add error icon

packages/artplayer/src/mask.js

@@ -1,12 +1,23 @@
-import { append } from './utils';
+import { append, setStyle } from './utils';
 import Component from './utils/component';
 
 export default class Mask extends Component {
     constructor(art) {
         super(art);
+
         this.name = 'mask';
         const { template, icons, events } = art;
-        append(template.$state, icons.state);
+
+        const $state = append(template.$state, icons.state);
+        const $error = append(template.$state, icons.error);
+
+        setStyle($error, 'display', 'none');
+
+        art.on('destroy', () => {
+            setStyle($state, 'display', 'none');
+            setStyle($error, 'display', null);
+        });
+
         events.proxy(template.$state, 'click', () => art.play());
     }
 }