protected void computeInformation()
{
	if (fProposal instanceof ICompletionProposalExtension3)
	{
		setCustomInformationControlCreator(((ICompletionProposalExtension3) fProposal)
				.getInformationControlCreator());
	}
	else
	{
		setCustomInformationControlCreator(null);
	}

	// compute subject area
	Point size = fProposalTable.getShell().getSize();

	// set information & subject area
	setInformation(fInformation, new Rectangle(0, 0, size.x, size.y));
}
 

/**
 * Extracts the replacement string from an <code>ICompletionProposal</code>. If <code>proposal</code> is a
 * <code>ICompletionProposalExtension3</code>, its <code>getCompletionText</code> method is called, otherwise, the
 * display string is used.
 * 
 * @param proposal
 *            the proposal to extract the text from
 * @return the proposals completion text
 * @since 3.1
 */
private CharSequence getPrefixCompletion(ICompletionProposal proposal)
{
	CharSequence insertion = null;
	if (proposal instanceof ICompletionProposalExtension3)
	{
		insertion = ((ICompletionProposalExtension3) proposal).getPrefixCompletionText(
				fContentAssistSubjectControlAdapter.getDocument(), fFilterOffset);
	}

	if (insertion == null)
	{
		insertion = proposal.getDisplayString();
	}

	return insertion;
}
 

public IInformationControlCreator getInformationControlCreator() {
  return ((ICompletionProposalExtension3) jdtProposal).getInformationControlCreator();
}
 

/**
 * Extracts the completion offset of an <code>ICompletionProposal</code>. If <code>proposal</code> is a
 * <code>ICompletionProposalExtension3</code>, its <code>getCompletionOffset</code> method is called, otherwise, the
 * invocation offset of this popup is shown.
 * 
 * @param proposal
 *            the proposal to extract the offset from
 * @return the proposals completion offset, or <code>fInvocationOffset</code>
 * @since 3.1
 */
private int getPrefixCompletionOffset(ICompletionProposal proposal)
{
	if (proposal instanceof ICompletionProposalExtension3)
	{
		return ((ICompletionProposalExtension3) proposal).getPrefixCompletionStart(
				fContentAssistSubjectControlAdapter.getDocument(), fFilterOffset);
	}
	return fInvocationOffset;
}