Use QComObject with QWindowsUiaMainProvider

This change adds QComObject as base to QWindowsUiaMainProvider in order
to reuse its implementation of IUnknown.

Change-Id: I48808262364992f90f18fc881594f151eeb29a3f
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>

2 files changed, 16 insertions, 29 deletions

diff --git a/src/plugins/platforms/windows/uiautomation/qwindowsuiamainprovider.cpp b/src/plugins/platforms/windows/uiautomation/qwindowsuiamainprovider.cpp
index 29cd1c6237..95ddbcced6 100644
--- a/src/plugins/platforms/windows/uiautomation/qwindowsuiamainprovider.cpp
+++ b/src/plugins/platforms/windows/uiautomation/qwindowsuiamainprovider.cpp
@@ -18,7 +18,6 @@
 #include "qwindowsuiagriditemprovider.h"
 #include "qwindowsuiawindowprovider.h"
 #include "qwindowsuiaexpandcollapseprovider.h"
-#include "qwindowscombase.h"
 #include "qwindowscontext.h"
 #include "qwindowsuiautils.h"
 #include "qwindowsuiaprovidercache.h"
@@ -62,9 +61,8 @@ QWindowsUiaMainProvider *QWindowsUiaMainProvider::providerForAccessible(QAccessi
     return provider;
 }
 
-QWindowsUiaMainProvider::QWindowsUiaMainProvider(QAccessibleInterface *a, int initialRefCount)
-    : QWindowsUiaBaseProvider(QAccessible::uniqueId(a)),
-      m_ref(initialRefCount)
+QWindowsUiaMainProvider::QWindowsUiaMainProvider(QAccessibleInterface *a)
+    : QWindowsUiaBaseProvider(QAccessible::uniqueId(a))
 {
 }
 
@@ -208,33 +206,26 @@ void QWindowsUiaMainProvider::notifyTextChange(QAccessibleEvent *event)
 
 HRESULT STDMETHODCALLTYPE QWindowsUiaMainProvider::QueryInterface(REFIID iid, LPVOID *iface)
 {
-    if (!iface)
-        return E_INVALIDARG;
-    *iface = nullptr;
-
-    QAccessibleInterface *accessible = accessibleInterface();
+    HRESULT result = QComObject::QueryInterface(iid, iface);
 
-    const bool result = qWindowsComQueryUnknownInterfaceMulti<IRawElementProviderSimple>(this, iid, iface)
-        || qWindowsComQueryInterface<IRawElementProviderSimple>(this, iid, iface)
-        || qWindowsComQueryInterface<IRawElementProviderFragment>(this, iid, iface)
-        || (accessible && hwndForAccessible(accessible) && qWindowsComQueryInterface<IRawElementProviderFragmentRoot>(this, iid, iface));
-    return result ? S_OK : E_NOINTERFACE;
-}
+    if (SUCCEEDED(result) && iid == __uuidof(IRawElementProviderFragmentRoot)) {
+        QAccessibleInterface *accessible = accessibleInterface();
+        if (accessible && hwndForAccessible(accessible)) {
+            result = S_OK;
+        } else {
+            result = E_NOINTERFACE;
+            iface = nullptr;
+        }
+    }
 
-ULONG QWindowsUiaMainProvider::AddRef()
-{
-    return ++m_ref;
+    return result;
 }
 
 ULONG STDMETHODCALLTYPE QWindowsUiaMainProvider::Release()
 {
     QMutexLocker locker(&m_mutex);
 
-    if (!--m_ref) {
-        delete this;
-        return 0;
-    }
-    return m_ref;
+    return QComObject::Release();
 }
 
 HRESULT QWindowsUiaMainProvider::get_ProviderOptions(ProviderOptions *pRetVal)
diff --git a/src/plugins/platforms/windows/uiautomation/qwindowsuiamainprovider.h b/src/plugins/platforms/windows/uiautomation/qwindowsuiamainprovider.h
index 24181f9536..99db0ed318 100644
--- a/src/plugins/platforms/windows/uiautomation/qwindowsuiamainprovider.h
+++ b/src/plugins/platforms/windows/uiautomation/qwindowsuiamainprovider.h
@@ -20,15 +20,13 @@ QT_BEGIN_NAMESPACE
 // The main UI Automation class.
 class QWindowsUiaMainProvider :
     public QWindowsUiaBaseProvider,
-    public IRawElementProviderSimple,
-    public IRawElementProviderFragment,
-    public IRawElementProviderFragmentRoot
+    public QComObject<IRawElementProviderSimple, IRawElementProviderFragment, IRawElementProviderFragmentRoot>
 {
     Q_OBJECT
     Q_DISABLE_COPY_MOVE(QWindowsUiaMainProvider)
 public:
     static QWindowsUiaMainProvider *providerForAccessible(QAccessibleInterface *accessible);
-    explicit QWindowsUiaMainProvider(QAccessibleInterface *a, int initialRefCount = 1);
+    explicit QWindowsUiaMainProvider(QAccessibleInterface *a);
     virtual ~QWindowsUiaMainProvider();
     static void notifyFocusChange(QAccessibleEvent *event);
     static void notifyStateChange(QAccessibleStateChangeEvent *event);
@@ -39,7 +37,6 @@ public:
 
     // IUnknown
     HRESULT STDMETHODCALLTYPE QueryInterface(REFIID id, LPVOID *iface) override;
-    ULONG STDMETHODCALLTYPE AddRef() override;
     ULONG STDMETHODCALLTYPE Release() override;
 
     // IRawElementProviderSimple methods
@@ -63,7 +60,6 @@ public:
 private:
     QString automationIdForAccessible(const QAccessibleInterface *accessible);
     static void fillVariantArrayForRelation(QAccessibleInterface *accessible, QAccessible::Relation relation, VARIANT *pRetVal);
-    ULONG m_ref;
     static QMutex m_mutex;
 };