// the selected item's image
cellList.addListSelectionListener(this);
// Add support for drag from the preview image label
dragSource = DragSource.getDefaultDragSource();
gestureListener = new PaletteDragGestureListener();
// Create a listener for changes to the list of registered Cell
// factories, to be used in setVisible(). When the list changes we
// simply do a fresh update of all values.
cellListener = new CellRegistryListener() {