Update src/streamlit_app.py

src/streamlit_app.py

@@ -13,28 +13,15 @@ forums](https://discuss.streamlit.io).
 In the meantime, below is an example of what you can do with just a few lines of code:
 """
 
-num_points = st.slider("Number of points in spiral", 1, 10000, 1100)
-num_turns = st.slider("Number of turns in spiral", 1, 300, 31)
-
-indices = np.linspace(0, 1, num_points)
-theta = 2 * np.pi * num_turns * indices
-radius = indices
-
-x = radius * np.cos(theta)
-y = radius * np.sin(theta)
+import streamlit as st
+from streamlit_folium import st_folium
+from folium.plugins import Draw
+import folium
 
-df = pd.DataFrame({
-    "x": x,
-    "y": y,
-    "idx": indices,
-    "rand": np.random.randn(num_points),
-})
+m = folium.Map(location=[40.7128, -74.0060], zoom_start=12)
+Draw(export=True).add_to(m)
+output = st_folium(m, width=700, height=500)
 
-st.altair_chart(alt.Chart(df, height=700, width=700)
-    .mark_point(filled=True)
-    .encode(
-        x=alt.X("x", axis=None),
-        y=alt.Y("y", axis=None),
-        color=alt.Color("idx", legend=None, scale=alt.Scale()),
-        size=alt.Size("rand", legend=None, scale=alt.Scale(range=[1, 150])),
-    ))
+if output and 'last_active_drawing' in output:
+    geojson_data = output['last_active_drawing']
+    st.write("Geofence drawn:", geojson_data)