MainWindow gets drag/drop from Overview

.. the chartspace widget used by the athlete view and
   overview chart now passes drag and drop events up to
   mainwindow so they can be processed

src/Charts/UserChartOverviewItem.h

@@ -56,6 +56,7 @@ class UserChartOverviewItem : public ChartSpaceItem
         QString getConfig() const { return chart->settings(); }
         void setConfig(QString config) { chart->applySettings(config); }
 
+        QGraphicsProxyWidget *proxy;
     protected:
         bool sceneEvent(QEvent *) override { return false; } // override the default one
 
@@ -66,7 +67,6 @@ class UserChartOverviewItem : public ChartSpaceItem
 
     private:
         // embedding
-        QGraphicsProxyWidget *proxy;
         UserChart *chart;
         ChartSpace *space_;
 

src/Gui/ChartSpace.cpp

@@ -54,7 +54,7 @@ ChartSpace::ChartSpace(Context *context, int scope, GcWindow *window) :
 
     // add a view and scene and centre
     scene = new QGraphicsScene(this);
-    view = new QGraphicsView(this);
+    view = new GGraphicsView(context, this);
 
     // hardware acceleration is important for this widget
 #if QT_VERSION < 0x060000

src/Gui/ChartSpace.h

@@ -52,6 +52,25 @@ class ChartSpaceItemFactory;
 // we need a scope for a chart space, one or more of
 enum OverviewScope { ANALYSIS=0x01, TRENDS=0x02, ATHLETES=0x04 };
 
+// we need to intercept the graphics scene drag and drop
+// events and send them to MainWindow
+class GGraphicsView : public QGraphicsView
+{
+    public:
+        GGraphicsView(Context *context, QWidget *parent) : QGraphicsView(parent), context(context) {
+            setAcceptDrops(true);
+        }
+
+    protected:
+        void dragEnterEvent(QDragEnterEvent *event) { context->mainWindow->dragEnterEvent(event); }
+        void dragLeaveEvent(QDragLeaveEvent *event) { context->mainWindow->dragLeaveEvent(event); }
+        void dropEvent(QDropEvent *event) { context->mainWindow->dropEvent(event); }
+        void dragMoveEvent(QDragMoveEvent *event) { context->mainWindow->dragMoveEvent(event); }
+
+    private:
+        Context *context;
+};
+
 // must be subclassed to add items to a ChartSpace
 class ChartSpaceItem : public QGraphicsWidget
 {

src/Gui/MainWindow.h

@@ -70,6 +70,7 @@ class Athlete;
 class AthleteLoader;
 class Context;
 class AthleteTab;
+class GGraphicsView;
 
 
 extern QList<MainWindow *> mainwindows; // keep track of all the MainWindows we have open
@@ -108,6 +109,7 @@ class MainWindow : public QMainWindow
         // have already been opened
         friend class ::ChooseCyclistDialog;
         friend class ::AthleteLoader;
+        friend class ::GGraphicsView;
         QMap<QString,AthleteTab*> athletetabs;
         AthleteTab *currentAthleteTab;
         QList<AthleteTab*> tabList;