From 802cde35019354ab3c4749ef1ae7ea71b404e31b Mon Sep 17 00:00:00 2001
From: David Luzar <5153846+dwelle@users.noreply.github.com>
Date: Fri, 30 Jan 2026 16:28:36 +0100
Subject: [PATCH] feat: support customizing TTD welcome screen (#10719)

* feat: support customizing TTD welcome screen

* remove debug
---
 .../components/TTDDialog/Chat/Chat.scss       |  4 ++--
 .../TTDDialog/Chat/ChatInterface.tsx          | 22 +++++++++----------
 .../TTDDialog/Chat/TTDChatPanel.tsx           |  8 +++----
 .../components/TTDDialog/TTDDialog.tsx        |  7 ++++++
 .../TTDDialog/TTDWelcomeMessage.tsx           | 11 ++++++++++
 .../components/TTDDialog/TextToDiagram.tsx    |  6 +++++
 .../excalidraw/components/TTDDialog/types.ts  |  5 +++++
 7 files changed, 44 insertions(+), 19 deletions(-)
 create mode 100644 packages/excalidraw/components/TTDDialog/TTDWelcomeMessage.tsx

diff --git a/packages/excalidraw/components/TTDDialog/Chat/Chat.scss b/packages/excalidraw/components/TTDDialog/Chat/Chat.scss
index 01b5a96012..63671ed66e 100644
--- a/packages/excalidraw/components/TTDDialog/Chat/Chat.scss
+++ b/packages/excalidraw/components/TTDDialog/Chat/Chat.scss
@@ -48,14 +48,14 @@ $verticalBreakpoint: 861px;
       }
     }
 
-    &__empty-state {
+    &__welcome-screen {
       display: flex;
       align-items: center;
       justify-content: center;
       height: 100%;
       min-height: 200px;
 
-      &-content {
+      &__welcome-message {
         text-align: center;
 
         h3 {
diff --git a/packages/excalidraw/components/TTDDialog/Chat/ChatInterface.tsx b/packages/excalidraw/components/TTDDialog/Chat/ChatInterface.tsx
index 312c49ac9c..1f0a302351 100644
--- a/packages/excalidraw/components/TTDDialog/Chat/ChatInterface.tsx
+++ b/packages/excalidraw/components/TTDDialog/Chat/ChatInterface.tsx
@@ -6,6 +6,8 @@ import { InlineIcon } from "../../InlineIcon";
 
 import { t } from "../../../i18n";
 
+import { TTDWelcomeMessage } from "../TTDWelcomeMessage";
+
 import { ChatMessage } from "./ChatMessage";
 
 import type { TChat, TTTDDialog } from "../types";
@@ -20,13 +22,13 @@ export const ChatInterface = ({
   onGenerate,
   isGenerating,
   rateLimits,
-  placeholder,
   onAbort,
   onMermaidTabClick,
   onAiRepairClick,
   onDeleteMessage,
   onInsertMessage,
   onRetry,
+  renderWelcomeScreen,
   renderWarning,
 }: {
   chatId: string;
@@ -41,17 +43,13 @@ export const ChatInterface = ({
   } | null;
   onViewAsMermaid?: () => void;
   generatedResponse?: string | null;
-  placeholder: {
-    title: string;
-    description: string;
-    hint: string;
-  };
   onAbort?: () => void;
   onMermaidTabClick?: (message: TChat.ChatMessage) => void;
   onAiRepairClick?: (message: TChat.ChatMessage) => void;
   onDeleteMessage?: (messageId: string) => void;
   onInsertMessage?: (message: TChat.ChatMessage) => void;
   onRetry?: (message: TChat.ChatMessage) => void;
+  renderWelcomeScreen?: TTTDDialog.renderWelcomeScreen;
   renderWarning?: TTTDDialog.renderWarning;
 }) => {
   const messagesEndRef = useRef<HTMLDivElement>(null);
@@ -113,12 +111,12 @@ export const ChatInterface = ({
     <div className="chat-interface">
       <div className="chat-interface__messages">
         {messages.length === 0 ? (
-          <div className="chat-interface__empty-state">
-            <div className="chat-interface__empty-state-content">
-              <h3>{placeholder.title}</h3>
-              <p>{placeholder.description}</p>
-              <p>{placeholder.hint}</p>
-            </div>
+          <div className="chat-interface__welcome-screen">
+            {renderWelcomeScreen ? (
+              renderWelcomeScreen({ rateLimits: rateLimits ?? null })
+            ) : (
+              <TTDWelcomeMessage />
+            )}
           </div>
         ) : (
           messages.map((message, index) => (
diff --git a/packages/excalidraw/components/TTDDialog/Chat/TTDChatPanel.tsx b/packages/excalidraw/components/TTDDialog/Chat/TTDChatPanel.tsx
index a9e66df6e4..25aa30df88 100644
--- a/packages/excalidraw/components/TTDDialog/Chat/TTDChatPanel.tsx
+++ b/packages/excalidraw/components/TTDDialog/Chat/TTDChatPanel.tsx
@@ -40,6 +40,7 @@ export const TTDChatPanel = ({
   onInsertMessage,
   onRetry,
   onViewAsMermaid,
+  renderWelcomeScreen,
   renderWarning,
 }: {
   chatId: string;
@@ -68,6 +69,7 @@ export const TTDChatPanel = ({
 
