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/TriggerDataComposite.java
cmbActionType.setItems( this.triggerMatrix.getSupportedActionsDisplayName( condition ) );
		
		cmbActionType.add( Messages.getString( "TriggerDataComposite.Lbl.None" ), 0 ); 
	}
	/**
	 * Provides a mapper method to switch trigger Combo text to fixed index
	 * constants.
	 * 
	 * @return fixed index defined as constants
	 */
	private int getTriggerIndex( )
	{
		
		if ( cmbActionType.getText( )
				.equals( LiteralHelper.actionTypeSet.getDisplayNameByName( ActionType.SHOW_TOOLTIP_LITERAL.getName( ) ) ) )
		{
			return INDEX_2_TOOLTIP;
		}
		if ( cmbActionType.getText( )
				.equals( LiteralHelper.actionTypeSet.getDisplayNameByName( ActionType.URL_REDIRECT_LITERAL.getName( ) ) ) )
		{
			return INDEX_1_URL_REDIRECT;
		}
		if ( cmbActionType.getText( )
				.equals( LiteralHelper.actionTypeSet.getDisplayNameByName( ActionType.INVOKE_SCRIPT_LITERAL.getName( ) ) ) )
		{
			return INDEX_4_SCRIPT;
		}
		if ( cmbActionType.getText( )
				.equals( LiteralHelper.actionTypeSet.getDisplayNameByName( ActionType.HIGHLIGHT_LITERAL.getName( ) ) ) )