OS X: Fix pan gestures.

The QPanGesture recognizer requires single-point touch events. The touch
implementation in Qt 4 would test Qt::WA_TouchPadAcceptSingleTouchEvents
and forward single touch events if set.

Making this work in Qt 5 is a little bit more involved since the platform
plugins don't know about widgets.

Change the Cocoa touch implementation to send single-point touch events
to QWidgetWindow windows only. Make QApplication forward single-point
touch events only if the target widget has the
Qt::WA_TouchPadAcceptSingleTouchEvents attribute set.

Task-number: QTBUG-35893
Change-Id: I68712a5e3efb4ece7a81ca42f49c412e525eeb3a
Reviewed-by: Jake Petroules <jake.petroules@petroules.com>

1 files changed, 11 insertions, 4 deletions

diff --git a/src/plugins/platforms/cocoa/qnsview.mm b/src/plugins/platforms/cocoa/qnsview.mm
index 8c0119f68f..cfcbb8053c 100644
--- a/src/plugins/platforms/cocoa/qnsview.mm
+++ b/src/plugins/platforms/cocoa/qnsview.mm
@@ -1124,10 +1124,17 @@ static QTabletEvent::TabletDevice wacomTabletDevice(NSEvent *theEvent)
     }
 }
 
+- (bool) shouldSendSingleTouch
+{
+    // QtWidgets expects single-point touch events, QtDeclarative does not.
+    // Until there is an API we solve this by looking at the window class type.
+    return m_window->inherits("QWidgetWindow");
+}
+
 - (void)touchesBeganWithEvent:(NSEvent *)event
 {
     const NSTimeInterval timestamp = [event timestamp];
-    const QList<QWindowSystemInterface::TouchPoint> points = QCocoaTouch::getCurrentTouchPointList(event, /*acceptSingleTouch= ### true or false?*/false);
+    const QList<QWindowSystemInterface::TouchPoint> points = QCocoaTouch::getCurrentTouchPointList(event, [self shouldSendSingleTouch]);
     qCDebug(lcQpaTouch) << "touchesBeganWithEvent" << points;
     QWindowSystemInterface::handleTouchEvent(m_window, timestamp * 1000, touchDevice, points);
 }
@@ -1135,7 +1142,7 @@ static QTabletEvent::TabletDevice wacomTabletDevice(NSEvent *theEvent)
 - (void)touchesMovedWithEvent:(NSEvent *)event
 {
     const NSTimeInterval timestamp = [event timestamp];
-    const QList<QWindowSystemInterface::TouchPoint> points = QCocoaTouch::getCurrentTouchPointList(event, /*acceptSingleTouch= ### true or false?*/false);
+    const QList<QWindowSystemInterface::TouchPoint> points = QCocoaTouch::getCurrentTouchPointList(event, [self shouldSendSingleTouch]);
     qCDebug(lcQpaTouch) << "touchesMovedWithEvent" << points;
     QWindowSystemInterface::handleTouchEvent(m_window, timestamp * 1000, touchDevice, points);
 }
@@ -1143,7 +1150,7 @@ static QTabletEvent::TabletDevice wacomTabletDevice(NSEvent *theEvent)
 - (void)touchesEndedWithEvent:(NSEvent *)event
 {
     const NSTimeInterval timestamp = [event timestamp];
-    const QList<QWindowSystemInterface::TouchPoint> points = QCocoaTouch::getCurrentTouchPointList(event, /*acceptSingleTouch= ### true or false?*/false);
+    const QList<QWindowSystemInterface::TouchPoint> points = QCocoaTouch::getCurrentTouchPointList(event, [self shouldSendSingleTouch]);
     qCDebug(lcQpaTouch) << "touchesEndedWithEvent" << points;
     QWindowSystemInterface::handleTouchEvent(m_window, timestamp * 1000, touchDevice, points);
 }
@@ -1151,7 +1158,7 @@ static QTabletEvent::TabletDevice wacomTabletDevice(NSEvent *theEvent)
 - (void)touchesCancelledWithEvent:(NSEvent *)event
 {
     const NSTimeInterval timestamp = [event timestamp];
-    const QList<QWindowSystemInterface::TouchPoint> points = QCocoaTouch::getCurrentTouchPointList(event, /*acceptSingleTouch= ### true or false?*/false);
+    const QList<QWindowSystemInterface::TouchPoint> points = QCocoaTouch::getCurrentTouchPointList(event, [self shouldSendSingleTouch]);
     qCDebug(lcQpaTouch) << "touchesCancelledWithEvent" << points;
     QWindowSystemInterface::handleTouchEvent(m_window, timestamp * 1000, touchDevice, points);
 }