   onViewAsMermaid: () => void;
 
+  renderWelcomeScreen?: TTTDDialog.renderWelcomeScreen;
   renderWarning?: TTTDDialog.renderWarning;
 }) => {
   const [rateLimits] = useAtom(rateLimitsAtom);
@@ -151,11 +153,7 @@ export const TTDChatPanel = ({
         onInsertMessage={onInsertMessage}
         onRetry={onRetry}
         rateLimits={rateLimits}
-        placeholder={{
-          title: t("chat.placeholder.title"),
-          description: t("chat.placeholder.description"),
-          hint: t("chat.placeholder.hint"),
-        }}
+        renderWelcomeScreen={renderWelcomeScreen}
         renderWarning={renderWarning}
       />
     </TTDDialogPanel>
diff --git a/packages/excalidraw/components/TTDDialog/TTDDialog.tsx b/packages/excalidraw/components/TTDDialog/TTDDialog.tsx
index a77167613e..a16c0cc385 100644
--- a/packages/excalidraw/components/TTDDialog/TTDDialog.tsx
+++ b/packages/excalidraw/components/TTDDialog/TTDDialog.tsx
@@ -15,6 +15,8 @@ import { TTDDialogTab } from "./TTDDialogTab";
 
 import "./TTDDialog.scss";
 
+import { TTDWelcomeMessage } from "./TTDWelcomeMessage";
+
 import type {
   MermaidToExcalidrawLibProps,
   TTDPersistenceAdapter,
@@ -25,6 +27,7 @@ export const TTDDialog = (
   props:
     | {
         onTextSubmit: TTTDDialog.onTextSubmit;
+        renderWelcomeScreen?: TTTDDialog.renderWelcomeScreen;
         renderWarning?: TTTDDialog.renderWarning;
         persistenceAdapter: TTDPersistenceAdapter;
       }
@@ -39,6 +42,8 @@ export const TTDDialog = (
   return <TTDDialogBase {...props} tab={appState.openDialog.tab} />;
 };
 
