Use High DPI pixmaps in prominent examples and tests

Set AA_UseHighDpiPixmaps.

Task-number: QTBUG-52622
Change-Id: Ic4373a9c94952f50bc1ad36bcc0dec850efc124a
Reviewed-by: Robert Loehning <robert.loehning@qt.io>
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>

examples/widgets/desktop/systray/main.cpp

@@ -59,6 +59,8 @@ int main(int argc, char *argv[])
 {
     Q_INIT_RESOURCE(systray);
 
+    QCoreApplication::setAttribute(Qt::AA_UseHighDpiPixmaps);
+
     QApplication app(argc, argv);
 
     if (!QSystemTrayIcon::isSystemTrayAvailable()) {

examples/widgets/dialogs/classwizard/main.cpp

@@ -59,6 +59,8 @@ int main(int argc, char *argv[])
 {
     Q_INIT_RESOURCE(classwizard);
 
+    QCoreApplication::setAttribute(Qt::AA_UseHighDpiPixmaps);
+
     QApplication app(argc, argv);
 
 #ifndef QT_NO_TRANSLATION

examples/widgets/dialogs/licensewizard/main.cpp

@@ -59,6 +59,8 @@ int main(int argc, char *argv[])
 {
     Q_INIT_RESOURCE(licensewizard);
 
+    QCoreApplication::setAttribute(Qt::AA_UseHighDpiPixmaps);
+
     QApplication app(argc, argv);
 
 #ifndef QT_NO_TRANSLATION

examples/widgets/dialogs/standarddialogs/main.cpp

@@ -59,6 +59,7 @@
 
 int main(int argc, char *argv[])
 {
+    QCoreApplication::setAttribute(Qt::AA_UseHighDpiPixmaps);
     QApplication app(argc, argv);
     QGuiApplication::setApplicationDisplayName(Dialog::tr("Standard Dialogs"));
 

examples/widgets/dialogs/trivialwizard/trivialwizard.cpp

@@ -123,6 +123,8 @@ QWizardPage *createConclusionPage()
 int main(int argc, char *argv[])
 //! [9] //! [11]
 {
+    QCoreApplication::setAttribute(Qt::AA_UseHighDpiPixmaps);
+
     QApplication app(argc, argv);
 
 #ifndef QT_NO_TRANSLATION

tests/manual/dialogs/main.cpp

@@ -126,6 +126,10 @@ void MainWindow::aboutDialog()
 
 int main(int argc, char *argv[])
 {
+#if QT_VERSION >= 0x050600
+    QCoreApplication::setAttribute(Qt::AA_UseHighDpiPixmaps);
+#endif
+
     for (int a = 1; a < argc; ++a) {
         if (!qstrcmp(argv[a], "-n")) {
             qDebug("AA_DontUseNativeDialogs");