feat: add a Nano Banana Lite sample (#2814)

Author: thatfiredev

firebase-ai/app/src/main/java/com/google/firebase/quickstart/ai/feature/text/NanoBananaLiteViewModel.kt

@@ -0,0 +1,50 @@
+package com.google.firebase.quickstart.ai.feature.text
+
+import kotlinx.serialization.Serializable
+
+import com.google.firebase.Firebase
+import com.google.firebase.ai.Chat
+import com.google.firebase.ai.ai
+import com.google.firebase.ai.type.Content
+import com.google.firebase.ai.type.GenerativeBackend
+import com.google.firebase.ai.type.ImageSize
+import com.google.firebase.ai.type.ResponseModality
+import com.google.firebase.ai.type.generationConfig
+import com.google.firebase.ai.type.imageConfig
+import com.google.firebase.quickstart.ai.ui.UiChatMessage
+
+@Serializable
+object NanoBananaLiteRoute
+
+class NanoBananaLiteViewModel : ChatViewModel() {
+
+    override val initialPrompt: String = """
+        A kawaii-style sticker of a happy red panda wearing a tiny bamboo hat.
+        It's munching on a green bamboo leaf. The design features bold,
+        clean outlines, simple cel-shading, and a vibrant color palette.
+        The background must be white.
+        """.trimIndent()
+
+    private val chat: Chat
+
+    init {
+        val generativeModel = Firebase.ai(
+            backend = GenerativeBackend.googleAI()
+        ).generativeModel(
+            modelName = "gemini-3.1-flash-lite-image", // aka Nano Banana Lite
+            generationConfig = generationConfig {
+                responseModalities = listOf(ResponseModality.TEXT, ResponseModality.IMAGE)
+                imageConfig = imageConfig {
+                    // Nano Banana Lite currently only supports 1K output
+                    imageSize = ImageSize.SIZE_1K
+                }
+            }
+        )
+        chat = generativeModel.startChat()
+    }
+
+    override suspend fun performSendMessage(prompt: Content, currentMessages: List<UiChatMessage>) {
+        val response = chat.sendMessage(prompt)
+        validateAndDisplayResponse(response, currentMessages)
+    }
+}

firebase-ai/app/src/main/java/com/google/firebase/quickstart/ai/ui/navigation/FirebaseAISamples.kt

@@ -20,6 +20,8 @@ import com.google.firebase.quickstart.ai.feature.text.ImageBlogCreatorRoute
 import com.google.firebase.quickstart.ai.feature.text.ImageBlogCreatorViewModel
 import com.google.firebase.quickstart.ai.feature.text.NanoBanana2Route
 import com.google.firebase.quickstart.ai.feature.text.NanoBanana2ViewModel
+import com.google.firebase.quickstart.ai.feature.text.NanoBananaLiteRoute
+import com.google.firebase.quickstart.ai.feature.text.NanoBananaLiteViewModel
 import com.google.firebase.quickstart.ai.feature.text.NanoBananaProRoute
 import com.google.firebase.quickstart.ai.feature.text.NanoBananaProViewModel
 import com.google.firebase.quickstart.ai.feature.text.NanoBananaRoute
@@ -86,6 +88,14 @@ val FIREBASE_AI_SAMPLES = listOf(
         viewModelClass = ImageBlogCreatorViewModel::class,
         categories = listOf(Category.MULTIMODAL_UNDERSTANDING)
     ),
+    Sample(
+        title = "Gemini 3.1 Flash Image Lite (Nano Banana Lite)",
+        description = "Generate and/or edit images using Nano Banana Lite",
+        route = NanoBananaLiteRoute,
+        screenType = ScreenType.CHAT,
+        viewModelClass = NanoBananaLiteViewModel::class,
+        categories = listOf(Category.NANO_BANANA, Category.GEMINI3)
+    ),
     Sample(
         title = "Gemini 3.1 Flash Image (Nano Banana 2)",
         description = "Generate and/or edit images using Nano Banana 2",