loading icon in export panel added

CHANGELOG

@@ -7,6 +7,7 @@ minerva (16.3.0) unstable; urgency=medium
     Identifier (like in pathway WP2118)
   * Small improvement: import from GPML parse information about Reactome
     Pathway Identifier (like in pathway WP3165)
+  * Small improvement: LOADING icon when initializing export TAB added (#1839)
   * Small improvement: allow to login to DAPI by press key Enter (#1853)
   * Small improvement: link to home of API-docs in API-docs (#1779)
   * Small improvement: provide server-side Stack Trace when reporting error

frontend-js/src/main/js/gui/export/ElementExportPanel.js

@@ -8,6 +8,7 @@ var ValidationError = require('../../ValidationError');
 var IdentifiedElement = require('../../map/data/IdentifiedElement');
 
 var Functions = require('../../Functions');
+var GuiConnector = require('../../GuiConnector');
 
 // noinspection JSUnusedLocalSymbols
 var logger = require('../../logger');
@@ -47,6 +48,7 @@ ElementExportPanel.prototype.init = function () {
   submapDiv.appendChild(self._createSelectSubmapDiv(self.getProject().getModels()));
   element.appendChild(submapDiv);
   element.appendChild(self._createSelectColumnDiv(self.getAllColumns()));
+  GuiConnector.showProcessing("LOADING...");
   return self.getServerConnector().getProjectStatistics(self.getProject().getProjectId()).then(function (statistics) {
     return self._createMiriamTypeDiv(statistics.getElementAnnotations());
   }).then(function (div) {
@@ -60,7 +62,7 @@ ElementExportPanel.prototype.init = function () {
     element.appendChild(self._createDownloadButton());
   }).then(function () {
     $(window).trigger('resize');
-  });
+  }).finally(GuiConnector.hideProcessing);
 };
 
 /**