ui/src/main/java/ucar/nc2/ui/image/SourcePicture.java
public void addListener ( SourcePictureListener listener ) {
		Tools.log("SourcePicture.addListener: listener added on SourcePicture " + Integer.toString(this.hashCode()) + " of class: " + listener.getClass().toString() );
		sourcePictureListeners.add( listener );
		//showListeners();
	}
public void addListener ( SourcePictureListener listener ) {
		Tools.log("SourcePicture.addListener: listener added on SourcePicture " + Integer.toString(this.hashCode()) + " of class: " + listener.getClass().toString() );
		sourcePictureListeners.add( listener );
		//showListeners();
	}
method to register the listening object of the status events