demarches-normaliennes/app/assets/javascripts/api_carto/lib/leaflet.spin.js

if (typeof L != 'undefined') {
    L.SpinMapMixin = {
        spin: function (state, options) {
            if (!!state) {
                // start spinning !
                if (!this._spinner) {
                    this._spinner = new Spinner(options).spin(this._container);
                    this._spinning = 0;
                }
                this._spinning++;
            }
            else {
                this._spinning--;
                if (this._spinning <= 0) {
                    // end spinning !
                    if (this._spinner) {
                        this._spinner.stop();
                        this._spinner = null;
                    }
                }
            }
        }
    };

    L.Map.include(L.SpinMapMixin);

    L.Map.addInitHook(function () {
        this.on('layeradd', function (e) {
            // If added layer is currently loading, spin !
            if (e.layer.loading) this.spin(true);
            if (typeof e.layer.on != 'function') return;
            e.layer.on('data:loading', function () { this.spin(true); }, this);
            e.layer.on('data:loaded',  function () { this.spin(false); }, this);
        }, this);
        this.on('layerremove', function (e) {
            // Clean-up
            if (e.layer.loading) this.spin(false);
            if (typeof e.layer.on != 'function') return;
            e.layer.off('data:loaded');
            e.layer.off('data:loading');
        }, this);
    });
}