Bug 54737 Libraries dialog doesn't remember status of items in library tree
Preferences > Java > Build Path > User Libraries: The dialog does not seem to correctly remember the status of the items in the "Defined user libraries" tree. When I leave the dialog I close (un-cascade) all items. When I open the dialog again, most of the items are open (cascaded) again. This is disturbing because I cannot overview the items. It's like opening the Windows explorer with not only the drives shown but all folders being open.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/dialogfields/TreeListDialogField.java
}
	}
	/**
	* Adds an element at a position.
	*/
	public void insertElementAt(Object element, int index) {
		if (fElements.contains(element)) {
			return;
		}
		fElements.add(index, element);
		if (fTree != null) {
			fTree.add(fParentElement, element);
			if (fTreeExpandLevel != -1) {
				fTree.expandToLevel(element, fTreeExpandLevel);
			}
		}
		dialogFieldChanged();
	}
	/**
	* Adds an element at a position.
	*/
	public void removeAllElements() {
		if (fElements.size() > 0) {
			fElements.clear();
			refresh();
			dialogFieldChanged();
		}
	}
	/**
	* Removes an element from the list.