Add geolocation error feedback (re: #7376)

data/core.yaml

@@ -538,6 +538,7 @@ en:
     key: L
     title: Show My Location
     locating: "Locating, please wait..."
+    location_unavailable: Your location is unavailable
   inspector:
     zoom_to:
       key: Z

dist/locales/en.json

@@ -680,7 +680,8 @@
         "geolocate": {
             "key": "L",
             "title": "Show My Location",
-            "locating": "Locating, please wait..."
+            "locating": "Locating, please wait...",
+            "cannot_locate": "Your location is unavailable"
         },
         "inspector": {
             "zoom_to": {

modules/ui/geolocate.js

@@ -5,6 +5,7 @@ import { tooltip } from '../util/tooltip';
 import { geoExtent } from '../geo';
 import { modeBrowse } from '../modes/browse';
 import { svgIcon } from '../svg/icon';
+import { uiFlash } from './flash';
 import { uiLoading } from './loading';
 import { uiTooltipHtml } from './tooltipHtml';
 
@@ -33,7 +34,7 @@ export function uiGeolocate(context) {
         }
         // This timeout ensures that we still call finish() even if
         // the user declines to share their location in Firefox
-        _timeoutID = setTimeout(finish, 10000 /* 10sec */ );
+        _timeoutID = setTimeout(error, 10000 /* 10sec */ );
     }
 
     function zoomTo() {
@@ -52,6 +53,9 @@ export function uiGeolocate(context) {
     }
 
     function error() {
+        uiFlash()
+            .text(t('geolocate.location_unavailable'))
+            .iconName('#iD-icon-geolocate')();
         finish();
     }
 
@@ -66,7 +70,7 @@ export function uiGeolocate(context) {
     }
 
     return function(selection) {
-        if (!navigator.geolocation) return;
+        if (!navigator.geolocation || !navigator.geolocation.getCurrentPosition) return;
 
         _button = selection
             .append('button')