Continuous Tooltip Update in Swing

I have a custom swing component that is implemented similar to a JTree. It has a ComponentUI that renders an object list using a CellRenderer. The tooltip now correctly shows for each rendered cell, however it doesn't track the mouse as I would like. For instance, if I have boxes layed out like this;

 [ box A ]    [ box B 开发者_Go百科]   [ box C ]   [ box D ]

If i drag the mouse across these boxes I will see the tooltip for box A where the mouse crosses the box A boundary. As I continue to move the mouse the tooltip will not track the pointer. When I leave the box the tooltip will appropriately disappear. When i cross box B the same thing happens.

My guess is that the tooltip is only updating the view when the contents of getToolTipText(MouseEvent event) change. The behavior I would like is to have the tooltip track the pointer position regardless of the contents returned by getToolTipText. A quick hack is to add and remove an empty space based on an even/odd number of calls to the method. This works, but bleh, it can't be the way I am supposed to do it.

I'm looking for a graceful non-hack way of solving this problem. I'm hoping someone knows of some arcane flag somewhere that forces the tooltip to follow the mouse regardless of mouse content.

Override getToolTipLocation in your cell renderer.

I tried to use getToolTipLocation to set tooltip's position when pointing on elements of a JList, but it didn't work.

After inserting breakpoints it came out that in such code:

public class DefinitionListCellRenderer extends JTextArea implements
        ListCellRenderer, ComponentListener {

...

    @Override
    public Point getToolTipLocation(MouseEvent event) {
        Point pt = new Point(event.getX(), event.getY());
        return pt;
    }


...

}

getToolTipLocation isn't even called!! Could you please say, why? DefinitionListCellRenderer is a single item on a list (has getListCellRendererComponent() ).