From 339e7fe94d88fb688d2267301e1d7b83319dbbf5 Mon Sep 17 00:00:00 2001
From: Marco 'Lubber' Wienkoop <c64@lubber.de>
Date: Tue, 30 Jun 2020 13:03:26 +0200
Subject: [PATCH] feat(calendar): avoid unnecessary redraw

Whenever a calendar popup is shown the calendar gets redrawn several times even if nothing was changed!
---
 src/definitions/modules/calendar.js | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/definitions/modules/calendar.js b/src/definitions/modules/calendar.js
index 7cb9377ee0..39c1e3d86d 100644
--- a/src/definitions/modules/calendar.js
+++ b/src/definitions/modules/calendar.js
@@ -157,7 +157,7 @@ $.fn.calendar = function(parameters) {
             var onShow = function () {
               //reset the focus date onShow
               module.set.focusDate(module.get.date());
-              module.set.mode(settings.startMode);
+              module.set.mode(module.get.validatedMode(settings.startMode));
               return settings.onShow.apply($container, arguments);
             };
             var on = module.setting('on');
@@ -197,6 +197,7 @@ $.fn.calendar = function(parameters) {
               date = parser.date($input.val(), settings);
             }
             module.set.date(date, settings.formatInput, false);
+            module.set.mode(module.get.mode(), false);
           }
         },
 
@@ -622,6 +623,9 @@ $.fn.calendar = function(parameters) {
           mode: function () {
             //only returns valid modes for the current settings
             var mode = $module.data(metadata.mode) || settings.startMode;
+            return module.get.validatedMode(mode);
+          },
+          validatedMode: function(mode){
             var validModes = module.get.validModes();
             if ($.inArray(mode, validModes) >= 0) {
               return mode;
@@ -739,7 +743,7 @@ $.fn.calendar = function(parameters) {
                 module.set.monthOffset(monthOffset, false);
               }
             }
-            var changed = module.set.dataKeyValue(metadata.focusDate, date, refreshCalendar);
+            var changed = module.set.dataKeyValue(metadata.focusDate, date, !!date && refreshCalendar);
             updateFocus = (updateFocus !== false && changed && refreshCalendar === false) || focusDateUsedForRange != updateRange;
             focusDateUsedForRange = updateRange;
             if (updateFocus) {