Add Flutter sample

README.md

@@ -51,10 +51,11 @@ documentation: https://ai.google.dev/docs
 
 ## Packages
 
-| Package | Description | Version |
-| --- | --- | --- |
+| Package                                            | Description | Version |
+|----------------------------------------------------| --- | --- |
 | [google_generative_ai](pkgs/google_generative_ai/) | The Google Generative AI SDK for Dart - allows access to state-of-the-art LLMs. |  |
-| [samples](samples/) | Dart samples for `package:google_generative_ai`. |  |
+| [samples/dart](samples/dart/)                      | Dart samples for `package:google_generative_ai`. |  |
+| [samples/flutter](samples/flutter/)                | Flutter sample for `package:google_generative_ai`. |  |
 
 ## Contributing
 

samples/pubspec.yaml → samples/dart/pubspec.yaml

@@ -7,7 +7,7 @@ environment:
 dependencies:
   path: ^1.9.0
   google_generative_ai:
-    path: ../pkgs/google_generative_ai
+    path: ../../pkgs/google_generative_ai
 
 dev_dependencies:
   lints: ^3.0.0

samples/flutter_app/.gitignore

@@ -0,0 +1,55 @@
+# env.json contains the API key for this sample app.
+env.json
+
+# Ignore platform-specific directories, since the user will run
+# `flutter create` as described in the README
+android/
+web/
+ios/
+macos/
+linux/
+windows/
+
+# Miscellaneous
+*.class
+*.log
+*.pyc
+*.swp
+.DS_Store
+.atom/
+.buildlog/
+.history
+.svn/
+migrate_working_dir/
+
+# IntelliJ related
+*.iml
+*.ipr
+*.iws
+.idea/
+
+# The .vscode folder contains launch configuration and tasks you configure in
+# VS Code which you may wish to be included in version control, so this line
+# is commented out by default.
+#.vscode/
+
+# Flutter/Dart/Pub related
+**/doc/api/
+**/ios/Flutter/.last_build_id
+.dart_tool/
+.flutter-plugins
+.flutter-plugins-dependencies
+.pub-cache/
+.pub/
+/build/
+
+# Symbolication related
+app.*.symbols
+
+# Obfuscation related
+app.*.map.json
+
+# Android Studio will place build artifacts here
+/android/app/debug
+/android/app/profile
+/android/app/release

samples/flutter_app/.metadata

@@ -0,0 +1,45 @@
+# This file tracks properties of this Flutter project.
+# Used by Flutter tool to assess capabilities and perform upgrades etc.
+#
+# This file should be version controlled and should not be manually edited.
+
+version:
+  revision: "787a51fa08ee6872245bb809c5d2ee57408d0370"
+  channel: "main"
+
+project_type: app
+
+# Tracks metadata for the flutter migrate command
+migration:
+  platforms:
+    - platform: root
+      create_revision: 787a51fa08ee6872245bb809c5d2ee57408d0370
+      base_revision: 787a51fa08ee6872245bb809c5d2ee57408d0370
+    - platform: android
+      create_revision: 787a51fa08ee6872245bb809c5d2ee57408d0370
+      base_revision: 787a51fa08ee6872245bb809c5d2ee57408d0370
+    - platform: ios
+      create_revision: 787a51fa08ee6872245bb809c5d2ee57408d0370
+      base_revision: 787a51fa08ee6872245bb809c5d2ee57408d0370
+    - platform: linux
+      create_revision: 787a51fa08ee6872245bb809c5d2ee57408d0370
+      base_revision: 787a51fa08ee6872245bb809c5d2ee57408d0370
+    - platform: macos
+      create_revision: 787a51fa08ee6872245bb809c5d2ee57408d0370
+      base_revision: 787a51fa08ee6872245bb809c5d2ee57408d0370
+    - platform: web
+      create_revision: 787a51fa08ee6872245bb809c5d2ee57408d0370
+      base_revision: 787a51fa08ee6872245bb809c5d2ee57408d0370
+    - platform: windows
+      create_revision: 787a51fa08ee6872245bb809c5d2ee57408d0370
+      base_revision: 787a51fa08ee6872245bb809c5d2ee57408d0370
+
+  # User provided section
+
+  # List of Local paths (relative to this file) that should be
+  # ignored by the migrate tool.
+  #
+  # Files that are not part of the templates will be ignored by default.
+  unmanaged_files:
+    - 'lib/main.dart'
+    - 'ios/Runner.xcodeproj/project.pbxproj'

samples/flutter_app/README.md

@@ -0,0 +1,25 @@
+# Flutter generative AI sample
+
+A Flutter chat application that uses the `google_generative_ai` package.
+
+## Getting started
+Create the project files for each target platform by using the `flutter create`
+command in this project's directory.
+
+```bash
+flutter create .
+```
+
+Create a new file, `env.json` to store your API key:
+
+```json
+{
+  "api_key": "<YOUR_API_KEY_HERE>"
+}
+```
+
+Specify the `env.json` file when you run the app:
+
+```bash
+flutter run -d android --dart-define-from-file=env.json
+```

samples/flutter_app/analysis_options.yaml

@@ -0,0 +1,3 @@
+include: package:flutter_lints/flutter.yaml
+linter:
+  rules:

