Code structure

lib/entity_widgets/state/select_state.dart

@@ -0,0 +1,46 @@
+part of '../../main.dart';
+
+class SelectStateWidget extends StatefulWidget {
+
+  SelectStateWidget({Key key}) : super(key: key);
+
+  @override
+  _SelectStateWidgetState createState() => _SelectStateWidgetState();
+}
+
+class _SelectStateWidgetState extends State<SelectStateWidget> {
+
+  void setNewState(domain, entityId, newValue) {
+    eventBus.fire(new ServiceCallEvent(domain, "select_option", entityId,
+        {"option": "$newValue"}));
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final entityModel = EntityModel.of(context);
+    final SelectEntity entity = entityModel.entity;
+    Widget ctrl;
+    if (entity.listOptions.isNotEmpty) {
+      ctrl = DropdownButton<String>(
+        value: entity.state,
+        items: entity.listOptions.map((String value) {
+          return new DropdownMenuItem<String>(
+            value: value,
+            child: new Text(value),
+          );
+        }).toList(),
+        onChanged: (_) {
+          setNewState(entity.domain, entity.entityId,_);
+        },
+      );
+    } else {
+      ctrl = Text('---');
+    }
+    return Expanded(
+      //width: Entity.INPUT_WIDTH,
+      child: ctrl,
+    );
+  }
+
+
+}