Replace QWindowsComBase with QComObject

Currently with have two base classes for COM-objects that implement
basic IUnknown functionality and the idea is to remove duplication and
keep just one. Since QComObject supports more features than
QWindowsComBase, such as multiple inheritance and intermediate interface
querying, we should switch to the former one.

Change-Id: Ief6567496de9f547b936de91d634c6998ba59a75
Reviewed-by: Jøger Hansegård <joger.hansegard@qt.io>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

20 files changed, 50 insertions, 59 deletions

diff --git a/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp b/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp
index 5197bcc31d..0ce0b0e2a7 100644
--- a/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp
+++ b/src/plugins/platforms/windows/qwindowsdialoghelpers.cpp
@@ -4,7 +4,6 @@
 #define QT_NO_URL_CAST_FROM_STRING 1
 
 #include <QtCore/qt_windows.h>
-#include "qwindowscombase.h"
 #include "qwindowsdialoghelpers.h"
 
 #include "qwindowscontext.h"
@@ -33,6 +32,7 @@
 #include <QtCore/qtemporaryfile.h>
 #include <QtCore/private/qfunctions_win_p.h>
 #include <QtCore/private/qsystemerror_p.h>
+#include <QtCore/private/qcomobject_p.h>
 
 #include <algorithm>
 #include <vector>
@@ -423,7 +423,7 @@ inline void QWindowsFileDialogSharedData::fromOptions(const QSharedPointer<QFile
 
 class QWindowsNativeFileDialogBase;
 
-class QWindowsNativeFileDialogEventHandler : public QWindowsComBase<IFileDialogEvents>
+class QWindowsNativeFileDialogEventHandler : public QComObject<IFileDialogEvents>
 {
     Q_DISABLE_COPY_MOVE(QWindowsNativeFileDialogEventHandler)
 public:
diff --git a/src/plugins/platforms/windows/qwindowsdrag.cpp b/src/plugins/platforms/windows/qwindowsdrag.cpp
index e8ec8d24a2..c6f55c3509 100644
--- a/src/plugins/platforms/windows/qwindowsdrag.cpp
+++ b/src/plugins/platforms/windows/qwindowsdrag.cpp
@@ -29,6 +29,7 @@
 #include <QtCore/qbuffer.h>
 #include <QtCore/qpoint.h>
 #include <QtCore/qpointer.h>
+#include <QtCore/private/qcomobject_p.h>
 
 #include <shlobj.h>
 
@@ -168,7 +169,7 @@ static Qt::MouseButtons lastButtons = Qt::NoButton;
     \internal
 */
 
-class QWindowsOleDropSource : public QWindowsComBase<IDropSource>
+class QWindowsOleDropSource : public QComObject<IDropSource>
 {
 public:
     enum Mode {
diff --git a/src/plugins/platforms/windows/qwindowsdrag.h b/src/plugins/platforms/windows/qwindowsdrag.h
index 92abda295f..a2d0e54044 100644
--- a/src/plugins/platforms/windows/qwindowsdrag.h
+++ b/src/plugins/platforms/windows/qwindowsdrag.h
@@ -4,12 +4,12 @@
 #ifndef QWINDOWSDRAG_H
 #define QWINDOWSDRAG_H
 
-#include "qwindowscombase.h"
 #include "qwindowsinternalmimedata.h"
 
 #include <qpa/qplatformdrag.h>
 #include <QtGui/qpixmap.h>
 #include <QtGui/qdrag.h>
+#include <QtCore/private/qcomobject_p.h>
 
 struct IDropTargetHelper;
 
@@ -23,7 +23,7 @@ public:
     IDataObject *retrieveDataObject() const override;
 };
 
