fTextTools.getPreferenceStore().addPropertyChangeListener(propertyListener);
fPreferenceStore.addPropertyChangeListener(propertyListener);
		public JavaSourcePreviewerUpdater() {					    JFaceResources.getFontRegistry().addListener(fontListener);			fTextTools.getPreferenceStore().addPropertyChangeListener(propertyListener);						fSourceViewer.getTextWidget().addDisposeListener(new DisposeListener() {				public void widgetDisposed(DisposeEvent e) {					JFaceResources.getFontRegistry().removeListener(fontListener);					fTextTools.getPreferenceStore().removePropertyChangeListener(propertyListener);				}			});		}