Bug 256651 [FieldAssist] Wrong location calculation of proposal popup shell if content control is near bottom in the screen
bundles/org.eclipse.jface/src/org/eclipse/jface/fieldassist/ContentProposalAdapter.java
Assert.isNotNull(controlContentAdapter);
		this.control = control;
		this.controlContentAdapter = controlContentAdapter;
		
		this.proposalProvider = proposalProvider;
		this.triggerKeyStroke = keyStroke;
		if (autoActivationCharacters != null) {
			this.autoActivateString = new String(autoActivationCharacters);
		}
		addControlListener(control);
	}
	/**
	 * Get the control on which the content proposal adapter is installed.
	 * 
	 * @return the control on which the proposal adapter is installed.
	 */
	public Control getControl() {
		return control;
	}
	/**
	 * Get the label provider that is used to show proposals.
	 * 
	 * @return the {@link ILabelProvider} used to show proposals, or
	 *         <code>null</code> if one has not been installed.
	 */
	public ILabelProvider getLabelProvider() {
		return labelProvider;
	}
	/**
	 * Return a boolean indicating whether the receiver is enabled.