if (apexCompletionProcessor != null) {
assistant.setContentAssistProcessor(apexCompletionProcessor, IDocument.DEFAULT_CONTENT_TYPE);
apexCompletionProcessor.setContentAssistant(assistant);
}
assistant.setContentAssistProcessor(new ApexDocCompletionProcessor(), ApexPartitionScanner.APEX_DOC);
assistant.enableAutoActivation(true);
assistant.setAutoActivationDelay(500);
assistant.setProposalPopupOrientation(IContentAssistant.PROPOSAL_STACKED);
assistant.setContextInformationPopupOrientation(IContentAssistant.CONTEXT_INFO_BELOW);
assistant.setShowEmptyList(true); // display no proposal when code assist is triggered by ctrl+space, but display nothing when triggered by auto-activation