iOS: Send window-system event also when embedded in native iOS app

The iOS event dispatcher has been split into two; one dealing with the
QPA event processing, which we should always do, and one dealing with
the longjumping that we do when running the user's main on a separate
stack.

Change-Id: I1f819db33c608aad130ff23cbbadcf84363a32d2
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>
(cherry picked from commit 5414d372d42278b146ce1cdf1096c4e91e7039ad)

src/plugins/platforms/ios/qioseventdispatcher.h

@@ -49,18 +49,29 @@ class QIOSEventDispatcher : public QEventDispatcherCoreFoundation
     Q_OBJECT
 
 public:
-    explicit QIOSEventDispatcher(QObject *parent = 0);
+    static QIOSEventDispatcher* create();
-
-    bool processEvents(QEventLoop::ProcessEventsFlags flags) override;
     bool processPostedEvents() override;
 
+protected:
+    explicit QIOSEventDispatcher(QObject *parent = 0);
+};
+
+class QIOSJumpingEventDispatcher : public QIOSEventDispatcher
+{
+    Q_OBJECT
+
+public:
+    QIOSJumpingEventDispatcher(QObject *parent = 0);
+    bool processEvents(QEventLoop::ProcessEventsFlags flags) override;
+
+    // Public since we can't friend Objective-C methods
     void handleRunLoopExit(CFRunLoopActivity activity);
 
     void interruptEventLoopExec();
 
 private:
     uint m_processEventLevel;
-    RunLoopObserver<QIOSEventDispatcher> m_runLoopExitObserver;
+    RunLoopObserver<QIOSJumpingEventDispatcher> m_runLoopExitObserver;
 };
 
 QT_END_NAMESPACE

src/plugins/platforms/ios/qioseventdispatcher.mm

@@ -403,7 +403,7 @@ static const char kApplicationWillTerminateExitCode = char(SIGTERM | 0x80);
         // so we'll never see the exit activity and have a chance to return from
         // QEventLoop::exec(). We initiate the return manually as a workaround.
         qCDebug(lcEventDispatcher) << "Manually triggering return from event loop exec";
-        static_cast<QIOSEventDispatcher *>(qApp->eventDispatcher())->interruptEventLoopExec();
+        static_cast<QIOSJumpingEventDispatcher *>(qApp->eventDispatcher())->interruptEventLoopExec();
         break;
     case kJumpedFromUserMainTrampoline:
         // The user's main has returned, so we're ready to let iOS terminate the application
@@ -419,20 +419,48 @@ static const char kApplicationWillTerminateExitCode = char(SIGTERM | 0x80);
 QT_BEGIN_NAMESPACE
 QT_USE_NAMESPACE
 
+QIOSEventDispatcher *QIOSEventDispatcher::create()
+{
+    if (isQtApplication() && rootLevelRunLoopIntegration())
+        return new QIOSJumpingEventDispatcher;
+
+    return new QIOSEventDispatcher;
+}
+
 QIOSEventDispatcher::QIOSEventDispatcher(QObject *parent)
     : QEventDispatcherCoreFoundation(parent)
-    , m_processEventLevel(0)
-    , m_runLoopExitObserver(this, &QIOSEventDispatcher::handleRunLoopExit, kCFRunLoopExit)
 {
     // We want all delivery of events from the system to be handled synchronously
     QWindowSystemInterface::setSynchronousWindowSystemEvents(true);
 }
 
-bool __attribute__((returns_twice)) QIOSEventDispatcher::processEvents(QEventLoop::ProcessEventsFlags flags)
+/*!
+    Override of the CoreFoundation posted events runloop source callback
+    so that we can send window system (QPA) events in addition to sending
+    normal Qt events.
+*/
+bool QIOSEventDispatcher::processPostedEvents()
 {
-    if (!rootLevelRunLoopIntegration())
+    // Don't send window system events if the base CF dispatcher has determined
-        return QEventDispatcherCoreFoundation::processEvents(flags);
+    // that events should not be sent for this pass of the runloop source.
+    if (!QEventDispatcherCoreFoundation::processPostedEvents())
+        return false;
 
+    qCDebug(lcEventDispatcher) << "Sending window system events for" << m_processEvents.flags;
+    QWindowSystemInterface::sendWindowSystemEvents(m_processEvents.flags);
+
+    return true;
+}
+
+QIOSJumpingEventDispatcher::QIOSJumpingEventDispatcher(QObject *parent)
+    : QIOSEventDispatcher(parent)
+    , m_processEventLevel(0)
+    , m_runLoopExitObserver(this, &QIOSJumpingEventDispatcher::handleRunLoopExit, kCFRunLoopExit)
+{
+}
+
+bool __attribute__((returns_twice)) QIOSJumpingEventDispatcher::processEvents(QEventLoop::ProcessEventsFlags flags)
+{
     if (applicationAboutToTerminate) {
         qCDebug(lcEventDispatcher) << "Detected QEventLoop exec after application termination";
         // Re-issue exit, and return immediately
@@ -475,25 +503,7 @@ bool __attribute__((returns_twice)) QIOSEventDispatcher::processEvents(QEventLoo
     return processedEvents;
 }
 
-/*!
+void QIOSJumpingEventDispatcher::handleRunLoopExit(CFRunLoopActivity activity)
-    Override of the CoreFoundation posted events runloop source callback
-    so that we can send window system (QPA) events in addition to sending
-    normal Qt events.
-*/
-bool QIOSEventDispatcher::processPostedEvents()
-{
-    // Don't send window system events if the base CF dispatcher has determined
-    // that events should not be sent for this pass of the runloop source.
-    if (!QEventDispatcherCoreFoundation::processPostedEvents())
-        return false;
-
-    qCDebug(lcEventDispatcher) << "Sending window system events for" << m_processEvents.flags;
-    QWindowSystemInterface::sendWindowSystemEvents(m_processEvents.flags);
-
-    return true;
-}
-
-void QIOSEventDispatcher::handleRunLoopExit(CFRunLoopActivity activity)
 {
     Q_UNUSED(activity);
     Q_ASSERT(activity == kCFRunLoopExit);
@@ -502,7 +512,7 @@ void QIOSEventDispatcher::handleRunLoopExit(CFRunLoopActivity activity)
         interruptEventLoopExec();
 }
 
-void QIOSEventDispatcher::interruptEventLoopExec()
+void QIOSJumpingEventDispatcher::interruptEventLoopExec()
 {
     Q_ASSERT(m_processEventLevel == 1);
 

src/plugins/platforms/ios/qiosintegration.mm

@@ -217,10 +217,7 @@ QPlatformOffscreenSurface *QIOSIntegration::createPlatformOffscreenSurface(QOffs
 
 QAbstractEventDispatcher *QIOSIntegration::createEventDispatcher() const
 {
-    if (isQtApplication())
+    return QIOSEventDispatcher::create();
-        return new QIOSEventDispatcher;
-    else
-        return new QEventDispatcherCoreFoundation;
 }
 
 QPlatformFontDatabase * QIOSIntegration::fontDatabase() const