Bug 294462 [FieldAssist] ControlDecoration#showHoverText doesn't check if the widget is visible
If the HOVER-Text is set on decoration of a widget which is invisible the Hover-Shell is still poping up because it doesn't check if the control is invisible make the Hover appearing somewhere on the screen.
bundles/org.eclipse.jface/src/org/eclipse/jface/fieldassist/ControlDecoration.java
} else {
							
						}
					}
				}
			}
			public void mouseEnter(MouseEvent event) {
				
			}
		};
		compositeListener = new Listener() {
			public void handleEvent(Event event) {
				
				if (!visible) {
					return;
				}
				
				switch (event.type) {
				case SWT.MouseDown:
					if (!selectionListeners.isEmpty())
						notifySelectionListeners(event);
					break;
				case SWT.MouseDoubleClick:
					if (!selectionListeners.isEmpty())
						notifySelectionListeners(event);
					break;
				case SWT.MenuDetect:
					if (!menuDetectListeners.isEmpty())
						notifyMenuDetectListeners(event);
					break;