@Override public void complete_HEX( EObject model, RuleCall ruleCall, ContentAssistContext context, ICompletionProposalAcceptor acceptor) { ICompletionProposalAcceptor priorityOptimizer = getCustomAcceptor(model, "integer", acceptor); String proposalText = "0x1"; ICompletionProposal proposal = createCompletionProposal( proposalText, proposalText + " - " + ruleCall.getRule().getName(), null, context); if (proposal instanceof ConfigurableCompletionProposal) { ConfigurableCompletionProposal configurable = (ConfigurableCompletionProposal) proposal; configurable.setSelectionStart(configurable.getReplacementOffset() + 2); configurable.setSelectionLength(proposalText.length() - 2); configurable.setAutoInsertable(false); configurable.setSimpleLinkedMode(context.getViewer(), '\t', ' '); } priorityOptimizer.accept(proposal); }