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
public void editorContextMenuAboutToShow(IMenuManager menu) {
			
		super.editorContextMenuAboutToShow(menu);
		menu.appendToGroup(ITextEditorActionConstants.GROUP_UNDO, new Separator(IContextMenuConstants.GROUP_OPEN));	
		menu.insertAfter(IContextMenuConstants.GROUP_OPEN, new GroupMarker(IContextMenuConstants.GROUP_SHOW));	
		
		ActionContext context= new ActionContext(getSelectionProvider().getSelection());
		fContextMenuGroup.setContext(context);
		fContextMenuGroup.fillContextMenu(menu);
		fContextMenuGroup.setContext(null);
	}			
	
	/**
	 * Creates the outline page used with this editor.
	 */
	protected JavaOutlinePage createOutlinePage() {
		JavaOutlinePage page= new JavaOutlinePage(fOutlinerContextMenuId, this);
		fOutlineSelectionChangedListener.install(page);
		setOutlinePageInput(page, getEditorInput());
		return page;
	}
	
	/**
	 * Informs the editor that its outliner has been closed.
	 */
	public void outlinePageClosed() {
		if (fOutlinePage != null) {
			fOutlineSelectionChangedListener.uninstall(fOutlinePage);
			fOutlinePage= null;
			resetHighlightRange();