make the theme handling in musredit more flexible. At the same time adopted some part to more modern c++.

src/musredit_qt6/musredit/PTextEdit.cpp

@@ -88,11 +88,11 @@
 PTextEdit::PTextEdit( QWidget *parent )
     : QMainWindow( parent )
 {
-  bool gotTheme = getTheme();
-
   // reads and manages the conents of the xml-startup (musredit_startup.xml) file
   fAdmin = std::make_unique<PAdmin>();
 
+  bool gotTheme = getTheme();
+
   // set default setting of the fDarkMenuIconIcons only if a theme has been recognized, otherwise take the
   // one from the xml startup file.
   if (gotTheme) {
@@ -117,8 +117,6 @@ PTextEdit::PTextEdit( QWidget *parent )
   }
 
   // initialize stuff
-//as35  fMusrT0Action = nullptr;
-
   fMsr2DataParam = nullptr;
   fFindReplaceData = nullptr;
 
@@ -136,7 +134,6 @@ PTextEdit::PTextEdit( QWidget *parent )
 
   textFamily(fAdmin->getFontName());
   textSize(QString("%1").arg(fAdmin->getFontSize()));
-  fFontChanging = false;
 
   QString iconName("");
   if (fDarkMenuIcon)
@@ -165,12 +162,6 @@ PTextEdit::PTextEdit( QWidget *parent )
  */
 void PTextEdit::aboutToQuit()
 {
-/* //as35
-  if (fMusrT0Action) {
-    delete fMusrT0Action;
-    fMusrT0Action = nullptr;
-  }
-*/ //as35
   if (fMsr2DataParam) {
     delete fMsr2DataParam;
     fMsr2DataParam = nullptr;
@@ -1193,7 +1184,6 @@ void PTextEdit::fileNew()
   PSubTextEdit *edit = new PSubTextEdit( fAdmin.get() );
   edit->setFont(QFont(fAdmin->getFontName(), fAdmin->getFontSize()));
   edit->setCenterOnScroll(true);
-
   doConnections( edit );
   fTabWidget->addTab( edit, tr( "noname" ) );
   fTabWidget->setCurrentIndex(fTabWidget->indexOf(edit));
@@ -2732,6 +2722,7 @@ void PTextEdit::musrPrefs()
   }
 
   if (dlg->exec() == QDialog::Accepted) {
+    fAdmin->setIgnoreThemeAutoDetection(dlg->getIgnoreThemeAutoDetection());
     fAdmin->setDarkThemeIconsMenuFlag(dlg->getDarkThemeIconsMenuFlag());
     fAdmin->setDarkThemeIconsToolbarFlag(dlg->getDarkThemeIconsToolbarFlag());
     fAdmin->setMusrviewShowFourierFlag(dlg->getMusrviewShowFourierFlag());
@@ -3346,6 +3337,9 @@ void PTextEdit::jumpToBlock(int idx)
  */
 bool PTextEdit::getTheme()
 {
+  if (fAdmin->getIgnoreThemeAutoDetection())
+    return false;
+
   fDarkMenuIcon = false; // true if theme is dark
   fDarkToolBarIcon = false; // needed for ubuntu dark since there the menu icons are dark, however the toolbar icons are plain!
 
@@ -3377,10 +3371,9 @@ bool PTextEdit::getTheme()
 
   if (str.contains("dark", Qt::CaseInsensitive)) {
     fDarkMenuIcon = true;
-    if (str.contains("ubuntu", Qt::CaseInsensitive)) {
-      fDarkMenuIcon = false;
-      fDarkToolBarIcon = false;
-    } else if (str.contains("xfce", Qt::CaseInsensitive)) {
+    if (str.contains("ubuntu", Qt::CaseInsensitive) ||
+        str.contains("xfce", Qt::CaseInsensitive) ||
+        str.contains("mx", Qt::CaseInsensitive)) {
       fDarkMenuIcon = false;
       fDarkToolBarIcon = false;
     } else {