private void updateComponent() {
		if (!SystemUtilities.isEventDispatchThread()) {
			throw new AssertException("Must be in swing thread");
		}
		taskViewerComponent.removeAll();
		for (AbstractTaskInfo element : runningList) {
			taskViewerComponent.add(element.getComponent());
		}

		if (waitingList.size() > 0 && runningList.size() > 0) {
			taskViewerComponent.add(new JSeparator());
		}

		for (AbstractTaskInfo element : waitingList) {
			taskViewerComponent.add(element.getComponent());
		}

		Container parent = taskViewerComponent.getParent();
		if (parent != null) {
			parent.validate();
		}
	}
Uses a layered pane to create a "watermark effect" to show when the GTaskManger is suspended.
Ghidra/Framework/Project/src/main/java/ghidra/framework/task/gui/taskview/TaskViewer.java