Bug 295386 [FieldAssist] ControlDecoration#showHoverText doesn't check if the widget is visible
bundles/org.eclipse.jface/src/org/eclipse/jface/fieldassist/ControlDecoration.java
.println("Removed listener>>>" + listenerType + " from>>>" + widget); 
		}
	}
	
	/**
	 * Return a boolean indicating whether the decoration is visible. This
	 * method considers the visibility state of the decoration (
	 * {@link #hide()} and {@link #show()}), the visibility state of the 
	 * associated control ({@link Control#isVisible()}), and the focus state 
	 * of the control if applicable ({@link #setShowOnlyOnFocus(boolean)}. 
	 * When this method returns <code>true</code>, it means that the decoration 
	 * should be visible. However, this method does not consider the case where 
	 * the decoration should be visible, but is obscured by another window or
	 * control, or positioned off the screen. In these cases, the decoration
	 * will still be considered visible.
	 * 
	 * @return <code>true</code> if the decoration is visible, and
	 *         <code>false</code> if it is not.
	 * 
	 * @see #setShowOnlyOnFocus(boolean)
	 * @see #hide()
	 * @see #show()
     *
	 * @since 3.6
	 */
	public boolean isVisible() {
		return shouldShowDecoration();
	}
}