Bug 298415 StackRenderer assumes the shell has not been disposed when forcing a re-layout
bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/workbench/ui/renderers/swt/StackRenderer.java
*/
	@Override
	protected void showChild(MElementContainer<MUIElement> stack,
			MUIElement part) {
		
		super.showChild(stack, part);
		MUILabel itemPart = (MUILabel) part;
		CTabFolder ctf = (CTabFolder) stack.getWidget();
		int createFlags = 0;
		CTabItem cti = findItemForPart(stack, part);
		if (cti == null) {
			int index = calcIndexFor(stack, part);
			
			
			cti = new ETabItem((ETabFolder) ctf, createFlags, index);
			cti.setData(OWNING_ME, part);
			cti.setText(getLabel(itemPart, itemPart.getLabel()));
			cti.setImage(getImage(itemPart));
			cti.setToolTipText(itemPart.getTooltip());
			Control widget = (Control) part.getWidget();
			if (widget != null)
				cti.setControl(widget);
			
			
			String cssClassName = (String) ctf
					.getData("org.eclipse.e4.ui.css.CssClassName"); 
			stylingEngine.setClassname(cti, cssClassName);
		}
		
		hookTabControllerLogic(stack, part, cti);