1 files changed, 33 insertions, 21 deletions
diff --git a/src/plugins/platforms/windows/qwindowswindow.cpp b/src/plugins/platforms/windows/qwindowswindow.cpp
index 6201da7b72..8a6466c9cf 100644
--- a/src/plugins/platforms/windows/qwindowswindow.cpp
+++ b/src/plugins/platforms/windows/qwindowswindow.cpp
@@ -482,26 +482,22 @@ struct WindowCreationData
     typedef QWindowsWindowData WindowData;
     enum Flags { ForceChild = 0x1, ForceTopLevel = 0x2 };
 
-    WindowCreationData() : parentHandle(0), type(Qt::Widget), style(0), exStyle(0),
-        topLevel(false), popup(false), dialog(false),
-        tool(false), embedded(false), hasAlpha(false) {}
-
     void fromWindow(const QWindow *w, const Qt::WindowFlags flags, unsigned creationFlags = 0);
     inline WindowData create(const QWindow *w, const WindowData &data, QString title) const;
     inline void applyWindowFlags(HWND hwnd) const;
     void initialize(const QWindow *w, HWND h, bool frameChange, qreal opacityLevel) const;
 
     Qt::WindowFlags flags;
-    HWND parentHandle;
-    Qt::WindowType type;
-    unsigned style;
-    unsigned exStyle;
-    bool topLevel;
-    bool popup;
-    bool dialog;
-    bool tool;
-    bool embedded;
-    bool hasAlpha;
+    HWND parentHandle = nullptr;
+    Qt::WindowType type = Qt::Widget;
+    unsigned style = 0;
+    unsigned exStyle = 0;
+    bool topLevel = false;
+    bool popup = false;
+    bool dialog = false;
+    bool tool = false;
+    bool embedded = false;
+    bool hasAlpha = false;
 };
 
 QDebug operator<<(QDebug debug, const WindowCreationData &d)
@@ -555,12 +551,6 @@ static QScreen *screenForName(const QWindow *w, const QString &name)
     return winScreen;
 }
 
-static QScreen *forcedScreenForGLWindow(const QWindow *w)
-{
-    const QString forceToScreen = GpuDescription::detect().gpuSuitableScreen;
-    return forceToScreen.isEmpty() ? nullptr : screenForName(w, forceToScreen);
-}
-
 static QPoint calcPosition(const QWindow *w, const QWindowCreationContextPtr &context, const QMargins &invMargins)
 {
     const QPoint orgPos(context->frameX - invMargins.left(), context->frameY - invMargins.top());
@@ -569,7 +559,7 @@ static QPoint calcPosition(const QWindow *w, const QWindowCreationContextPtr &co
         return orgPos;
 
     // Workaround for QTBUG-50371
-    const QScreen *screenForGL = forcedScreenForGLWindow(w);
+    const QScreen *screenForGL = QWindowsWindow::forcedScreenForGLWindow(w);
     if (!screenForGL)
         return orgPos;
 
@@ -1364,6 +1354,28 @@ void QWindowsWindow::setDropSiteEnabled(bool dropEnabled)
 #endif // QT_CONFIG(clipboard) && QT_CONFIG(draganddrop)
 }
 
+bool QWindowsWindow::m_screenForGLInitialized = false;
+
+void QWindowsWindow::displayChanged()
+{
+    m_screenForGLInitialized = false;
+}
+
+void QWindowsWindow::settingsChanged()
+{
+    m_screenForGLInitialized = false;
+}
+
+QScreen *QWindowsWindow::forcedScreenForGLWindow(const QWindow *w)
+{
+    static QString forceToScreen;
+    if (!m_screenForGLInitialized) {
+        forceToScreen = GpuDescription::detect().gpuSuitableScreen;
+        m_screenForGLInitialized = true;
+    }
+    return forceToScreen.isEmpty() ? nullptr : screenForName(w, forceToScreen);
+}
+
 // Returns topmost QWindowsWindow ancestor even if there are embedded windows in the chain.
 // Returns this window if it is the topmost ancestor.
 QWindow *QWindowsWindow::topLevelOf(QWindow *w)