use common version function for splash and about screen

forms/loadingscreen.ui

@@ -47,7 +47,7 @@
       </font>
      </property>
      <property name="text">
-      <string>Version 6.0.0</string>
+      <string>Version X.x.x</string>
      </property>
      <property name="alignment">
       <set>Qt::AlignCenter</set>

include/ui/aboutporymap.h

@@ -13,6 +13,8 @@ class AboutPorymap : public QDialog
 public:
     explicit AboutPorymap(QWidget *parent = nullptr);
     ~AboutPorymap();
+
+    static QString getVersionString();
 private:
     Ui::AboutPorymap *ui;
 };

src/ui/aboutporymap.cpp

@@ -9,15 +9,19 @@ AboutPorymap::AboutPorymap(QWidget *parent) :
     setAttribute(Qt::WA_DeleteOnClose);
 
     static const QString commitHash = PORYMAP_LATEST_COMMIT;
-    this->ui->label_Version->setText(QString("Version %1%2\nQt %3 (%4)\n%5")
+    this->ui->label_Version->setText(getVersionString());
+
+    layout()->setSizeConstraint(QLayout::SetFixedSize);
+}
+
+QString AboutPorymap::getVersionString() {
+    static const QString commitHash = PORYMAP_LATEST_COMMIT;
+    return QString("Version %1%2\nQt %3 (%4)\n%5")
                                         .arg(QCoreApplication::applicationVersion())
                                         .arg(commitHash.isEmpty() ? "" : QString(" (%1)").arg(commitHash))
                                         .arg(QStringLiteral(QT_VERSION_STR))
                                         .arg(QSysInfo::buildCpuArchitecture())
-                                        .arg(QStringLiteral(__DATE__))
-                                    );
-
-    layout()->setSizeConstraint(QLayout::SetFixedSize);
+                                        .arg(QStringLiteral(__DATE__));
 }
 
 AboutPorymap::~AboutPorymap()

src/ui/loadingscreen.cpp

@@ -1,5 +1,6 @@
 
 #include "loadingscreen.h"
+#include "aboutporymap.h"
 #include "ui_loadingscreen.h"
 #include "qgifimage.h"
 
@@ -25,6 +26,11 @@ PorymapLoadingScreen::PorymapLoadingScreen(QWidget *parent) : QWidget(parent), u
 }
 
 void PorymapLoadingScreen::start() {
+    static bool shownVersion = false;
+    if (!shownVersion) {
+        this->ui->labelVersion->setText(AboutPorymap::getVersionString());
+        shownVersion = true;
+    }
     this->timer.start(120);
     this->show();
 }