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/filebuffers/CompilationUnitDocumentProvider2.java
fGlobalAnnotationModelListener.removeListener(listener);
	}
	/*
	 * @see org.eclipse.jdt.internal.ui.javaeditor.ICompilationUnitDocumentProvider#getWorkingCopy(java.lang.Object)
	 */
	public ICompilationUnit getWorkingCopy(Object element) {
		FileInfo fileInfo= getFileInfo(element);		
		if (fileInfo instanceof CompilationUnitInfo) {
			CompilationUnitInfo info= (CompilationUnitInfo) fileInfo;
			return info.fCopy;
		}
		return null;
	}
	
	/*
	 * @see org.eclipse.jdt.internal.ui.javaeditor.ICompilationUnitDocumentProvider#shutdown()
	 */
	public void shutdown() {
		JavaPlugin.getDefault().getPreferenceStore().removePropertyChangeListener(fPropertyListener);
		Iterator e= getConnectedElementsIterator();
		while (e.hasNext())
			disconnect(e.next());
	}
	
	/*
	 * @see org.eclipse.jdt.internal.ui.javaeditor.ICompilationUnitDocumentProvider#saveDocumentContent(org.eclipse.core.runtime.IProgressMonitor, java.lang.Object, org.eclipse.jface.text.IDocument, boolean)
	 */
	public void saveDocumentContent(IProgressMonitor monitor, Object element, IDocument document, boolean overwrite) throws CoreException {
		if (!fIsAboutToSave)
			return;