Make GestureCancelPolicy work for graphicsview

Reviewed-By: Denis

5 files changed, 109 insertions, 22 deletions

diff --git a/src/gui/graphicsview/qgraphicsscene.cpp b/src/gui/graphicsview/qgraphicsscene.cpp
index c459d21..9279fe3 100644
--- a/src/gui/graphicsview/qgraphicsscene.cpp
+++ b/src/gui/graphicsview/qgraphicsscene.cpp
@@ -5941,6 +5941,13 @@ void QGraphicsScenePrivate::gestureEventHandler(QGestureEvent *event)
             continue;
         }
     }
+    foreach (QGesture *g, startedGestures) {
+        if (g->gestureCancelPolicy() == QGesture::CancelAllInContext) {
+            DEBUG() << "lets try to cancel some";
+            // find gestures in context in Qt::GestureStarted or Qt::GestureUpdated state and cancel them
+            cancelGesturesForChildren(g, event->widget());
+        }
+    }
 
     // forget about targets for gestures that have ended
     foreach (QGesture *g, allGestures) {
@@ -5955,6 +5962,89 @@ void QGraphicsScenePrivate::gestureEventHandler(QGestureEvent *event)
     }
 }
 
+void QGraphicsScenePrivate::cancelGesturesForChildren(QGesture *original, QWidget *viewport)
+{
+    Q_ASSERT(original);
+    QGraphicsItem *originalItem = gestureTargets.value(original);
+    Q_ASSERT(originalItem);
+
+    // iterate over all active gestures and for each find the owner
+    // if the owner is part of our sub-hierarchy, cancel it.
+
+    QSet<QGesture *> canceledGestures;
+    QHash<QGesture *, QGraphicsObject *>::Iterator iter = gestureTargets.begin();
+    while (iter != gestureTargets.end()) {
+        QGraphicsObject *item = iter.value();
+        // note that we don't touch the gestures for our originalItem
+        if (item != originalItem && originalItem->isAncestorOf(item)) {
+            DEBUG() << "  found a gesture to cancel" << iter.key();
+            iter.key()->d_func()->state = Qt::GestureCanceled;
+            canceledGestures << iter.key();
+        }
+        ++iter;
+    }
+
+    // sort them per target item by cherry picking from almostCanceledGestures and delivering
+    QSet<QGesture *> almostCanceledGestures = canceledGestures;
+    QSet<QGesture *>::Iterator setIter;
+    while (!almostCanceledGestures.isEmpty()) {
+        QGraphicsObject *target = 0;
+        QSet<QGesture*> gestures;
+        setIter = almostCanceledGestures.begin();
+        // sort per target item
+        while (setIter != almostCanceledGestures.end()) {
+            QGraphicsObject *item = gestureTargets.value(*setIter);
+            if (target == 0)
+                target = item;
+            if (target == item) {
+                gestures << *setIter;
+                setIter = almostCanceledGestures.erase(setIter);
+            } else {
+                ++setIter;
+            }
+        }
+        Q_ASSERT(target);
+
+        QList<QGesture *> list = gestures.toList();
+        QGestureEvent ev(list);
+        sendEvent(target, &ev);
+
+        foreach (QGesture *g, list) {
+            if (ev.isAccepted() || ev.isAccepted(g))
+                gestures.remove(g);
+        }
+
+        foreach (QGesture *g, gestures) {
+            if (!g->hasHotSpot())
+                continue;
+
+            QPoint screenPos = g->hotSpot().toPoint();
+            QList<QGraphicsItem *> items = itemsAtPosition(screenPos, QPointF(), viewport);
+            for (int j = 0; j < items.size(); ++j) {
+                QGraphicsObject *item = items.at(j)->toGraphicsObject();
+                if (!item)
+                    continue;
+                QGraphicsItemPrivate *d = item->QGraphicsItem::d_func();
+                if (d->gestureContext.contains(g->gestureType())) {
+                    QList<QGesture *> list;
+                    list << g;
+                    QGestureEvent ev(list);
+                    sendEvent(item, &ev);
+                    if (ev.isAccepted() || ev.isAccepted(g))
+                        break; // successfully delivered
+                }
+            }
+        }
+    }
+
+    QGestureManager *gm = QApplicationPrivate::instance()->gestureManager;
+    Q_ASSERT(gm); // it would be very odd if we got called without a manager.
+    for (setIter = canceledGestures.begin(); setIter != canceledGestures.end(); ++setIter) {
+        gm->recycle(*setIter);
+        gestureTargets.remove(*setIter);
+    }
+}
+
 QT_END_NAMESPACE
 
