Bug 326177 EPartService's getActivePart() does not appear to work properly for an application with multiple windows
Based on the code in PartServiceCreationFunction, the EPartService implementation being returned when an application's context is queried seems to be a window-level EPartService implementation.
tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/application/EPartServiceTest.java
EPartService.class.getName());
		partService.hidePart(part);
		assertFalse(part.isToBeRendered());
		assertEquals(tagged ? null : window, part.getParent());
	}
	public void testHidePart_Tagged_True() {
		testHidePart_Tagged(true);
	}
	public void testHidePart_Tagged_False() {
		testHidePart_Tagged(false);
	}
	public void testGetDirtyParts() {
		MApplication application = createApplication(1, new String[1][0]);
		MWindow window = application.getChildren().get(0);
		getEngine().createGui(window);
		EPartService partService = (EPartService) window.getContext().get(
				EPartService.class.getName());
		Collection<MPart> dirtyParts = partService.getDirtyParts();
		assertNotNull(dirtyParts);
		assertEquals(0, dirtyParts.size());
	}
	public void testGetDirtyParts2() {
		MApplication application = createApplication("partId");
		MWindow window = application.getChildren().get(0);
		getEngine().createGui(window);
		EPartService partService = (EPartService) window.getContext().get(
				EPartService.class.getName());
		Collection<MPart> dirtyParts = partService.getDirtyParts();
		assertNotNull(dirtyParts);
		assertEquals(0, dirtyParts.size());