From ecf783332a07ceda056f09d1cab30771e8f91433 Mon Sep 17 00:00:00 2001
From: joshua <Joshua@qelectrotech.org>
Date: Sun, 18 Apr 2021 20:03:13 +0200
Subject: [PATCH] Improve element collection loading time

According to Qt creator flame graph, call QSettings take lot of time.
When loading the element collection, each items of the collection get
the current language by calling the function QString
QETApp::langFromSetting().
This function instantiate a QSettings object each time and take a lot of
time.
Now the QSettings is instantiate only at the first call, and the value
is stored in memory, then all other call of the function don't
instantiate a QSettings, but just return the value in memory.
---
 sources/qetapp.cpp | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/sources/qetapp.cpp b/sources/qetapp.cpp
index cf737472d..31b7d6421 100644
--- a/sources/qetapp.cpp
+++ b/sources/qetapp.cpp
@@ -71,6 +71,9 @@ QString QETApp::m_user_custom_elements_dir = QString();
 QString QETApp::m_user_custom_tbt_dir = QString();
 QETApp *QETApp::m_qetapp = nullptr;
 
+bool lang_is_set = false;
+QString system_language = QString();
+
 
 /**
 	@brief QETApp::QETApp
@@ -227,11 +230,16 @@ void QETApp::setLanguage(const QString &desired_language) {
 */
 QString QETApp::langFromSetting()
 {
-	QSettings settings;
-	QString system_language = settings.value("lang", "system").toString();
-	if(system_language == "system") {
-		system_language = QLocale::system().name().left(2);
+	if (!lang_is_set)
+	{
+		QSettings settings;
+		system_language = settings.value("lang", "system").toString();
+		if(system_language == "system") {
+			system_language = QLocale::system().name().left(2);
+		}
+		lang_is_set = true;
 	}
+
 	return system_language;
 }
 /**