 #include "moc_qgraphicsscene.cpp"
diff --git a/src/gui/graphicsview/qgraphicsscene_p.h b/src/gui/graphicsview/qgraphicsscene_p.h
index cd20fd0..f8db084 100644
--- a/src/gui/graphicsview/qgraphicsscene_p.h
+++ b/src/gui/graphicsview/qgraphicsscene_p.h
@@ -288,6 +288,7 @@ public:
                            QMap<Qt::GestureType, QGesture *> *conflictedGestures,
                            QList<QList<QGraphicsObject *> > *conflictedItems,
                            QHash<QGesture *, QGraphicsObject *> *normalGestures);
+    void cancelGesturesForChildren(QGesture *original, QWidget *viewport);
 
     void updateInputMethodSensitivityInViews();
 
diff --git a/src/gui/kernel/qgesture.h b/src/gui/kernel/qgesture.h
index 524d26e..8614ecb 100644
--- a/src/gui/kernel/qgesture.h
+++ b/src/gui/kernel/qgesture.h
@@ -97,6 +97,7 @@ private:
     friend class QGestureEvent;
     friend class QGestureRecognizer;
     friend class QGestureManager;
+    friend class QGraphicsScenePrivate;
 };
 
 class QPanGesturePrivate;
diff --git a/src/gui/kernel/qgesturemanager.cpp b/src/gui/kernel/qgesturemanager.cpp
index f1abc89..1d33c84 100644
--- a/src/gui/kernel/qgesturemanager.cpp
+++ b/src/gui/kernel/qgesturemanager.cpp
@@ -346,12 +346,7 @@ bool QGestureManager::filterEventThroughContexts(const QMultiHash<QObject *,
     QSet<QGesture *> endedGestures =
             finishedGestures + canceledGestures + undeliveredGestures;
     foreach (QGesture *gesture, endedGestures) {
-        if (QGestureRecognizer *recognizer = m_gestureToRecognizer.value(gesture, 0)) {
-            gesture->setGestureCancelPolicy(QGesture::CancelNone);
-            recognizer->reset(gesture);
-        } else {
-            cleanupGesturesForRemovedRecognizer(gesture);
-        }
+        recycle(gesture);
         m_gestureTargets.remove(gesture);
     }
     return ret;
@@ -409,15 +404,8 @@ void QGestureManager::cancelGesturesForChildren(QGesture *original)
         deliverEvents(gestures, &undeliveredGestures);
     }
 
-    for (iter = cancelledGestures.begin(); iter != cancelledGestures.end(); ++iter) {
-        QGestureRecognizer *recognizer = m_gestureToRecognizer.value(*iter, 0);
-        if (recognizer) {
-            (*iter)->setGestureCancelPolicy(QGesture::CancelNone);
-            recognizer->reset(*iter);
-        } else {
-            cleanupGesturesForRemovedRecognizer(*iter);
-        }
-    }
+    for (iter = cancelledGestures.begin(); iter != cancelledGestures.end(); ++iter)
+        recycle(*iter);
 }
 
 void QGestureManager::cleanupGesturesForRemovedRecognizer(QGesture *gesture)
@@ -667,19 +655,24 @@ void QGestureManager::timerEvent(QTimerEvent *event)
             it = m_maybeGestures.erase(it);
             DEBUG() << "QGestureManager::timerEvent: gesture stopped due to timeout:"
                     << gesture;
-            QGestureRecognizer *recognizer = m_gestureToRecognizer.value(gesture, 0);
-            if (recognizer) {
-                gesture->setGestureCancelPolicy(QGesture::CancelNone);
-                recognizer->reset(gesture);
-            } else {
-                cleanupGesturesForRemovedRecognizer(gesture);
-            }
+            recycle(gesture);
         } else {
             ++it;
         }
     }
 }
 
+void QGestureManager::recycle(QGesture *gesture)
+{
+    QGestureRecognizer *recognizer = m_gestureToRecognizer.value(gesture, 0);
+    if (recognizer) {
+        gesture->setGestureCancelPolicy(QGesture::CancelNone);
+        recognizer->reset(gesture);
+    } else {
+        cleanupGesturesForRemovedRecognizer(gesture);
+    }
+}
+
 QT_END_NAMESPACE
 
 #include "moc_qgesturemanager_p.cpp"
diff --git a/src/gui/kernel/qgesturemanager_p.h b/src/gui/kernel/qgesturemanager_p.h
index 4958cdb..d60aedc 100644
--- a/src/gui/kernel/qgesturemanager_p.h
+++ b/src/gui/kernel/qgesturemanager_p.h
@@ -81,6 +81,8 @@ public:
 
     void cleanupCachedGestures(QObject *target, Qt::GestureType type);
 
+    void recycle(QGesture *gesture);
+
 protected:
     void timerEvent(QTimerEvent *event);
     bool filterEventThroughContexts(const QMultiHash<QObject *, Qt::GestureType> &contexts,