6 files changed, 85 insertions, 0 deletions
diff --git a/src/corelib/kernel/qcoreevent.cpp b/src/corelib/kernel/qcoreevent.cpp
index 191ceaa37b1..68d48dbe257 100644
--- a/src/corelib/kernel/qcoreevent.cpp
+++ b/src/corelib/kernel/qcoreevent.cpp
@@ -183,6 +183,7 @@ QT_BEGIN_NAMESPACE
     \value ParentAboutToChange              The widget parent is about to change.
     \value ParentChange                     The widget parent has changed.
     \value PlatformPanel                    A platform specific panel has been requested.
+    \value PlatformSurface                  A native platform surface has been created or is about to be destroyed.
     \value Polish                           The widget is polished.
     \value PolishRequest                    The widget should be polished.
     \value QueryWhatsThis                   The widget should accept the event if it has "What's This?" help.
diff --git a/src/corelib/kernel/qcoreevent.h b/src/corelib/kernel/qcoreevent.h
index 170f319ec90..08077214323 100644
--- a/src/corelib/kernel/qcoreevent.h
+++ b/src/corelib/kernel/qcoreevent.h
@@ -275,6 +275,8 @@ public:
         WindowChangeInternal = 215,             // internal for QQuickWidget
         ScreenChangeInternal = 216,
 
+        PlatformSurface = 217,                  // Platform surface created or about to be destroyed
+
         // 512 reserved for Qt Jambi's MetaCall event
         // 513 reserved for Qt Jambi's DeleteOnMainThread event
 
diff --git a/src/gui/kernel/qevent.cpp b/src/gui/kernel/qevent.cpp
index a8539e8013a..67c4e3f5123 100644
--- a/src/gui/kernel/qevent.cpp
+++ b/src/gui/kernel/qevent.cpp
@@ -1324,6 +1324,55 @@ QExposeEvent::~QExposeEvent()
 }
 
 /*!
+    \class QPlatformSurfaceEvent
+    \since 5.5
+    \brief The QPlatformSurfaceEvent class is used to notify about native platform surface events.
+    \inmodule QtGui
+
+    \ingroup events
+
+    Platform window events are synchronously sent to windows and offscreen surfaces when their
+    underlying native surfaces are created or are about to be destroyed.
+
+    Applications can respond to these events to know when the underlying platform
+    surface exists.
+*/
+
+/*!
+    \enum QPlatformSurfaceEvent::SurfaceEventType
+
+    This enum describes the type of platform surface event. The possible types are:
+
+    \value SurfaceCreated               The underlying native surface has been created
+    \value SurfaceAboutToBeDestroyed    The underlying native surface will be destroyed immediately after this event
+
+    The \c SurfaceAboutToBeDestroyed event type is useful as a means of stopping rendering to
+    a platform window before it is destroyed.
+*/
+
+/*!
+    \fn QPlatformSurfaceEvent::SurfaceEventType QPlatformSurfaceEvent::surfaceEventType() const
+
+    Returns the specific type of platform surface event.
+*/
+
+/*!
+    Constructs a platform surface event for the given \a surfaceEventType.
+*/
+QPlatformSurfaceEvent::QPlatformSurfaceEvent(SurfaceEventType surfaceEventType)
+    : QEvent(PlatformSurface)
+    , m_surfaceEventType(surfaceEventType)
+{
+}
+
+/*!
+  \internal
+*/
+QPlatformSurfaceEvent::~QPlatformSurfaceEvent()
+{
+}
+
+/*!
     \fn const QRegion &QExposeEvent::region() const
 
     Returns the window area that has been exposed. The region is given in local coordinates.
diff --git a/src/gui/kernel/qevent.h b/src/gui/kernel/qevent.h
index f91bc0a8307..0b6d96a5908 100644
--- a/src/gui/kernel/qevent.h
+++ b/src/gui/kernel/qevent.h
@@ -410,6 +410,23 @@ protected:
     QRegion rgn;
 };
 
+class Q_GUI_EXPORT QPlatformSurfaceEvent : public QEvent
+{
+public:
+    enum SurfaceEventType {
+        SurfaceCreated,
+        SurfaceAboutToBeDestroyed
+    };
+
+    explicit QPlatformSurfaceEvent(SurfaceEventType surfaceEventType);
+    ~QPlatformSurfaceEvent();
+
+    inline SurfaceEventType surfaceEventType() const { return m_surfaceEventType; }
+
+protected:
+    SurfaceEventType m_surfaceEventType;
+};
+
 class Q_GUI_EXPORT QResizeEvent : public QEvent
 {
 public:
diff --git a/src/gui/kernel/qoffscreensurface.cpp b/src/gui/kernel/qoffscreensurface.cpp
index 5cf77de5d8f..fb1dfd8df53 100644
--- a/src/gui/kernel/qoffscreensurface.cpp
+++ b/src/gui/kernel/qoffscreensurface.cpp
@@ -180,6 +180,9 @@ void QOffscreenSurface::create()
             d->offscreenWindow->setGeometry(0, 0, d->size.width(), d->size.height());
             d->offscreenWindow->create();
         }
+
+        QPlatformSurfaceEvent e(QPlatformSurfaceEvent::SurfaceCreated);
+        QGuiApplication::sendEvent(this, &e);
     }
 }
 
@@ -191,6 +194,10 @@ void QOffscreenSurface::create()
 void QOffscreenSurface::destroy()
 {
     Q_D(QOffscreenSurface);
+
+    QPlatformSurfaceEvent e(QPlatformSurfaceEvent::SurfaceAboutToBeDestroyed);
+    QGuiApplication::sendEvent(this, &e);
+
     delete d->platformOffscreenSurface;
     d->platformOffscreenSurface = 0;
     if (d->offscreenWindow) {
diff --git a/src/gui/kernel/qwindow.cpp b/src/gui/kernel/qwindow.cpp
index e23e0f8e57a..a3b7f38c80a 100644
--- a/src/gui/kernel/qwindow.cpp
+++ b/src/gui/kernel/qwindow.cpp
@@ -404,6 +404,11 @@ void QWindowPrivate::create(bool recursive)
                     window->d_func()->platformWindow->setParent(platformWindow);
             }
         }
+
+        if (platformWindow) {
+            QPlatformSurfaceEvent e(QPlatformSurfaceEvent::SurfaceCreated);
+            QGuiApplication::sendEvent(q, &e);
+        }
     }
 }
 
@@ -1590,6 +1595,10 @@ void QWindow::destroy()
     bool wasVisible = isVisible();
 
     setVisible(false);
+
+    QPlatformSurfaceEvent e(QPlatformSurfaceEvent::SurfaceAboutToBeDestroyed);
+    QGuiApplication::sendEvent(this, &e);
+
     delete d->platformWindow;
     d->resizeEventPending = true;
     d->receivedExpose = false;