add warning message

app.py

@@ -37,6 +37,16 @@ def gradio_inference(
     height=1024
 ):
     """Wrapper function for Gradio interface"""
+    # Check if mask has been drawn
+    if image_data is None or "layers" not in image_data or not image_data["layers"]:
+        raise gr.Error("Please draw a mask over the clothing area before generating!")
+    
+    # Check if mask is empty (all black)
+    mask = image_data["layers"][0]
+    mask_array = np.array(mask)
+    if np.all(mask_array < 10):
+        raise gr.Error("The mask is empty! Please draw over the clothing area you want to replace.")
+
     # Use temporary directory
     with tempfile.TemporaryDirectory() as tmp_dir:
         # Save inputs to temp directory
@@ -86,6 +96,14 @@ with gr.Blocks() as demo:
     # gr.Video("example/github.mp4", label="Demo Video: How to use the tool")
     
     with gr.Column():
+        gr.Markdown("""
+        ### ⚠️ Important:
+        1. Click 'Edit' on the Model Image
+        2. Draw a mask over the clothing area you want to replace
+        3. Click 'Save' when done
+        4. Then click 'Generate Try-On'
+        """)
+        
         with gr.Row():
             with gr.Column():
                 image_input = gr.ImageMask(