Code Editor for app.py

import streamlit as st
import plotly.graph_objects as go

# Initialize the figure in session state if it doesn't exist
if "fig" not in st.session_state:
    # Create an empty figure with a white background
    st.session_state.fig = go.Figure()
    st.session_state.fig.update_layout(
        plot_bgcolor='white',
        xaxis=dict(range=[0, 10]),
        yaxis=dict(range=[0, 10])
    )
    
# Initialize rectangle counter
if "rect_count" not in st.session_state:
    st.session_state.rect_count = 0

# Button to add rectangle
if st.button("Add Rectangle", type="primary"):
    # Calculate position based on count to avoid complete overlap
    offset = st.session_state.rect_count % 5
    
    # Add a rectangle shape
    st.session_state.fig.add_shape(
        type="rect",
        x0=1 + offset,
        y0=1 + offset,
        x1=3 + offset,
        y1=3 + offset,
        line=dict(color="RoyalBlue"),
        fillcolor="LightSkyBlue",
        opacity=0.7,
    )
    
    st.session_state.rect_count += 1

# Display the figure
st.plotly_chart(st.session_state.fig, use_container_width=True)

# Show current count of rectangles
st.write(f"Number of rectangles: {st.session_state.rect_count}")