Fix touch to mouse synthesis/propagation.

Having mouse events synthesised from both QtGui and internally in QtQuick  is
not a great way togo about things, especially when QtGui doesn't have the same
degree of knowledge as QtQuick about the items in the scene.

Thus, we now accept all events inside QtQuick to block QtGui synthesis, which
should fix a significant amount of edge-case touch breakage/bad behavior.

Change-Id: I14e1c87761c8f43160049b5e6f9da15b4e5edbb7
Done-with: Martin Jones <martin.jones@jollamobile.com>
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>

4 files changed, 36 insertions, 14 deletions

diff --git a/src/quick/items/qquickflickable.cpp b/src/quick/items/qquickflickable.cpp
index 15627aad84..fa18d4aa30 100644
--- a/src/quick/items/qquickflickable.cpp
+++ b/src/quick/items/qquickflickable.cpp
@@ -2048,12 +2048,13 @@ bool QQuickFlickable::sendMouseEvent(QQuickItem *item, QMouseEvent *event)
         if ((grabber && stealThisEvent && !grabber->keepMouseGrab() && grabber != this) || grabberDisabled) {
             d->clearDelayedPress();
             grabMouse();
+        } else if (d->delayedPressEvent) {
+            grabMouse();
         }
 
-        // Do not accept this event when filtering, as this would force the mouse grab to the child
         const bool filtered = stealThisEvent || d->delayedPressEvent || grabberDisabled;
         if (filtered) {
-            event->setAccepted(false);
+            event->setAccepted(true);
         }
         return filtered;
     } else if (d->lastPosTime != -1) {
diff --git a/src/quick/items/qquickitem.cpp b/src/quick/items/qquickitem.cpp
index a0329f7afc..f565fba1bb 100644
--- a/src/quick/items/qquickitem.cpp
+++ b/src/quick/items/qquickitem.cpp
@@ -6629,15 +6629,7 @@ void QQuickItem::grabMouse()
     if (!d->window)
         return;
     QQuickWindowPrivate *windowPriv = QQuickWindowPrivate::get(d->window);
-    if (windowPriv->mouseGrabberItem == this)
-        return;
-
-    QQuickItem *oldGrabber = windowPriv->mouseGrabberItem;
-    windowPriv->mouseGrabberItem = this;
-    if (oldGrabber) {
-        QEvent ev(QEvent::UngrabMouse);
-        d->window->sendEvent(oldGrabber, &ev);
-    }
+    windowPriv->setMouseGrabber(this);
 }
 
 /*!
diff --git a/src/quick/items/qquickwindow.cpp b/src/quick/items/qquickwindow.cpp
index dfc70d7e68..f355afcea5 100644
--- a/src/quick/items/qquickwindow.cpp
+++ b/src/quick/items/qquickwindow.cpp
@@ -599,6 +599,28 @@ bool QQuickWindowPrivate::translateTouchToMouse(QQuickItem *item, QTouchEvent *e
     return false;
 }
 
+void QQuickWindowPrivate::setMouseGrabber(QQuickItem *grabber)
+{
+    Q_Q(QQuickWindow);
+    if (mouseGrabberItem == grabber)
+        return;
+
+    QQuickItem *oldGrabber = mouseGrabberItem;
+    mouseGrabberItem = grabber;
+
+    if (touchMouseId != -1) {
+        // update the touch item for mouse touch id to the new grabber
+        itemForTouchPointId.remove(touchMouseId);
+        if (grabber)
+            itemForTouchPointId[touchMouseId] = grabber;
+    }
+
+    if (oldGrabber) {
+        QEvent ev(QEvent::UngrabMouse);
+        q->sendEvent(oldGrabber, &ev);
+    }
+}
+
 void QQuickWindowPrivate::transformTouchPoints(QList<QTouchEvent::TouchPoint> &touchPoints, const QTransform &transform)
 {
     QMatrix4x4 transformMatrix(transform);
@@ -1221,8 +1243,11 @@ bool QQuickWindow::event(QEvent *e)
     case QEvent::TouchEnd: {
         QTouchEvent *touch = static_cast<QTouchEvent*>(e);
         d->translateTouchEvent(touch);
-        // return in order to avoid the QWindow::event below
-        return d->deliverTouchEvent(touch);
+        d->deliverTouchEvent(touch);
+        // we consume all touch events ourselves to avoid duplicate
+        // mouse delivery by QtGui mouse synthesis
+        e->accept();
+        return true;
     }
         break;
     case QEvent::TouchCancel:
@@ -1776,7 +1801,10 @@ bool QQuickWindowPrivate::deliverMatchingPointsToItem(QQuickItem *item, QTouchEv
     // First check whether the parent wants to be a filter,
     // and if the parent accepts the event we are done.
     if (sendFilteredTouchEvent(item->parentItem(), item, event)) {
-        event->accept();
+        // If the touch was accepted (regardless by whom or in what form),
+        // update acceptedNewPoints
+        foreach (int id, matchingNewPoints)
+            acceptedNewPoints->insert(id);
         return true;
     }
 
diff --git a/src/quick/items/qquickwindow_p.h b/src/quick/items/qquickwindow_p.h
index c23745b5f1..418633b6ac 100644
--- a/src/quick/items/qquickwindow_p.h
+++ b/src/quick/items/qquickwindow_p.h
@@ -127,6 +127,7 @@ public:
     QPointF lastMousePosition;
     bool translateTouchToMouse(QQuickItem *item, QTouchEvent *event);
     void translateTouchEvent(QTouchEvent *touchEvent);
+    void setMouseGrabber(QQuickItem *grabber);
     static void transformTouchPoints(QList<QTouchEvent::TouchPoint> &touchPoints, const QTransform &transform);
     static QMouseEvent *cloneMouseEvent(QMouseEvent *event, QPointF *transformedLocalPos = 0);
     bool deliverInitialMousePressEvent(QQuickItem *, QMouseEvent *);