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
*/
	public int open() {
		addControlListener();
		int value = super.open();
		showProposalDescription(getSelectedProposal().getDescription());
		return value;
	}
	/**
	 * Closes this popup. This method is extended to remove the control
	 * listener.
	 * 
	 * @return <code>true</code> if the window is (or was already) closed, and
	 *         <code>false</code> if it is still open
	 */
	public boolean close() {
		removeControlListener();
		return super.close();
	}
	/*
	 * Get the proposals from the proposal provider. The provider may or may not
	 * filter the proposals based on the specified filter text.
	 */
	private IContentProposal[] getProposals(String filterString) {
		if (proposalProvider == null)
			return null;
		int position = adapter.getControlContentAdapter().getCursorPosition(
				adapter.getControl());
		String contents = adapter.getControlContentAdapter()
				.getControlContents(adapter.getControl());
		IContentProposal[] proposals = proposalProvider.getProposals(contents,