Bug 280695 [CSS][UI] Style newly created widgets in tab folders/stacks
bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/workbench/ui/renderers/swt/StackModelFactory.java
folderContext.set(IContextConstants.DEBUG_STRING, "TabFolder"); 
			final IEclipseContext toplevelContext = getToplevelContext(part);
			final IStylingEngine engine = (IStylingEngine) folderContext
					.get(IStylingEngine.class.getName());
			folderContext.runAndTrack(new Runnable() {
				public void run() {
					IEclipseContext currentActive = toplevelContext;
					IEclipseContext child;
					while (currentActive != folderContext
							&& (child = (IEclipseContext) currentActive
									.get("activeChild")) != null && child != currentActive) { 
						currentActive = child;
					}
					
					if (currentActive == folderContext) {
						engine.setClassname(ctf, "active"); 
					} else {
						engine.setClassname(ctf, "inactive"); 
					}
				}
			}, ""); 
		}
		return newWidget;
	}
	public void postProcess(MPart<?> part) {
		super.postProcess(part);
		if (!(part instanceof MStack))
			return;
		CTabFolder ctf = (CTabFolder) part.getWidget();
		MPart<?> selPart = ((MStack) part).getActiveChild();