QQuickEventPoint::grabber: allow grabbing either an item or a handler

QQuickPointerHandler and QQuickItem have only QObject in common.

Change-Id: I8fb68cc1779f42049db1e0eb5ff60019a1c674d3
Reviewed-by: Jan Arve Sæther <jan-arve.saether@theqtcompany.com>

5 files changed, 101 insertions, 57 deletions

diff --git a/src/quick/handlers/qquickpointerhandler.cpp b/src/quick/handlers/qquickpointerhandler.cpp
index 293eae914e..038e7f2571 100644
--- a/src/quick/handlers/qquickpointerhandler.cpp
+++ b/src/quick/handlers/qquickpointerhandler.cpp
@@ -64,11 +64,10 @@ QQuickPointerHandler::QQuickPointerHandler(QObject *parent)
 
 void QQuickPointerHandler::setGrab(QQuickEventPoint *point, bool grab)
 {
-    // TODO eventually the handler itself should be the grabber, instead of the target Item
     if (grab)
-        point->setGrabber(m_target);
-    else if (point->grabber() == m_target)
-        point->setGrabber(nullptr);
+        point->setPointerHandlerGrabber(this);
+    else if (point->pointerHandlerGrabber() == this)
+        point->setPointerHandlerGrabber(nullptr);
 }
 
 QPointF QQuickPointerHandler::eventPos(const QQuickEventPoint *point) const
diff --git a/src/quick/items/qquickevents.cpp b/src/quick/items/qquickevents.cpp
index 7e84d27836..e8f333f953 100644
--- a/src/quick/items/qquickevents.cpp
+++ b/src/quick/items/qquickevents.cpp
@@ -40,12 +40,14 @@
 #include "qquickevents_p_p.h"
 #include <QtGui/private/qguiapplication_p.h>
 #include <QtQuick/private/qquickitem_p.h>
+#include <QtQuick/private/qquickpointerhandler_p.h>
 #include <QtQuick/private/qquickwindow_p.h>
 #include <private/qdebug_p.h>
 
 QT_BEGIN_NAMESPACE
 
 Q_LOGGING_CATEGORY(lcPointerEvents, "qt.quick.pointer.events")
+Q_DECLARE_LOGGING_CATEGORY(lcPointerHandlerDispatch)
 
 /*!
     \qmltype KeyEvent
@@ -525,14 +527,40 @@ void QQuickEventPoint::reset(Qt::TouchPointState state, QPointF scenePos, quint6
     m_velocity = velocity;
 }
 
-QQuickItem *QQuickEventPoint::grabber() const
+QObject *QQuickEventPoint::grabber() const
 {
     return m_grabber.data();
 }
 
-void QQuickEventPoint::setGrabber(QQuickItem *grabber)
+void QQuickEventPoint::setGrabber(QObject *grabber)
 {
-    m_grabber = QPointer<QQuickItem>(grabber);
+    qCDebug(lcPointerHandlerDispatch) << this << grabber;
+    m_grabber = QPointer<QObject>(grabber);
+    m_grabberIsHandler = (qmlobject_cast<QQuickPointerHandler *>(grabber) != nullptr);
+}
+
+QQuickItem *QQuickEventPoint::itemGrabber() const
+{
+    return (m_grabberIsHandler ? nullptr : static_cast<QQuickItem *>(m_grabber.data()));
+}
+
+void QQuickEventPoint::setItemGrabber(QQuickItem *grabber)
+{
+    qCDebug(lcPointerHandlerDispatch) << this << grabber;
+    m_grabber = QPointer<QObject>(grabber);
+    m_grabberIsHandler = false;
+}
+
+QQuickPointerHandler *QQuickEventPoint::pointerHandlerGrabber() const
+{
+    return (m_grabberIsHandler ? static_cast<QQuickPointerHandler *>(m_grabber.data()) : nullptr);
+}
+
+void QQuickEventPoint::setPointerHandlerGrabber(QQuickPointerHandler *grabber)
+{
+    qCDebug(lcPointerHandlerDispatch) << this << grabber;
+    m_grabber = QPointer<QObject>(grabber);
+    m_grabberIsHandler = true;
 }
 
 void QQuickEventPoint::setAccepted(bool accepted)
@@ -620,11 +648,11 @@ QQuickPointerEvent *QQuickPointerTouchEvent::reset(QEvent *event)
         m_touchPoints.insert(i, new QQuickEventTouchPoint(this));
 
     // Make sure the grabbers are right from one event to the next
-    QVector<QQuickItem*> grabbers;
+    QVector<QObject*> grabbers;
     // Copy all grabbers, because the order of points might have changed in the event.
     // The ID is all that we can rely on (release might remove the first point etc).
     for (int i = 0; i < newPointCount; ++i) {
-        QQuickItem *grabber = nullptr;
+        QObject *grabber = nullptr;
         if (auto point = pointById(tps.at(i).id()))
             grabber = point->grabber();
         grabbers.append(grabber);
@@ -636,7 +664,7 @@ QQuickPointerEvent *QQuickPointerTouchEvent::reset(QEvent *event)
         if (point->state() == QQuickEventPoint::Pressed) {
             if (grabbers.at(i))
                 qWarning() << "TouchPointPressed without previous release event" << point;
-            point->setGrabber(nullptr);
+            point->setItemGrabber(nullptr);
         } else {
             point->setGrabber(grabbers.at(i));
         }
@@ -659,7 +687,7 @@ QQuickEventPoint *QQuickPointerTouchEvent::point(int i) const {
 
 QQuickEventPoint::QQuickEventPoint(QQuickPointerEvent *parent)
   : QObject(parent), m_pointId(0), m_grabber(nullptr), m_timestamp(0), m_pressTimestamp(0),
-    m_state(QQuickEventPoint::Released), m_valid(false), m_accept(false)
+    m_state(QQuickEventPoint::Released), m_valid(false), m_accept(false), m_grabberIsHandler(false)
 {
     Q_UNUSED(m_reserved);
 }
@@ -680,16 +708,16 @@ QMouseEvent *QQuickPointerMouseEvent::asMouseEvent(const QPointF &localPos) cons
     return event;
 }
 
-QVector<QQuickItem *> QQuickPointerMouseEvent::grabbers() const
+QVector<QObject *> QQuickPointerMouseEvent::grabbers() const
 {
-    QVector<QQuickItem *> result;
-    if (QQuickItem *grabber = m_mousePoint->grabber())
+    QVector<QObject *> result;
+    if (QObject *grabber = m_mousePoint->grabber())
         result << grabber;
     return result;
 }
 
 void QQuickPointerMouseEvent::clearGrabbers() const {
-    m_mousePoint->setGrabber(nullptr);
+    m_mousePoint->setItemGrabber(nullptr);
 }
 
 bool QQuickPointerMouseEvent::isPressEvent() const
@@ -707,12 +735,12 @@ bool QQuickPointerTouchEvent::allPointsAccepted() const {
     return true;
 }
 
-QVector<QQuickItem *> QQuickPointerTouchEvent::grabbers() const
+QVector<QObject *> QQuickPointerTouchEvent::grabbers() const
 {
-    QVector<QQuickItem *> result;
+    QVector<QObject *> result;
     for (int i = 0; i < m_pointCount; ++i) {
         auto point = m_touchPoints.at(i);
-        if (QQuickItem *grabber = point->grabber()) {
+        if (QObject *grabber = point->grabber()) {
             if (!result.contains(grabber))
                 result << grabber;
         }
diff --git a/src/quick/items/qquickevents_p_p.h b/src/quick/items/qquickevents_p_p.h
index c64478e856..b954c8a4ec 100644
--- a/src/quick/items/qquickevents_p_p.h
+++ b/src/quick/items/qquickevents_p_p.h
@@ -68,6 +68,7 @@ class QQuickPointerEvent;
 class QQuickPointerMouseEvent;
 class QQuickPointerTabletEvent;
 class QQuickPointerTouchEvent;
+class QQuickPointerHandler;
 
 class QQuickKeyEvent : public QObject
 {
@@ -255,7 +256,7 @@ class Q_QUICK_PRIVATE_EXPORT QQuickEventPoint : public QObject
     Q_PROPERTY(quint64 pointId READ pointId)
     Q_PROPERTY(qreal timeHeld READ timeHeld)
     Q_PROPERTY(bool accepted READ isAccepted WRITE setAccepted)
-    Q_PROPERTY(QQuickItem *grabber READ grabber WRITE setGrabber)
+    Q_PROPERTY(QObject *grabber READ grabber WRITE setGrabber)
 
 public:
     enum State {
@@ -282,20 +283,27 @@ public:
     qreal timeHeld() const { return (m_timestamp - m_pressTimestamp) / 1000.0; }
     bool isAccepted() const { return m_accept; }
     void setAccepted(bool accepted = true);
-    QQuickItem *grabber() const;
-    void setGrabber(QQuickItem *grabber);
+    QObject *grabber() const;
+    void setGrabber(QObject *grabber);
+
+    QQuickItem *itemGrabber() const;
+    void setItemGrabber(QQuickItem *grabber);
+
+    QQuickPointerHandler *pointerHandlerGrabber() const;
+    void setPointerHandlerGrabber(QQuickPointerHandler *grabber);
 
 private:
     QPointF m_scenePos;
     QVector2D m_velocity;
     quint64 m_pointId;
-    QPointer<QQuickItem> m_grabber;
+    QPointer<QObject> m_grabber;
     ulong m_timestamp;
     ulong m_pressTimestamp;
     State m_state;
     bool m_valid : 1;
     bool m_accept : 1;
-    int m_reserved : 30;
+    bool m_grabberIsHandler : 1;
+    int m_reserved : 29;
 
     Q_DISABLE_COPY(QQuickEventPoint)
 };
@@ -368,7 +376,7 @@ public: // helpers for C++ only (during event delivery)
     virtual int pointCount() const = 0;
     virtual QQuickEventPoint *point(int i) const = 0;
     virtual QQuickEventPoint *pointById(quint64 pointId) const = 0;
-    virtual QVector<QQuickItem *> grabbers() const = 0;
+    virtual QVector<QObject *> grabbers() const = 0;
     virtual void clearGrabbers() const = 0;
 
     ulong timestamp() const { return m_event->timestamp(); }
@@ -397,7 +405,7 @@ public:
     QQuickEventPoint *point(int i) const override;
     QQuickEventPoint *pointById(quint64 pointId) const override;
     bool allPointsAccepted() const override;
-    QVector<QQuickItem *> grabbers() const override;
+    QVector<QObject *> grabbers() const override;
     void clearGrabbers() const override;
 
     QMouseEvent *asMouseEvent(const QPointF& localPos) const;
@@ -427,7 +435,7 @@ public:
     QQuickEventPoint *pointById(quint64 pointId) const override;
     const QTouchEvent::TouchPoint *touchPointById(int pointId) const;
     bool allPointsAccepted() const override;
-    QVector<QQuickItem *> grabbers() const override;
+    QVector<QObject *> grabbers() const override;
     void clearGrabbers() const override;
 
     QMouseEvent *syntheticMouseEvent(int pointID, QQuickItem *relativeTo) const;
diff --git a/src/quick/items/qquickwindow.cpp b/src/quick/items/qquickwindow.cpp
index fc6bfc43a4..b2727f113e 100644
--- a/src/quick/items/qquickwindow.cpp
+++ b/src/quick/items/qquickwindow.cpp
@@ -46,6 +46,7 @@
 #include "qquickevents_p_p.h"
 
 #include <private/qquickdrag_p.h>
+#include <private/qquickpointerhandler_p.h>
 
 #include <QtQuick/private/qsgrenderer_p.h>
 #include <QtQuick/private/qsgtexture_p.h>
@@ -656,7 +657,7 @@ bool QQuickWindowPrivate::deliverTouchAsMouse(QQuickItem *item, QQuickPointerEve
                 if (!q->mouseGrabberItem())
                     item->grabMouse();
                 auto pointerEventPoint = pointerEvent->pointById(p.id());
-                pointerEventPoint->setGrabber(item);
+                pointerEventPoint->setItemGrabber(item);
 
                 if (checkIfDoubleClicked(event->timestamp())) {
                     QScopedPointer<QMouseEvent> mouseDoubleClick(touchToMouseEvent(QEvent::MouseButtonDblClick, p, event, item, false));
@@ -740,14 +741,14 @@ void QQuickWindowPrivate::setMouseGrabber(QQuickItem *grabber)
 
     QQuickPointerEvent *event = QQuickPointerDevice::genericMouseDevice()->pointerEvent();
     Q_ASSERT(event->pointCount() == 1);
-    event->point(0)->setGrabber(grabber);
+    event->point(0)->setItemGrabber(grabber);
 
     if (grabber && touchMouseId != -1 && touchMouseDevice) {
         // update the touch item for mouse touch id to the new grabber
         qCDebug(DBG_TOUCH_TARGET) << "TP (mouse)" << touchMouseId << "->" << q->mouseGrabberItem();
         auto point = touchMouseDevice->pointerEvent()->pointById(touchMouseId);
         if (point)
-            point->setGrabber(grabber);
+            point->setItemGrabber(grabber);
     }
 
     if (oldGrabber) {
@@ -758,10 +759,10 @@ void QQuickWindowPrivate::setMouseGrabber(QQuickItem *grabber)
     }
 }
 
-void QQuickWindowPrivate::grabTouchPoints(QQuickItem *grabber, const QVector<int> &ids)
+void QQuickWindowPrivate::grabTouchPoints(QObject *grabber, const QVector<int> &ids)
 {
     Q_Q(QQuickWindow);
-    QSet<QQuickItem*> ungrab;
+    QSet<QObject*> ungrab;
     for (int i = 0; i < ids.count(); ++i) {
         // FIXME: deprecate this function, we need a device
         const auto touchDevices = QQuickPointerDevice::touchDevices();
@@ -769,7 +770,7 @@ void QQuickWindowPrivate::grabTouchPoints(QQuickItem *grabber, const QVector<int
             auto point = device->pointerEvent()->pointById(ids.at(i));
             if (!point)
                 continue;
-            QQuickItem *oldGrabber = point->grabber();
+            QObject *oldGrabber = point->grabber();
             if (oldGrabber == grabber)
                 continue;
 
@@ -784,8 +785,10 @@ void QQuickWindowPrivate::grabTouchPoints(QQuickItem *grabber, const QVector<int
             setMouseGrabber(nullptr);
         }
     }
-    for (QQuickItem *oldGrabber : qAsConst(ungrab))
-        oldGrabber->touchUngrabEvent();
+    for (QObject *oldGrabber : qAsConst(ungrab))
+        if (QQuickItem *item = qmlobject_cast<QQuickItem *>(oldGrabber))
+            item->touchUngrabEvent();
+        // TODO else if the old grabber was a PointerHandler, notify it somehow?
 }
 
 void QQuickWindowPrivate::removeGrabber(QQuickItem *grabber, bool mouse, bool touch)
@@ -797,7 +800,7 @@ void QQuickWindowPrivate::removeGrabber(QQuickItem *grabber, bool mouse, bool to
             auto pointerEvent = device->pointerEvent();
             for (int i = 0; i < pointerEvent->pointCount(); ++i) {
                 if (pointerEvent->point(i)->grabber() == grabber) {
-                    pointerEvent->point(i)->setGrabber(nullptr);
+                    pointerEvent->point(i)->setItemGrabber(nullptr);
                     // FIXME send ungrab event only once
                     grabber->touchUngrabEvent();
                 }
@@ -1466,7 +1469,7 @@ QQuickItem *QQuickWindow::mouseGrabberItem() const
 {
     QQuickPointerEvent *event = QQuickPointerDevice::genericMouseDevice()->pointerEvent();
     Q_ASSERT(event->pointCount());
-    return event->point(0)->grabber();
+    return event->point(0)->itemGrabber();
 }
 
 
@@ -1609,7 +1612,13 @@ void QQuickWindowPrivate::deliverMouseEvent(QQuickPointerMouseEvent *pointerEven
     Q_Q(QQuickWindow);
     auto point = pointerEvent->point(0);
     lastMousePosition = point->scenePos();
-    QQuickItem *grabber = point->grabber();
+
+    if (point->pointerHandlerGrabber()) {
+        point->pointerHandlerGrabber()->handlePointerEvent(pointerEvent);
+        return;
+    }
+
+    QQuickItem *grabber = point->itemGrabber();
     if (grabber) {
         // if the update consists of changing button state, then don't accept it
         // unless the button is one in which the item is interested
@@ -1620,12 +1629,6 @@ void QQuickWindowPrivate::deliverMouseEvent(QQuickPointerMouseEvent *pointerEven
             return;
         }
 
-        // Let the Item's handlers (if any) have the event first.
-        QQuickItemPrivate *itemPrivate = QQuickItemPrivate::get(grabber);
-        itemPrivate->handlePointerEvent(pointerEvent);
-        if (pointerEvent->allPointsAccepted())
-            return;
-
         // send update
         QPointF localPos = grabber->mapFromScene(lastMousePosition);
         auto me = pointerEvent->asMouseEvent(localPos);
@@ -1845,10 +1848,14 @@ bool QQuickWindowPrivate::deliverTouchCancelEvent(QTouchEvent *event)
     // A TouchCancel event will typically not contain any points.
     // Deliver it to all items that have active touches.
     QQuickPointerEvent *pointerEvent = QQuickPointerDevice::touchDevice(event->device())->pointerEvent();
-    QVector<QQuickItem *> grabbers = pointerEvent->grabbers();
-
-    for (QQuickItem *grabber: qAsConst(grabbers)) {
-        q->sendEvent(grabber, event);
+    QVector<QObject *> grabbers = pointerEvent->grabbers();
+
+    for (QObject *grabber: qAsConst(grabbers)) {
+        if (QQuickItem *grabberItem = qmlobject_cast<QQuickItem *>(grabber))
+            q->sendEvent(grabberItem, event);
+        else //if (QQuickPointerHandler *grabberHandler = qmlobject_cast<QQuickPointerHandler *>(grabber))
+//            grabberHandler->handlePointerEvent()
+            qWarning("unexpected: can't deliver touch cancel to a PointerHandler (yet?)");
     }
     touchMouseId = -1;
     touchMouseDevice = nullptr;
@@ -1986,8 +1993,6 @@ void QQuickWindow::mouseReleaseEvent(QMouseEvent *event)
 
 void QQuickWindowPrivate::handleMouseEvent(QMouseEvent *event)
 {
-    Q_Q(QQuickWindow);
-
     if (event->source() == Qt::MouseEventSynthesizedBySystem) {
         event->accept();
         return;
@@ -2020,7 +2025,7 @@ void QQuickWindowPrivate::handleMouseEvent(QMouseEvent *event)
         updateCursor(event->windowPos());
     #endif
 
-        if (!q->mouseGrabberItem()) {
+        if (!QQuickPointerDevice::genericMouseDevice()->pointerEvent()->point(0)->grabber()) {
             QPointF last = lastMousePosition.isNull() ? event->windowPos() : lastMousePosition;
             lastMousePosition = event->windowPos();
 
