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/GanttLineAttributesComposite.java
cbVisible.setText( Messages.getString( "LineAttributesComposite.Lbl.IsVisible" ) ); 
			cbVisible.setSelection( laCurrent.isVisible( ) );
			cbVisible.addSelectionListener( this );
			if ( bEnabled )
			{
				bEnableUI = cbVisible.getSelection( );
			}
		}
		if ( bEnableStyles )
		{
			lblStyle = new Label( cmpContent, SWT.NONE );
			GridData gdLStyle = new GridData( GridData.HORIZONTAL_ALIGN_BEGINNING );
			lblStyle.setLayoutData( gdLStyle );
			lblStyle.setText( Messages.getString( "LineAttributesComposite.Lbl.Style" ) ); 
			lblStyle.setEnabled( bEnableUI );
			cmbStyle = new LineStyleChooserComposite( cmpContent, SWT.DROP_DOWN
					| SWT.READ_ONLY, getSWTLineStyle( laCurrent.getStyle( ) ) );
			GridData gdCBStyle = new GridData( GridData.FILL_HORIZONTAL );
			gdCBStyle.horizontalSpan = 5;
			cmbStyle.setLayoutData( gdCBStyle );
			cmbStyle.addListener( this );
			cmbStyle.setEnabled( bEnableUI );
		}
		if ( bEnableWidths )
		{
			lblWidth = new Label( cmpContent, SWT.NONE );
			GridData gdLWidth = new GridData( GridData.HORIZONTAL_ALIGN_BEGINNING );
			lblWidth.setLayoutData( gdLWidth );
			lblWidth.setText( Messages.getString( "LineAttributesComposite.Lbl.Width" ) ); 
			lblWidth.setEnabled( bEnableUI );