Bug 41443 overview ruler not working
smoke test for 20030812 The overview ruler in the Java editor does not work when starting with a fresh workspace as described in the smoke test scenario.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaEditor.java
private CompositeActionGroup fContextMenuGroup;
	/**
	 * Whether quick diff information is displayed, either on a change ruler or the line number ruler.
	 * @since 3.0
	 */
	private boolean fIsChangeInformationShown;
		
	/**
	 * Returns the most narrow java element including the given offset.
	 * 
	 * @param offset the offset inside of the requested element
	 * @return the most narrow java element
	 */
	abstract protected IJavaElement getElementAt(int offset);
	
	/**
	 * Returns the java element of this editor's input corresponding to the given IJavaElement
	 */
	abstract protected IJavaElement getCorrespondingElement(IJavaElement element);
	
	/**
	 * Sets the input of the editor's outline page.
	 */
	abstract protected void setOutlinePageInput(JavaOutlinePage page, IEditorInput input);
	
	
	/**
	 * Default constructor.
	 */
	public JavaEditor() {