feat(AI): Replace Imagen with Nano Banana usage

ai/ai-react-app/src/App.tsx

@@ -2,10 +2,10 @@ import { useEffect, useState } from "react";
 import MainLayout from "./components/Layout/MainLayout";
 
 // Defines the primary modes or views available in the application.
-export type AppMode = "chat" | "imagenGen" | "live";
+export type AppMode = "chat" | "nanobanana" | "live";
 
 function App() {
-  // State to manage which main view ('chat' or 'imagenGen') is currently active.
+  // State to manage which main view ('chat' or 'nanobanana') is currently active.
   const [activeMode, setActiveMode] = useState<AppMode>("chat");
 
   useEffect(() => {

ai/ai-react-app/src/components/Common/PromptInput.tsx

@@ -6,7 +6,6 @@ import {
   CountTokensResponse,
   Part,
   getGenerativeModel,
-  ImagenModelParams,
 } from "firebase/ai";
 import { fileToGenerativePart } from "../../utils/fileUtils";
 import { AppMode } from "../../App";
@@ -23,8 +22,8 @@ interface PromptInputProps {
   activeMode: AppMode;
   aiInstance: AI;
   currentParams?: ModelParams;
-  currentImagenParams?: ImagenModelParams;
   selectedFile: File | null;
+  selectedAspectRatio?: string;
 }
 
 const PromptInput: React.FC<PromptInputProps> = ({
@@ -39,6 +38,7 @@ const PromptInput: React.FC<PromptInputProps> = ({
   aiInstance,
   currentParams,
   selectedFile,
+  selectedAspectRatio,
 }) => {
   const [tokenCount, setTokenCount] = useState<CountTokensResponse | null>(
     null,
@@ -55,11 +55,15 @@ const PromptInput: React.FC<PromptInputProps> = ({
     setTokenCountError(null);
 
     const currentPromptText = prompt.trim();
+    let textToCount = currentPromptText;
+    if (selectedAspectRatio) {
+      textToCount += `\nUse aspect ratio ${selectedAspectRatio}`;
+    }
     const parts: Part[] = [];
 
     // Add text part if present
-    if (currentPromptText) {
-      parts.push({ text: currentPromptText });
+    if (textToCount) {
+      parts.push({ text: textToCount });
     }
 
     // Add file part if present
@@ -137,15 +141,22 @@ const PromptInput: React.FC<PromptInputProps> = ({
 
       {/* Main Input Area */}
       <div className={styles.inputArea}>
-        <textarea
-          className={styles.promptTextarea}
-          value={prompt}
-          onChange={(e) => onPromptChange(e.target.value)}
-          placeholder={placeholder}
-          disabled={isLoading || isCountingTokens} // Disable if main loading OR counting
-          rows={3}
-          aria-label="Prompt input"
-        />
+        <div style={{ display: 'flex', flexDirection: 'column', flexGrow: 1 }}>
+          <textarea
+            className={styles.promptTextarea}
+            value={prompt}
+            onChange={(e) => onPromptChange(e.target.value)}
+            placeholder={placeholder}
+            disabled={isLoading || isCountingTokens} // Disable if main loading OR counting
+            rows={3}
+            aria-label="Prompt input"
+          />
+          {selectedAspectRatio && (
+            <div style={{ color: '#aaa', fontSize: '0.9em', marginTop: '5px', width: '100%' }}>
+              Use aspect ratio {selectedAspectRatio}
+            </div>
+          )}
+        </div>
         <button
           className={styles.runButton}
           onClick={onSubmit}

ai/ai-react-app/src/components/Layout/LeftSidebar.tsx

@@ -40,7 +40,7 @@ const LeftSidebar: React.FC<LeftSidebarProps> = ({
   // Define the available modes and their display names
   const modes: { id: AppMode; label: string }[] = [
     { id: "chat", label: "Chat" },
-    { id: "imagenGen", label: "Imagen Generation" },
+    { id: "nanobanana", label: "Nano Banana" },
     { id: "live", label: "Live Conversation" },
   ];
 

