Bug 319169 [UI] active parts in Detached windows prevent activating a part in the main window
Start with a fresh WS Detach the Outline view using DnD Now you can no longer activate any part in the main window (i.e. Package Explorer). The cause seems to be that the 'rootContainer' has become the DW's MTrimmedWindow rather than the DW's containing MPerspective. This causes the PartService's 'activate' to fail the 'isInContainer()' test...
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/ui/internal/workbench/PartServiceImpl.java
}
	}
	public MPart findPart(String id) {
		MApplicationElement element = modelService.find(id, rootContainer);
		if (element instanceof MPlaceholder) {
			((MPlaceholder) element).getRef().setCurSharedRef((MPlaceholder) element);
			element = ((MPlaceholder) element).getRef();
		}
		return element instanceof MPart ? (MPart) element : null;
	}
	public Collection<MPart> getParts() {
		return modelService.findElements(rootContainer, null, MPart.class, null);
	}
	public boolean isPartVisible(MPart part) {
		if (isInContainer(part)) {
			MElementContainer<?> parent = part.getParent();
			if (parent instanceof MPartStack) {
				return parent.getSelectedElement() == part;
			}
			return part.isVisible();
		}
		return false;
	}
	private boolean isInContainer(MPart part) {
		return isInContainer(rootContainer, part);
	}
	private boolean isInContainer(MElementContainer<?> container, MPart part) {
		for (Object object : container.getChildren()) {
			if (object == part) {
				return true;