Layer: refactor openPopup/openTooltip: use common function (#6613)

* Layer: refactor openPopup/openTooltip: use common function DivOverlay._prepareOpen

* More clear error message when trying to attach popup/tooltip to layer
without getLatLng function

src/layer/DivOverlay.js

@@ -1,4 +1,5 @@
 import {Layer} from './Layer';
+import {FeatureGroup} from './FeatureGroup';
 import * as Util from '../core/Util';
 import {toLatLng} from '../geo/LatLng';
 import {toPoint} from '../geometry/Point';
@@ -158,6 +159,38 @@ export var DivOverlay = Layer.extend({
 		return this;
 	},
 
+	_prepareOpen: function (parent, layer, latlng) {
+		if (!(layer instanceof Layer)) {
+			latlng = layer;
+			layer = parent;
+		}
+
+		if (layer instanceof FeatureGroup) {
+			for (var id in parent._layers) {
+				layer = parent._layers[id];
+				break;
+			}
+		}
+
+		if (!latlng) {
+			if (layer.getCenter) {
+				latlng = layer.getCenter();
+			} else if (layer.getLatLng) {
+				latlng = layer.getLatLng();
+			} else {
+				throw new Error('Unable to get source layer LatLng.');
+			}
+		}
+
+		// set overlay source to this layer
+		this._source = layer;
+
+		// update the overlay (content, layout, ect...)
+		this.update();
+
+		return latlng;
+	},
+
 	_updateContent: function () {
 		if (!this._content) { return; }
 

src/layer/Popup.js

@@ -4,7 +4,6 @@ import * as DomUtil from '../dom/DomUtil';
 import {Point, toPoint} from '../geometry/Point';
 import {Map} from '../map/Map';
 import {Layer} from './Layer';
-import {FeatureGroup} from './FeatureGroup';
 import * as Util from '../core/Util';
 import {Path} from './vector/Path';
 
@@ -418,28 +417,8 @@ Layer.include({
 	// @method openPopup(latlng?: LatLng): this
 	// Opens the bound popup at the specified `latlng` or at the default popup anchor if no `latlng` is passed.
 	openPopup: function (layer, latlng) {
-		if (!(layer instanceof Layer)) {
-			latlng = layer;
-			layer = this;
-		}
-
-		if (layer instanceof FeatureGroup) {
-			for (var id in this._layers) {
-				layer = this._layers[id];
-				break;
-			}
-		}
-
-		if (!latlng) {
-			latlng = layer.getCenter ? layer.getCenter() : layer.getLatLng();
-		}
-
 		if (this._popup && this._map) {
-			// set popup source to this layer
-			this._popup._source = layer;
-
-			// update the popup (content, layout, ect...)
-			this._popup.update();
+			latlng = this._popup._prepareOpen(this, layer, latlng);
 
 			// open the popup on the map
 			this._map.openPopup(this._popup, latlng);

src/layer/Tooltip.js

@@ -4,7 +4,6 @@ import {DivOverlay} from './DivOverlay';
 import {toPoint} from '../geometry/Point';
 import {Map} from '../map/Map';
 import {Layer} from './Layer';
-import {FeatureGroup} from './FeatureGroup';
 import * as Util from '../core/Util';
 import * as DomUtil from '../dom/DomUtil';
 
@@ -312,29 +311,8 @@ Layer.include({
 	// @method openTooltip(latlng?: LatLng): this
 	// Opens the bound tooltip at the specified `latlng` or at the default tooltip anchor if no `latlng` is passed.
 	openTooltip: function (layer, latlng) {
-		if (!(layer instanceof Layer)) {
-			latlng = layer;
-			layer = this;
-		}
-
-		if (layer instanceof FeatureGroup) {
-			for (var id in this._layers) {
-				layer = this._layers[id];
-				break;
-			}
-		}
-
-		if (!latlng) {
-			latlng = layer.getCenter ? layer.getCenter() : layer.getLatLng();
-		}
-
 		if (this._tooltip && this._map) {
-
-			// set tooltip source to this layer
-			this._tooltip._source = layer;
-
-			// update the tooltip (content, layout, ect...)
-			this._tooltip.update();
+			latlng = this._tooltip._prepareOpen(this, layer, latlng);
 
 			// open the tooltip on the map
 			this._map.openTooltip(this._tooltip, latlng);