utils/folium.py

import branca
import folium
import geopandas as gpd
import streamlit as st
from folium.plugins import Draw


def get_map_crop():
    m = folium.Map(
        location=[50, 32],
        zoom_start=4,
        tiles="Esri.WorldImagery",
        attributionControl=False,
        prefer_canvas=True,
    )
    Draw(
        export=False,
        show_geometry_on_click=False,
        draw_options={
            "polyline": False,
            "polygon": False,
            "circle": False,
            "circlemarker": False,
            "marker": False,
        },
    ).add_to(m)
    legend_html = """
    {% macro html(this, kwargs) %}
    <div style="
        position: fixed; 
        bottom: 35px;
        left: 30px;
        width: 130px;
        line-height: 3px;
        height: 120px;
        z-index:9999;
        font-size:14px;
        ">
        <p><a style="color:#00ff00;font-size:150%;margin-left:20px;">&FilledSmallSquare;</a>&emsp;Grassland</p>
        <p><a style="color:#8b4513;font-size:150%;margin-left:20px;">&FilledSmallSquare;</a>&emsp;Cereals</p>
        <p><a style="color:#ffffff;font-size:150%;margin-left:20px;">&FilledSmallSquare;</a>&emsp;Other</p>
        <p><a style="color:#00ffff;font-size:150%;margin-left:20px;">&FilledSmallSquare;</a>&emsp;Flowers</p>
        <p><a style="color:#800080;font-size:150%;margin-left:20px;">&FilledSmallSquare;</a>&emsp;Vegetables</p>
        <p><a style="color:#006400;font-size:150%;margin-left:20px;">&FilledSmallSquare;</a>&emsp;Fruit trees</p>
    </div>
    <div style="
        position: fixed; 
        bottom: 50px;
        left: 30px;
        width: 130px;
        line-height: 3px;
        height: 120px; 
        z-index:9998;
        font-size:14px;
        background-color: #ffffff;

        opacity: 0.85;
        ">
    </div>
    {% endmacro %}
    """
    legend = branca.element.MacroElement()
    legend._template = branca.element.Template(legend_html)
    m.get_root().add_child(legend)
    return m


def get_parquet(tile_path, id_classes):
    data = gpd.read_parquet(tile_path).to_crs(epsg="4326")
    data["class_name"] = [id_classes[i] for i in data["class"]]
    data["geometry"] = data["geometry"].simplify(0.0001)
    return data


def draw_gdf(
    _map,
    tile_path,
    name,
    _style_call,
    id_classes,
):
    if tile_path not in st.session_state.keys():
        tile_gdf = get_parquet(tile_path, id_classes)
    else:
        tile_gdf = st.session_state[tile_path]
    feature_group = folium.FeatureGroup(f"{name} layer")
    tooltip = folium.GeoJsonTooltip(
        fields=["class_name", "area"],
        aliases=["Crop type: \t", "Area (m²): \t"],
        localize=True,
        sticky=False,
        labels=True,
        style="""
                background-color: #F0EFEF;
                border: 2px solid black;
                border-radius: 3px;
                box-shadow: 3px;
            """,
        max_width=800,
    )

    folium.GeoJson(tile_gdf, style_function=_style_call, tooltip=tooltip).add_to(
        feature_group
    )
    feature_group.add_to(_map)
    bound = feature_group.get_bounds()
    _map.fit_bounds(bound)


def get_clean_rendering_container(app_state: str):
    """Makes sure we can render from a clean slate on state changes."""
    slot_in_use = st.session_state.slot_in_use = st.session_state.get(
        "slot_in_use", "a"
    )
    if app_state != st.session_state.get("previous_state", app_state):
        if slot_in_use == "a":
            slot_in_use = st.session_state.slot_in_use = "b"
        else:
            slot_in_use = st.session_state.slot_in_use = "a"

    st.session_state.previous_state = app_state

    slot = {
        "a": st.empty(),
        "b": st.empty(),
    }[slot_in_use]

    return slot.container()