Be smarter when to show group toggle

src/cards/ha-domain-card.html

@@ -30,7 +30,7 @@
     <ha-card>
       <div class='header horizontal layout center'>
         <div class='flex name'>[[computeDomainTitle(domain)]]</div>
-        <template is='dom-if' if='[[groupEntity]]'>
+        <template is='dom-if' if='[[showGroupToggle(groupEntity, states)]]'>
           <ha-entity-toggle state-obj='[[groupEntity]]'></ha-entity-toggle>
         </template>
       </div>

src/cards/ha-domain-card.js

@@ -1,5 +1,6 @@
 import Polymer from '../polymer';
 import { moreInfoActions } from '../util/home-assistant-js-instance';
+import canToggle from '../util/can-toggle';
 
 require('../components/ha-card');
 require('../components/entity/ha-entity-toggle');
@@ -32,4 +33,13 @@ export default new Polymer({
     const entityId = ev.model.item.entityId;
     this.async(() => moreInfoActions.selectEntity(entityId), 1);
   },
+
+  showGroupToggle(groupEntity, states) {
+    if (!groupEntity || groupEntity.state !== 'on' && groupEntity.state !== 'off') {
+      return false;
+    }
+
+    // only show if we can toggle 2+ entities in group
+    return states.reduce((sum, state) => sum + canToggle(state.entityId), 0) > 1;
+  },
 });

src/util/can-toggle.js

@@ -1,7 +1,7 @@
 import {
   reactor,
   serviceGetters,
-} from '../util/home-assistant-js-instance';
+} from './home-assistant-js-instance';
 
 // Return boolean if entity can be toggled.
 export default function canToggle(entityId) {