feat: app UI fonts

lib/app/view/app.dart

@@ -1,4 +1,5 @@
 import 'package:api_client/api_client.dart';
+import 'package:app_ui/app_ui.dart';
 import 'package:dash_ai_search/home/home.dart';
 import 'package:dash_ai_search/l10n/l10n.dart';
 import 'package:flutter/material.dart';
@@ -14,12 +15,7 @@ class App extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
-      theme: ThemeData(
-        appBarTheme: AppBarTheme(
-          backgroundColor: Theme.of(context).colorScheme.inversePrimary,
-        ),
-        useMaterial3: true,
-      ),
+      theme: VertexTheme.standard,
       localizationsDelegates: AppLocalizations.localizationsDelegates,
       supportedLocales: AppLocalizations.supportedLocales,
       home: const HomePage(),

lib/home/widgets/logo.dart

@@ -7,15 +7,14 @@ class Logo extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    final theme = Theme.of(context);
     final l10n = context.l10n;
 
     return Row(
       children: [
         Text(
           l10n.vertexAI,
-          style: const TextStyle(
-            fontSize: 18,
-            fontWeight: FontWeight.w400,
+          style: theme.textTheme.bodyLarge?.copyWith(
             color: Colors.black,
           ),
         ),
@@ -24,9 +23,7 @@ class Logo extends StatelessWidget {
         const SizedBox(width: 4),
         Text(
           l10n.flutter,
-          style: const TextStyle(
-            fontSize: 18,
-            fontWeight: FontWeight.w400,
+          style: theme.textTheme.bodyLarge?.copyWith(
             color: Colors.black,
           ),
         ),

lib/home/widgets/welcome_view.dart

@@ -7,6 +7,7 @@ class WelcomeView extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    final theme = Theme.of(context);
     final l10n = context.l10n;
 
     return Center(
@@ -17,10 +18,8 @@ class WelcomeView extends StatelessWidget {
             Text(
               l10n.initialScreenTitle,
               textAlign: TextAlign.center,
-              style: const TextStyle(
-                fontSize: 72,
-                fontWeight: FontWeight.w700,
-                color: Color(0xFF020F30),
+              style: theme.textTheme.displayLarge?.copyWith(
+                color: Colors.black,
               ),
             ),
             const SizedBox(height: 40),

packages/app_ui/lib/app_ui.dart

@@ -1,5 +1,10 @@
+/// UI Toolkit
+library app_ui;
+
 import 'package:app_ui/src/generated/assets.gen.dart';
 
+export 'src/theme/vertex_theme.dart';
+export 'src/typography/vertex_text_styles.dart';
 export 'src/widgets/widgets.dart';
 
 /// Global reference to actual app_ui icons.

packages/app_ui/lib/src/theme/vertex_theme.dart

@@ -0,0 +1,23 @@
+import 'package:app_ui/src/typography/vertex_text_styles.dart';
+import 'package:flutter/material.dart';
+
+/// {@template vertex_theme}
+/// The default [ThemeData].
+/// {@endtemplate}
+class VertexTheme {
+  /// Standard `ThemeData` for VertexAI UI.
+  static ThemeData get standard {
+    return ThemeData(
+      textTheme: _textTheme,
+      useMaterial3: true,
+    );
+  }
+
+  static TextTheme get _textTheme {
+    return TextTheme(
+      displayLarge: VertexTextStyles.display,
+      bodyLarge: VertexTextStyles.body,
+      labelLarge: VertexTextStyles.label,
+    );
+  }
+}

packages/app_ui/lib/src/typography/typography.dart

@@ -0,0 +1 @@
+export 'vertex_text_styles.dart';

packages/app_ui/lib/src/typography/vertex_text_styles.dart

@@ -0,0 +1,38 @@
+import 'package:flutter/material.dart';
+
+/// {@template vertex_text_styles}
+/// App Text Style Definitions
+/// {@endtemplate}
+class VertexTextStyles {
+  /// {@macro vertex_text_styles}
+
+  static TextStyle get _baseTextStyle => const TextStyle(
+        fontWeight: FontWeight.w400,
+        package: 'app_ui',
+        fontFamily: 'GoogleSans',
+        color: Colors.black,
+      );
+
+  /// Title Style
+  static TextStyle get display => _baseTextStyle.copyWith(
+        fontSize: 72,
+        fontWeight: FontWeight.bold,
+        height: 1.11,
+        letterSpacing: -2,
+      );
+
+  /// Button Style
+  static TextStyle get body => _baseTextStyle.copyWith(
+        fontSize: 18,
+        height: 1.3,
+        letterSpacing: -0.5,
+      );
+
+  /// Label Style
+  static TextStyle get label => _baseTextStyle.copyWith(
+        fontSize: 14,
+        fontWeight: FontWeight.bold,
+        height: 1.7,
+        letterSpacing: 2,
+      );
+}

packages/app_ui/pubspec.yaml

@@ -14,20 +14,27 @@ dependencies:
 
 dev_dependencies:
   build_runner: ^2.4.6
+  flutter_gen_runner: ^5.3.2
   flutter_test:
     sdk: flutter
-  flutter_gen_runner: ^5.3.2
   mocktail: ^1.0.0
   very_good_analysis: ^5.1.0
 
+flutter:
+  assets: 
+    - assets/icons/
+  fonts:
+    - family: GoogleSans
+      fonts:
+        - asset: assets/fonts/GoogleSansText-Bold.ttf
+          weight: 700
+        - asset: assets/fonts/GoogleSansText-Regular.ttf
+          weight: 400
+
 flutter_gen:
+  uses-material-design: true
   assets:
     outputs:
       package_parameter_enabled: true
   output: lib/src/generated/
-  line_length: 80
-
-flutter:
-  uses-material-design: true
-  assets: 
-    - assets/icons/
+  line_length: 80  

packages/app_ui/test/src/theme/vertex_theme_test.dart

@@ -0,0 +1,11 @@
+import 'package:app_ui/app_ui.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  group('VertexTheme themeData', () {
+    test('is defined for standard', () {
+      expect(VertexTheme.standard, isA<ThemeData>());
+    });
+  });
+}

packages/app_ui/test/src/typography/vertex_text_styles_test.dart

@@ -0,0 +1,13 @@
+import 'package:app_ui/app_ui.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  group('VertexTextStyles', () {
+    test('is defined for both display, body, and label', () {
+      expect(VertexTextStyles.display, isA<TextStyle>());
+      expect(VertexTextStyles.body, isA<TextStyle>());
+      expect(VertexTextStyles.label, isA<TextStyle>());
+    });
+  });
+}