Bug 201042 [Accessibility]Chart scritp should not add by auto when click the down in keyboard[17]
Description: Chart scritp should not add by auto when click the down in keyboard[0704] Step: 1. New a chart and switch to script view. 2. Let the point on the script function selection. 3. Click the down on keyboard. Actual result: A function will add by auto. Expected result: Customer can not select the function under the second function by keyboard, and it should not be added by auto.
chart/org.eclipse.birt.chart.ui.extension/src/org/eclipse/birt/chart/ui/swt/composites/HeadStyleAttributeComposite.java
SelectionListener, Listener {
	private transient Composite cmpContent = null;
	private transient Label lblHeadStyle = null;
	private transient HeadStyleChooserComposite cmbHeadStyle = null;
	private transient LineDecorator laCurrent = null;
	private transient Vector vListeners = null;
	public static final int STYLE_CHANGED_EVENT = 1;
	/**
	 * @param parent
	 * @param style
	 */
	public HeadStyleAttributeComposite(Composite parent, int style,
			LineDecorator laCurrent) 
	{
		super(parent, style);
		this.laCurrent = laCurrent;
		init();
		placeComponents();
	}
	private void init() 
	{
		this.setSize(getParent().getClientArea().width, getParent()
				.getClientArea().height);
		vListeners = new Vector();
	}
	private void placeComponents() {