samples/flutter_app/lib/main.dart

@@ -0,0 +1,219 @@
+// Copyright 2024 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import 'package:flutter/material.dart';
+import 'package:google_generative_ai/google_generative_ai.dart' hide Text;
+
+void main() {
+  runApp(const GenerativeAISample());
+}
+
+class GenerativeAISample extends StatelessWidget {
+  const GenerativeAISample({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      title: 'Flutter + Generative AI',
+      theme: ThemeData(
+        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
+        useMaterial3: true,
+      ),
+      home: const ChatScreen(title: 'Flutter + Generative AI'),
+    );
+  }
+}
+
+class ChatScreen extends StatefulWidget {
+  const ChatScreen({super.key, required this.title});
+
+  final String title;
+
+  @override
+  State<ChatScreen> createState() => _ChatScreenState();
+}
+
+class _ChatScreenState extends State<ChatScreen> {
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text(widget.title),
+      ),
+      body: const ChatWidget(),
+    );
+  }
+}
+
+class ChatWidget extends StatefulWidget {
+  const ChatWidget({super.key});
+
+  @override
+  State<ChatWidget> createState() => _ChatWidgetState();
+}
+
+class _ChatWidgetState extends State<ChatWidget> {
+  late final GenerativeModel _model;
+  late final ChatSession _chat;
+  late final _textController = TextEditingController();
+  final List<Message> _messages = [];
+  bool _loading = false;
+
+  @override
+  void initState() {
+    super.initState();
+    _model = GenerativeModel(model: 'gemini-pro', apiKey: const String.fromEnvironment('api_key'));
+    _chat = _model.startChat();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Padding(
+      padding: const EdgeInsets.all(8.0),
+      child: Column(
+        mainAxisAlignment: MainAxisAlignment.center,
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Expanded(
+            child: ListView.builder(
+              itemBuilder: (context, idx) {
+                var message = _messages[idx];
+                return MessageWidget(message: message);
+              },
+              itemCount: _messages.length,
+            ),
+          ),
+          Row(
+            children: [
+              Expanded(
+                child: TextField(
+                  decoration:
+                      const InputDecoration(hintText: 'Enter a prompt...'),
+                  controller: _textController,
+                  onSubmitted: (String value) {
+                    _sendChatMessage(value);
+                  },
+                ),
+              ),
+              if (!_loading)
+                IconButton(
+                  onPressed: () async {
+                    _sendChatMessage(_textController.text);
+                  },
+                  icon: const Icon(Icons.send),
+                )
+              else
+                const CircularProgressIndicator(),
+            ],
+          ),
+        ],
+      ),
+    );
+  }
+
+  Future<void> _sendChatMessage(String message) async {
+    setState(() {
+      _messages.add(Message(message, isFromUser: true));
+      _loading = true;
+    });
+
+    try {
+      var response = await _chat.sendMessage(Content.text(message));
+      var text = response.text;
+
+      if (text == null) {
+        _showError('No response from API.');
+        return;
+      } else {
+        setState(() {
+          _messages.add(Message(text));
+          _loading = false;
+        });
+      }
+    } catch (e) {
+      _showError(e.toString());
+      setState(() {
+        _loading = false;
+      });
+    } finally {
+      _textController.clear();
+      setState(() {
+        _loading = false;
+      });
+    }
+  }
+
+  void _showError(String message) {
+    showDialog(
+      context: context,
+      builder: (context) {
+        return AlertDialog(
+          title: const Text('Something went wrong'),
+          content: SingleChildScrollView(
+            child: Text(message),
+          ),
+          actions: [
+            TextButton(
+              onPressed: () {
+                Navigator.of(context).pop();
+              },
+              child: const Text('OK'),
+            )
+          ],
+        );
+      },
+    );
+  }
+}
+
+class Message {
+  final bool isFromUser;
+  final String text;
+  Message(this.text, {this.isFromUser = false});
+}
+
+class MessageWidget extends StatelessWidget {
+  final Message message;
+
+  const MessageWidget({
+    super.key,
+    required this.message,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    return Row(
+      mainAxisAlignment:
+          message.isFromUser ? MainAxisAlignment.end : MainAxisAlignment.start,
+      children: [
+        Flexible(
+          child: Container(
+            constraints: const BoxConstraints(maxWidth: 600),
+            decoration: BoxDecoration(
+              color: message.isFromUser
+                  ? Theme.of(context).colorScheme.primaryContainer
+                  : Theme.of(context).colorScheme.surfaceVariant,
+              borderRadius: BorderRadius.circular(8.0),
+            ),
+            padding: const EdgeInsets.all(8.0),
+            margin: const EdgeInsets.only(bottom: 8),
+            child: SelectionArea(
+              child: Text(message.text),
+            ),
+          ),
+        ),
+      ],
+    );
+  }
+}

samples/flutter_app/pubspec.yaml

@@ -0,0 +1,18 @@
+name: generative_ai_flutter
+description: "Sample app for the google_generative_ai package"
+publish_to: 'none'
+version: 1.0.0
+environment:
+  sdk: ^3.2.0
+dependencies:
+  flutter:
+    sdk: flutter
+  cupertino_icons: ^1.0.6
+  google_generative_ai:
+    path: ../../pkgs/google_generative_ai
+dev_dependencies:
+  flutter_test:
+    sdk: flutter
+  flutter_lints: ^3.0.0
+flutter:
+  uses-material-design: true