Relay mouse event synthesization information

Make platform plugins, like the windows one, able to indicate
if a mouse event is synthesized from a touch event by the OS.
This will be valuable information for the Quick2 event handlers.

No new member variables are added to QMouseEvent. Instead, the enum
value is encoded in the caps member, there are plenty of bits
available in it.

This introduces Qt::MouseEventSource and QMouseEvent::source() as
public APIs.

Change-Id: If087a0bafb33a6cd7891bd07b84871358f6aba69
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>

1 files changed, 26 insertions, 6 deletions

diff --git a/src/gui/kernel/qguiapplication.cpp b/src/gui/kernel/qguiapplication.cpp
index b242a3cc68..07ee8e9a64 100644
--- a/src/gui/kernel/qguiapplication.cpp
+++ b/src/gui/kernel/qguiapplication.cpp
@@ -1560,6 +1560,7 @@ void QGuiApplicationPrivate::processMouseEvent(QWindowSystemInterfacePrivate::Mo
 
     QMouseEvent ev(type, localPoint, localPoint, globalPoint, button, buttons, e->modifiers);
     ev.setTimestamp(e->timestamp);
+    setMouseEventSource(&ev, e->source);
 #ifndef QT_NO_CURSOR
     if (const QScreen *screen = window->screen())
         if (QPlatformCursor *cursor = screen->handle()->cursor())
@@ -1612,6 +1613,7 @@ void QGuiApplicationPrivate::processMouseEvent(QWindowSystemInterfacePrivate::Mo
         QMouseEvent dblClickEvent(doubleClickType, localPoint, localPoint, globalPoint,
                                   button, buttons, e->modifiers);
         dblClickEvent.setTimestamp(e->timestamp);
+        setMouseEventSource(&dblClickEvent, e->source);
         QGuiApplication::sendSpontaneousEvent(window, &dblClickEvent);
     }
 }
@@ -2024,7 +2026,8 @@ void QGuiApplicationPrivate::processTouchEvent(QWindowSystemInterfacePrivate::To
                                                                synthIt->pos,
                                                                synthIt->screenPos,
                                                                Qt::NoButton,
-                                                               e->modifiers);
+                                                               e->modifiers,
+                                                               Qt::MouseEventSynthesizedByQt);
                 fake.synthetic = true;
                 processMouseEvent(&fake);
             }
@@ -3103,9 +3106,16 @@ void QGuiApplicationPrivate::_q_updateFocusObject(QObject *object)
     emit q->focusObjectChanged(object);
 }
 
+enum {
+    MouseCapsMask = 0xFF,
+    MouseSourceMaskDst = 0xFF00,
+    MouseSourceMaskSrc = MouseCapsMask,
+    MouseSourceShift = 8,
+};
+
 int QGuiApplicationPrivate::mouseEventCaps(QMouseEvent *event)
 {
-    return event->caps;
+    return event->caps & MouseCapsMask;
 }
 
 QVector2D QGuiApplicationPrivate::mouseEventVelocity(QMouseEvent *event)
@@ -3115,16 +3125,26 @@ QVector2D QGuiApplicationPrivate::mouseEventVelocity(QMouseEvent *event)
 
 void QGuiApplicationPrivate::setMouseEventCapsAndVelocity(QMouseEvent *event, int caps, const QVector2D &velocity)
 {
-    event->caps = caps;
+    Q_ASSERT(caps <= MouseCapsMask);
+    event->caps &= ~MouseCapsMask;
+    event->caps |= caps & MouseCapsMask;
     event->velocity = velocity;
 }
 
-void QGuiApplicationPrivate::setMouseEventCapsAndVelocity(QMouseEvent *event, QMouseEvent *other)
+Qt::MouseEventSource QGuiApplicationPrivate::mouseEventSource(const QMouseEvent *event)
 {
-    event->caps = other->caps;
-    event->velocity = other->velocity;
+    return Qt::MouseEventSource((event->caps & MouseSourceMaskDst) >> MouseSourceShift);
 }
 
+void QGuiApplicationPrivate::setMouseEventSource(QMouseEvent *event, Qt::MouseEventSource source)
+{
+    // Mouse event synthesization status is encoded in the caps field because
+    // QTouchDevice::CapabilityFlag uses only 6 bits from it.
+    int value = source;
+    Q_ASSERT(value <= MouseSourceMaskSrc);
+    event->caps &= ~MouseSourceMaskDst;
+    event->caps |= (value & MouseSourceMaskSrc) << MouseSourceShift;
+}
 
 #include "moc_qguiapplication.cpp"