Changes: Automate grabbing of Tap and Hold gestures by M*ListItems.

Fixes: NB#196165 - longTapped not emitted by MListItem

RevBy: Sergiy Dubovik

Details: By default MWidgets don't grab TapAndHold gesture. However
M*ListItem(s) provide a signal for long tap. It can't work if widget
doesn't call grabGesture(Qt::TapAndHold). Asking user to call it
is awkward. M*ListItem is going to grab tap and hold gesture when
someone subscribes to M*ListItem::longTap(QPointF) and will
ungrab when all receivers will disconnect.

6 files changed, 63 insertions, 9 deletions

diff --git a/src/corelib/widgets/mlistitem.cpp b/src/corelib/widgets/mlistitem.cpp
index ae6c8d57..a08168cb 100644
--- a/src/corelib/widgets/mlistitem.cpp
+++ b/src/corelib/widgets/mlistitem.cpp
@@ -33,6 +33,15 @@ MListItemPrivate::~MListItemPrivate()
 {
 }
 
+void MListItemPrivate::updateLongTapConnections()
+{
+    Q_Q(MListItem);
+    if (q->receivers(SIGNAL(longTapped(QPointF))) > 0)
+        q->grabGesture(Qt::TapAndHoldGesture);
+    else
+        q->ungrabGesture(Qt::TapAndHoldGesture);
+}
+
 MListItem::MListItem(QGraphicsItem *parent)
     : MWidgetController(new MListItemPrivate, new MListItemModel, parent)
 {
@@ -51,3 +60,21 @@ void MListItem::longTap(const QPointF &pos)
 {
     emit longTapped(pos);
 }
+
+void MListItem::connectNotify(const char *signal)
+{
+    Q_D(MListItem);
+
+    if (QLatin1String(signal) == SIGNAL(longTapped(QPointF))) {
+        d->updateLongTapConnections();
+    }
+}
+
+void MListItem::disconnectNotify(const char *signal)
+{
+    Q_D(MListItem);
+
+    if (QLatin1String(signal) == SIGNAL(longTapped(QPointF))) {
+        d->updateLongTapConnections();
+    }
+}
diff --git a/src/corelib/widgets/mlistitem.h b/src/corelib/widgets/mlistitem.h
index 46048f43..7c612936 100644
--- a/src/corelib/widgets/mlistitem.h
+++ b/src/corelib/widgets/mlistitem.h
@@ -72,12 +72,20 @@ Q_SIGNALS:
 
     /*!
       \brief The signal is emitted when the list cell has been tapped and holded.
-
-      If the MListItem is used outside MList, the user needs to invoke
-      item->grabGesture(Qt::TapAndHoldGesture) to start receiving longTapped() signal.
     */
     void longTapped(const QPointF &pos);
 
+protected:
+    /*!
+       Handler of notifications of new receivers connected to MListItem signals.
+    */
+    virtual void connectNotify(const char *signal);
+
+    /*!
+       Handler of notifications of receivers disconnecting from MListItem signals.
+    */
+    virtual void disconnectNotify(const char *signal);
+
     
 private:   
     Q_DECLARE_PRIVATE(MListItem)
diff --git a/src/corelib/widgets/mlistitem_p.h b/src/corelib/widgets/mlistitem_p.h
index 5f71dbc9..611debeb 100644
--- a/src/corelib/widgets/mlistitem_p.h
+++ b/src/corelib/widgets/mlistitem_p.h
@@ -30,6 +30,8 @@ public:
     MListItemPrivate();
     virtual ~MListItemPrivate();
 
+    void updateLongTapConnections();
+
 private:
     Q_DECLARE_PUBLIC(MListItem)
 };
diff --git a/src/views/mlistview.cpp b/src/views/mlistview.cpp
index 70b77061..aca643bf 100644
--- a/src/views/mlistview.cpp
+++ b/src/views/mlistview.cpp
@@ -108,6 +108,8 @@ void MListView::updateData(const QList<const char *>& modifications)
             longTap(model()->longTap());
         } else if (member == MListModel::ListIndexDisplayMode) {
             d_ptr->updateListIndexVisibility();
+        } else if (member == MListModel::LongTapEnabled) {
+            d_ptr->updateItemConnections();
         }
     }
 }
diff --git a/src/views/mlistview_p.cpp b/src/views/mlistview_p.cpp
index 4da4c9f9..d4018a67 100644
--- a/src/views/mlistview_p.cpp
+++ b/src/views/mlistview_p.cpp
@@ -205,13 +205,8 @@ MWidget *MListViewPrivate::createCell(int row)
         QObject::connect(cell, SIGNAL(clicked()), q_ptr, SLOT(itemClick()), Qt::UniqueConnection);
     }
 
-    if (cell->metaObject()->indexOfSignal("longTapped(QPointF)") != -1) {
-        QObject::connect(cell, SIGNAL(longTapped(QPointF)), q_ptr, SLOT(_q_itemLongTapped(QPointF)), Qt::UniqueConnection);
-    }
+    updateItemLongTapConnection(cell);
 
-    if (controllerModel->longTapEnabled()) {
-        cell->grabGesture(Qt::TapAndHoldGesture);
-    }
     return cell;
 }
 
@@ -383,6 +378,23 @@ void MListViewPrivate::connectSignalsFromModelToListView()
     }
 }
 
+void MListViewPrivate::updateItemConnections()
+{
+    foreach (MWidget *cell, visibleItems) {
+        updateItemLongTapConnection(cell);
+    }
+}
+
+void MListViewPrivate::updateItemLongTapConnection(MWidget *cell)
+{
+    if (cell->metaObject()->indexOfSignal("longTapped(QPointF)") != -1) {
+        if (controllerModel->longTapEnabled())
+            QObject::connect(cell, SIGNAL(longTapped(QPointF)), q_ptr, SLOT(_q_itemLongTapped(QPointF)), Qt::UniqueConnection);
+        else
+            QObject::disconnect(cell, SIGNAL(longTapped(QPointF)), q_ptr, SLOT(_q_itemLongTapped(QPointF)));
+    }
+}
+
 void MListViewPrivate::resetModel(MListModel *mListModel)
 {
     forceRepaint = true;
diff --git a/src/views/mlistview_p.h b/src/views/mlistview_p.h
index bef98acd..5d858eae 100644
--- a/src/views/mlistview_p.h
+++ b/src/views/mlistview_p.h
@@ -151,6 +151,9 @@ public:
     virtual void disconnectSignalsFromModelToListView();
     virtual void connectSignalsFromModelToListView();
 
+    virtual void updateItemConnections();
+    virtual void updateItemLongTapConnection(MWidget *cell);
+
 public Q_SLOTS:
     void movingDetectionTimerTimeout();
     void viewportPositionChanged(const QPointF &pos);