-class QWindowsOleDropTarget : public QWindowsComBase<IDropTarget>
+class QWindowsOleDropTarget : public QComObject<IDropTarget>
 {
 public:
     explicit QWindowsOleDropTarget(QWindow *w);
diff --git a/src/plugins/platforms/windows/qwindowsole.h b/src/plugins/platforms/windows/qwindowsole.h
index b687384684..016f9dd04c 100644
--- a/src/plugins/platforms/windows/qwindowsole.h
+++ b/src/plugins/platforms/windows/qwindowsole.h
@@ -4,12 +4,12 @@
 #ifndef QWINDOWSOLE_H
 #define QWINDOWSOLE_H
 
-#include "qwindowscombase.h"
 #include <QtCore/qt_windows.h>
 
 #include <QtCore/qlist.h>
 #include <QtCore/qmap.h>
 #include <QtCore/qpointer.h>
+#include <QtCore/private/qcomobject_p.h>
 
 #include <objidl.h>
 
@@ -18,7 +18,7 @@ QT_BEGIN_NAMESPACE
 class QMimeData;
 class QWindow;
 
-class QWindowsOleDataObject : public QWindowsComBase<IDataObject>
+class QWindowsOleDataObject : public QComObject<IDataObject>
 {
 public:
     explicit QWindowsOleDataObject(QMimeData *mimeData);
@@ -47,7 +47,7 @@ private:
     DWORD performedEffect = DROPEFFECT_NONE;
 };
 
-class QWindowsOleEnumFmtEtc : public QWindowsComBase<IEnumFORMATETC>
+class QWindowsOleEnumFmtEtc : public QComObject<IEnumFORMATETC>
 {
 public:
     explicit QWindowsOleEnumFmtEtc(const QList<FORMATETC> &fmtetcs);
diff --git a/src/plugins/platforms/windows/uiautomation/qwindowsuiabaseprovider.h b/src/plugins/platforms/windows/uiautomation/qwindowsuiabaseprovider.h
index c899b4096e..445d71587a 100644
--- a/src/plugins/platforms/windows/uiautomation/qwindowsuiabaseprovider.h
+++ b/src/plugins/platforms/windows/uiautomation/qwindowsuiabaseprovider.h
@@ -10,8 +10,8 @@
 #include <QtGui/qaccessible.h>
 #include <QtCore/qpointer.h>
 
-#include <qwindowscombase.h>
 #include <QtGui/private/qwindowsuiawrapper_p.h>
+#include <QtCore/private/qcomobject_p.h>
 
 QT_BEGIN_NAMESPACE
 
diff --git a/src/plugins/platforms/windows/uiautomation/qwindowsuiaexpandcollapseprovider.h b/src/plugins/platforms/windows/uiautomation/qwindowsuiaexpandcollapseprovider.h
index 49b37ba295..b384eb521c 100644
--- a/src/plugins/platforms/windows/uiautomation/qwindowsuiaexpandcollapseprovider.h
+++ b/src/plugins/platforms/windows/uiautomation/qwindowsuiaexpandcollapseprovider.h
@@ -13,7 +13,7 @@ QT_BEGIN_NAMESPACE
 
 // Implements the Expand/Collapse control pattern provider. Used for menu items with submenus.
 class QWindowsUiaExpandCollapseProvider : public QWindowsUiaBaseProvider,
-                                          public QWindowsComBase<IExpandCollapseProvider>
+                                          public QComObject<IExpandCollapseProvider>
 {
     Q_DISABLE_COPY_MOVE(QWindowsUiaExpandCollapseProvider)
 public:
diff --git a/src/plugins/platforms/windows/uiautomation/qwindowsuiagriditemprovider.h b/src/plugins/platforms/windows/uiautomation/qwindowsuiagriditemprovider.h
index b501616966..289a867869 100644
--- a/src/plugins/platforms/windows/uiautomation/qwindowsuiagriditemprovider.h
+++ b/src/plugins/platforms/windows/uiautomation/qwindowsuiagriditemprovider.h
@@ -13,7 +13,7 @@ QT_BEGIN_NAMESPACE
 
