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
action= new DeletePreviousSubWordAction();
		action.setActionDefinitionId(ITextEditorActionDefinitionIds.DELETE_PREVIOUS_WORD);
		setAction(ITextEditorActionDefinitionIds.DELETE_PREVIOUS_WORD, action);
		textWidget.setKeyBinding(SWT.CTRL | SWT.BS, SWT.NULL);
		action= new DeleteNextSubWordAction();
		action.setActionDefinitionId(ITextEditorActionDefinitionIds.DELETE_NEXT_WORD);
		setAction(ITextEditorActionDefinitionIds.DELETE_NEXT_WORD, action);
		textWidget.setKeyBinding(SWT.CTRL | SWT.DEL, SWT.NULL);
		
		action= new SelectPreviousSubWordAction();
		action.setActionDefinitionId(ITextEditorActionDefinitionIds.SELECT_WORD_PREVIOUS);
		setAction(ITextEditorActionDefinitionIds.SELECT_WORD_PREVIOUS, action);
		textWidget.setKeyBinding(SWT.CTRL | SWT.SHIFT | SWT.ARROW_LEFT, SWT.NULL);
		
		action= new SelectNextSubWordAction();
		action.setActionDefinitionId(ITextEditorActionDefinitionIds.SELECT_WORD_NEXT);
		setAction(ITextEditorActionDefinitionIds.SELECT_WORD_NEXT, action);
		textWidget.setKeyBinding(SWT.CTRL | SWT.SHIFT | SWT.ARROW_RIGHT, SWT.NULL);
	}
	/*
	 * @see org.eclipse.ui.texteditor.ExtendedTextEditor#createCompositeRuler()
	 */
	protected CompositeRuler createCompositeRuler() {
		if (!getPreferenceStore().getBoolean(PreferenceConstants.EDITOR_ANNOTATION_ROLL_OVER))
			return super.createCompositeRuler();
		
		CompositeRuler ruler= new CompositeRuler();
		AnnotationRulerColumn column= new AnnotationRulerColumn(VERTICAL_RULER_WIDTH, getAnnotationAccess());
		column.setHover(new JavaExpandHover(ruler, ruler, new IDoubleClickListener() {