Merge #623: Getting ready to Qt 6 (9/n). Apply Qt 6 specific changes

d8d99d0 qt6: Do not use deprecated high DPI attributes in Qt 6 (Hennadii Stepanov)
8927bb8 refactor: Fix style in `initTranslations()` function (Hennadii Stepanov)
ad73447 qt6: Do not use deprecated `QLibraryInfo::path` in Qt 6 (Hennadii Stepanov)
3f51d0b qt6: Fix type registration (Hennadii Stepanov)

Pull request description:

  One more step in migration to Qt 6.

  Could be tested with hebasto/bitcoin#3 or bitcoin/bitcoin#24798.

  No behavior change when compiling with Qt 5.

ACKs for top commit:
  laanwj:
    Code review ACK d8d99d0
  jarolrod:
    ACK d8d99d0

Tree-SHA512: e5f92a80f8622e5f95dd98a90783956a26d3c8382b9ca8e479fb6c152cfdc85a2f6084e78d463ceea1e0f0b3ac72d2b086c8ca24967b2b6070553317e9e3252e

Author: laanwj

src/qt/bitcoin.cpp

@@ -96,7 +96,11 @@ static void RegisterMetaTypes()
     qRegisterMetaType<QMessageBox::Icon>("QMessageBox::Icon");
     qRegisterMetaType<interfaces::BlockAndHeaderTipInfo>("interfaces::BlockAndHeaderTipInfo");
 
+#if (QT_VERSION < QT_VERSION_CHECK(6, 0, 0))
     qRegisterMetaTypeStreamOperators<BitcoinUnit>("BitcoinUnit");
+#else
+    qRegisterMetaType<BitcoinUnit>("BitcoinUnit");
+#endif
 }
 
 static QString GetLangTerritory()
@@ -135,21 +139,30 @@ static void initTranslations(QTranslator &qtTranslatorBase, QTranslator &qtTrans
     // - First load the translator for the base language, without territory
     // - Then load the more specific locale translator
 
+#if (QT_VERSION < QT_VERSION_CHECK(6, 0, 0))
+    const QString translation_path{QLibraryInfo::location(QLibraryInfo::TranslationsPath)};
+#else
+    const QString translation_path{QLibraryInfo::path(QLibraryInfo::TranslationsPath)};
+#endif
     // Load e.g. qt_de.qm
-    if (qtTranslatorBase.load("qt_" + lang, QLibraryInfo::location(QLibraryInfo::TranslationsPath)))
+    if (qtTranslatorBase.load("qt_" + lang, translation_path)) {
         QApplication::installTranslator(&qtTranslatorBase);
+    }
 
     // Load e.g. qt_de_DE.qm
-    if (qtTranslator.load("qt_" + lang_territory, QLibraryInfo::location(QLibraryInfo::TranslationsPath)))
+    if (qtTranslator.load("qt_" + lang_territory, translation_path)) {
         QApplication::installTranslator(&qtTranslator);
+    }
 
     // Load e.g. bitcoin_de.qm (shortcut "de" needs to be defined in bitcoin.qrc)
-    if (translatorBase.load(lang, ":/translations/"))
+    if (translatorBase.load(lang, ":/translations/")) {
         QApplication::installTranslator(&translatorBase);
+    }
 
     // Load e.g. bitcoin_de_DE.qm (shortcut "de_DE" needs to be defined in bitcoin.qrc)
-    if (translator.load(lang_territory, ":/translations/"))
+    if (translator.load(lang_territory, ":/translations/")) {
         QApplication::installTranslator(&translator);
+    }
 }
 
 static bool InitSettings()
@@ -517,9 +530,11 @@ int GuiMain(int argc, char* argv[])
     Q_INIT_RESOURCE(bitcoin);
     Q_INIT_RESOURCE(bitcoin_locale);
 
+#if (QT_VERSION < QT_VERSION_CHECK(6, 0, 0))
     // Generate high-dpi pixmaps
     QApplication::setAttribute(Qt::AA_UseHighDpiPixmaps);
     QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
+#endif
 
 #if defined(QT_QPA_PLATFORM_ANDROID)
     QApplication::setAttribute(Qt::AA_DontUseNativeMenuBar);