Timeline: Use of dragMode

Handle multiple selection (SHIFT + CLICK) and movements inside the
timeline frame (CTRL + CLICK)

src/gui/TracksView.cpp

@@ -114,7 +114,6 @@ void TracksView::drawBackground( QPainter* painter, const QRectF& rect )
 
 void TracksView::mouseMoveEvent( QMouseEvent* event )
 {
-    //int xPos = event->x();
     int mappedXPos = ( int )( mapToScene( event->pos() ).x() + 0.5 );
     if ( event->buttons() == Qt::LeftButton && event->modifiers() == Qt::NoModifier )
     {
@@ -126,7 +125,25 @@ void TracksView::mouseMoveEvent( QMouseEvent* event )
 
 void TracksView::mousePressEvent( QMouseEvent* event )
 {
-    //int xPos = event->x();
+
+    QList<QGraphicsItem*> collisionList = items( event->pos() );
+
+    if ( event->modifiers() == Qt::ControlModifier && collisionList.count() == 0 )
+    {
+        setDragMode( QGraphicsView::ScrollHandDrag );
+        QGraphicsView::mousePressEvent( event );
+        return;
+    }
+
+    if ( event->modifiers() & Qt::ShiftModifier && collisionList.count() == 0 )
+    {
+        setDragMode( QGraphicsView::RubberBandDrag );
+        if ( !event->modifiers() & Qt::ControlModifier )
+            scene()->clearSelection();
+        QGraphicsView::mousePressEvent( event );
+        return;
+    }
+
     int mappedXPos = ( int )( mapToScene( event->pos() ).x() + 0.5 );
     if ( event->buttons() == Qt::LeftButton && event->modifiers() == Qt::NoModifier )
     {
@@ -136,6 +153,11 @@ void TracksView::mousePressEvent( QMouseEvent* event )
     QGraphicsView::mousePressEvent( event );
 }
 
+void TracksView::mouseReleaseEvent( QMouseEvent* event )
+{
+    setDragMode( QGraphicsView::NoDrag );
+}
+
 void TracksView::wheelEvent( QWheelEvent* event )
 {
     if ( event->modifiers() == Qt::ControlModifier )

src/gui/TracksView.h

@@ -51,6 +51,7 @@ protected:
     virtual void drawBackground( QPainter* painter, const QRectF& rect );
     virtual void mouseMoveEvent( QMouseEvent* event );
     virtual void mousePressEvent( QMouseEvent* event );
+    virtual void mouseReleaseEvent( QMouseEvent* event );
     virtual void wheelEvent( QWheelEvent* event );
     virtual void dragEnterEvent( QDragEnterEvent* event );
     virtual void dropEvent( QDropEvent* event );