/**
 * Creates a context frame for the given offset.
 * 
 * @param information
 *            the context information
 * @param offset
 *            the offset
 * @return the created context frame
 * @since 3.0
 */
private ContextFrame createContextFrame(IContextInformation information, int offset)
{
	IContextInformationValidator validator = fContentAssistSubjectControlAdapter.getContextInformationValidator(
			fContentAssistant, offset);

	if (validator != null)
	{
		int beginOffset = (information instanceof IContextInformationExtension) ? ((IContextInformationExtension) information)
				.getContextInformationPosition() : offset;
		if (beginOffset == -1)
		{
			beginOffset = offset;
		}
		int visibleOffset = fContentAssistSubjectControlAdapter.getWidgetSelectionRange().x
				- (offset - beginOffset);
		IContextInformationPresenter presenter = fContentAssistSubjectControlAdapter
				.getContextInformationPresenter(fContentAssistant, offset);
		return new ContextFrame(information, beginOffset, offset, visibleOffset, validator, presenter);
	}

	return null;
}
 

public void install(IContextInformation info, ITextViewer viewer, int offset)
{
	this._contextInformation = info;
	this._viewer = viewer;

	if (info instanceof IContextInformationExtension)
	{
		this._startingOffset = ((IContextInformationExtension) info).getContextInformationPosition();
	}
	else
	{
		this._startingOffset = offset;
	}
}