Timeline: ensure the cursor is always visible when dragging

src/gui/TracksView.cpp

@@ -52,6 +52,9 @@ TracksView::TracksView( QGraphicsScene* scene, QWidget* parent )
 
     m_cursorLine = new GraphicsCursorItem( maxHeight, QPen( QColor( 220, 30, 30 ) ) );
     m_scene->addItem( m_cursorLine );
+
+    connect( m_cursorLine, SIGNAL( cursorPositionChanged(int) ),
+             this, SLOT( ensureCursorVisible() ) );
 }
 
 void TracksView::dragEnterEvent( QDragEnterEvent* event )
@@ -217,3 +220,9 @@ void TracksView::setScale( double scaleFactor )
     }
     centerOn( m_cursorLine );
 }
+
+void TracksView::ensureCursorVisible()
+{
+    if ( horizontalScrollBar()->isVisible() )
+        m_cursorLine->ensureVisible( QRectF(), 150, 50 );
+}

src/gui/TracksView.h

@@ -60,6 +60,9 @@ protected:
     virtual void dropEvent( QDropEvent* event );
     virtual void dragMoveEvent( QDragMoveEvent* event );
 
+private slots:
+    void ensureCursorVisible();
+
 private:
     QGraphicsScene* m_scene;
     int m_tracksHeight;