2 files changed, 16 insertions, 0 deletions
diff --git a/src/gui/kernel/qplatformwindow.cpp b/src/gui/kernel/qplatformwindow.cpp
index 34a1fabc76..9217aca400 100644
--- a/src/gui/kernel/qplatformwindow.cpp
+++ b/src/gui/kernel/qplatformwindow.cpp
@@ -690,6 +690,20 @@ QRect QPlatformWindow::windowGeometry() const
 }
 
 /*!
+    Returns the closest acceptable geometry for a given geometry before
+    a resize/move event for platforms that support it, for example to
+    implement heightForWidth().
+*/
+QRectF QPlatformWindow::windowClosestAcceptableGeometry(const QRectF &nativeRect) const
+{
+    QWindow *qWindow = window();
+    const QRectF rectF = QHighDpi::fromNativePixels(nativeRect, qWindow);
+    const QRectF correctedGeometryF = qt_window_private(qWindow)->closestAcceptableGeometry(rectF);
+    return !correctedGeometryF.isEmpty() && rectF != correctedGeometryF
+        ? QHighDpi::toNativePixels(correctedGeometryF, qWindow) : nativeRect;
+}
+
+/*!
     \class QPlatformWindow
     \since 4.8
     \internal
diff --git a/src/gui/kernel/qplatformwindow.h b/src/gui/kernel/qplatformwindow.h
index c1f2a4bdf1..692ae862db 100644
--- a/src/gui/kernel/qplatformwindow.h
+++ b/src/gui/kernel/qplatformwindow.h
@@ -138,6 +138,8 @@ public:
     QSize windowBaseSize() const;
     QSize windowSizeIncrement() const;
     QRect windowGeometry() const;
+    QRectF windowClosestAcceptableGeometry(const QRectF &nativeRect) const;
+
 protected:
     static QString formatWindowTitle(const QString &title, const QString &separator);
     QPlatformScreen *screenForGeometry(const QRect &newGeometry) const;