+TTDDialog.WelcomeMessage = TTDWelcomeMessage;
+
 /**
  * Text to diagram (TTD) dialog
  */
@@ -54,6 +59,7 @@ const TTDDialogBase = withInternalFallback(
         onTextSubmit(
           props: TTTDDialog.OnTextSubmitProps,
         ): Promise<TTTDDialog.OnTextSubmitRetValue>;
+        renderWelcomeScreen?: TTTDDialog.renderWelcomeScreen;
         renderWarning?: TTTDDialog.renderWarning;
         persistenceAdapter: TTDPersistenceAdapter;
       }
@@ -110,6 +116,7 @@ const TTDDialogBase = withInternalFallback(
               <TextToDiagram
                 mermaidToExcalidrawLib={mermaidToExcalidrawLib}
                 onTextSubmit={rest.onTextSubmit}
+                renderWelcomeScreen={rest.renderWelcomeScreen}
                 renderWarning={rest.renderWarning}
                 persistenceAdapter={rest.persistenceAdapter}
               />
diff --git a/packages/excalidraw/components/TTDDialog/TTDWelcomeMessage.tsx b/packages/excalidraw/components/TTDDialog/TTDWelcomeMessage.tsx
new file mode 100644
index 0000000000..ae213a8b60
--- /dev/null
+++ b/packages/excalidraw/components/TTDDialog/TTDWelcomeMessage.tsx
@@ -0,0 +1,11 @@
+import { t } from "../../i18n";
+
+export const TTDWelcomeMessage = () => {
+  return (
+    <div className="chat-interface__welcome-screen__welcome-message">
+      <h3>{t("chat.placeholder.title")}</h3>
+      <p>{t("chat.placeholder.description")}</p>
+      <p>{t("chat.placeholder.hint")}</p>
+    </div>
+  );
+};
diff --git a/packages/excalidraw/components/TTDDialog/TextToDiagram.tsx b/packages/excalidraw/components/TTDDialog/TextToDiagram.tsx
index e93775a76b..da547602aa 100644
--- a/packages/excalidraw/components/TTDDialog/TextToDiagram.tsx
+++ b/packages/excalidraw/components/TTDDialog/TextToDiagram.tsx
@@ -35,6 +35,7 @@ import type {
 const TextToDiagramContent = ({
   mermaidToExcalidrawLib,
   onTextSubmit,
+  renderWelcomeScreen,
   renderWarning,
   persistenceAdapter,
 }: {
@@ -42,6 +43,7 @@ const TextToDiagramContent = ({
   onTextSubmit: (
     props: TTTDDialog.OnTextSubmitProps,
   ) => Promise<TTTDDialog.OnTextSubmitRetValue>;
+  renderWelcomeScreen?: TTTDDialog.renderWelcomeScreen;
   renderWarning?: TTTDDialog.renderWarning;
   persistenceAdapter: TTDPersistenceAdapter;
 }) => {
@@ -220,6 +222,7 @@ const TextToDiagramContent = ({
         onRetry={handleRetry}
         onViewAsMermaid={onViewAsMermaid}
         renderWarning={renderWarning}
+        renderWelcomeScreen={renderWelcomeScreen}
       />
       {showPreview && (
         <TTDPreviewPanel
@@ -237,6 +240,7 @@ const TextToDiagramContent = ({
 export const TextToDiagram = ({
   mermaidToExcalidrawLib,
   onTextSubmit,
+  renderWelcomeScreen,
   renderWarning,
   persistenceAdapter,
 }: {
@@ -244,6 +248,7 @@ export const TextToDiagram = ({
   onTextSubmit(
     props: TTTDDialog.OnTextSubmitProps,
   ): Promise<TTTDDialog.OnTextSubmitRetValue>;
+  renderWelcomeScreen?: TTTDDialog.renderWelcomeScreen;
   renderWarning?: TTTDDialog.renderWarning;
   persistenceAdapter: TTDPersistenceAdapter;
 }) => {
@@ -251,6 +256,7 @@ export const TextToDiagram = ({
     <TextToDiagramContent
       mermaidToExcalidrawLib={mermaidToExcalidrawLib}
       onTextSubmit={onTextSubmit}
+      renderWelcomeScreen={renderWelcomeScreen}
       renderWarning={renderWarning}
       persistenceAdapter={persistenceAdapter}
     />
diff --git a/packages/excalidraw/components/TTDDialog/types.ts b/packages/excalidraw/components/TTDDialog/types.ts
index d3c8e3061d..7f79894b92 100644
--- a/packages/excalidraw/components/TTDDialog/types.ts
+++ b/packages/excalidraw/components/TTDDialog/types.ts
@@ -116,4 +116,9 @@ export namespace TTTDDialog {
   export type renderWarning = (
     chatMessage: TChat.ChatMessage,
   ) => React.ReactNode | undefined;
+
+  export type renderWelcomeScreen = (props: {
+    /** null if not rate limit data currently available */
+    rateLimits: RateLimits | null;
+  }) => React.ReactNode | undefined;
 }