Bug 52801 "Press F2 for focus" does not work for spell-checking hovers
"Press F2 for focus" does not work for spell-checking hovers.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaEditor.java
* 
	 * @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() {
		super();
		JavaTextTools textTools= JavaPlugin.getDefault().getJavaTextTools();
		setSourceViewerConfiguration(new JavaSourceViewerConfiguration(textTools, this, IJavaPartitions.JAVA_PARTITIONING));
		setRangeIndicator(new DefaultRangeIndicator());
		IPreferenceStore store= JavaPlugin.getDefault().getPreferenceStore();
		setPreferenceStore(store);
		setKeyBindingScopes(new String[] { "org.eclipse.jdt.ui.javaEditorScope" });  
		fMarkOccurrenceAnnotations= store.getBoolean(PreferenceConstants.EDITOR_MARK_OCCURRENCES);
		fStickyOccurrenceAnnotations= store.getBoolean(PreferenceConstants.EDITOR_STICKY_OCCURRENCES);