hide button by style attribute

gadget_json_generated_form_child.js

@@ -420,7 +420,10 @@
                 "ui-shadow-inset ui-btn ui-btn-inline ui-corner-all" +
                 " ui-btn-icon-notext ui-icon-btn ui-icon-plus ui-input-btn");
               input.type = "button";
-              input.hidden = !ret;
+              input.title = title;
+              if (!ret) {
+                input.setAttribute("style", "display: none;");
+              }
               gadget.props.add_buttons.push({
                 element: input,
                 event: function () {
@@ -432,7 +435,11 @@
                       return true;
                     })
                     .push(function (r) {
-                      input.hidden = !r;
+                      if (!r) {
+                        input.setAttribute("style", "display: none;");
+                      } else {
+                        input.removeAttribute("style");
+                      }
                       return checkValidityAndNotifyChange(gadget);
                     });
                 },
@@ -445,7 +452,11 @@
                       return true;
                     })
                     .push(function (r) {
-                      input.hidden = !r;
+                      if (!r) {
+                        input.setAttribute("style", "display: none;");
+                      } else {
+                        input.removeAttribute("style");
+                      }
                     });
                 }
               });