Make mouse interaction work

- events need to be accepted, otherwise they don't have effect on the
  drag, and it doesn't get released
- slightly more intelligent starting of drag, saves quite some cycles
  and is way more correct this way

The "attach pixmap of dragged item" is still disabled. This probably
needs to be rethought entirely. One option would be to ditch this class
in favour of QtQuick 2's Drag, DragEvent and DropArea. Food for API
discussion.

src/declarativeimports/draganddrop/DeclarativeDragArea.cpp

@@ -43,6 +43,7 @@ DeclarativeDragArea::DeclarativeDragArea(QQuickItem *parent)
     m_source(0),
     m_target(0),
     m_enabled(true),
+    m_draggingJustStarted(false),
     m_supportedActions(Qt::MoveAction),
     m_defaultAction(Qt::MoveAction),
     m_data(new DeclarativeMimeData())    // m_data is owned by us, and we shouldn't pass it to Qt directly as it will automatically delete it after the drag and drop.
@@ -195,6 +196,7 @@ void DeclarativeDragArea::setDefaultAction(Qt::DropAction action)
 void DeclarativeDragArea::mousePressEvent(QMouseEvent* event)
 {
     m_buttonDownPos = event->screenPos();
+    m_draggingJustStarted = true;
 }
 
 
@@ -205,42 +207,44 @@ void DeclarativeDragArea::mouseMoveEvent(QMouseEvent *event)
             < m_startDragDistance) {
         return;
     }
+    if (m_draggingJustStarted) {
+        emit dragStarted();
+        m_draggingJustStarted = false;
 
-    emit dragStarted();
+        QDrag *drag = new QDrag(parent());
+        DeclarativeMimeData* dataCopy = new DeclarativeMimeData(m_data); //Qt will take ownership of this copy and delete it.
+        drag->setMimeData(dataCopy);
 
-    QDrag *drag = new QDrag(parent());
-    DeclarativeMimeData* dataCopy = new DeclarativeMimeData(m_data); //Qt will take ownership of this copy and delete it.
-    drag->setMimeData(dataCopy);
+        if (!m_delegateImage.isNull()) {
+            drag->setPixmap(QPixmap::fromImage(m_delegateImage));
+        } else if (m_delegate) {
+            // Render the delegate to a Pixmap
+    //         QQuickItem* item = qobject_cast<QQuickItem *>(m_delegate->create(m_delegate->creationContext()));
 
-    if (!m_delegateImage.isNull()) {
-        drag->setPixmap(QPixmap::fromImage(m_delegateImage));
-    } else if (m_delegate) {
-        // Render the delegate to a Pixmap
-//         QQuickItem* item = qobject_cast<QQuickItem *>(m_delegate->create(m_delegate->creationContext()));
+    //         QGraphicsScene scene;
+    //         scene.addItem(item);
 
-//         QGraphicsScene scene;
-//         scene.addItem(item);
+    //         QPixmap pixmap(scene.sceneRect().width(), scene.sceneRect().height());
+    //         pixmap.fill(Qt::transparent);
+    //
+    //         QPainter painter(&pixmap);
+    //         painter.setRenderHint(QPainter::Antialiasing);
+    //         painter.setRenderHint(QPainter::SmoothPixmapTransform);
+    //         scene.render(&painter);
+    //         painter.end();
+    //         delete item;
+    //
+    //         drag->setPixmap(pixmap);
+            drag->setPixmap(QIcon::fromTheme("plasma").pixmap(64,64));
+        }
 
-//         QPixmap pixmap(scene.sceneRect().width(), scene.sceneRect().height());
-//         pixmap.fill(Qt::transparent);
-//
-//         QPainter painter(&pixmap);
-//         painter.setRenderHint(QPainter::Antialiasing);
-//         painter.setRenderHint(QPainter::SmoothPixmapTransform);
-//         scene.render(&painter);
-//         painter.end();
-//         delete item;
-//
-//         drag->setPixmap(pixmap);
-        drag->setPixmap(QIcon::fromTheme("plasma").pixmap(64,64));
+        drag->setHotSpot(QPoint(drag->pixmap().width()/2, drag->pixmap().height()/2)); // TODO: Make a property for that
+        //setCursor(Qt::OpenHandCursor);    //TODO? Make a property for the cursor
+
+        Qt::DropAction action = drag->exec(m_supportedActions, m_defaultAction);
+        emit drop(action);
     }
 
-    drag->setHotSpot(QPoint(drag->pixmap().width()/2, drag->pixmap().height()/2)); // TODO: Make a property for that
-
-    //setCursor(Qt::OpenHandCursor);    //TODO? Make a property for the cursor
-
-    Qt::DropAction action = drag->exec(m_supportedActions, m_defaultAction);
-    emit drop(action);
 }
 
 bool DeclarativeDragArea::childMouseEventFilter(QQuickItem *item, QEvent *event)

src/declarativeimports/draganddrop/DeclarativeDragArea.h

@@ -142,6 +142,7 @@ private:
     QQuickItem* m_source;
     QQuickItem* m_target;
     bool m_enabled;
+    bool m_draggingJustStarted;
     Qt::DropActions m_supportedActions;
     Qt::DropAction m_defaultAction;
     DeclarativeMimeData* const m_data;

src/declarativeimports/draganddrop/DeclarativeDropArea.cpp

@@ -39,9 +39,11 @@ DeclarativeDropArea::DeclarativeDropArea(QQuickItem *parent)
 
 }
 
-void DeclarativeDropArea::dragEnterEvent(QDragEnterEvent *event) {
+void DeclarativeDropArea::dragEnterEvent(QDragEnterEvent *event)
+{
     DeclarativeDragDropEvent dde(event, this);
     qDebug() << "enter.";
+    event->accept();
     emit dragEnter(&dde);
 }
 
@@ -56,6 +58,7 @@ void DeclarativeDropArea::dragMoveEvent(QDragMoveEvent *event)
 {
     DeclarativeDragDropEvent dde(event, this);
     qDebug() << "move.";
+    event->accept();
     emit dragMove(&dde);
 }