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/CompilationUnitDocumentProvider.java
handleCoreException(ex, ex.getMessage());
					}
				}
			}
			
			/*
			 * @see IProblemRequestor#beginReporting()
			 */
			public void beginReporting() {
				ICompilationUnit unit= getWorkingCopy(fInput);
				if (unit != null && unit.getJavaProject().isOnClasspath(unit))
					fCollectedProblems= new ArrayList();
				else
					fCollectedProblems= null;
			}
			
			/*
			 * @see IProblemRequestor#acceptProblem(IProblem)
			 */
			public void acceptProblem(IProblem problem) {
				if (isActive())
					fCollectedProblems.add(problem);
			}
			/*
			 * @see IProblemRequestor#endReporting()
			 */
			public void endReporting() {
				if (!isActive())
					return;