feat(demo): add generative ai simulation demo

Author: mlopezFC

src/test/java/com/flowingcode/vaadin/addons/chatassistant/ChatAssistantDemoView.java

@@ -35,6 +35,7 @@ public ChatAssistantDemoView() {
     addDemo(ChatAssistantDemo.class);
     addDemo(ChatAssistantLazyLoadingDemo.class);
     addDemo(ChatAssistantMarkdownDemo.class);
+    addDemo(ChatAssistantGenerativeDemo.class);
     setSizeFull();
   }
 }

src/test/java/com/flowingcode/vaadin/addons/chatassistant/ChatAssistantGenerativeDemo.java

@@ -0,0 +1,144 @@
+/*-
+ * #%L
+ * Chat Assistant Add-on
+ * %%
+ * Copyright (C) 2023 - 2025 Flowing Code
+ * %%
+ * 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.
+ * #L%
+ */
+package com.flowingcode.vaadin.addons.chatassistant;
+
+import com.flowingcode.vaadin.addons.demo.DemoSource;
+import com.flowingcode.vaadin.addons.demo.SourcePosition;
+import com.google.common.base.Strings;
+import com.vaadin.flow.component.UI;
+import com.vaadin.flow.component.avatar.Avatar;
+import com.vaadin.flow.component.button.Button;
+import com.vaadin.flow.component.dependency.CssImport;
+import com.vaadin.flow.component.orderedlayout.VerticalLayout;
+import com.vaadin.flow.component.textfield.TextArea;
+import com.vaadin.flow.data.renderer.ComponentRenderer;
+import com.vaadin.flow.router.PageTitle;
+import com.vaadin.flow.router.Route;
+import java.time.LocalDateTime;
+import java.util.Arrays;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.concurrent.TimeUnit;
+import java.util.stream.Stream;
+
+@DemoSource(sourcePosition = SourcePosition.PRIMARY)
+@PageTitle("Generative Answer Demo")
+@SuppressWarnings("serial")
+@Route(value = "chat-assistant/generative-demo", layout = ChatAssistantDemoView.class)
+@CssImport("./styles/chat-assistant-styles-demo.css")
+public class ChatAssistantGenerativeDemo extends VerticalLayout {
+  
+  public ChatAssistantGenerativeDemo() {
+    String sampleText = "Hi, I'm an advanced language model. I'm here to help you demonstrate"
+        + " how a text-streaming chat component works in Vaadin. As you can see, each word appears"
+        + " with a slight pause, simulating the time it would take me to \"think\" and generate"
+        + " the next word. I hope this is useful for your demonstration!";
+    
+    ChatAssistant<CustomMessage> chatAssistant = new ChatAssistant<>();
+    chatAssistant.setAvatarProvider(()->new Avatar("Chat Assistant","chatbot.png"));
+    TextArea message = new TextArea();
+    message.setLabel("Enter a message from the assistant");
+    message.setSizeFull();
+    message.setValue(sampleText);
+    message.addKeyPressListener(ev->{
+      if (Strings.isNullOrEmpty(chatAssistant.getWhoIsTyping())) {
+        chatAssistant.setWhoIsTyping("Assistant is generating an answer ...");
+      }
+    });
+    message.addBlurListener(ev->chatAssistant.clearWhoIsTyping());
+    chatAssistant.setMessagesRenderer(new ComponentRenderer<CustomChatMessage,CustomMessage>(m -> {
+      return new CustomChatMessage(m); 
+    },
+        (component, m) -> {
+          ((CustomChatMessage) component).setMessage(m);
+          return component;
+        }));
+    chatAssistant.setSubmitListener(se -> {
+      chatAssistant.sendMessage(CustomMessage.builder().messageTime(LocalDateTime.now())
+          .name("User").content(se.getValue()).tagline("Generated by user").build());
+    });
+
+    Button chat = new Button("Chat");
+    chat.addClickListener(ev -> {
+      CustomMessage m = CustomMessage.builder().content(message.getValue()).messageTime(LocalDateTime.now())
+          .name("Assistant").avatar("chatbot.png").tagline("Generated by assistant").build();
+
+      chatAssistant.sendMessage(m);
+      message.clear();
+    });
+    Button chatWithThinking = new Button("Chat With Generative Thinking");
+    chatWithThinking.addClickListener(ev -> {
+      String messageToSend = message.getValue();
+      message.setValue("");
+      CustomMessage delayedMessage = CustomMessage.builder().loading(true).content("")
+          .messageTime(LocalDateTime.now())
+          .name("Assistant").avatar("chatbot.png").tagline("Generated by assistant").build();
+
+      UI currentUI = UI.getCurrent();
+      chatAssistant.sendMessage(delayedMessage);
+
+      CompletableFuture.runAsync(() -> {
+        try {
+          TimeUnit.MILLISECONDS.sleep(500);
+          currentUI.access(() -> {
+            delayedMessage.setLoading(false);
+          });
+          streamWords(messageToSend)
+          .forEach(item -> {
+            currentUI.access(() -> {
+              delayedMessage.setContent(delayedMessage.getContent() + " " + item);
+              chatAssistant.updateMessage(delayedMessage); 
+            });
+          });
+        } catch (InterruptedException e) {
+          Thread.currentThread().interrupt();
+        }
+      });
+
+      message.clear();
+    });
+    chatAssistant.sendMessage(CustomMessage.builder().content("Hello, I am here to assist you")
+        .messageTime(LocalDateTime.now())
+        .name("Assistant").avatar("chatbot.png").tagline("Generated by assistant").build());
+    
+    add(message, chat, chatWithThinking, chatAssistant);
+  }
+  
+  public Stream<String> streamWords(String fullText) {
+    if (fullText == null || fullText.isEmpty()) {
+        return Stream.empty();
+    }
+
+    String[] words = fullText.split("\\s+");
+
+    return Arrays.stream(words)
+        .map(word -> {
+            try {
+                long delay = ThreadLocalRandom.current().nextLong(50, 250);
+                Thread.sleep(delay);
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt(); 
+            }
+            
+            return word + " ";
+        });
+}
+  
+}