llama : move end-user examples to tools directory (#13249)

* llama : move end-user examples to tools directory

---------

Co-authored-by: Xuan Son Nguyen <son@huggingface.co>

tools/server/webui/src/utils/llama-vscode.ts

@@ -0,0 +1,60 @@
+import { useEffect, useState } from 'react';
+import { MessageExtraContext } from './types';
+import { ChatTextareaApi } from '../components/useChatTextarea.ts';
+
+// Extra context when using llama.cpp WebUI from llama-vscode, inside an iframe
+// Ref: https://github.com/ggml-org/llama.cpp/pull/11940
+
+interface SetTextEvData {
+  text: string;
+  context: string;
+}
+
+/**
+ * To test it:
+ * window.postMessage({ command: 'setText', text: 'Spot the syntax error', context: 'def test()\n  return 123' }, '*');
+ */
+
+export const useVSCodeContext = (textarea: ChatTextareaApi) => {
+  const [extraContext, setExtraContext] = useState<MessageExtraContext | null>(
+    null
+  );
+
+  // Accept setText message from a parent window and set inputMsg and extraContext
+  useEffect(() => {
+    const handleMessage = (event: MessageEvent) => {
+      if (event.data?.command === 'setText') {
+        const data: SetTextEvData = event.data;
+        textarea.setValue(data?.text);
+        if (data?.context && data.context.length > 0) {
+          setExtraContext({
+            type: 'context',
+            content: data.context,
+          });
+        }
+        textarea.focus();
+      }
+    };
+
+    window.addEventListener('message', handleMessage);
+    return () => window.removeEventListener('message', handleMessage);
+  }, [textarea]);
+
+  // Add a keydown listener that sends the "escapePressed" message to the parent window
+  useEffect(() => {
+    const handleKeyDown = (event: KeyboardEvent) => {
+      if (event.key === 'Escape') {
+        window.parent.postMessage({ command: 'escapePressed' }, '*');
+      }
+    };
+
+    window.addEventListener('keydown', handleKeyDown);
+    return () => window.removeEventListener('keydown', handleKeyDown);
+  }, []);
+
+  return {
+    extraContext,
+    // call once the user message is sent, to clear the extra context
+    clearExtraContext: () => setExtraContext(null),
+  };
+};