Bug 96917 [implementation] If two editors use the 2.x-compatible API, one or both doesn't work
At least one problem is that 3.0 installs partitioners for every editor that might possibly edit a file, but each editor expects its own partitioner to be installed. Leading to the famous white screen with blue line.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/CompilationUnitDocumentProvider.java
*/
			private static final int INFO_LAYER;
			/**
			 * The layer in which warning problem annotations representing are located.
			 */
			private static final int WARNING_LAYER;
			/**
			 * The layer in which error problem annotations representing are located.
			 */
			private static final int ERROR_LAYER;
			static {
				AnnotationPreferenceLookup lookup= EditorsUI.getAnnotationPreferenceLookup();
				TASK_LAYER= computeLayer("org.eclipse.ui.workbench.texteditor.task", lookup); 
				INFO_LAYER= computeLayer("org.eclipse.jdt.ui.info", lookup); 
				WARNING_LAYER= computeLayer("org.eclipse.jdt.ui.warning", lookup); 
				ERROR_LAYER= computeLayer("org.eclipse.jdt.ui.error", lookup); 
			}
			private static int computeLayer(String annotationType, AnnotationPreferenceLookup lookup) {
				Annotation annotation= new Annotation(annotationType, false, null);
				AnnotationPreference preference= lookup.getAnnotationPreference(annotation);
				if (preference != null)
					return preference.getPresentationLayer() + 1;
				else
					return IAnnotationAccessExtension.DEFAULT_LAYER + 1;
			}
			private static Image fgQuickFixImage;
			private static Image fgQuickFixErrorImage;
			private static boolean fgQuickFixImagesInitialized= false;
			private ICompilationUnit fCompilationUnit;
			private List fOverlaids;