Bug 72615 [Viewers] Need and ITableFontProvider
We released an ITabelColorProvider for M2 - we should have a corresponding ITableFontProvider
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/StructuredViewer.java
Control control = getControl();
		DropTarget dropTarget = new DropTarget(control, operations);
		dropTarget.setTransfer(transferTypes);
		dropTarget.addDropListener(listener);
	}
	/**
	 * Adds the given filter to this viewer, and triggers refiltering and
	 * resorting of the elements.
	 * 
	 * @param filter
	 *            a viewer filter
	 */
	public void addFilter(ViewerFilter filter) {
		if (filters == null)
			filters = new ArrayList();
		filters.add(filter);
		refresh();
	}
	/**
	 * Asserts that the given array of elements is itself non- <code>null</code>
	 * and contains no <code>null</code> elements.
	 * 
	 * @param elements
	 *            the array to check
	 */
	protected void assertElementsNotNull(Object[] elements) {
		Assert.isNotNull(elements);
		for (int i = 0, n = elements.length; i < n; ++i) {
			Assert.isNotNull(elements[i]);
		}