3 files changed, 43 insertions, 13 deletions

diff --git a/src/quick/handlers/qquickmultipointhandler.cpp b/src/quick/handlers/qquickmultipointhandler.cpp
index f404788de4..2a9ecd341c 100644
--- a/src/quick/handlers/qquickmultipointhandler.cpp
+++ b/src/quick/handlers/qquickmultipointhandler.cpp
@@ -146,7 +146,7 @@ void QQuickMultiPointHandler::onActiveChanged()
     }
 }
 
-void QQuickMultiPointHandler::onGrabChanged(QQuickPointerHandler *, QQuickEventPoint::GrabTransition transition, QQuickEventPoint *)
+void QQuickMultiPointHandler::onGrabChanged(QQuickPointerHandler *grabber, QQuickEventPoint::GrabTransition transition, QQuickEventPoint *point)
 {
     Q_D(QQuickMultiPointHandler);
     // If another handler or item takes over this set of points, assume it has
@@ -155,6 +155,20 @@ void QQuickMultiPointHandler::onGrabChanged(QQuickPointerHandler *, QQuickEventP
     // (e.g. between DragHandler and PinchHandler).
     if (transition == QQuickEventPoint::UngrabExclusive || transition == QQuickEventPoint::CancelGrabExclusive)
         d->currentPoints.clear();
+    if (grabber != this)
+        return;
+    switch (transition) {
+    case QQuickEventPoint::GrabExclusive:
+    case QQuickEventPoint::GrabPassive:
+    case QQuickEventPoint::UngrabPassive:
+    case QQuickEventPoint::UngrabExclusive:
+    case QQuickEventPoint::CancelGrabPassive:
+    case QQuickEventPoint::CancelGrabExclusive:
+        QQuickPointerHandler::onGrabChanged(grabber, transition, point);
+        break;
+    case QQuickEventPoint::OverrideGrabPassive:
+        return; // don't emit
+    }
 }
 