 // Implements the Grid Item control pattern provider. Used by items within a table/tree.
 class QWindowsUiaGridItemProvider : public QWindowsUiaBaseProvider,
-                                    public QWindowsComBase<IGridItemProvider>
+                                    public QComObject<IGridItemProvider>
 {
     Q_DISABLE_COPY_MOVE(QWindowsUiaGridItemProvider)
 public:
diff --git a/src/plugins/platforms/windows/uiautomation/qwindowsuiagridprovider.h b/src/plugins/platforms/windows/uiautomation/qwindowsuiagridprovider.h
index b905133f6b..d33bbd0429 100644
--- a/src/plugins/platforms/windows/uiautomation/qwindowsuiagridprovider.h
+++ b/src/plugins/platforms/windows/uiautomation/qwindowsuiagridprovider.h
@@ -12,8 +12,7 @@
 QT_BEGIN_NAMESPACE
 
 // Implements the Grid control pattern provider. Used by tables/trees.
-class QWindowsUiaGridProvider : public QWindowsUiaBaseProvider,
-                                public QWindowsComBase<IGridProvider>
+class QWindowsUiaGridProvider : public QWindowsUiaBaseProvider, public QComObject<IGridProvider>
 {
     Q_DISABLE_COPY_MOVE(QWindowsUiaGridProvider)
 public:
diff --git a/src/plugins/platforms/windows/uiautomation/qwindowsuiainvokeprovider.h b/src/plugins/platforms/windows/uiautomation/qwindowsuiainvokeprovider.h
index eca7e73039..ec006c673e 100644
--- a/src/plugins/platforms/windows/uiautomation/qwindowsuiainvokeprovider.h
+++ b/src/plugins/platforms/windows/uiautomation/qwindowsuiainvokeprovider.h
@@ -12,8 +12,7 @@
 QT_BEGIN_NAMESPACE
 
 // Implements the Invoke control pattern provider.
-class QWindowsUiaInvokeProvider : public QWindowsUiaBaseProvider,
-                                  public QWindowsComBase<IInvokeProvider>
+class QWindowsUiaInvokeProvider : public QWindowsUiaBaseProvider, public QComObject<IInvokeProvider>
 {
     Q_DISABLE_COPY_MOVE(QWindowsUiaInvokeProvider)
 public:
diff --git a/src/plugins/platforms/windows/uiautomation/qwindowsuiarangevalueprovider.h b/src/plugins/platforms/windows/uiautomation/qwindowsuiarangevalueprovider.h
index 3e06961a82..ffb5ae155b 100644
--- a/src/plugins/platforms/windows/uiautomation/qwindowsuiarangevalueprovider.h
+++ b/src/plugins/platforms/windows/uiautomation/qwindowsuiarangevalueprovider.h
@@ -13,7 +13,7 @@ QT_BEGIN_NAMESPACE
 
 // Implements the Range Value control pattern provider.
 class QWindowsUiaRangeValueProvider : public QWindowsUiaBaseProvider,
-                                      public QWindowsComBase<IRangeValueProvider>
+                                      public QComObject<IRangeValueProvider>
 {
     Q_DISABLE_COPY_MOVE(QWindowsUiaRangeValueProvider)
 public:
diff --git a/src/plugins/platforms/windows/uiautomation/qwindowsuiaselectionitemprovider.h b/src/plugins/platforms/windows/uiautomation/qwindowsuiaselectionitemprovider.h
index b510ae951c..ee34fd9edd 100644
--- a/src/plugins/platforms/windows/uiautomation/qwindowsuiaselectionitemprovider.h
+++ b/src/plugins/platforms/windows/uiautomation/qwindowsuiaselectionitemprovider.h
@@ -13,7 +13,7 @@ QT_BEGIN_NAMESPACE
 
