Preserve scroll position on toggle emoji panel, add attachment

js/views/file_input_view.js

@@ -72,6 +72,7 @@
 
     render() {
       this.attachmentListView.update(this.getPropsForAttachmentList());
+      this.trigger('staged-attachments-changed');
     },
 
     getPropsForAttachmentList() {
@@ -120,7 +121,6 @@
 
     onCloseAttachment(attachment) {
       this.attachments = _.without(this.attachments, attachment);
-      this.trigger('attachments-changed');
       this.render();
     },
 
@@ -130,7 +130,6 @@
 
     onClose() {
       this.attachments = [];
-      this.trigger('attachments-changed');
       this.render();
     },
 
@@ -271,7 +270,6 @@
 
       this.attachments.push(attachment);
       this.render();
-      this.trigger('attachments-changed');
     },
 
     async maybeAddAttachment(file) {