iOS: Take advantage of new synchronous API for QPA event delivery

By using the SynchronousDelivery specialization instead of flushing all
window system events, we remove the risk of flushing an event that was
added without our knowledge.

For example, QGuiApplicationPrivate::processMouseEvent() used to prepend
a mouse move event to the QPA queue, which is why we had a check for
QWidgetWindow when flushing geometry changes. processMouseEvent no longer
sends the move event via the QPA queue, so that's no longer an issue,
but if it were to be reintroduced, we wouldn't need to check for
QWidgetWindow, as we're not flushing all events anymore.

Change-Id: Ib346ea9501cd88ddda6c2137981d3eb0922192a0
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>

1 files changed, 11 insertions, 24 deletions

diff --git a/src/plugins/platforms/ios/quiview.mm b/src/plugins/platforms/ios/quiview.mm
index 5c493617b1..2a1444e9e5 100644
--- a/src/plugins/platforms/ios/quiview.mm
+++ b/src/plugins/platforms/ios/quiview.mm
@@ -164,8 +164,7 @@
             requestedGeometry : qt_window_private(m_qioswindow->window())->geometry;
 
     QWindow *window = m_qioswindow->window();
-    QWindowSystemInterface::handleGeometryChange(window, actualGeometry, previousGeometry);
-    QWindowSystemInterface::flushWindowSystemEvents(window->inherits("QWidgetWindow") ? QEventLoop::ExcludeUserInputEvents : QEventLoop::AllEvents);
+    QWindowSystemInterface::handleGeometryChange<QWindowSystemInterface::SynchronousDelivery>(window, actualGeometry, previousGeometry);
 
     if (actualGeometry.size() != previousGeometry.size()) {
         // Trigger expose event on resize
@@ -197,8 +196,7 @@
         region = QRect(QPoint(), bounds);
     }
 
-    QWindowSystemInterface::handleExposeEvent(m_qioswindow->window(), region);
-    QWindowSystemInterface::flushWindowSystemEvents();
+    QWindowSystemInterface::handleExposeEvent<QWindowSystemInterface::SynchronousDelivery>(m_qioswindow->window(), region);
 }
 
 // -------------------------------------------------------------------------
@@ -223,13 +221,10 @@
 
     qImDebug() << m_qioswindow->window() << "became first responder";
 
-    if (qGuiApp->focusWindow() != m_qioswindow->window()) {
-        QWindowSystemInterface::handleWindowActivated(m_qioswindow->window());
-        QWindowSystemInterface::flushWindowSystemEvents();
-    } else {
-        qImDebug() << m_qioswindow->window()
-            << "already active, not sending window activation";
-    }
+    if (qGuiApp->focusWindow() != m_qioswindow->window())
+        QWindowSystemInterface::handleWindowActivated<QWindowSystemInterface::SynchronousDelivery>(m_qioswindow->window());
+    else
+        qImDebug() << m_qioswindow->window() << "already active, not sending window activation";
 
     return YES;
 }
@@ -264,10 +259,8 @@
     qImDebug() << m_qioswindow->window() << "resigned first responder";
 
     UIResponder *newResponder = FirstResponderCandidate::currentCandidate();
-    if ([self responderShouldTriggerWindowDeactivation:newResponder]) {
-        QWindowSystemInterface::handleWindowActivated(0);
-        QWindowSystemInterface::flushWindowSystemEvents();
-    }
+    if ([self responderShouldTriggerWindowDeactivation:newResponder])
+        QWindowSystemInterface::handleWindowActivated<QWindowSystemInterface::SynchronousDelivery>(0);
 
     return YES;
 }
@@ -357,10 +350,8 @@
 
 - (void)sendTouchEventWithTimestamp:(ulong)timeStamp
 {
-    // Send touch event synchronously
     QIOSIntegration *iosIntegration = QIOSIntegration::instance();
-    QWindowSystemInterface::handleTouchEvent(m_qioswindow->window(), timeStamp, iosIntegration->touchDevice(), m_activeTouches.values());
-    QWindowSystemInterface::flushWindowSystemEvents();
+    QWindowSystemInterface::handleTouchEvent<QWindowSystemInterface::SynchronousDelivery>(m_qioswindow->window(), timeStamp, iosIntegration->touchDevice(), m_activeTouches.values());
 }
 
 - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
@@ -438,10 +429,8 @@
 
     NSTimeInterval timestamp = event ? event.timestamp : [[NSProcessInfo processInfo] systemUptime];
 
-    // Send cancel touch event synchronously
     QIOSIntegration *iosIntegration = static_cast<QIOSIntegration *>(QGuiApplicationPrivate::platformIntegration());
-    QWindowSystemInterface::handleTouchCancelEvent(m_qioswindow->window(), ulong(timestamp * 1000), iosIntegration->touchDevice());
-    QWindowSystemInterface::flushWindowSystemEvents();
+    QWindowSystemInterface::handleTouchCancelEvent<QWindowSystemInterface::SynchronousDelivery>(m_qioswindow->window(), ulong(timestamp * 1000), iosIntegration->touchDevice());
 }
 
 - (int)mapPressTypeToKey:(UIPress*)press
@@ -464,14 +453,12 @@
     // When handling the event (for example, as a back button), both press and
     // release events must be handled accordingly.
 
-    QScopedValueRollback<bool> syncRollback(QWindowSystemInterfacePrivate::synchronousWindowSystemEvents, true);
-
     bool handled = false;
     for (UIPress* press in presses) {
         int key = [self mapPressTypeToKey:press];
         if (key == Qt::Key_unknown)
             continue;
-        if (QWindowSystemInterface::handleKeyEvent(m_qioswindow->window(), type, key, Qt::NoModifier))
+        if (QWindowSystemInterface::handleKeyEvent<QWindowSystemInterface::SynchronousDelivery>(m_qioswindow->window(), type, key, Qt::NoModifier))
             handled = true;
     }