Provide public API for native event filtering, moved up from QPA.

The previous API was hard to use (global function, no type safety,
manual chaining), and confusing (app vs dispatcher split only made
sense on Windows). Installing and removing out of order would have
the risk of setting back a dangling pointer (crash). Meanwhile QPA
added type safety, and this new API models the QObject::installEventFilter
API for ease of use. The virtual method is in a new interface,
QAbstractNativeEventFilter.

QPA was even calling the dispatcher event filter with QPA-private event
classes, which made no sense (refactoring leftover from when the code
was in the dispatcher). Now the QPA plugins trigger the qcoreapp event
filters with the actual native events directly.

Change-Id: Ie35e47c59c862383bcaf857b28d54f7c72547882
Reviewed-by: Marius Storm-Olsen <marius.storm-olsen@nokia.com>

3 files changed, 4 insertions, 40 deletions

diff --git a/src/plugins/platforms/windows/qwindowscontext.cpp b/src/plugins/platforms/windows/qwindowscontext.cpp
index 37493fe3db..b12975174f 100644
--- a/src/plugins/platforms/windows/qwindowscontext.cpp
+++ b/src/plugins/platforms/windows/qwindowscontext.cpp
@@ -240,13 +240,6 @@ QWindowsContext *QWindowsContext::m_instance = 0;
 typedef QHash<HWND, QWindowsWindow *> HandleBaseWindowHash;
 
 struct QWindowsContextPrivate {
-    typedef QPlatformNativeInterface::EventFilter EventFilter;
-
-    enum EventFilterType
-    {
-        GenericWindowsEventFilter,
-        EventFilterTypeCount
-    };
 
     QWindowsContextPrivate();
 
@@ -262,7 +255,6 @@ struct QWindowsContextPrivate {
     QSharedPointer<QWindowCreationContext> m_creationContext;
     const HRESULT m_oleInitializeResult;
     const QByteArray m_eventType;
-    EventFilter m_eventFilters[EventFilterTypeCount];
     QWindow *m_lastActiveWindow;
 };
 
@@ -289,7 +281,6 @@ QWindowsContextPrivate::QWindowsContextPrivate() :
         m_systemInfo |= QWindowsContext::SI_RTL_Extensions;
         m_keyMapper.setUseRTLExtensions(true);
     }
-    qFill(m_eventFilters, m_eventFilters + EventFilterTypeCount, EventFilter(0));
 }
 
 QWindowsContext::QWindowsContext() :
@@ -695,27 +686,6 @@ QByteArray QWindowsContext::comErrorString(HRESULT hr)
 }
 
 /*!
-     \brief Set event filter.
-
-     \sa QWindowsNativeInterface
-*/
-
-QWindowsContext::EventFilter QWindowsContext::setEventFilter(const QByteArray &eventType, EventFilter filter)
-{
-    int eventFilterType = -1;
-    if (eventType == d->m_eventType)
-        eventFilterType = QWindowsContextPrivate::GenericWindowsEventFilter;
-    if (eventFilterType < 0) {
-        qWarning("%s: Attempt to set unsupported event filter '%s'.",
-                 __FUNCTION__, eventType.constData());
-        return 0;
-    }
-    const EventFilter previous = d->m_eventFilters[eventFilterType];
-    d->m_eventFilters[eventFilterType] = filter;
-    return previous;
-}
-
-/*!
      \brief Main windows procedure registered for windows.
 
      \sa QWindowsGuiEventDispatcher
@@ -736,11 +706,10 @@ bool QWindowsContext::windowsProc(HWND hwnd, UINT message,
     msg.pt.y = GET_Y_LPARAM(lParam);
 
     long filterResult = 0;
-    if (d->m_eventFilters[QWindowsContextPrivate::GenericWindowsEventFilter]) {
-        if (d->m_eventFilters[QWindowsContextPrivate::GenericWindowsEventFilter](&msg, &filterResult)) {
-            *result = LRESULT(filterResult);
-            return true;
-        }
+    QCoreApplication* coreApp = QCoreApplication::instance();
+    if (coreApp && coreApp->filterNativeEvent(d->m_eventType, &msg, &filterResult)) {
+        *result = LRESULT(filterResult);
+        return true;
     }
     // Events without an associated QWindow or events we are not interested in.
     switch (et) {
diff --git a/src/plugins/platforms/windows/qwindowscontext.h b/src/plugins/platforms/windows/qwindowscontext.h
index 0b18196abe..e4fde55464 100644
--- a/src/plugins/platforms/windows/qwindowscontext.h
+++ b/src/plugins/platforms/windows/qwindowscontext.h
@@ -107,7 +107,6 @@ class QWindowsContext
 {
     Q_DISABLE_COPY(QWindowsContext)
 public:
-    typedef bool (*EventFilter)(void *message, long *result);
 
     enum SystemInfoFlags
     {
@@ -143,8 +142,6 @@ public:
     HDC displayContext() const;
     int screenDepth() const;
 
-    EventFilter setEventFilter(const QByteArray &eventType, EventFilter filter);
-
     static QWindowsContext *instance();
 
     static QString windowsErrorMessage(unsigned long errorCode);
diff --git a/src/plugins/platforms/windows/qwindowsintegration.cpp b/src/plugins/platforms/windows/qwindowsintegration.cpp
index 1ff142bc98..f32f8cd689 100644
--- a/src/plugins/platforms/windows/qwindowsintegration.cpp
+++ b/src/plugins/platforms/windows/qwindowsintegration.cpp
@@ -102,8 +102,6 @@ public:
 #endif
     virtual void *nativeResourceForWindow(const QByteArray &resource, QWindow *window);
     virtual void *nativeResourceForBackingStore(const QByteArray &resource, QBackingStore *bs);
-    virtual EventFilter setEventFilter(const QByteArray &eventType, EventFilter filter)
-        { return QWindowsContext::instance()->setEventFilter(eventType, filter); }
 
     Q_INVOKABLE void *createMessageWindow(const QString &classNameTemplate,
                                           const QString &windowName,