leaflet/src/layer/FeatureGroup.js

JavaScript library for mobile-friendly interactive maps

/*
 * L.FeatureGroup extends L.LayerGroup by introducing mouse events and additional methods
 * shared between a group of interactive layers (like vectors or markers).
 */

L.FeatureGroup = L.LayerGroup.extend({

	addLayer: function (layer) {
		if (this.hasLayer(layer)) {
			return this;
		}

		layer.addEventParent(this);

		L.LayerGroup.prototype.addLayer.call(this, layer);

		return this.fire('layeradd', {layer: layer});
	},

	removeLayer: function (layer) {
		if (!this.hasLayer(layer)) {
			return this;
		}
		if (layer in this._layers) {
			layer = this._layers[layer];
		}

		layer.removeEventParent(this);

		L.LayerGroup.prototype.removeLayer.call(this, layer);

		return this.fire('layerremove', {layer: layer});
	},

	setStyle: function (style) {
		return this.invoke('setStyle', style);
	},

	bringToFront: function () {
		return this.invoke('bringToFront');
	},

	bringToBack: function () {
		return this.invoke('bringToBack');
	},

	getBounds: function () {
		var bounds = new L.LatLngBounds();

		for (var id in this._layers) {
			var layer = this._layers[id];
			bounds.extend(layer.getBounds ? layer.getBounds() : layer.getLatLng());
		}
		return bounds;
	}
});

L.featureGroup = function (layers) {
	return new L.FeatureGroup(layers);
};