 // Implements the Selection Item control pattern provider. Used for List items and radio buttons.
 class QWindowsUiaSelectionItemProvider : public QWindowsUiaBaseProvider,
-                                         public QWindowsComBase<ISelectionItemProvider>
+                                         public QComObject<ISelectionItemProvider>
 {
     Q_DISABLE_COPY_MOVE(QWindowsUiaSelectionItemProvider)
 public:
diff --git a/src/plugins/platforms/windows/uiautomation/qwindowsuiaselectionprovider.h b/src/plugins/platforms/windows/uiautomation/qwindowsuiaselectionprovider.h
index 8717e54ee7..7a899e4261 100644
--- a/src/plugins/platforms/windows/uiautomation/qwindowsuiaselectionprovider.h
+++ b/src/plugins/platforms/windows/uiautomation/qwindowsuiaselectionprovider.h
@@ -11,27 +11,28 @@
 
 QT_BEGIN_NAMESPACE
 
+namespace QtPrivate {
+
+template <>
+struct QComObjectTraits<ISelectionProvider2>
+{
+    static constexpr bool isGuidOf(REFIID riid) noexcept
+    {
+        return QComObjectTraits<ISelectionProvider2, ISelectionProvider>::isGuidOf(riid);
+    }
+};
+
+} // namespace QtPrivate
+
 // Implements the Selection control pattern provider. Used for Lists.
 class QWindowsUiaSelectionProvider : public QWindowsUiaBaseProvider,
-                                     public QWindowsComBase<ISelectionProvider2>
+                                     public QComObject<ISelectionProvider2>
 {
     Q_DISABLE_COPY_MOVE(QWindowsUiaSelectionProvider)
 public:
     explicit QWindowsUiaSelectionProvider(QAccessible::Id id);
     virtual ~QWindowsUiaSelectionProvider();
 
-    // override to support ISelectionProvider and ISelectionProvider2 at the same time
-    HRESULT STDMETHODCALLTYPE QueryInterface(REFIID id, LPVOID *iface) override
-    {
-        HRESULT res = QWindowsComBase<ISelectionProvider2>::QueryInterface(id, iface);
-        // QWindowsComBase<ISelectionProvider2>::QueryInterface doesn't handle ISelectionProvider,
-        // from which ISelectionProvider2 inherits
-        if (res == E_NOINTERFACE)
-            res = qWindowsComQueryInterface<ISelectionProvider>(this, id, iface) ? S_OK : E_NOINTERFACE;
-
-        return res;
-    };
-
     // ISelectionProvider
     HRESULT STDMETHODCALLTYPE GetSelection(SAFEARRAY **pRetVal) override;
     HRESULT STDMETHODCALLTYPE get_CanSelectMultiple(BOOL *pRetVal) override;
diff --git a/src/plugins/platforms/windows/uiautomation/qwindowsuiatableitemprovider.h b/src/plugins/platforms/windows/uiautomation/qwindowsuiatableitemprovider.h
index 8aed180671..3bb0e1027e 100644
--- a/src/plugins/platforms/windows/uiautomation/qwindowsuiatableitemprovider.h
+++ b/src/plugins/platforms/windows/uiautomation/qwindowsuiatableitemprovider.h
@@ -13,7 +13,7 @@ QT_BEGIN_NAMESPACE
 
 // Implements the Table Item control pattern provider. Used by items within a table/tree.
 class QWindowsUiaTableItemProvider : public QWindowsUiaBaseProvider,
-                                     public QWindowsComBase<ITableItemProvider>
+                                     public QComObject<ITableItemProvider>
 {
     Q_DISABLE_COPY_MOVE(QWindowsUiaTableItemProvider)
 public:
diff --git a/src/plugins/platforms/windows/uiautomation/qwindowsuiatableprovider.h b/src/plugins/platforms/windows/uiautomation/qwindowsuiatableprovider.h
index 6454bb9441..8beb11decf 100644
--- a/src/plugins/platforms/windows/uiautomation/qwindowsuiatableprovider.h
+++ b/src/plugins/platforms/windows/uiautomation/qwindowsuiatableprovider.h
@@ -12,8 +12,7 @@
 QT_BEGIN_NAMESPACE
 
