Bug 163345 [Field Assist] - API - Deprecate DecoratedField and related classes
If ControlDecoration is adopted in replacement of DecoratedField by all existing SDK clients, then we should deprecate DecoratedField.
bundles/org.eclipse.jface/src/org/eclipse/jface/fieldassist/DecoratedField.java
* and will be hidden when the mouse exits the control. This method can be
	 * used to hide a hover that was shown using <code>showHoverText</code>,
	 * or to programatically hide the current decoration hover.
	 * 
	 * <p>
	 * This message has no effect if there is no current hover.
	 * 
	 */
	public void hideHover() {
		if (hover != null) {
			hover.setVisible(false);
		}
	}
	/*
	 * The target control gained focus. Any decorations that should show only
	 * when they have the focus should be shown here.
	 */
	private void controlFocusGained() {
		for (int i = 0; i < DECORATION_SLOTS; i++) {
			if (decDatas[i] != null && decDatas[i].showOnFocus) {
				setVisible(decDatas[i], true);
			}
		}
	}
	/*
	 * The target control lost focus. Any decorations that should show only when
	 * they have the focus should be hidden here.
	 */
	private void controlFocusLost() {
		for (int i = 0; i < DECORATION_SLOTS; i++) {