Bug 80473 [rulers][preferences] allow disabling of range indicator on left of java editor
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaEditor.java
setPreferenceStore(createCombinedPreferenceStore(input));
			internalDoSetInput(input);
			return;
		}
		
		getSourceViewerDecorationSupport(sourceViewer).uninstall();
		((ISourceViewerExtension2)sourceViewer).unconfigure();
		setPreferenceStore(createCombinedPreferenceStore(input));
		
		sourceViewer.configure(getSourceViewerConfiguration());
		getSourceViewerDecorationSupport(sourceViewer).install(getPreferenceStore());
		internalDoSetInput(input);
	}
	private void internalDoSetInput(IEditorInput input) throws CoreException {
		ISourceViewer sourceViewer= getSourceViewer();
		JavaSourceViewer javaSourceViewer= null;
		if (sourceViewer instanceof JavaSourceViewer)
			javaSourceViewer= (JavaSourceViewer)sourceViewer;
		
		if (javaSourceViewer != null && isFoldingEnabled())
			javaSourceViewer.prepareDelayedProjection();
		
		super.doSetInput(input);
		if (javaSourceViewer != null && javaSourceViewer.getReconciler() == null) {
			IReconciler reconciler= getSourceViewerConfiguration().getReconciler(javaSourceViewer);
			if (reconciler != null) {
				reconciler.install(javaSourceViewer);
				javaSourceViewer.setReconciler(reconciler);
			}
		}