Bug 125418 [Field Assist] - API - Should ContentProposalPopup be public?
In the initial release of the field assist API, the ContentProposalPopup is public. There's really no reason for this to be the case, as the popup is driven by the ContentProposalAdapter. The ContentProposalPopup should likely be made an inner type of the adapter.
bundles/org.eclipse.jface/src/org/eclipse/jface/fieldassist/ContentProposalPopup.java
/*
	 * Request the proposals from the proposal provider, and recompute any
	 * caches. Repopulate the popup if it is open.
	 */
	private void recomputeProposals(String filterText) {
		setProposals(getProposals(filterText));
	}
	/*
	 * Filter the provided list of content proposals according to the filter
	 * text.
	 */
	private IContentProposal[] filterProposals(IContentProposal[] proposals,
			String filterString) {
		if (filterString.length() == 0)
			return proposals;
		
		
		ArrayList list = new ArrayList();
		for (int i = 0; i < proposals.length; i++) {
			String string = getString(proposals[i]);
			if (string.length() >= filterString.length()
					&& string.substring(0, filterString.length())
							.equalsIgnoreCase(filterString))
				list.add(proposals[i]);
		}
		return (IContentProposal[]) list.toArray(new IContentProposal[list
				.size()]);
	}
}