/** Backup old event handlers for restore. */ final void backupGui() { canvasKeyListeners = canvas.getKeyListeners(); windowKeyListeners = window.getKeyListeners(); ijKeyListeners = IJ.getInstance().getKeyListeners(); canvasMouseListeners = canvas.getMouseListeners(); canvasMouseMotionListeners = canvas.getMouseMotionListeners(); windowMouseWheelListeners = window.getMouseWheelListeners(); clearGui(); }