 // Implements the Table control pattern provider. Used by tables/trees.
-class QWindowsUiaTableProvider : public QWindowsUiaBaseProvider,
-                                 public QWindowsComBase<ITableProvider>
+class QWindowsUiaTableProvider : public QWindowsUiaBaseProvider, public QComObject<ITableProvider>
 {
     Q_DISABLE_COPY_MOVE(QWindowsUiaTableProvider)
 public:
diff --git a/src/plugins/platforms/windows/uiautomation/qwindowsuiatextprovider.cpp b/src/plugins/platforms/windows/uiautomation/qwindowsuiatextprovider.cpp
index ae108c604d..172836232e 100644
--- a/src/plugins/platforms/windows/uiautomation/qwindowsuiatextprovider.cpp
+++ b/src/plugins/platforms/windows/uiautomation/qwindowsuiatextprovider.cpp
@@ -26,20 +26,6 @@ QWindowsUiaTextProvider::~QWindowsUiaTextProvider()
 {
 }
 
-HRESULT STDMETHODCALLTYPE QWindowsUiaTextProvider::QueryInterface(REFIID iid, LPVOID *iface)
-{
-    qCDebug(lcQpaUiAutomation) << __FUNCTION__ << this;
-
-    if (!iface)
-        return E_INVALIDARG;
-    *iface = nullptr;
-
-    const bool result = qWindowsComQueryUnknownInterfaceMulti<ITextProvider>(this, iid, iface)
-        || qWindowsComQueryInterface<ITextProvider>(this, iid, iface)
-        || qWindowsComQueryInterface<ITextProvider2>(this, iid, iface);
-    return result ? S_OK : E_NOINTERFACE;
-}
-
 // Returns an array of providers for the selected text ranges.
 HRESULT STDMETHODCALLTYPE QWindowsUiaTextProvider::GetSelection(SAFEARRAY **pRetVal)
 {
diff --git a/src/plugins/platforms/windows/uiautomation/qwindowsuiatextprovider.h b/src/plugins/platforms/windows/uiautomation/qwindowsuiatextprovider.h
index 5e6d430f1a..8f886510b4 100644
--- a/src/plugins/platforms/windows/uiautomation/qwindowsuiatextprovider.h
+++ b/src/plugins/platforms/windows/uiautomation/qwindowsuiatextprovider.h
@@ -12,18 +12,27 @@
 
 QT_BEGIN_NAMESPACE
 
+namespace QtPrivate {
+
+template <>
+struct QComObjectTraits<ITextProvider2>
+{
+    static constexpr bool isGuidOf(REFIID riid) noexcept
+    {
+        return QComObjectTraits<ITextProvider2, ITextProvider>::isGuidOf(riid);
+    }
+};
+
+} // namespace QtPrivate
+
 // Implements the Text control pattern provider. Used for text controls.
-class QWindowsUiaTextProvider : public QWindowsUiaBaseProvider,
-                                public QWindowsComBase<ITextProvider2>
+class QWindowsUiaTextProvider : public QWindowsUiaBaseProvider, public QComObject<ITextProvider2>
 {
     Q_DISABLE_COPY_MOVE(QWindowsUiaTextProvider)
 public:
     explicit QWindowsUiaTextProvider(QAccessible::Id id);
     ~QWindowsUiaTextProvider();
 