ai/ai-react-app/src/components/Layout/MainLayout.tsx

@@ -3,24 +3,23 @@ import TopBar from "./TopBar";
 import LeftSidebar from "./LeftSidebar";
 import RightSidebar from "./RightSidebar";
 import ChatView from "../../views/ChatView";
-import ImagenView from "../../views/ImagenView";
+import NanoBananaView from "../../views/NanoBananaView";
 import LiveView from "../../views/LiveView";
 import { AppMode } from "../../App";
 import {
   UsageMetadata,
   ModelParams,
-  ImagenModelParams,
   BackendType,
   AI,
   VertexAIBackend,
   GoogleAIBackend,
   getAI,
+  ResponseModality,
 } from "firebase/ai";
 import {
   AVAILABLE_GENERATIVE_MODELS,
-  AVAILABLE_IMAGEN_MODELS,
+  AVAILABLE_NANO_BANANA_MODELS,
   defaultGenerativeParams,
-  defaultImagenParams,
 } from "../../services/firebaseAIService";
 import styles from "./MainLayout.module.css";
 import { getApp } from "firebase/app";
@@ -46,10 +45,13 @@ const MainLayout: React.FC<MainLayoutProps> = ({
     model: AVAILABLE_GENERATIVE_MODELS[0],
     ...defaultGenerativeParams,
   });
-  const [imagenParams, setImagenParams] = useState<ImagenModelParams>({
-    model: AVAILABLE_IMAGEN_MODELS[0],
-    ...defaultImagenParams,
+  const [nanoBananaParams, setNanoBananaParams] = useState<ModelParams>({
+    model: AVAILABLE_NANO_BANANA_MODELS[0],
+    generationConfig: {
+      responseModalities: [ResponseModality.TEXT, ResponseModality.IMAGE],
+    },
   });
+  const [selectedAspectRatio, setSelectedAspectRatio] = useState<string | undefined>();
 
   const [usageMetadata, setUsageMetadata] = useState<UsageMetadata | null>(
     null,
@@ -60,7 +62,9 @@ const MainLayout: React.FC<MainLayoutProps> = ({
     try {
       const backendInstance =
         activeBackendType === BackendType.VERTEX_AI
-          ? new VertexAIBackend()
+          ? activeMode === "nanobanana"
+            ? new VertexAIBackend("global")
+            : new VertexAIBackend()
           : new GoogleAIBackend();
       const aiInstance = getAI(getApp(), { backend: backendInstance });
       setActiveAI(aiInstance);
@@ -75,14 +79,14 @@ const MainLayout: React.FC<MainLayoutProps> = ({
       );
       setActiveAI(null);
     }
-  }, [activeBackendType]);
+  }, [activeBackendType, activeMode]);
 
   useEffect(() => {
     setUsageMetadata(null);
   }, [activeMode]);
 
   useEffect(() => {
-    const validModes: AppMode[] = ["chat", "imagenGen", "live"];
+    const validModes: AppMode[] = ["chat", "nanobanana", "live"];
     if (!validModes.includes(activeMode)) {
       console.warn(`Invalid activeMode "${activeMode}". Resetting to "chat".`);
       setActiveMode("chat");
@@ -109,9 +113,9 @@ const MainLayout: React.FC<MainLayoutProps> = ({
             activeMode={activeMode}
           />
         );
-      case "imagenGen":
+      case "nanobanana":
         return (
-          <ImagenView aiInstance={activeAI} currentParams={imagenParams} />
+          <NanoBananaView aiInstance={activeAI} currentParams={nanoBananaParams} selectedAspectRatio={selectedAspectRatio} />
         );
       case "live":
         return (
@@ -152,8 +156,10 @@ const MainLayout: React.FC<MainLayoutProps> = ({
             activeMode={activeMode}
             generativeParams={generativeParams}
             setGenerativeParams={setGenerativeParams}
-            imagenParams={imagenParams}
-            setImagenParams={setImagenParams}
+            nanoBananaParams={nanoBananaParams}
+            setNanoBananaParams={setNanoBananaParams}
+            selectedAspectRatio={selectedAspectRatio}
+            setSelectedAspectRatio={setSelectedAspectRatio}
           />
         </div>
       </div>