qt: use main window as close overlay parent

src/yuzu/main.cpp

@@ -1815,9 +1815,8 @@ void GMainWindow::OnShutdownBegin() {
 }
 
 void GMainWindow::OnShutdownBeginDialog() {
-    shutdown_dialog =
-        new OverlayDialog(render_window, *system, QString{}, tr("Closing software..."), QString{},
-                          QString{}, Qt::AlignHCenter | Qt::AlignVCenter);
+    shutdown_dialog = new OverlayDialog(this, *system, QString{}, tr("Closing software..."),
+                                        QString{}, QString{}, Qt::AlignHCenter | Qt::AlignVCenter);
     shutdown_dialog->open();
 }
 

src/yuzu/util/overlay_dialog.cpp

@@ -3,6 +3,7 @@
 
 #include <QKeyEvent>
 #include <QScreen>
+#include <QWindow>
 
 #include "core/core.h"
 #include "core/hid/hid_types.h"
@@ -162,7 +163,7 @@ void OverlayDialog::MoveAndResizeWindow() {
     const auto height = static_cast<float>(parentWidget()->height());
 
     // High DPI
-    const float dpi_scale = qApp->screenAt(pos)->logicalDotsPerInch() / 96.0f;
+    const float dpi_scale = parentWidget()->windowHandle()->screen()->logicalDotsPerInch() / 96.0f;
 
     const auto title_text_font_size = BASE_TITLE_FONT_SIZE * (height / BASE_HEIGHT) / dpi_scale;
     const auto body_text_font_size =