-    // IUnknown overrides
-    HRESULT STDMETHODCALLTYPE QueryInterface(REFIID id, LPVOID *iface) override;
-
     // ITextProvider
     HRESULT STDMETHODCALLTYPE GetSelection(SAFEARRAY **pRetVal) override;
     HRESULT STDMETHODCALLTYPE GetVisibleRanges(SAFEARRAY **pRetVal) override;
diff --git a/src/plugins/platforms/windows/uiautomation/qwindowsuiatextrangeprovider.h b/src/plugins/platforms/windows/uiautomation/qwindowsuiatextrangeprovider.h
index d9a9c67ee0..a37429a603 100644
--- a/src/plugins/platforms/windows/uiautomation/qwindowsuiatextrangeprovider.h
+++ b/src/plugins/platforms/windows/uiautomation/qwindowsuiatextrangeprovider.h
@@ -13,7 +13,7 @@ QT_BEGIN_NAMESPACE
 
 // Implements the Text Range control pattern provider. Used for text controls.
 class QWindowsUiaTextRangeProvider : public QWindowsUiaBaseProvider,
-                                     public QWindowsComBase<ITextRangeProvider>
+                                     public QComObject<ITextRangeProvider>
 {
     Q_DISABLE_COPY_MOVE(QWindowsUiaTextRangeProvider)
 public:
diff --git a/src/plugins/platforms/windows/uiautomation/qwindowsuiatoggleprovider.h b/src/plugins/platforms/windows/uiautomation/qwindowsuiatoggleprovider.h
index 742e26f6d6..17150dfbe0 100644
--- a/src/plugins/platforms/windows/uiautomation/qwindowsuiatoggleprovider.h
+++ b/src/plugins/platforms/windows/uiautomation/qwindowsuiatoggleprovider.h
@@ -12,8 +12,7 @@
 QT_BEGIN_NAMESPACE
 
 // Implements the Toggle control pattern provider. Used for checkboxes.
-class QWindowsUiaToggleProvider : public QWindowsUiaBaseProvider,
-                                  public QWindowsComBase<IToggleProvider>
+class QWindowsUiaToggleProvider : public QWindowsUiaBaseProvider, public QComObject<IToggleProvider>
 {
     Q_DISABLE_COPY_MOVE(QWindowsUiaToggleProvider)
 public:
diff --git a/src/plugins/platforms/windows/uiautomation/qwindowsuiavalueprovider.h b/src/plugins/platforms/windows/uiautomation/qwindowsuiavalueprovider.h
index 2f52019d33..8c0a6b8ee7 100644
--- a/src/plugins/platforms/windows/uiautomation/qwindowsuiavalueprovider.h
+++ b/src/plugins/platforms/windows/uiautomation/qwindowsuiavalueprovider.h
@@ -13,8 +13,7 @@ QT_BEGIN_NAMESPACE
 
 // Implements the Value control pattern provider.
 // Supported for all controls that can return text(QAccessible::Value).
-class QWindowsUiaValueProvider : public QWindowsUiaBaseProvider,
-                                 public QWindowsComBase<IValueProvider>
+class QWindowsUiaValueProvider : public QWindowsUiaBaseProvider, public QComObject<IValueProvider>
 {
     Q_DISABLE_COPY_MOVE(QWindowsUiaValueProvider)
 public:
diff --git a/src/plugins/platforms/windows/uiautomation/qwindowsuiawindowprovider.h b/src/plugins/platforms/windows/uiautomation/qwindowsuiawindowprovider.h
index e277b3f5c5..89a1655232 100644
--- a/src/plugins/platforms/windows/uiautomation/qwindowsuiawindowprovider.h
+++ b/src/plugins/platforms/windows/uiautomation/qwindowsuiawindowprovider.h
@@ -11,8 +11,7 @@
 
 QT_BEGIN_NAMESPACE
 
-class QWindowsUiaWindowProvider : public QWindowsUiaBaseProvider,
-                                  public QWindowsComBase<IWindowProvider>
+class QWindowsUiaWindowProvider : public QWindowsUiaBaseProvider, public QComObject<IWindowProvider>
 {
     Q_DISABLE_COPY(QWindowsUiaWindowProvider)
 public: