GUIX - Vertical List

Hi.

I am working to implement vertical scroll lists in a new application and have some questions.  

1 - In this product there is no touchscreen and all user interaction is through external hardware.  I am trying to get the vertical list to scroll from hardware inputs and found this example in the knowledge base:

https://en-us.knowledgebase.renesas.com/English_Content/Renesas_Synergy%E2%84%A2_Platform/Renesas_Synergy_Knowledge_Base/How_do_I_create_vertical_scroll_animation_for_a_list_using_GUIX_within_SSP%2C_without_touch_inputs%3F 

Using this as a guide I am able to scroll the list properly using hardware.  I then added a vertical scrollbar to the list, but the scrollbar does not respond to the GX_EVENT_VERTICAL_SCROLL event.  For prototyping this I am currently using the S7G2-SK.  Adding the touchscreen control in I am able to use touch events to move the list up and down with all the changes reflected scrollbar.  Can someone point me to what I must be missing in my implementation?

Here is a snippet of this implementation:

GX_EVENT gxe;

gxe.gx_event_type = GX_EVENT_VERTICAL_SCROLL;

gxe.gx_event_sender = GX_ID_NONE;

gxe.gx_event_target = 0;

gxe.gx_event_display_handle = 0;

gxe.gx_event_payload.gx_event_intdata[1] = 0;
gxe.gx_event_payload.gx_event_intdata[0] = 10;

for (j = 1; j<MOVE_POSITION; j++)
{
gx_vertical_list_event_process (&window1.window1_vertical_list, &gxe);
}

2 - This application will have many instances of vertical lists to configure different system parameters.  Most of these lists will have varying number of items.  Can I design the GUI with a single list that has the maximum number of rows defined and then have the application change the number of rows at runtime?  

Thanks for any help!

- jamie