instance.currentCanvas = null; instance.currentDisplayable = null;
if (instance.currentDisplayable != nextDisplayable ) { System.out.println("MasterCanvas: setting instance.currentCanvas to NULL!!!"); instance.currentCanvas = null; instance.currentDisplayable = null; }
	public static void setCurrent( Display display, Displayable nextDisplayable ) {		if ( ! (nextDisplayable instanceof AccessibleCanvas) ) {			if (instance != null && instance.currentCanvas != null) {				instance.currentCanvas.hideNotify();				instance.currentCanvas = null;				instance.currentDisplayable = null;			}			display.setCurrent( nextDisplayable );			return;		}		if ( instance == null ) {			instance = new MasterCanvas();		}		if ( instance.currentCanvas != null ) {			instance.currentCanvas.hideNotify();		}		AccessibleCanvas canvas = ( (AccessibleCanvas) nextDisplayable );		instance.currentCanvas = canvas;		instance.currentDisplayable = nextDisplayable;		canvas.showNotify();		if ( !instance.isShown() ) {			display.setCurrent( instance );		} else {			instance.repaint();		}	}