutter project from your local file to check all deep links status',
-        textAlign: TextAlign.center,
-        style: TextStyle(
-          color: Theme.of(context).textTheme.displayLarge!.color,
+      return Center(
+        child: Column(
+          mainAxisAlignment: MainAxisAlignment.center,
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            Text(
+              'Project loading...',
+              style: theme.regularTextStyle,
+            ),
+            Container(
+              width: _kLinearProgressIndicatorWidth,
+              padding: const EdgeInsets.symmetric(vertical: densePadding),
+              child: const LinearProgressIndicator(),
+            ),
+            Text(
+              'The first load will take longer than usual',
+              style: theme.subtleTextStyle,
+            ),
+          ],
         ),
       );
     }
-    return Center(
-      child: Column(
-        mainAxisAlignment: MainAxisAlignment.center,
-        children: [
-          Padding(
-            padding: const EdgeInsets.all(defaultSpacing),
-            child: child,
+    return Column(
+      mainAxisAlignment: MainAxisAlignment.center,
+      children: [
+        Padding(
+          padding: const EdgeInsets.all(defaultSpacing),
+          child: Text(
+            'Pick a local flutter project to check the status of all deep links.',
+            textAlign: TextAlign.center,
+            style: theme.textTheme.titleSmall,
           ),
-          DirectoryPicker(
-            onDirectoryPicked: _handleDirectoryPicked,
-            enabled: !_retrievingFlutterProject,
-          ),
-        ],
-      ),
+        ),
+        DirectoryPicker(
+          onDirectoryPicked: _handleDirectoryPicked,
+          enabled: !_retrievingFlutterProject,
+        ),
+      ],
     );
   }
 }