Bug 28698 Ctrl+O (show outline) does not work if the file being shown in the editor is read only
M4 The summary tells all. Works if the file is not read only. Is this by design?
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/CompilationUnitEditor.java
}
				
				try {		
					ITypedRegion partition= document.getPartition(offset);
					if (! IDocument.DEFAULT_CONTENT_TYPE.equals(partition.getType()) && partition.getOffset() != offset)
						return;
					final char character= event.character;
					final char closingCharacter= getPeerCharacter(character);		
					final StringBuffer buffer= new StringBuffer();
					buffer.append(character);
					buffer.append(closingCharacter);
					document.replace(offset, length, buffer.toString());
					LinkedPositionManager manager= new LinkedPositionManager(document);
					manager.addPosition(offset + 1, 0);
					fOffset= offset;
					fLength= 2;
			
					LinkedPositionUI editor= new LinkedPositionUI(sourceViewer, manager);
					editor.setCancelListener(this);
					editor.setExitPolicy(new ExitPolicy(closingCharacter));
					editor.setFinalCaretOffset(offset + 2);
					editor.enter();
					IRegion newSelection= editor.getSelectedRegion();
					sourceViewer.setSelectedRange(newSelection.getOffset(), newSelection.getLength());
	
					event.doit= false;
				} catch (BadLocationException e) {
				}
				break;	
			}