階層化ドロップダウンの不具合修正、実装完了

plugin/kintone-addins/src/util/ui-helper.ts

@@ -0,0 +1,37 @@
+import $ from 'jquery';
+/**
+ * 画面処理中のLoadding表示
+ */
+export class Snipper {
+    private spinnerElement: JQuery<HTMLElement>;;
+    private container :JQuery<HTMLElement>;
+    constructor(selector: string) {
+      this.container = $(selector??'body');
+      this.spinnerElement=this.createSpinner();
+    }
+  
+    createSpinner() {
+      const html =[
+        '<div class="bs-scope alc-loading alc-dnone">',
+        '<div class="spinner-border" style="width: 3rem; height: 3rem;" role="status">',
+        '<span class="visually-hidden"></span>',
+        '</div></div>'
+        ].join("");
+      const spinner = $(html);
+      this.container.append(spinner);
+      return spinner;
+    }
+  
+    removeSpinner() {
+        this.spinnerElement.remove();
+    }
+  
+    showSpinner() {
+        this.spinnerElement.removeClass('alc-dnone');
+    }
+  
+    hideSpinner() {
+        this.spinnerElement.addClass('alc-dnone');
+    }
+  }
+