Disable Add Note '4' shortcut when notes layer is not enabled

(also return to browse mode if notes or osm layers get disabled)
(closes #5190)

modules/ui/map_data.js

@@ -8,6 +8,7 @@ import { d3keybinding as d3_keybinding } from '../lib/d3.keybinding.js';
 import { svgIcon } from '../svg';
 import { t, textDirection } from '../util/locale';
 import { tooltip } from '../util/tooltip';
+import { modeBrowse } from '../modes';
 import { uiBackground } from './background';
 import { uiDisclosure } from './disclosure';
 import { uiHelp } from './help';
@@ -75,6 +76,11 @@ export function uiMapData(context) {
         var layer = layers.layer(which);
         if (layer) {
             layer.enabled(enabled);
+
+            if (!enabled && (which === 'osm' || which === 'notes')) {
+                context.enter(modeBrowse(context));
+            }
+
             update();
         }
     }

modules/ui/modes.js

@@ -60,7 +60,7 @@ export function uiModes(context) {
 
         modes.forEach(function(mode) {
             keybinding.on(mode.key, function() {
-                if (mode.id === 'add-note' && !notesEditable()) return;
+                if (mode.id === 'add-note' && !(notesEnabled() && notesEditable())) return;
                 if (mode.id !== 'add-note' && !editable()) return;
 
                 if (mode.id === context.mode().id) {