title: Tracking mouse move in QGraphicsScene class
body: <p>I subclassed QGraphicsScene and added method mouseMoveEvent to handle mouse move event. I created a ruler on top of GraphicsView and have the ruler tracking mouse movement. In the QGraphicsScene::mousemoveEvent I calls mouseMoveEvent of the ruler widget explcitely. The purpose is to have the ruler knows that the current mouse position.</p>
  
  <p>Now it seems that QGraphicsScene::mousemoveEvent is not called when I move the mouse. However, I can get it to work if I press the left mouse button and move it while holding the button. This is not what I'd like to see; I'd like this method is called whenever I place the mouse over the view and move the mouse.</p>
  
  <p>Is there any workaround?</p>