Add support for external drag and drop in Quick items.

Add dragType enums with values of None, Automatic, Internal (default).
Setting to Automatic allows startDrag to be called automatically.
Setting to Internal (default) retains old behavior.

Add mimeData to Drag item to enable external drags.

Call startDrag to start drag manually or change from internal drag to
external drag. Added events dragStarted and dragFinished that get
invoked from startDrag.

Mime data must be specified in the mimeData property as
mime-type / data pairs.

Moved QQuickDrag from qquickmousearea* files to qquickdrag* files to
reduce header interdependencies that caused linking errors in other
modules and also to improve code organization.

Allow DropArea to receive and process external data.

Introduced new variable containsDrag to QQuickDropAreaPrivate. This
replaces mimeData which was previously being used to determine if a
drop operation was currently occurring. The problem was that mimeData
was being externally destructed.

Also introduced accessor methods for getting color, html, image, text,
and urls out of the drop. This facilitates dropping of external data of
those types onto a DropArea.

Added example quick/externaldraganddrop.

Task-number: QTBUG-27498
Change-Id: I1420df7c161ea3399e49a23305273e106baa246f
Reviewed-by: Alan Alpert (Personal) <416365416c@gmail.com>

1 files changed, 87 insertions, 4 deletions

diff --git a/src/quick/items/qquickdrag_p.h b/src/quick/items/qquickdrag_p.h
index 3680fd5754..098fcc61b9 100644
--- a/src/quick/items/qquickdrag_p.h
+++ b/src/quick/items/qquickdrag_p.h
@@ -143,18 +143,90 @@ private:
 };
 
 class QQmlV4Function;
+class QQuickDragAttached;
+class Q_AUTOTEST_EXPORT QQuickDrag : public QObject
+{
+    Q_OBJECT
+
+    Q_ENUMS(Axis DragType)
+    Q_PROPERTY(QQuickItem *target READ target WRITE setTarget NOTIFY targetChanged RESET resetTarget)
+    Q_PROPERTY(Axis axis READ axis WRITE setAxis NOTIFY axisChanged)
+    Q_PROPERTY(qreal minimumX READ xmin WRITE setXmin NOTIFY minimumXChanged)
+    Q_PROPERTY(qreal maximumX READ xmax WRITE setXmax NOTIFY maximumXChanged)
+    Q_PROPERTY(qreal minimumY READ ymin WRITE setYmin NOTIFY minimumYChanged)
+    Q_PROPERTY(qreal maximumY READ ymax WRITE setYmax NOTIFY maximumYChanged)
+    Q_PROPERTY(bool active READ active NOTIFY activeChanged)
+    Q_PROPERTY(bool filterChildren READ filterChildren WRITE setFilterChildren NOTIFY filterChildrenChanged)
+    //### consider drag and drop
+
+public:
+    QQuickDrag(QObject *parent=0);
+    ~QQuickDrag();
+
+    enum DragType { None, Automatic, Internal };
+
+    QQuickItem *target() const;
+    void setTarget(QQuickItem *target);
+    void resetTarget();
+
+    enum Axis { XAxis=0x01, YAxis=0x02, XAndYAxis=0x03, XandYAxis=XAndYAxis };
+    Axis axis() const;
+    void setAxis(Axis);
+
+    qreal xmin() const;
+    void setXmin(qreal);
+    qreal xmax() const;
+    void setXmax(qreal);
+    qreal ymin() const;
+    void setYmin(qreal);
+    qreal ymax() const;
+    void setYmax(qreal);
+
+    bool active() const;
+    void setActive(bool);
+
+    bool filterChildren() const;
+    void setFilterChildren(bool);
+
+    static QQuickDragAttached *qmlAttachedProperties(QObject *obj);
+
+Q_SIGNALS:
+    void targetChanged();
+    void axisChanged();
+    void minimumXChanged();
+    void maximumXChanged();
+    void minimumYChanged();
+    void maximumYChanged();
+    void activeChanged();
+    void filterChildrenChanged();
+
+private:
+    QQuickItem *_target;
+    Axis _axis;
+    qreal _xmin;
+    qreal _xmax;
+    qreal _ymin;
+    qreal _ymax;
+    bool _active : 1;
+    bool _filterChildren: 1;
+    Q_DISABLE_COPY(QQuickDrag)
+};
 
 class QQuickDragAttachedPrivate;
 class QQuickDragAttached : public QObject
 {
     Q_OBJECT
+    Q_DECLARE_PRIVATE(QQuickDragAttached)
+
     Q_PROPERTY(bool active READ isActive WRITE setActive NOTIFY activeChanged)
     Q_PROPERTY(QObject *source READ source WRITE setSource NOTIFY sourceChanged RESET resetSource)
     Q_PROPERTY(QObject *target READ target NOTIFY targetChanged)
     Q_PROPERTY(QPointF hotSpot READ hotSpot WRITE setHotSpot NOTIFY hotSpotChanged)
     Q_PROPERTY(QStringList keys READ keys WRITE setKeys NOTIFY keysChanged)
+    Q_PROPERTY(QVariantMap mimeData READ mimeData WRITE setMimeData NOTIFY mimeDataChanged)
     Q_PROPERTY(Qt::DropActions supportedActions READ supportedActions WRITE setSupportedActions NOTIFY supportedActionsChanged)
     Q_PROPERTY(Qt::DropAction proposedAction READ proposedAction WRITE setProposedAction NOTIFY proposedActionChanged)
+    Q_PROPERTY(QQuickDrag::DragType dragType READ dragType WRITE setDragType NOTIFY dragTypeChanged)
 public:
     QQuickDragAttached(QObject *parent);
     ~QQuickDragAttached();
@@ -174,36 +246,47 @@ public:
     QStringList keys() const;
     void setKeys(const QStringList &keys);
 
+    QVariantMap mimeData() const;
+    void setMimeData(const QVariantMap &mimeData);
+
     Qt::DropActions supportedActions() const;
     void setSupportedActions(Qt::DropActions actions);
 
     Qt::DropAction proposedAction() const;
     void setProposedAction(Qt::DropAction action);
 
+    QQuickDrag::DragType dragType() const;
+    void setDragType(QQuickDrag::DragType dragType);
+
     Q_INVOKABLE int drop();
 
     bool event(QEvent *event);
 
 public Q_SLOTS:
     void start(QQmlV4Function *);
+    void startDrag(QQmlV4Function *);
     void cancel();
 
 Q_SIGNALS:
+    void dragStarted();
+    void dragFinished(Qt::DropAction dropAction);
+
     void activeChanged();
     void sourceChanged();
     void targetChanged();
     void hotSpotChanged();
     void keysChanged();
+    void mimeDataChanged();
     void supportedActionsChanged();
     void proposedActionChanged();
-
-private:
-    Q_DECLARE_PRIVATE(QQuickDragAttached)
+    void dragTypeChanged();
 };
 
-
 QT_END_NAMESPACE
 
+QML_DECLARE_TYPE(QQuickDrag)
+QML_DECLARE_TYPEINFO(QQuickDrag, QML_HAS_ATTACHED_PROPERTIES)
+
 #endif // QT_NO_DRAGANDDROP
 
 #endif