Fixed refresh issue

app.py

@@ -12,8 +12,10 @@ init_session_state()
 st.title("Pro Code Playground")
 st.markdown("Write, execute & export multi-language snippets, with built‑in AI assistance.")
 
-# Language selector
+# Row for language selector + theme toggle
 lang_col, spacer, theme_col = st.columns([3, 6, 1])
+
+# Language dropdown
 with lang_col:
     lang = st.selectbox(
         "Language",
@@ -22,7 +24,7 @@ with lang_col:
         key="language"
     )
 
-# Load default code if editor is empty
+# Default code snippets for each language
 DEFAULT_SNIPPETS = {
     "Python": '''a = int(input())\nb = int(input())\nprint("Sum:", a + b)''',
     "C": '''#include <stdio.h>\nint main() {\n    int a, b;\n    scanf("%d %d", &a, &b);\n    printf("Sum: %d\\n", a + b);\n    return 0;\n}''',
@@ -32,8 +34,17 @@ DEFAULT_SNIPPETS = {
     "C#": '''using System;\npublic class Program {\n    public static void Main(string[] args) {\n        int a = Convert.ToInt32(Console.ReadLine());\n        int b = Convert.ToInt32(Console.ReadLine());\n        Console.WriteLine("Sum: " + (a + b));\n    }\n}'''
 }
 
-if st.session_state.code.strip() == "":
-    st.session_state.code = DEFAULT_SNIPPETS.get(lang, "")
+# Detect language change and reset code if appropriate
+prev_lang = st.session_state.get("prev_language")
+default_code = DEFAULT_SNIPPETS.get(lang, "")
+old_default = DEFAULT_SNIPPETS.get(prev_lang, "") if prev_lang else ""
+
+is_editor_empty_or_default = st.session_state.code.strip() in ["", old_default]
+
+if lang != prev_lang and is_editor_empty_or_default:
+    st.session_state.code = default_code
+
+st.session_state.prev_language = lang
 
 
 with theme_col: