start making explicit exclusive or passive grabs

Change-Id: I4a6e3c72d69e893fec2e39f4faab24af6d00c7e0
Reviewed-by: Jan Arve Sæther <jan-arve.saether@qt.io>

7 files changed, 42 insertions, 18 deletions

diff --git a/src/quick/handlers/qquickdraghandler.cpp b/src/quick/handlers/qquickdraghandler.cpp
index 6caee6be13..9575f7ede9 100644
--- a/src/quick/handlers/qquickdraghandler.cpp
+++ b/src/quick/handlers/qquickdraghandler.cpp
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2017 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtQuick module of the Qt Toolkit.
@@ -80,6 +80,7 @@ void QQuickDragHandler::handleEventPoint(QQuickEventPoint *point)
     case QQuickEventPoint::Pressed:
         if (target() && target()->parentItem())
             m_startPos = target()->parentItem()->mapToScene(target()->position());
+        setPassiveGrab(point);
         break;
     case QQuickEventPoint::Updated: {
         QPointF delta = point->scenePos() - point->scenePressPos();
@@ -96,7 +97,7 @@ void QQuickDragHandler::handleEventPoint(QQuickEventPoint *point)
             }
         } else if ((m_xAxis.enabled() && QQuickWindowPrivate::dragOverThreshold(delta.x(), Qt::XAxis, point)) ||
                    (m_yAxis.enabled() && QQuickWindowPrivate::dragOverThreshold(delta.y(), Qt::YAxis, point))) {
-            setGrab(point, true);
+            setExclusiveGrab(point);
         }
     } break;
     default:
diff --git a/src/quick/handlers/qquickdraghandler_p.h b/src/quick/handlers/qquickdraghandler_p.h
index 69fa297b3c..6250615091 100644
--- a/src/quick/handlers/qquickdraghandler_p.h
+++ b/src/quick/handlers/qquickdraghandler_p.h
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2017 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtQuick module of the Qt Toolkit.
diff --git a/src/quick/handlers/qquickmultipointerhandler.cpp b/src/quick/handlers/qquickmultipointerhandler.cpp
index d3b986bcce..4b931641a2 100644
--- a/src/quick/handlers/qquickmultipointerhandler.cpp
+++ b/src/quick/handlers/qquickmultipointerhandler.cpp
@@ -213,7 +213,7 @@ void QQuickMultiPointerHandler::acceptPoints(const QVector<QQuickEventPoint *> &
 void QQuickMultiPointerHandler::grabPoints(QVector<QQuickEventPoint *> points)
 {
     for (QQuickEventPoint* point : points)
-        setGrab(point, true);
+        setExclusiveGrab(point);
 }
 
 QT_END_NAMESPACE
diff --git a/src/quick/handlers/qquickpointerhandler.cpp b/src/quick/handlers/qquickpointerhandler.cpp
index 0398863ba3..c91fb2de88 100644
--- a/src/quick/handlers/qquickpointerhandler.cpp
+++ b/src/quick/handlers/qquickpointerhandler.cpp
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2017 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtQuick module of the Qt Toolkit.
@@ -42,6 +42,7 @@
 QT_BEGIN_NAMESPACE
 
 Q_LOGGING_CATEGORY(lcPointerHandlerDispatch, "qt.quick.handler.dispatch")
+Q_LOGGING_CATEGORY(lcPointerHandlerActive, "qt.quick.handler.active")
 
 /*!
     \qmltype PointerHandler
@@ -73,22 +74,42 @@ QQuickPointerHandler::~QQuickPointerHandler()
     }
 }
 
-void QQuickPointerHandler::setGrab(QQuickEventPoint *point, bool grab)
+void QQuickPointerHandler::setPassiveGrab(QQuickEventPoint *point, bool grab)
+{
+    if (grab) {
+        point->setGrabberPointerHandler(this, false);
+        emit grabChanged(point);
+    } else if (point->grabberPointerHandler() == this) {
+        // TODO should giving up passive grab imply giving up exclusive grab too?
+        // we're being inconsistent here: check whether the exclusive grabber is this,
+        // then say that the passive grab was canceled.
+        point->cancelPassiveGrab(this);
+        emit grabChanged(point);
+    }
+}
+
+void QQuickPointerHandler::setExclusiveGrab(QQuickEventPoint *point, bool grab)
 {
     QQuickPointerHandler *oldGrabber = point->grabberPointerHandler();
     if (grab && oldGrabber != this) {
         if (oldGrabber)
             oldGrabber->handleGrabCancel(point);
-        point->setGrabberPointerHandler(this);
+        point->setGrabberPointerHandler(this, true);
         onGrabChanged(point);
-        emit grabChanged(point);
+//        emit grabChanged(point); // TODO maybe
     } else if (!grab && oldGrabber == this) {
-        point->setGrabberPointerHandler(nullptr);
+        point->setGrabberPointerHandler(nullptr, true);
         onGrabChanged(point);
-        emit grabChanged(point);
+//        emit grabChanged(point); // TODO maybe
     }
 }
 
+void QQuickPointerHandler::cancelAllGrabs(QQuickEventPoint *point)
+{
+    point->cancelAllGrabs(this);
+    emit grabChanged(point);
+}
+
 QPointF QQuickPointerHandler::eventPos(const QQuickEventPoint *point) const
 {
     return (target() ? target()->mapFromScene(point->scenePos()) : point->scenePos());
@@ -164,6 +185,7 @@ bool QQuickPointerHandler::wantsPointerEvent(QQuickPointerEvent *event)
 void QQuickPointerHandler::setActive(bool active)
 {
     if (m_active != active) {
+        qCDebug(lcPointerHandlerActive) << this << m_active << "->" << active;
         m_active = active;
         onActiveChanged();
         emit activeChanged();
diff --git a/src/quick/handlers/qquickpointerhandler_p.h b/src/quick/handlers/qquickpointerhandler_p.h
index 85f1096410..526a60262b 100644
--- a/src/quick/handlers/qquickpointerhandler_p.h
+++ b/src/quick/handlers/qquickpointerhandler_p.h
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2017 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtQuick module of the Qt Toolkit.
@@ -99,7 +99,9 @@ protected:
     void setActive(bool active);
     virtual void onActiveChanged() { }
     virtual void onGrabChanged(QQuickEventPoint *) { }
-    void setGrab(QQuickEventPoint *point, bool grab);
+    void setPassiveGrab(QQuickEventPoint *point, bool grab = true);
+    void setExclusiveGrab(QQuickEventPoint *point, bool grab = true);
+    void cancelAllGrabs(QQuickEventPoint *point);
     virtual void handleGrabCancel(QQuickEventPoint *point);
     QPointF eventPos(const QQuickEventPoint *point) const;
     bool parentContains(const QQuickEventPoint *point) const;
diff --git a/src/quick/handlers/qquickpointersinglehandler.cpp b/src/quick/handlers/qquickpointersinglehandler.cpp
index aeaa9d8309..41c9e1f322 100644
--- a/src/quick/handlers/qquickpointersinglehandler.cpp
+++ b/src/quick/handlers/qquickpointersinglehandler.cpp
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2017 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtQuick module of the Qt Toolkit.
@@ -70,8 +70,8 @@ bool QQuickPointerSingleHandler::wantsPointerEvent(QQuickPointerEvent *event)
             if (wantsEventPoint(point)) {
                 point->setAccepted();
                 return true;
-            } else if (point->grabber() == this) {
-                point->cancelGrab();
+            } else {
+                point->cancelAllGrabs(this);
             }
         } else {
             qCWarning(DBG_TOUCH_TARGET) << this << "pointId" << m_pointId
@@ -125,7 +125,7 @@ void QQuickPointerSingleHandler::handlePointerEventImpl(QQuickPointerEvent *even
             emit pointIdChanged();
             break;
         case QQuickEventPoint::Released:
-            setGrab(currentPoint, false);
+            setExclusiveGrab(currentPoint, false);
             reset();
             break;
         default:
diff --git a/src/quick/handlers/qquicktaphandler.cpp b/src/quick/handlers/qquicktaphandler.cpp
index 51a496001c..5065e87e8e 100644
--- a/src/quick/handlers/qquicktaphandler.cpp
+++ b/src/quick/handlers/qquicktaphandler.cpp
@@ -253,8 +253,7 @@ void QQuickTapHandler::setPressed(bool press, bool cancel, QQuickEventPoint *poi
             m_longPressTimer.stop();
             m_holdTimer.invalidate();
         }
-        if (m_gesturePolicy != DragThreshold)
-            setGrab(point, press);
+        setPassiveGrab(point, press);
         if (!cancel && !press && point->timeHeld() < longPressThreshold()) {
             // Assuming here that pointerEvent()->timestamp() is in ms.
             qreal ts = point->pointerEvent()->timestamp() / 1000.0;