Bug 91409 Project Open/Close items are disabled when Package Explorer active
Project Open/Close option in the Project menu is disabled in Plugin prespective.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/PackageExplorerActionGroup.java
String property= event.getProperty();
			if (IWorkingSetManager.CHANGE_WORKING_SET_CONTENT_CHANGE.equals(property)) {
				TreeViewer viewer= fPart.getViewer();
				viewer.getControl().setRedraw(false);
				viewer.refresh();
				viewer.getControl().setRedraw(true);
			}
		}
	}
	private boolean doubleClickGoesInto() {
		return PreferenceConstants.DOUBLE_CLICK_GOES_INTO.equals(PreferenceConstants.getPreferenceStore().getString(PreferenceConstants.DOUBLE_CLICK));
	}
	public FrameAction getUpAction() {
		return fUpAction;
	}
	public FrameAction getBackAction() {
		return fBackAction;
	}
	public FrameAction getForwardAction() {
		return fForwardAction;
	}
	public ViewActionGroup getWorkingSetActionGroup() {
	    return fViewActionGroup;
	}
	
	public CustomFiltersActionGroup getCustomFilterActionGroup() {
	    return fCustomFiltersActionGroup;
	}
}