Do not show panel when disabled

src/components/calendar/Calendar.vue

@@ -618,6 +618,7 @@ export default {
             }        
         },
         onButtonClick() {
+            if (this.isEnabled()) {
                 if (!this.overlayVisible) {
                     this.$refs.input.$el.focus();
                     this.overlayVisible = true;
@@ -625,6 +626,7 @@ export default {
                 else {
                     this.overlayVisible = false;
                 }
+            }
         },
         isDateDisabled(day, month, year) {
             if (this.disabledDates) {