Windows: Introduce helper class for implementing COM interfaces

Task-number: QTBUG-43190
Change-Id: I565e3c57631c32a88ac7598758526c349ddf3312
Reviewed-by: Jan Arve Sæther <jan-arve.saether@qt.io>
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>

1 files changed, 1 insertions, 68 deletions

diff --git a/src/plugins/platforms/windows/qwindowsdrag.cpp b/src/plugins/platforms/windows/qwindowsdrag.cpp
index 550415e889..9275958456 100644
--- a/src/plugins/platforms/windows/qwindowsdrag.cpp
+++ b/src/plugins/platforms/windows/qwindowsdrag.cpp
@@ -215,7 +215,7 @@ static inline Qt::MouseButtons toQtMouseButtons(DWORD keyState)
     \ingroup qt-lighthouse-win
 */
 
-class QWindowsOleDropSource : public IDropSource
+class QWindowsOleDropSource : public QWindowsComBase<IDropSource>
 {
 public:
     enum Mode {
@@ -228,11 +228,6 @@ public:
 
     void createCursors();
 
-    // IUnknown methods
-    STDMETHOD(QueryInterface)(REFIID riid, void ** ppvObj);
-    STDMETHOD_(ULONG,AddRef)(void);
-    STDMETHOD_(ULONG,Release)(void);
-
     // IDropSource methods
     STDMETHOD(QueryContinueDrag)(BOOL fEscapePressed, DWORD grfKeyState);
     STDMETHOD(GiveFeedback)(DWORD dwEffect);
@@ -257,7 +252,6 @@ private:
     ActionCursorMap m_cursors;
     QWindowsDragCursorWindow *m_touchDragWindow;
 
-    ULONG m_refs;
 #ifndef QT_NO_DEBUG_STREAM
     friend QDebug operator<<(QDebug, const QWindowsOleDropSource::CursorEntry &);
 #endif
@@ -268,7 +262,6 @@ QWindowsOleDropSource::QWindowsOleDropSource(QWindowsDrag *drag)
     , m_drag(drag)
     , m_currentButtons(Qt::NoButton)
     , m_touchDragWindow(0)
-    , m_refs(1)
 {
     qCDebug(lcQpaMime) << __FUNCTION__ << m_mode;
 }
@@ -373,38 +366,6 @@ void QWindowsOleDropSource::createCursors()
 #endif // !QT_NO_DEBUG_OUTPUT
 }
 
-//---------------------------------------------------------------------
-//                    IUnknown Methods
-//---------------------------------------------------------------------
-
-STDMETHODIMP
-QWindowsOleDropSource::QueryInterface(REFIID iid, void FAR* FAR* ppv)
-{
-    if (iid == IID_IUnknown || iid == IID_IDropSource) {
-      *ppv = this;
-      ++m_refs;
-      return NOERROR;
-    }
-    *ppv = NULL;
-    return ResultFromScode(E_NOINTERFACE);
-}
-
-STDMETHODIMP_(ULONG)
-QWindowsOleDropSource::AddRef(void)
-{
-    return ++m_refs;
-}
-
-STDMETHODIMP_(ULONG)
-QWindowsOleDropSource::Release(void)
-{
-    if (--m_refs == 0) {
-      delete this;
-      return 0;
-    }
-    return m_refs;
-}
-
 /*!
     \brief Check for cancel.
 */
@@ -504,34 +465,6 @@ QWindowsOleDropTarget::~QWindowsOleDropTarget()
     qCDebug(lcQpaMime) << __FUNCTION__ <<  this;
 }
 
-STDMETHODIMP
-QWindowsOleDropTarget::QueryInterface(REFIID iid, void FAR* FAR* ppv)
-{
-    if (iid == IID_IUnknown || iid == IID_IDropTarget) {
-      *ppv = this;
-      AddRef();
-      return NOERROR;
-    }
-    *ppv = NULL;
-    return ResultFromScode(E_NOINTERFACE);
-}
-
-STDMETHODIMP_(ULONG)
-QWindowsOleDropTarget::AddRef(void)
-{
-    return ++m_refs;
-}
-
-STDMETHODIMP_(ULONG)
-QWindowsOleDropTarget::Release(void)
-{
-    if (--m_refs == 0) {
-      delete this;
-      return 0;
-    }
-    return m_refs;
-}
-
 void QWindowsOleDropTarget::handleDrag(QWindow *window, DWORD grfKeyState,
                                        const QPoint &point, LPDWORD pdwEffect)
 {