MapComplete/Logic/Actors/StrayClickHandler.ts

import * as L from "leaflet";
import {UIEventSource} from "../UIEventSource";
import ScrollableFullScreen from "../../UI/Base/ScrollableFullScreen";
import FilteredLayer from "../../Models/FilteredLayer";
import Constants from "../../Models/Constants";
import BaseUIElement from "../../UI/BaseUIElement";

/**
 * The stray-click-hanlders adds a marker to the map if no feature was clicked.
 * Shows the given uiToShow-element in the messagebox
 */
export default class StrayClickHandler {
    private _lastMarker;

    constructor(
        state: {
            LastClickLocation: UIEventSource<{ lat: number, lon: number }>,
            selectedElement: UIEventSource<string>,
            filteredLayers: UIEventSource<FilteredLayer[]>,
            leafletMap: UIEventSource<L.Map>
        },
        uiToShow: ScrollableFullScreen,
        iconToShow: BaseUIElement) {
        const self = this;
        const leafletMap = state.leafletMap
        state.filteredLayers.data.forEach((filteredLayer) => {
            filteredLayer.isDisplayed.addCallback(isEnabled => {
                if (isEnabled && self._lastMarker && leafletMap.data !== undefined) {
                    // When a layer is activated, we remove the 'last click location' in order to force the user to reclick
                    // This reclick might be at a location where a feature now appeared...
                    state.leafletMap.data.removeLayer(self._lastMarker);
                }
            })
        })

        state.LastClickLocation.addCallback(function (lastClick) {

            if (self._lastMarker !== undefined) {
                state.leafletMap.data?.removeLayer(self._lastMarker);
            }

            if (lastClick === undefined) {
                return;
            }

            state.selectedElement.setData(undefined);
            const clickCoor: [number, number] = [lastClick.lat, lastClick.lon]
            self._lastMarker = L.marker(clickCoor, {
                icon: L.divIcon({
                    html: iconToShow.ConstructElement(),
                    iconSize: [50, 50],
                    iconAnchor: [25, 50],
                    popupAnchor: [0, -45]
                })
            });
            const popup = L.popup({
                autoPan: true,
                autoPanPaddingTopLeft: [15, 15],
                closeOnEscapeKey: true,
                autoClose: true
            }).setContent("<div id='strayclick' style='height: 65vh'></div>");
            self._lastMarker.addTo(leafletMap.data);
            self._lastMarker.bindPopup(popup);

            self._lastMarker.on("click", () => {
                if (leafletMap.data.getZoom() < Constants.userJourney.minZoomLevelToAddNewPoints) {
                    self._lastMarker.closePopup()
                    leafletMap.data.flyTo(clickCoor, Constants.userJourney.minZoomLevelToAddNewPoints)
                    return;
                }


                uiToShow.AttachTo("strayclick")
                uiToShow.Activate();
            });
        });

        state.selectedElement.addCallback(() => {
            if (self._lastMarker !== undefined) {
                leafletMap.data.removeLayer(self._lastMarker);
                this._lastMarker = undefined;
            }
        })

    }


}