iOS: Deliver all QWindowSystemInterface events synchronously

On iOS we want all delivery of events from the system to be handled
synchronously, as that's what the system expects.

We don't need to add a delivery template argument to each function
in QWindowSystemInterface that we want to delivery synchronously;
that's only needed for functions that a platform normally sends
asynch, but in some cases want to delivery synchronously.

For always delivering events synchronously we just need to change
the default delivery method.

The only events affected by this are the screen changes, and
window state change, which were not synchronous before, but
should be. All other events were already synchronous, though
either explicit delivery, of a flush.

Change-Id: Ib20ca342d1c076be0fbcf018c83735a416769cfe
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>

4 files changed, 10 insertions, 9 deletions

diff --git a/src/plugins/platforms/ios/qiosapplicationstate.mm b/src/plugins/platforms/ios/qiosapplicationstate.mm
index 13e7e1150f..7c8e1f9927 100644
--- a/src/plugins/platforms/ios/qiosapplicationstate.mm
+++ b/src/plugins/platforms/ios/qiosapplicationstate.mm
@@ -75,7 +75,7 @@ static void handleApplicationStateChanged(UIApplicationState uiApplicationState)
 {
     Qt::ApplicationState state = qtApplicationState(uiApplicationState);
     qCDebug(lcQpaApplication) << "moved to" << state;
-    QWindowSystemInterface::handleApplicationStateChanged<QWindowSystemInterface::SynchronousDelivery>(state);
+    QWindowSystemInterface::handleApplicationStateChanged(state);
 }
 
 QT_BEGIN_NAMESPACE
diff --git a/src/plugins/platforms/ios/qioseventdispatcher.mm b/src/plugins/platforms/ios/qioseventdispatcher.mm
index f49f81912e..429b7d9591 100644
--- a/src/plugins/platforms/ios/qioseventdispatcher.mm
+++ b/src/plugins/platforms/ios/qioseventdispatcher.mm
@@ -422,6 +422,8 @@ QIOSEventDispatcher::QIOSEventDispatcher(QObject *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)
diff --git a/src/plugins/platforms/ios/qiostextresponder.mm b/src/plugins/platforms/ios/qiostextresponder.mm
index 001985a128..33a0b6a42e 100644
--- a/src/plugins/platforms/ios/qiostextresponder.mm
+++ b/src/plugins/platforms/ios/qiostextresponder.mm
@@ -377,7 +377,6 @@
     QScopedValueRollback<BOOL> rollback(m_inSendEventToFocusObject, true);
     QWindowSystemInterface::handleKeyEvent(qApp->focusWindow(), QEvent::KeyPress, key, modifiers);
     QWindowSystemInterface::handleKeyEvent(qApp->focusWindow(), QEvent::KeyRelease, key, modifiers);
-    QWindowSystemInterface::flushWindowSystemEvents();
 }
 
 #ifndef QT_NO_SHORTCUT
diff --git a/src/plugins/platforms/ios/quiview.mm b/src/plugins/platforms/ios/quiview.mm
index bf26feac9f..a405fecee2 100644
--- a/src/plugins/platforms/ios/quiview.mm
+++ b/src/plugins/platforms/ios/quiview.mm
@@ -166,7 +166,7 @@
 
     QWindow *window = m_qioswindow->window();
     qCDebug(lcQpaWindow) << m_qioswindow->window() << "new geometry is" << actualGeometry;
-    QWindowSystemInterface::handleGeometryChange<QWindowSystemInterface::SynchronousDelivery>(window, actualGeometry, previousGeometry);
+    QWindowSystemInterface::handleGeometryChange(window, actualGeometry, previousGeometry);
 
     if (actualGeometry.size() != previousGeometry.size()) {
         // Trigger expose event on resize
@@ -199,7 +199,7 @@
     }
 
     qCDebug(lcQpaWindow) << m_qioswindow->window() << region << "isExposed" << m_qioswindow->isExposed();
-    QWindowSystemInterface::handleExposeEvent<QWindowSystemInterface::SynchronousDelivery>(m_qioswindow->window(), region);
+    QWindowSystemInterface::handleExposeEvent(m_qioswindow->window(), region);
 }
 
 // -------------------------------------------------------------------------
@@ -230,7 +230,7 @@
     }
 
     if (qGuiApp->focusWindow() != m_qioswindow->window())
-        QWindowSystemInterface::handleWindowActivated<QWindowSystemInterface::SynchronousDelivery>(m_qioswindow->window());
+        QWindowSystemInterface::handleWindowActivated(m_qioswindow->window());
     else
         qImDebug() << m_qioswindow->window() << "already active, not sending window activation";
 
@@ -268,7 +268,7 @@
 
     UIResponder *newResponder = FirstResponderCandidate::currentCandidate();
     if ([self responderShouldTriggerWindowDeactivation:newResponder])
-        QWindowSystemInterface::handleWindowActivated<QWindowSystemInterface::SynchronousDelivery>(0);
+        QWindowSystemInterface::handleWindowActivated(0);
 
     return YES;
 }
@@ -359,7 +359,7 @@
 - (void)sendTouchEventWithTimestamp:(ulong)timeStamp
 {
     QIOSIntegration *iosIntegration = QIOSIntegration::instance();
-    QWindowSystemInterface::handleTouchEvent<QWindowSystemInterface::SynchronousDelivery>(m_qioswindow->window(), timeStamp, iosIntegration->touchDevice(), m_activeTouches.values());
+    QWindowSystemInterface::handleTouchEvent(m_qioswindow->window(), timeStamp, iosIntegration->touchDevice(), m_activeTouches.values());
 }
 
 - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
@@ -438,7 +438,7 @@
     NSTimeInterval timestamp = event ? event.timestamp : [[NSProcessInfo processInfo] systemUptime];
 
     QIOSIntegration *iosIntegration = static_cast<QIOSIntegration *>(QGuiApplicationPrivate::platformIntegration());
-    QWindowSystemInterface::handleTouchCancelEvent<QWindowSystemInterface::SynchronousDelivery>(m_qioswindow->window(), ulong(timestamp * 1000), iosIntegration->touchDevice());
+    QWindowSystemInterface::handleTouchCancelEvent(m_qioswindow->window(), ulong(timestamp * 1000), iosIntegration->touchDevice());
 }
 
 - (int)mapPressTypeToKey:(UIPress*)press
@@ -466,7 +466,7 @@
         int key = [self mapPressTypeToKey:press];
         if (key == Qt::Key_unknown)
             continue;
-        if (QWindowSystemInterface::handleKeyEvent<QWindowSystemInterface::SynchronousDelivery>(m_qioswindow->window(), type, key, Qt::NoModifier))
+        if (QWindowSystemInterface::handleKeyEvent(m_qioswindow->window(), type, key, Qt::NoModifier))
             handled = true;
     }