 QVector<QQuickEventPoint *> QQuickMultiPointHandler::eligiblePoints(QQuickPointerEvent *event)
diff --git a/src/quick/handlers/qquickpointerhandler.cpp b/src/quick/handlers/qquickpointerhandler.cpp
index 03f8d8918c..a6c18feafe 100644
--- a/src/quick/handlers/qquickpointerhandler.cpp
+++ b/src/quick/handlers/qquickpointerhandler.cpp
@@ -346,10 +346,16 @@ bool QQuickPointerHandler::approveGrabTransition(QQuickEventPoint *point, QObjec
                         existingPhGrabber->metaObject()->className() == metaObject()->className())
                     allowed = true;
             } else if ((d->grabPermissions & CanTakeOverFromItems)) {
+                allowed = true;
                 QQuickItem * existingItemGrabber = point->grabberItem();
-                if (existingItemGrabber && !((existingItemGrabber->keepMouseGrab() && point->pointerEvent()->asPointerMouseEvent()) ||
-                                             (existingItemGrabber->keepTouchGrab() && point->pointerEvent()->asPointerTouchEvent()))) {
-                    allowed = true;
+                QQuickWindowPrivate *winPriv = QQuickWindowPrivate::get(parentItem()->window());
+                const bool isMouse = point->pointerEvent()->asPointerMouseEvent();
+                const bool isTouch = point->pointerEvent()->asPointerTouchEvent();
+                if (existingItemGrabber &&
+                        ((existingItemGrabber->keepMouseGrab() &&
+                          (isMouse || winPriv->isDeliveringTouchAsMouse())) ||
+                         (existingItemGrabber->keepTouchGrab() && isTouch))) {
+                    allowed = false;
                     // If the handler wants to steal the exclusive grab from an Item, the Item can usually veto
                     // by having its keepMouseGrab flag set.  But an exception is if that Item is a parent that
                     // normally filters events (such as a Flickable): it needs to be possible for e.g. a
@@ -358,14 +364,19 @@ bool QQuickPointerHandler::approveGrabTransition(QQuickEventPoint *point, QObjec
                     // at first and then expects to be able to steal the grab later on.  It cannot respect
                     // Flickable's wishes in that case, because then it would never have a chance.
                     if (existingItemGrabber->keepMouseGrab() &&
-                            !(existingItemGrabber->filtersChildMouseEvents() && existingItemGrabber->isAncestorOf(parentItem()))) {
-                        QQuickWindowPrivate *winPriv = QQuickWindowPrivate::get(parentItem()->window());
+                            existingItemGrabber->filtersChildMouseEvents() && existingItemGrabber->isAncestorOf(parentItem())) {
                         if (winPriv->isDeliveringTouchAsMouse() && point->pointId() == winPriv->touchMouseId) {
-                            qCDebug(lcPointerHandlerGrab) << this << "wants to grab touchpoint" << point->pointId()
-                                << "but declines to steal grab from touch-mouse grabber with keepMouseGrab=true" << existingItemGrabber;
-                            allowed = false;
+                            qCDebug(lcPointerHandlerGrab) << this << "steals touchpoint" << point->pointId()
+                                << "despite parent touch-mouse grabber with keepMouseGrab=true" << existingItemGrabber;
+                            allowed = true;
                         }
                     }
+                    if (!allowed) {
+                        qCDebug(lcPointerHandlerGrab) << this << "wants to grab point" << point->pointId()
+                                << "but declines to steal from grabber" << existingItemGrabber
+                                << "with keepMouseGrab=" << existingItemGrabber->keepMouseGrab()
+                                << "keepTouchGrab=" << existingItemGrabber->keepTouchGrab();
+                    }
                 }
             }
         }
diff --git a/src/quick/handlers/qquicktaphandler.cpp b/src/quick/handlers/qquicktaphandler.cpp
index f3674d6fa9..2284750f15 100644
--- a/src/quick/handlers/qquicktaphandler.cpp
+++ b/src/quick/handlers/qquicktaphandler.cpp
@@ -209,6 +209,8 @@ void QQuickTapHandler::timerEvent(QTimerEvent *event)
     If the spatial constraint is violated, \l pressed transitions immediately
     from true to false, regardless of the time held.
 
+    The \c gesturePolicy also affects grab behavior as described below.
+
     \value TapHandler.DragThreshold
            (the default value) The event point must not move significantly.
            If the mouse, finger or stylus moves past the system-wide drag
@@ -217,11 +219,13 @@ void QQuickTapHandler::timerEvent(QTimerEvent *event)
            can be useful whenever TapHandler needs to cooperate with other
            input handlers (for example \l DragHandler) or event-handling Items
            (for example QtQuick Controls), because in this case TapHandler
-           will not take the exclusive grab, but merely a passive grab.
+           will not take the exclusive grab, but merely a
+           \l {QPointerEvent::addPassiveGrabber()}{passive grab}.
 
     \value TapHandler.WithinBounds
            If the event point leaves the bounds of the \c parent Item, the tap
-           gesture is canceled. The TapHandler will take the exclusive grab on
+           gesture is canceled. The TapHandler will take the
+           \l {QPointerEvent::setExclusiveGrabber}{exclusive grab} on
            press, but will release the grab as soon as the boundary constraint
            is no longer satisfied.
 
@@ -232,8 +236,9 @@ void QQuickTapHandler::timerEvent(QTimerEvent *event)
            typical behavior for button widgets: you can cancel a click by
            dragging outside the button, and you can also change your mind by
            dragging back inside the button before release. Note that it's
-           necessary for TapHandler take the exclusive grab on press and retain
-           it until release in order to detect this gesture.
+           necessary for TapHandler to take the
+           \l {QPointerEvent::setExclusiveGrabber}{exclusive grab} on press
+           and retain it until release in order to detect this gesture.
 */
 void QQuickTapHandler::setGesturePolicy(QQuickTapHandler::GesturePolicy gesturePolicy)
 {