Add example for gcs generation

Author: cynthiajoan

packages/firebase_vertexai/firebase_vertexai/example/lib/pages/imagen_page.dart

@@ -14,6 +14,7 @@
 
 import 'package:flutter/material.dart';
 import 'package:firebase_vertexai/firebase_vertexai.dart';
+import 'package:firebase_storage/firebase_storage.dart';
 import '../widgets/message_widget.dart';
 
 class ImagenPage extends StatefulWidget {
@@ -120,6 +121,20 @@ class _ImagenPageState extends State<ImagenPage> {
                         Icons.image_search,
                         color: Theme.of(context).colorScheme.primary,
                       ),
+                      tooltip: 'Imagen raw data',
+                    )
+                  else
+                    const CircularProgressIndicator(),
+                  if (!_loading)
+                    IconButton(
+                      onPressed: () async {
+                        await _testImagenGCS(_textController.text);
+                      },
+                      icon: Icon(
+                        Icons.imagesearch_roller,
+                        color: Theme.of(context).colorScheme.primary,
+                      ),
+                      tooltip: 'Imagen GCS',
                     )
                   else
                     const CircularProgressIndicator(),
@@ -158,6 +173,36 @@ class _ImagenPageState extends State<ImagenPage> {
     });
   }
 
+  Future<void> _testImagenGCS(String prompt) async {
+    setState(() {
+      _loading = true;
+    });
+    var gcsUrl = 'gs://vertex-ai-example-ef5a2.appspot.com/imagen';
+
+    var response = await _imagenModel.generateImagesGCS(prompt, gcsUrl);
+
+    if (response.images.isNotEmpty) {
+      var imagenImage = response.images[0];
+      final returnImageUri = imagenImage.gcsUri;
+      final reference = FirebaseStorage.instance.refFromURL(returnImageUri);
+      final downloadUrl = await reference.getDownloadURL();
+      // Process the image
+      _generatedContent.add(
+        MessageData(
+          image: Image(image: NetworkImage(downloadUrl)),
+          text: prompt,
+          fromUser: false,
+        ),
+      );
+    } else {
+      // Handle the case where no images were generated
+      _showError('Error: No images were generated.');
+    }
+    setState(() {
+      _loading = false;
+    });
+  }
+
   void _showError(String message) {
     showDialog<void>(
       context: context,

packages/firebase_vertexai/firebase_vertexai/example/pubspec.yaml

@@ -20,6 +20,7 @@ dependencies:
   # Use with the CupertinoIcons class for iOS style icons.
   cupertino_icons: ^1.0.6
   firebase_core: ^3.10.1
+  firebase_storage: ^12.4.1
   firebase_vertexai: ^1.1.1
   flutter:
     sdk: flutter