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, 28 insertions, 10 deletions

diff --git a/tests/auto/testlib/selftests/benchlibeventcounter/tst_benchlibeventcounter.cpp b/tests/auto/testlib/selftests/benchlibeventcounter/tst_benchlibeventcounter.cpp
index b077291cc6..966c81ec30 100644
--- a/tests/auto/testlib/selftests/benchlibeventcounter/tst_benchlibeventcounter.cpp
+++ b/tests/auto/testlib/selftests/benchlibeventcounter/tst_benchlibeventcounter.cpp
@@ -87,7 +87,7 @@ void tst_BenchlibEventCounter::events()
     QAbstractEventDispatcher* ed = QAbstractEventDispatcher::instance();
     QBENCHMARK {
         for (int i = 0; i < eventCount; ++i) {
-            ed->filterEvent(0);
+            ed->filterNativeEvent("", 0, 0);
         }
     }
 }
diff --git a/tests/auto/testlib/selftests/benchliboptions/tst_benchliboptions.cpp b/tests/auto/testlib/selftests/benchliboptions/tst_benchliboptions.cpp
index 7673aa396e..c60addf972 100644
--- a/tests/auto/testlib/selftests/benchliboptions/tst_benchliboptions.cpp
+++ b/tests/auto/testlib/selftests/benchliboptions/tst_benchliboptions.cpp
@@ -88,9 +88,9 @@ void tst_BenchlibOptions::threeEvents()
 {
     QAbstractEventDispatcher* ed = QAbstractEventDispatcher::instance();
     QBENCHMARK {
-        ed->filterEvent(0);
-        ed->filterEvent(0);
-        ed->filterEvent(0);
+        ed->filterNativeEvent("", 0, 0);
+        ed->filterNativeEvent("", 0, 0);
+        ed->filterNativeEvent("", 0, 0);
     }
 }
 
diff --git a/tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp b/tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp
index 37e945ddb1..c670c5bf72 100644
--- a/tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp
+++ b/tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp
@@ -71,6 +71,7 @@
 #include <qcompleter.h>
 #include <qtableview.h>
 #include <qtreewidget.h>
+#include <qabstractnativeeventfilter.h>
 
 #include <QtWidgets/QGraphicsView>
 #include <QtWidgets/QGraphicsProxyWidget>
@@ -5505,16 +5506,17 @@ void tst_QWidget::minAndMaxSizeWithX11BypassWindowManagerHint()
     }
 }
 
-class ShowHideShowWidget : public QWidget
+class ShowHideShowWidget : public QWidget, public QAbstractNativeEventFilter
 {
     Q_OBJECT
 
     int state;
 public:
     bool gotExpectedMapNotify;
+    bool gotExpectedGlobalEvent;
 
     ShowHideShowWidget()
-        : state(0), gotExpectedMapNotify(false)
+        : state(0), gotExpectedMapNotify(false), gotExpectedGlobalEvent(false)
     {
         startTimer(1000);
     }
@@ -5531,19 +5533,32 @@ public:
         }
     }
 
-    bool nativeEvent(const QByteArray &eventType, void *message, long *)
+    bool isMapNotify(const QByteArray &eventType, void *message)
     {
         enum { XCB_MAP_NOTIFY = 19 };
-
         if (state == 1 && eventType == QByteArrayLiteral("xcb_generic_event_t")) {
             // XCB events have a uint8 response_type member at the beginning.
             const unsigned char responseType = *(const unsigned char *)(message);
-            if ((responseType & ~0x80) == XCB_MAP_NOTIFY)
-                gotExpectedMapNotify = true;
+            return ((responseType & ~0x80) == XCB_MAP_NOTIFY);
         }
         return false;
     }
 
+    bool nativeEvent(const QByteArray &eventType, void *message, long *)
+    {
+        if (isMapNotify(eventType, message))
+            gotExpectedMapNotify = true;
+        return false;
+    }
+
+    // QAbstractNativeEventFilter interface
+    virtual bool nativeEventFilter(const QByteArray &eventType, void *message, long *) Q_DECL_OVERRIDE
+    {
+        if (isMapNotify(eventType, message))
+            gotExpectedGlobalEvent = true;
+        return false;
+    }
+
 signals:
     void done();
 };
@@ -5554,6 +5569,8 @@ void tst_QWidget::showHideShowX11()
         QSKIP("This test is for X11 only.");
 
     ShowHideShowWidget w;
+    qApp->installNativeEventFilter(&w);
+
     w.show();
     w.hide();
 
@@ -5561,6 +5578,7 @@ void tst_QWidget::showHideShowX11()
     connect(&w, SIGNAL(done()), &eventLoop, SLOT(quit()));
     eventLoop.exec();
 
+    QVERIFY(w.gotExpectedGlobalEvent);
     QVERIFY(w.gotExpectedMapNotify);
 }