@@ -2188,7 +2193,7 @@ void QQuickWindowPrivate::deliverTouchEvent(QQuickPointerTouchEvent *event)
         if (point->state() == QQuickEventPoint::Released) {
             int id = point->pointId();
             qCDebug(DBG_TOUCH_TARGET) << "TP" << id << "released";
-            point->setGrabber(nullptr);
+            point->setItemGrabber(nullptr);
             if (id == touchMouseId) {
                 touchMouseId = -1;
                 touchMouseDevice = nullptr;
@@ -2208,8 +2213,12 @@ void QQuickWindowPrivate::deliverTouchEvent(QQuickPointerTouchEvent *event)
 bool QQuickWindowPrivate::deliverUpdatedTouchPoints(QQuickPointerTouchEvent *event, QSet<QQuickItem *> *hasFiltered)
 {
     const auto grabbers = event->grabbers();
-    for (auto grabber : grabbers)
-        deliverMatchingPointsToItem(grabber, event, hasFiltered);
+    for (auto grabber : grabbers) {
+        if (QQuickItem *grabberItem = qmlobject_cast<QQuickItem *>(grabber))
+            deliverMatchingPointsToItem(grabberItem, event, hasFiltered);
+        else if (QQuickPointerHandler *grabberHandler = qmlobject_cast<QQuickPointerHandler *>(grabber))
+            deliverMatchingPointsToItem(grabberHandler->target(), event, hasFiltered);
+    }
 
     return false;
 }
@@ -2310,7 +2319,7 @@ bool QQuickWindowPrivate::deliverMatchingPointsToItem(QQuickItem *item, QQuickPo
             auto pointerEventPoint = event->pointById(point.id());
             pointerEventPoint->setAccepted();
             if (point.state() == Qt::TouchPointPressed)
-                pointerEventPoint->setGrabber(item);
+                pointerEventPoint->setItemGrabber(item);
         }
     } else {
         // But if the event was not accepted then we know this item
@@ -2319,7 +2328,7 @@ bool QQuickWindowPrivate::deliverMatchingPointsToItem(QQuickItem *item, QQuickPo
             if (point.state() == Qt::TouchPointPressed) {
                 if (event->pointById(point.id())->grabber() == item) {
                     qCDebug(DBG_TOUCH_TARGET) << "TP" << point.id() << "disassociated";
-                    event->pointById(point.id())->setGrabber(nullptr);
+                    event->pointById(point.id())->setItemGrabber(nullptr);
                 }
             }
         }
@@ -2558,7 +2567,7 @@ bool QQuickWindowPrivate::sendFilteredTouchEvent(QQuickItem *target, QQuickItem
                             qCDebug(DBG_TOUCH_TARGET) << "TP" << tp.id() << "->" << target;
                             touchMouseId = tp.id();
                             touchMouseDevice = event->device();
-                            touchMouseDevice->pointerEvent()->pointById(tp.id())->setGrabber(target);
+                            touchMouseDevice->pointerEvent()->pointById(tp.id())->setItemGrabber(target);
                             target->grabMouse();
                         }
                         filtered = true;
diff --git a/src/quick/items/qquickwindow_p.h b/src/quick/items/qquickwindow_p.h
index 3328eb65c4..a2a53fd2ce 100644
--- a/src/quick/items/qquickwindow_p.h
+++ b/src/quick/items/qquickwindow_p.h
@@ -141,7 +141,7 @@ public:
     bool deliverTouchAsMouse(QQuickItem *item, QQuickPointerEvent *pointerEvent);
     void translateTouchEvent(QTouchEvent *touchEvent);
     void setMouseGrabber(QQuickItem *grabber);
-    void grabTouchPoints(QQuickItem *grabber, const QVector<int> &ids);
+    void grabTouchPoints(QObject *grabber, const QVector<int> &ids);
     void removeGrabber(QQuickItem *grabber, bool mouse = true, bool touch = true);
     static QMouseEvent *cloneMouseEvent(QMouseEvent *event, QPointF *transformedLocalPos = 0);
     void deliverMouseEvent(QQuickPointerMouseEvent *pointerEvent);