Bug 40785 [plan item] Overview ruler improvements
- navigation from ruler to editor - hovering over header area shows number of errors/warning (header annotations in general)
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaEditor.java
ISourceViewer viewer= createJavaSourceViewer(parent, verticalRuler, getOverviewRuler(), isOverviewRulerVisible(), styles);
		
		StyledText text= viewer.getTextWidget();
		text.addBidiSegmentListener(new  BidiSegmentListener() {
			public void lineGetSegments(BidiSegmentEvent event) {
				event.segments= getBidiLineSegments(event.lineOffset, event.lineText);
			}
		});
		
		JavaUIHelp.setHelp(this, text, IJavaHelpContextIds.JAVA_EDITOR);
		
		getSourceViewerDecorationSupport(viewer);				
		
		return viewer;
	}
	
	/*
	 * @see org.eclipse.ui.texteditor.ExtendedTextEditor#createAnnotationAccess()
	 */
	protected IAnnotationAccess createAnnotationAccess() {
		return new AnnotationAccess();
	}
	
	public final ISourceViewer getViewer() {
		return getSourceViewer();
	}
	
	/*
	 * @see AbstractTextEditor#createSourceViewer(Composite, IVerticalRuler, int)